adding ffmpeg specific version

1 files changed, 2110 insertions, 0 deletions

diff --git a/ffmpeg1/libavcodec/vp8.c b/ffmpeg1/libavcodec/vp8.c
new file mode 100644
index 0000000..ac929d0
--- /dev/null
+++ b/ffmpeg1/libavcodec/vp8.c
@@ -0,0 +1,2110 @@
+/*
+ * VP8 compatible video decoder
+ *
+ * Copyright (C) 2010 David Conrad
+ * Copyright (C) 2010 Ronald S. Bultje
+ * Copyright (C) 2010 Jason Garrett-Glaser
+ * Copyright (C) 2012 Daniel Kang
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "libavutil/imgutils.h"
+#include "avcodec.h"
+#include "internal.h"
+#include "vp8.h"
+#include "vp8data.h"
+#include "rectangle.h"
+#include "thread.h"
+
+#if ARCH_ARM
+#   include "arm/vp8.h"
+#endif
+
+static void free_buffers(VP8Context *s)
+{
+    int i;
+    if (s->thread_data)
+        for (i = 0; i < MAX_THREADS; i++) {
+            av_freep(&s->thread_data[i].filter_strength);
+            av_freep(&s->thread_data[i].edge_emu_buffer);
+        }
+    av_freep(&s->thread_data);
+    av_freep(&s->macroblocks_base);
+    av_freep(&s->intra4x4_pred_mode_top);
+    av_freep(&s->top_nnz);
+    av_freep(&s->top_border);
+
+    s->macroblocks = NULL;
+}
+
+static int vp8_alloc_frame(VP8Context *s, VP8Frame *f, int ref)
+{
+    int ret;
+    if ((ret = ff_thread_get_buffer(s->avctx, &f->tf,
+                                    ref ? AV_GET_BUFFER_FLAG_REF : 0)) < 0)
+        return ret;
+    if (!(f->seg_map = av_buffer_allocz(s->mb_width * s->mb_height))) {
+        ff_thread_release_buffer(s->avctx, &f->tf);
+        return AVERROR(ENOMEM);
+    }
+    return 0;
+}
+
+static void vp8_release_frame(VP8Context *s, VP8Frame *f)
+{
+    av_buffer_unref(&f->seg_map);
+    ff_thread_release_buffer(s->avctx, &f->tf);
+}
+
+static int vp8_ref_frame(VP8Context *s, VP8Frame *dst, VP8Frame *src)
+{
+    int ret;
+
+    vp8_release_frame(s, dst);
+
+    if ((ret = ff_thread_ref_frame(&dst->tf, &src->tf)) < 0)
+        return ret;
+    if (src->seg_map &&
+        !(dst->seg_map = av_buffer_ref(src->seg_map))) {
+        vp8_release_frame(s, dst);
+        return AVERROR(ENOMEM);
+    }
+
+    return 0;
+}
+
+
+static void vp8_decode_flush_impl(AVCodecContext *avctx, int free_mem)
+{
+    VP8Context *s = avctx->priv_data;
+    int i;
+
+    for (i = 0; i < FF_ARRAY_ELEMS(s->frames); i++)
+        vp8_release_frame(s, &s->frames[i]);
+    memset(s->framep, 0, sizeof(s->framep));
+
+    if (free_mem)
+        free_buffers(s);
+}
+
+static void vp8_decode_flush(AVCodecContext *avctx)
+{
+    vp8_decode_flush_impl(avctx, 0);
+}
+
+static int update_dimensions(VP8Context *s, int width, int height)
+{
+    AVCodecContext *avctx = s->avctx;
+    int i;
+
+    if (width  != s->avctx->width || ((width+15)/16 != s->mb_width || (height+15)/16 != s->mb_height) && s->macroblocks_base ||
+        height != s->avctx->height) {
+        if (av_image_check_size(width, height, 0, s->avctx))
+            return AVERROR_INVALIDDATA;
+
+        vp8_decode_flush_impl(s->avctx, 1);
+
+        avcodec_set_dimensions(s->avctx, width, height);
+    }
+
+    s->mb_width  = (s->avctx->coded_width +15) / 16;
+    s->mb_height = (s->avctx->coded_height+15) / 16;
+
+    s->mb_layout = (avctx->active_thread_type == FF_THREAD_SLICE) && (FFMIN(s->num_coeff_partitions, avctx->thread_count) > 1);
+    if (!s->mb_layout) { // Frame threading and one thread
+        s->macroblocks_base       = av_mallocz((s->mb_width+s->mb_height*2+1)*sizeof(*s->macroblocks));
+        s->intra4x4_pred_mode_top = av_mallocz(s->mb_width*4);
+    }
+    else // Sliced threading
+        s->macroblocks_base       = av_mallocz((s->mb_width+2)*(s->mb_height+2)*sizeof(*s->macroblocks));
+    s->top_nnz                    = av_mallocz(s->mb_width*sizeof(*s->top_nnz));
+    s->top_border                 = av_mallocz((s->mb_width+1)*sizeof(*s->top_border));
+    s->thread_data                = av_mallocz(MAX_THREADS*sizeof(VP8ThreadData));
+
+    for (i = 0; i < MAX_THREADS; i++) {
+        s->thread_data[i].filter_strength = av_mallocz(s->mb_width*sizeof(*s->thread_data[0].filter_strength));
+#if HAVE_THREADS
+        pthread_mutex_init(&s->thread_data[i].lock, NULL);
+        pthread_cond_init(&s->thread_data[i].cond, NULL);
+#endif
+    }
+
+    if (!s->macroblocks_base || !s->top_nnz || !s->top_border ||
+        (!s->intra4x4_pred_mode_top && !s->mb_layout))
+        return AVERROR(ENOMEM);
+
+    s->macroblocks        = s->macroblocks_base + 1;
+
+    return 0;
+}
+
+static void parse_segment_info(VP8Context *s)
+{
+    VP56RangeCoder *c = &s->c;
+    int i;
+
+    s->segmentation.update_map = vp8_rac_get(c);
+
+    if (vp8_rac_get(c)) { // update segment feature data
+        s->segmentation.absolute_vals = vp8_rac_get(c);
+
+        for (i = 0; i < 4; i++)
+            s->segmentation.base_quant[i]   = vp8_rac_get_sint(c, 7);
+
+        for (i = 0; i < 4; i++)
+            s->segmentation.filter_level[i] = vp8_rac_get_sint(c, 6);
+    }
+    if (s->segmentation.update_map)
+        for (i = 0; i < 3; i++)
+            s->prob->segmentid[i] = vp8_rac_get(c) ? vp8_rac_get_uint(c, 8) : 255;
+}
+
+static void update_lf_deltas(VP8Context *s)
+{
+    VP56RangeCoder *c = &s->c;
+    int i;
+
+    for (i = 0; i < 4; i++) {
+        if (vp8_rac_get(c)) {
+            s->lf_delta.ref[i] = vp8_rac_get_uint(c, 6);
+
+            if (vp8_rac_get(c))
+                s->lf_delta.ref[i] = -s->lf_delta.ref[i];
+        }
+    }
+
+    for (i = MODE_I4x4; i <= VP8_MVMODE_SPLIT; i++) {
+        if (vp8_rac_get(c)) {
+            s->lf_delta.mode[i] = vp8_rac_get_uint(c, 6);
+
+            if (vp8_rac_get(c))
+                s->lf_delta.mode[i] = -s->lf_delta.mode[i];
+        }
+    }
+}
+
+static int setup_partitions(VP8Context *s, const uint8_t *buf, int buf_size)
+{
+    const uint8_t *sizes = buf;
+    int i;
+
+    s->num_coeff_partitions = 1 << vp8_rac_get_uint(&s->c, 2);
+
+    buf      += 3*(s->num_coeff_partitions-1);
+    buf_size -= 3*(s->num_coeff_partitions-1);
+    if (buf_size < 0)
+        return -1;
+
+    for (i = 0; i < s->num_coeff_partitions-1; i++) {
+        int size = AV_RL24(sizes + 3*i);
+        if (buf_size - size < 0)
+            return -1;
+
+        ff_vp56_init_range_decoder(&s->coeff_partition[i], buf, size);
+        buf      += size;
+        buf_size -= size;
+    }
+    ff_vp56_init_range_decoder(&s->coeff_partition[i], buf, buf_size);
+
+    return 0;
+}
+
+static void get_quants(VP8Context *s)
+{
+    VP56RangeCoder *c = &s->c;
+    int i, base_qi;
+
+    int yac_qi     = vp8_rac_get_uint(c, 7);
+    int ydc_delta  = vp8_rac_get_sint(c, 4);
+    int y2dc_delta = vp8_rac_get_sint(c, 4);
+    int y2ac_delta = vp8_rac_get_sint(c, 4);
+    int uvdc_delta = vp8_rac_get_sint(c, 4);
+    int uvac_delta = vp8_rac_get_sint(c, 4);
+
+    for (i = 0; i < 4; i++) {
+        if (s->segmentation.enabled) {
+            base_qi = s->segmentation.base_quant[i];
+            if (!s->segmentation.absolute_vals)
+                base_qi += yac_qi;
+        } else
+            base_qi = yac_qi;
+
+        s->qmat[i].luma_qmul[0]    =           vp8_dc_qlookup[av_clip_uintp2(base_qi + ydc_delta , 7)];
+        s->qmat[i].luma_qmul[1]    =           vp8_ac_qlookup[av_clip_uintp2(base_qi             , 7)];
+        s->qmat[i].luma_dc_qmul[0] =       2 * vp8_dc_qlookup[av_clip_uintp2(base_qi + y2dc_delta, 7)];
+        /* 101581>>16 is equivalent to 155/100 */
+        s->qmat[i].luma_dc_qmul[1] = (101581 * vp8_ac_qlookup[av_clip_uintp2(base_qi + y2ac_delta, 7)]) >> 16;
+        s->qmat[i].chroma_qmul[0]  =           vp8_dc_qlookup[av_clip_uintp2(base_qi + uvdc_delta, 7)];
+        s->qmat[i].chroma_qmul[1]  =           vp8_ac_qlookup[av_clip_uintp2(base_qi + uvac_delta, 7)];
+
+        s->qmat[i].luma_dc_qmul[1] = FFMAX(s->qmat[i].luma_dc_qmul[1], 8);
+        s->qmat[i].chroma_qmul[0]  = FFMIN(s->qmat[i].chroma_qmul[0], 132);
+    }
+}
+
+/**
+ * Determine which buffers golden and altref should be updated with after this frame.
+ * The spec isn't clear here, so I'm going by my understanding of what libvpx does
+ *
+ * Intra frames update all 3 references
+ * Inter frames update VP56_FRAME_PREVIOUS if the update_last flag is set
+ * If the update (golden|altref) flag is set, it's updated with the current frame
+ *      if update_last is set, and VP56_FRAME_PREVIOUS otherwise.
+ * If the flag is not set, the number read means:
+ *      0: no update
+ *      1: VP56_FRAME_PREVIOUS
+ *      2: update golden with altref, or update altref with golden
+ */
+static VP56Frame ref_to_update(VP8Context *s, int update, VP56Frame ref)
+{
+    VP56RangeCoder *c = &s->c;
+
+    if (update)
+        return VP56_FRAME_CURRENT;
+
+    switch (vp8_rac_get_uint(c, 2)) {
+    case 1:
+        return VP56_FRAME_PREVIOUS;
+    case 2:
+        return (ref == VP56_FRAME_GOLDEN) ? VP56_FRAME_GOLDEN2 : VP56_FRAME_GOLDEN;
+    }
+    return VP56_FRAME_NONE;
+}
+
+static void update_refs(VP8Context *s)
+{
+    VP56RangeCoder *c = &s->c;
+
+    int update_golden = vp8_rac_get(c);
+    int update_altref = vp8_rac_get(c);
+
+    s->update_golden = ref_to_update(s, update_golden, VP56_FRAME_GOLDEN);
+    s->update_altref = ref_to_update(s, update_altref, VP56_FRAME_GOLDEN2);
+}
+
+static int decode_frame_header(VP8Context *s, const uint8_t *buf, int buf_size)
+{
+    VP56RangeCoder *c = &s->c;
+    int header_size, hscale, vscale, i, j, k, l, m, ret;
+    int width  = s->avctx->width;
+    int height = s->avctx->height;
+
+    s->keyframe  = !(buf[0] & 1);
+    s->profile   =  (buf[0]>>1) & 7;
+    s->invisible = !(buf[0] & 0x10);
+    header_size  = AV_RL24(buf) >> 5;
+    buf      += 3;
+    buf_size -= 3;
+
+    if (s->profile > 3)
+        av_log(s->avctx, AV_LOG_WARNING, "Unknown profile %d\n", s->profile);
+
+    if (!s->profile)
+        memcpy(s->put_pixels_tab, s->vp8dsp.put_vp8_epel_pixels_tab, sizeof(s->put_pixels_tab));
+    else    // profile 1-3 use bilinear, 4+ aren't defined so whatever
+        memcpy(s->put_pixels_tab, s->vp8dsp.put_vp8_bilinear_pixels_tab, sizeof(s->put_pixels_tab));
+
+    if (header_size > buf_size - 7*s->keyframe) {
+        av_log(s->avctx, AV_LOG_ERROR, "Header size larger than data provided\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    if (s->keyframe) {
+        if (AV_RL24(buf) != 0x2a019d) {
+            av_log(s->avctx, AV_LOG_ERROR, "Invalid start code 0x%x\n", AV_RL24(buf));
+            return AVERROR_INVALIDDATA;
+        }
+        width  = AV_RL16(buf+3) & 0x3fff;
+        height = AV_RL16(buf+5) & 0x3fff;
+        hscale = buf[4] >> 6;
+        vscale = buf[6] >> 6;
+        buf      += 7;
+        buf_size -= 7;
+
+        if (hscale || vscale)
+            avpriv_request_sample(s->avctx, "Upscaling");
+
+        s->update_golden = s->update_altref = VP56_FRAME_CURRENT;
+        for (i = 0; i < 4; i++)
+            for (j = 0; j < 16; j++)
+                memcpy(s->prob->token[i][j], vp8_token_default_probs[i][vp8_coeff_band[j]],
+                       sizeof(s->prob->token[i][j]));
+        memcpy(s->prob->pred16x16, vp8_pred16x16_prob_inter, sizeof(s->prob->pred16x16));
+        memcpy(s->prob->pred8x8c , vp8_pred8x8c_prob_inter , sizeof(s->prob->pred8x8c));
+        memcpy(s->prob->mvc      , vp8_mv_default_prob     , sizeof(s->prob->mvc));
+        memset(&s->segmentation, 0, sizeof(s->segmentation));
+        memset(&s->lf_delta, 0, sizeof(s->lf_delta));
+    }
+
+    ff_vp56_init_range_decoder(c, buf, header_size);
+    buf      += header_size;
+    buf_size -= header_size;
+
+    if (s->keyframe) {
+        if (vp8_rac_get(c))
+            av_log(s->avctx, AV_LOG_WARNING, "Unspecified colorspace\n");
+        vp8_rac_get(c); // whether we can skip clamping in dsp functions
+    }
+
+    if ((s->segmentation.enabled = vp8_rac_get(c)))
+        parse_segment_info(s);
+    else
+        s->segmentation.update_map = 0; // FIXME: move this to some init function?
+
+    s->filter.simple    = vp8_rac_get(c);
+    s->filter.level     = vp8_rac_get_uint(c, 6);
+    s->filter.sharpness = vp8_rac_get_uint(c, 3);
+
+    if ((s->lf_delta.enabled = vp8_rac_get(c)))
+        if (vp8_rac_get(c))
+            update_lf_deltas(s);
+
+    if (setup_partitions(s, buf, buf_size)) {
+        av_log(s->avctx, AV_LOG_ERROR, "Invalid partitions\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    if (!s->macroblocks_base || /* first frame */
+        width != s->avctx->width || height != s->avctx->height || (width+15)/16 != s->mb_width || (height+15)/16 != s->mb_height) {
+        if ((ret = update_dimensions(s, width, height)) < 0)
+            return ret;
+    }
+
+    get_quants(s);
+
+    if (!s->keyframe) {
+        update_refs(s);
+        s->sign_bias[VP56_FRAME_GOLDEN]               = vp8_rac_get(c);
+        s->sign_bias[VP56_FRAME_GOLDEN2 /* altref */] = vp8_rac_get(c);
+    }
+
+    // if we aren't saving this frame's probabilities for future frames,
+    // make a copy of the current probabilities
+    if (!(s->update_probabilities = vp8_rac_get(c)))
+        s->prob[1] = s->prob[0];
+
+    s->update_last = s->keyframe || vp8_rac_get(c);
+
+    for (i = 0; i < 4; i++)
+        for (j = 0; j < 8; j++)
+            for (k = 0; k < 3; k++)
+                for (l = 0; l < NUM_DCT_TOKENS-1; l++)
+                    if (vp56_rac_get_prob_branchy(c, vp8_token_update_probs[i][j][k][l])) {
+                        int prob = vp8_rac_get_uint(c, 8);
+                        for (m = 0; vp8_coeff_band_indexes[j][m] >= 0; m++)
+                            s->prob->token[i][vp8_coeff_band_indexes[j][m]][k][l] = prob;
+                    }
+
+    if ((s->mbskip_enabled = vp8_rac_get(c)))
+        s->prob->mbskip = vp8_rac_get_uint(c, 8);
+
+    if (!s->keyframe) {
+        s->prob->intra  = vp8_rac_get_uint(c, 8);
+        s->prob->last   = vp8_rac_get_uint(c, 8);
+        s->prob->golden = vp8_rac_get_uint(c, 8);
+
+        if (vp8_rac_get(c))
+            for (i = 0; i < 4; i++)
+                s->prob->pred16x16[i] = vp8_rac_get_uint(c, 8);
+        if (vp8_rac_get(c))
+            for (i = 0; i < 3; i++)
+                s->prob->pred8x8c[i]  = vp8_rac_get_uint(c, 8);
+
+        // 17.2 MV probability update
+        for (i = 0; i < 2; i++)
+            for (j = 0; j < 19; j++)
+                if (vp56_rac_get_prob_branchy(c, vp8_mv_update_prob[i][j]))
+                    s->prob->mvc[i][j] = vp8_rac_get_nn(c);
+    }
+
+    return 0;
+}
+
+static av_always_inline void clamp_mv(VP8Context *s, VP56mv *dst, const VP56mv *src)
+{
+    dst->x = av_clip(src->x, s->mv_min.x, s->mv_max.x);
+    dst->y = av_clip(src->y, s->mv_min.y, s->mv_max.y);
+}
+
+/**
+ * Motion vector coding, 17.1.
+ */
+static int read_mv_component(VP56RangeCoder *c, const uint8_t *p)
+{
+    int bit, x = 0;
+
+    if (vp56_rac_get_prob_branchy(c, p[0])) {
+        int i;
+
+        for (i = 0; i < 3; i++)
+            x += vp56_rac_get_prob(c, p[9 + i]) << i;
+        for (i = 9; i > 3; i--)
+            x += vp56_rac_get_prob(c, p[9 + i]) << i;
+        if (!(x & 0xFFF0) || vp56_rac_get_prob(c, p[12]))
+            x += 8;
+    } else {
+        // small_mvtree
+        const uint8_t *ps = p+2;
+        bit = vp56_rac_get_prob(c, *ps);
+        ps += 1 + 3*bit;
+        x  += 4*bit;
+        bit = vp56_rac_get_prob(c, *ps);
+        ps += 1 + bit;
+        x  += 2*bit;
+        x  += vp56_rac_get_prob(c, *ps);
+    }
+
+    return (x && vp56_rac_get_prob(c, p[1])) ? -x : x;
+}
+
+static av_always_inline
+const uint8_t *get_submv_prob(uint32_t left, uint32_t top)
+{
+    if (left == top)
+        return vp8_submv_prob[4-!!left];
+    if (!top)
+        return vp8_submv_prob[2];
+    return vp8_submv_prob[1-!!left];
+}
+
+/**
+ * Split motion vector prediction, 16.4.
+ * @returns the number of motion vectors parsed (2, 4 or 16)
+ */
+static av_always_inline
+int decode_splitmvs(VP8Context *s, VP56RangeCoder *c, VP8Macroblock *mb, int layout)
+{
+    int part_idx;
+    int n, num;
+    VP8Macroblock *top_mb;
+    VP8Macroblock *left_mb = &mb[-1];
+    const uint8_t *mbsplits_left = vp8_mbsplits[left_mb->partitioning],
+                  *mbsplits_top,
+                  *mbsplits_cur, *firstidx;
+    VP56mv *top_mv;
+    VP56mv *left_mv = left_mb->bmv;
+    VP56mv *cur_mv  = mb->bmv;
+
+    if (!layout) // layout is inlined, s->mb_layout is not
+        top_mb = &mb[2];
+    else
+        top_mb = &mb[-s->mb_width-1];
+    mbsplits_top = vp8_mbsplits[top_mb->partitioning];
+    top_mv = top_mb->bmv;
+
+    if (vp56_rac_get_prob_branchy(c, vp8_mbsplit_prob[0])) {
+        if (vp56_rac_get_prob_branchy(c, vp8_mbsplit_prob[1])) {
+            part_idx = VP8_SPLITMVMODE_16x8 + vp56_rac_get_prob(c, vp8_mbsplit_prob[2]);
+        } else {
+            part_idx = VP8_SPLITMVMODE_8x8;
+        }
+    } else {
+        part_idx = VP8_SPLITMVMODE_4x4;
+    }
+
+    num = vp8_mbsplit_count[part_idx];
+    mbsplits_cur = vp8_mbsplits[part_idx],
+    firstidx = vp8_mbfirstidx[part_idx];
+    mb->partitioning = part_idx;
+
+    for (n = 0; n < num; n++) {
+        int k = firstidx[n];
+        uint32_t left, above;
+        const uint8_t *submv_prob;
+
+        if (!(k & 3))
+            left = AV_RN32A(&left_mv[mbsplits_left[k + 3]]);
+        else
+            left  = AV_RN32A(&cur_mv[mbsplits_cur[k - 1]]);
+        if (k <= 3)
+            above = AV_RN32A(&top_mv[mbsplits_top[k + 12]]);
+        else
+            above = AV_RN32A(&cur_mv[mbsplits_cur[k - 4]]);
+
+        submv_prob = get_submv_prob(left, above);
+
+        if (vp56_rac_get_prob_branchy(c, submv_prob[0])) {
+            if (vp56_rac_get_prob_branchy(c, submv_prob[1])) {
+                if (vp56_rac_get_prob_branchy(c, submv_prob[2])) {
+                    mb->bmv[n].y = mb->mv.y + read_mv_component(c, s->prob->mvc[0]);
+                    mb->bmv[n].x = mb->mv.x + read_mv_component(c, s->prob->mvc[1]);
+                } else {
+                    AV_ZERO32(&mb->bmv[n]);
+                }
+            } else {
+                AV_WN32A(&mb->bmv[n], above);
+            }
+        } else {
+            AV_WN32A(&mb->bmv[n], left);
+        }
+    }
+
+    return num;
+}
+
+static av_always_inline
+void decode_mvs(VP8Context *s, VP8Macroblock *mb, int mb_x, int mb_y, int layout)
+{
+    VP8Macroblock *mb_edge[3] = { 0 /* top */,
+                                  mb - 1 /* left */,
+                                  0 /* top-left */ };
+    enum { CNT_ZERO, CNT_NEAREST, CNT_NEAR, CNT_SPLITMV };
+    enum { VP8_EDGE_TOP, VP8_EDGE_LEFT, VP8_EDGE_TOPLEFT };
+    int idx = CNT_ZERO;
+    int cur_sign_bias = s->sign_bias[mb->ref_frame];
+    int8_t *sign_bias = s->sign_bias;
+    VP56mv near_mv[4];
+    uint8_t cnt[4] = { 0 };
+    VP56RangeCoder *c = &s->c;
+
+    if (!layout) { // layout is inlined (s->mb_layout is not)
+        mb_edge[0] = mb + 2;
+        mb_edge[2] = mb + 1;
+    }
+    else {
+        mb_edge[0] = mb - s->mb_width-1;
+        mb_edge[2] = mb - s->mb_width-2;
+    }
+
+    AV_ZERO32(&near_mv[0]);
+    AV_ZERO32(&near_mv[1]);
+    AV_ZERO32(&near_mv[2]);
+
+    /* Process MB on top, left and top-left */
+    #define MV_EDGE_CHECK(n)\
+    {\
+        VP8Macroblock *edge = mb_edge[n];\
+        int edge_ref = edge->ref_frame;\
+        if (edge_ref != VP56_FRAME_CURRENT) {\
+            uint32_t mv = AV_RN32A(&edge->mv);\
+            if (mv) {\
+                if (cur_sign_bias != sign_bias[edge_ref]) {\
+                    /* SWAR negate of the values in mv. */\
+                    mv = ~mv;\
+                    mv = ((mv&0x7fff7fff) + 0x00010001) ^ (mv&0x80008000);\
+                }\
+                if (!n || mv != AV_RN32A(&near_mv[idx]))\
+                    AV_WN32A(&near_mv[++idx], mv);\
+                cnt[idx]      += 1 + (n != 2);\
+            } else\
+                cnt[CNT_ZERO] += 1 + (n != 2);\
+        }\
+    }
+
+    MV_EDGE_CHECK(0)
+    MV_EDGE_CHECK(1)
+    MV_EDGE_CHECK(2)
+
+    mb->partitioning = VP8_SPLITMVMODE_NONE;
+    if (vp56_rac_get_prob_branchy(c, vp8_mode_contexts[cnt[CNT_ZERO]][0])) {
+        mb->mode = VP8_MVMODE_MV;
+
+        /* If we have three distinct MVs, merge first and last if they're the same */
+        if (cnt[CNT_SPLITMV] && AV_RN32A(&near_mv[1 + VP8_EDGE_TOP]) == AV_RN32A(&near_mv[1 + VP8_EDGE_TOPLEFT]))
+            cnt[CNT_NEAREST] += 1;
+
+        /* Swap near and nearest if necessary */
+        if (cnt[CNT_NEAR] > cnt[CNT_NEAREST]) {
+            FFSWAP(uint8_t,     cnt[CNT_NEAREST],     cnt[CNT_NEAR]);
+            FFSWAP( VP56mv, near_mv[CNT_NEAREST], near_mv[CNT_NEAR]);
+        }
+
+        if (vp56_rac_get_prob_branchy(c, vp8_mode_contexts[cnt[CNT_NEAREST]][1])) {
+            if (vp56_rac_get_prob_branchy(c, vp8_mode_contexts[cnt[CNT_NEAR]][2])) {
+
+                /* Choose the best mv out of 0,0 and the nearest mv */
+                clamp_mv(s, &mb->mv, &near_mv[CNT_ZERO + (cnt[CNT_NEAREST] >= cnt[CNT_ZERO])]);
+                cnt[CNT_SPLITMV] = ((mb_edge[VP8_EDGE_LEFT]->mode    == VP8_MVMODE_SPLIT) +
+                                    (mb_edge[VP8_EDGE_TOP]->mode     == VP8_MVMODE_SPLIT)) * 2 +
+                                    (mb_edge[VP8_EDGE_TOPLEFT]->mode == VP8_MVMODE_SPLIT);
+
+                if (vp56_rac_get_prob_branchy(c, vp8_mode_contexts[cnt[CNT_SPLITMV]][3])) {
+                    mb->mode = VP8_MVMODE_SPLIT;
+                    mb->mv = mb->bmv[decode_splitmvs(s, c, mb, layout) - 1];
+                } else {
+                    mb->mv.y += read_mv_component(c, s->prob->mvc[0]);
+                    mb->mv.x += read_mv_component(c, s->prob->mvc[1]);
+                    mb->bmv[0] = mb->mv;
+                }
+            } else {
+                clamp_mv(s, &mb->mv, &near_mv[CNT_NEAR]);
+                mb->bmv[0] = mb->mv;
+            }
+        } else {
+            clamp_mv(s, &mb->mv, &near_mv[CNT_NEAREST]);
+            mb->bmv[0] = mb->mv;
+        }
+    } else {
+        mb->mode = VP8_MVMODE_ZERO;
+        AV_ZERO32(&mb->mv);
+        mb->bmv[0] = mb->mv;
+    }
+}
+
+static av_always_inline
+void decode_intra4x4_modes(VP8Context *s, VP56RangeCoder *c, VP8Macroblock *mb,
+                           int mb_x, int keyframe, int layout)
+{
+    uint8_t *intra4x4 = mb->intra4x4_pred_mode_mb;
+
+    if (layout == 1) {
+        VP8Macroblock *mb_top = mb - s->mb_width - 1;
+        memcpy(mb->intra4x4_pred_mode_top, mb_top->intra4x4_pred_mode_top, 4);
+    }
+    if (keyframe) {
+        int x, y;
+        uint8_t* top;
+        uint8_t* const left = s->intra4x4_pred_mode_left;
+        if (layout == 1)
+            top = mb->intra4x4_pred_mode_top;
+        else
+            top = s->intra4x4_pred_mode_top + 4 * mb_x;
+        for (y = 0; y < 4; y++) {
+            for (x = 0; x < 4; x++) {
+                const uint8_t *ctx;
+                ctx = vp8_pred4x4_prob_intra[top[x]][left[y]];
+                *intra4x4 = vp8_rac_get_tree(c, vp8_pred4x4_tree, ctx);
+                left[y] = top[x] = *intra4x4;
+                intra4x4++;
+            }
+        }
+    } else {
+        int i;
+        for (i = 0; i < 16; i++)
+            intra4x4[i] = vp8_rac_get_tree(c, vp8_pred4x4_tree, vp8_pred4x4_prob_inter);
+    }
+}
+
+static av_always_inline
+void decode_mb_mode(VP8Context *s, VP8Macroblock *mb, int mb_x, int mb_y,
+                    uint8_t *segment, uint8_t *ref, int layout)
+{
+    VP56RangeCoder *c = &s->c;
+
+    if (s->segmentation.update_map) {
+        int bit  = vp56_rac_get_prob(c, s->prob->segmentid[0]);
+        *segment = vp56_rac_get_prob(c, s->prob->segmentid[1+bit]) + 2*bit;
+    } else if (s->segmentation.enabled)
+        *segment = ref ? *ref : *segment;
+    mb->segment = *segment;
+
+    mb->skip = s->mbskip_enabled ? vp56_rac_get_prob(c, s->prob->mbskip) : 0;
+
+    if (s->keyframe) {
+        mb->mode = vp8_rac_get_tree(c, vp8_pred16x16_tree_intra, vp8_pred16x16_prob_intra);
+
+        if (mb->mode == MODE_I4x4) {
+            decode_intra4x4_modes(s, c, mb, mb_x, 1, layout);
+        } else {
+            const uint32_t modes = vp8_pred4x4_mode[mb->mode] * 0x01010101u;
+            if (s->mb_layout == 1)
+                AV_WN32A(mb->intra4x4_pred_mode_top, modes);
+            else
+                AV_WN32A(s->intra4x4_pred_mode_top + 4 * mb_x, modes);
+            AV_WN32A( s->intra4x4_pred_mode_left, modes);
+        }
+
+        mb->chroma_pred_mode = vp8_rac_get_tree(c, vp8_pred8x8c_tree, vp8_pred8x8c_prob_intra);
+        mb->ref_frame = VP56_FRAME_CURRENT;
+    } else if (vp56_rac_get_prob_branchy(c, s->prob->intra)) {
+        // inter MB, 16.2
+        if (vp56_rac_get_prob_branchy(c, s->prob->last))
+            mb->ref_frame = vp56_rac_get_prob(c, s->prob->golden) ?
+                VP56_FRAME_GOLDEN2 /* altref */ : VP56_FRAME_GOLDEN;
+        else
+            mb->ref_frame = VP56_FRAME_PREVIOUS;
+        s->ref_count[mb->ref_frame-1]++;
+
+        // motion vectors, 16.3
+        decode_mvs(s, mb, mb_x, mb_y, layout);
+    } else {
+        // intra MB, 16.1
+        mb->mode = vp8_rac_get_tree(c, vp8_pred16x16_tree_inter, s->prob->pred16x16);
+
+        if (mb->mode == MODE_I4x4)
+            decode_intra4x4_modes(s, c, mb, mb_x, 0, layout);
+
+        mb->chroma_pred_mode = vp8_rac_get_tree(c, vp8_pred8x8c_tree, s->prob->pred8x8c);
+        mb->ref_frame = VP56_FRAME_CURRENT;
+        mb->partitioning = VP8_SPLITMVMODE_NONE;
+        AV_ZERO32(&mb->bmv[0]);
+    }
+}
+
+#ifndef decode_block_coeffs_internal
+/**
+ * @param r arithmetic bitstream reader context
+ * @param block destination for block coefficients
+ * @param probs probabilities to use when reading trees from the bitstream
+ * @param i initial coeff index, 0 unless a separate DC block is coded
+ * @param qmul array holding the dc/ac dequant factor at position 0/1
+ * @return 0 if no coeffs were decoded
+ *         otherwise, the index of the last coeff decoded plus one
+ */
+static int decode_block_coeffs_internal(VP56RangeCoder *r, int16_t block[16],
+                                        uint8_t probs[16][3][NUM_DCT_TOKENS-1],
+                                        int i, uint8_t *token_prob, int16_t qmul[2])
+{
+    VP56RangeCoder c = *r;
+    goto skip_eob;
+    do {
+        int coeff;
+        if (!vp56_rac_get_prob_branchy(&c, token_prob[0]))   // DCT_EOB
+            break;
+
+skip_eob:
+        if (!vp56_rac_get_prob_branchy(&c, token_prob[1])) { // DCT_0
+            if (++i == 16)
+                break; // invalid input; blocks should end with EOB
+            token_prob = probs[i][0];
+            goto skip_eob;
+        }
+
+        if (!vp56_rac_get_prob_branchy(&c, token_prob[2])) { // DCT_1
+            coeff = 1;
+            token_prob = probs[i+1][1];
+        } else {
+            if (!vp56_rac_get_prob_branchy(&c, token_prob[3])) { // DCT 2,3,4
+                coeff = vp56_rac_get_prob_branchy(&c, token_prob[4]);
+                if (coeff)
+                    coeff += vp56_rac_get_prob(&c, token_prob[5]);
+                coeff += 2;
+            } else {
+                // DCT_CAT*
+                if (!vp56_rac_get_prob_branchy(&c, token_prob[6])) {
+                    if (!vp56_rac_get_prob_branchy(&c, token_prob[7])) { // DCT_CAT1
+                        coeff  = 5 + vp56_rac_get_prob(&c, vp8_dct_cat1_prob[0]);
+                    } else {                                    // DCT_CAT2
+                        coeff  = 7;
+                        coeff += vp56_rac_get_prob(&c, vp8_dct_cat2_prob[0]) << 1;
+                        coeff += vp56_rac_get_prob(&c, vp8_dct_cat2_prob[1]);
+                    }
+                } else {    // DCT_CAT3 and up
+                    int a = vp56_rac_get_prob(&c, token_prob[8]);
+                    int b = vp56_rac_get_prob(&c, token_prob[9+a]);
+                    int cat = (a<<1) + b;
+                    coeff  = 3 + (8<<cat);
+                    coeff += vp8_rac_get_coeff(&c, ff_vp8_dct_cat_prob[cat]);
+                }
+            }
+            token_prob = probs[i+1][2];
+        }
+        block[zigzag_scan[i]] = (vp8_rac_get(&c) ? -coeff : coeff) * qmul[!!i];
+    } while (++i < 16);
+
+    *r = c;
+    return i;
+}
+#endif
+
+/**
+ * @param c arithmetic bitstream reader context
+ * @param block destination for block coefficients
+ * @param probs probabilities to use when reading trees from the bitstream
+ * @param i initial coeff index, 0 unless a separate DC block is coded
+ * @param zero_nhood the initial prediction context for number of surrounding
+ *                   all-zero blocks (only left/top, so 0-2)
+ * @param qmul array holding the dc/ac dequant factor at position 0/1
+ * @return 0 if no coeffs were decoded
+ *         otherwise, the index of the last coeff decoded plus one
+ */
+static av_always_inline
+int decode_block_coeffs(VP56RangeCoder *c, int16_t block[16],
+                        uint8_t probs[16][3][NUM_DCT_TOKENS-1],
+                        int i, int zero_nhood, int16_t qmul[2])
+{
+    uint8_t *token_prob = probs[i][zero_nhood];
+    if (!vp56_rac_get_prob_branchy(c, token_prob[0]))   // DCT_EOB
+        return 0;
+    return decode_block_coeffs_internal(c, block, probs, i, token_prob, qmul);
+}
+
+static av_always_inline
+void decode_mb_coeffs(VP8Context *s, VP8ThreadData *td, VP56RangeCoder *c, VP8Macroblock *mb,
+                      uint8_t t_nnz[9], uint8_t l_nnz[9])
+{
+    int i, x, y, luma_start = 0, luma_ctx = 3;
+    int nnz_pred, nnz, nnz_total = 0;
+    int segment = mb->segment;
+    int block_dc = 0;
+
+    if (mb->mode != MODE_I4x4 && mb->mode != VP8_MVMODE_SPLIT) {
+        nnz_pred = t_nnz[8] + l_nnz[8];
+
+        // decode DC values and do hadamard
+        nnz = decode_block_coeffs(c, td->block_dc, s->prob->token[1], 0, nnz_pred,
+                                  s->qmat[segment].luma_dc_qmul);
+        l_nnz[8] = t_nnz[8] = !!nnz;
+        if (nnz) {
+            nnz_total += nnz;
+            block_dc = 1;
+            if (nnz == 1)
+                s->vp8dsp.vp8_luma_dc_wht_dc(td->block, td->block_dc);
+            else
+                s->vp8dsp.vp8_luma_dc_wht(td->block, td->block_dc);
+        }
+        luma_start = 1;
+        luma_ctx = 0;
+    }
+
+    // luma blocks
+    for (y = 0; y < 4; y++)
+        for (x = 0; x < 4; x++) {
+            nnz_pred = l_nnz[y] + t_nnz[x];
+            nnz = decode_block_coeffs(c, td->block[y][x], s->prob->token[luma_ctx], luma_start,
+                                      nnz_pred, s->qmat[segment].luma_qmul);
+            // nnz+block_dc may be one more than the actual last index, but we don't care
+            td->non_zero_count_cache[y][x] = nnz + block_dc;
+            t_nnz[x] = l_nnz[y] = !!nnz;
+            nnz_total += nnz;
+        }
+
+    // chroma blocks
+    // TODO: what to do about dimensions? 2nd dim for luma is x,
+    // but for chroma it's (y<<1)|x
+    for (i = 4; i < 6; i++)
+        for (y = 0; y < 2; y++)
+            for (x = 0; x < 2; x++) {
+                nnz_pred = l_nnz[i+2*y] + t_nnz[i+2*x];
+                nnz = decode_block_coeffs(c, td->block[i][(y<<1)+x], s->prob->token[2], 0,
+                                          nnz_pred, s->qmat[segment].chroma_qmul);
+                td->non_zero_count_cache[i][(y<<1)+x] = nnz;
+                t_nnz[i+2*x] = l_nnz[i+2*y] = !!nnz;
+                nnz_total += nnz;
+            }
+
+    // if there were no coded coeffs despite the macroblock not being marked skip,
+    // we MUST not do the inner loop filter and should not do IDCT
+    // Since skip isn't used for bitstream prediction, just manually set it.
+    if (!nnz_total)
+        mb->skip = 1;
+}
+
+static av_always_inline
+void backup_mb_border(uint8_t *top_border, uint8_t *src_y, uint8_t *src_cb, uint8_t *src_cr,
+                      int linesize, int uvlinesize, int simple)
+{
+    AV_COPY128(top_border, src_y + 15*linesize);
+    if (!simple) {
+        AV_COPY64(top_border+16, src_cb + 7*uvlinesize);
+        AV_COPY64(top_border+24, src_cr + 7*uvlinesize);
+    }
+}
+
+static av_always_inline
+void xchg_mb_border(uint8_t *top_border, uint8_t *src_y, uint8_t *src_cb, uint8_t *src_cr,
+                    int linesize, int uvlinesize, int mb_x, int mb_y, int mb_width,
+                    int simple, int xchg)
+{
+    uint8_t *top_border_m1 = top_border-32;     // for TL prediction
+    src_y  -=   linesize;
+    src_cb -= uvlinesize;
+    src_cr -= uvlinesize;
+
+#define XCHG(a,b,xchg) do {                     \
+        if (xchg) AV_SWAP64(b,a);               \
+        else      AV_COPY64(b,a);               \
+    } while (0)
+
+    XCHG(top_border_m1+8, src_y-8, xchg);
+    XCHG(top_border,      src_y,   xchg);
+    XCHG(top_border+8,    src_y+8, 1);
+    if (mb_x < mb_width-1)
+        XCHG(top_border+32, src_y+16, 1);
+
+    // only copy chroma for normal loop filter
+    // or to initialize the top row to 127
+    if (!simple || !mb_y) {
+        XCHG(top_border_m1+16, src_cb-8, xchg);
+        XCHG(top_border_m1+24, src_cr-8, xchg);
+        XCHG(top_border+16,    src_cb, 1);
+        XCHG(top_border+24,    src_cr, 1);
+    }
+}
+
+static av_always_inline
+int check_dc_pred8x8_mode(int mode, int mb_x, int mb_y)
+{
+    if (!mb_x) {
+        return mb_y ? TOP_DC_PRED8x8 : DC_128_PRED8x8;
+    } else {
+        return mb_y ? mode : LEFT_DC_PRED8x8;
+    }
+}
+
+static av_always_inline
+int check_tm_pred8x8_mode(int mode, int mb_x, int mb_y)
+{
+    if (!mb_x) {
+        return mb_y ? VERT_PRED8x8 : DC_129_PRED8x8;
+    } else {
+        return mb_y ? mode : HOR_PRED8x8;
+    }
+}
+
+static av_always_inline
+int check_intra_pred8x8_mode(int mode, int mb_x, int mb_y)
+{
+    if (mode == DC_PRED8x8) {
+        return check_dc_pred8x8_mode(mode, mb_x, mb_y);
+    } else {
+        return mode;
+    }
+}
+
+static av_always_inline
+int check_intra_pred8x8_mode_emuedge(int mode, int mb_x, int mb_y)
+{
+    switch (mode) {
+    case DC_PRED8x8:
+        return check_dc_pred8x8_mode(mode, mb_x, mb_y);
+    case VERT_PRED8x8:
+        return !mb_y ? DC_127_PRED8x8 : mode;
+    case HOR_PRED8x8:
+        return !mb_x ? DC_129_PRED8x8 : mode;
+    case PLANE_PRED8x8 /*TM*/:
+        return check_tm_pred8x8_mode(mode, mb_x, mb_y);
+    }
+    return mode;
+}
+
+static av_always_inline
+int check_tm_pred4x4_mode(int mode, int mb_x, int mb_y)
+{
+    if (!mb_x) {
+        return mb_y ? VERT_VP8_PRED : DC_129_PRED;
+    } else {
+        return mb_y ? mode : HOR_VP8_PRED;
+    }
+}
+
+static av_always_inline
+int check_intra_pred4x4_mode_emuedge(int mode, int mb_x, int mb_y, int *copy_buf)
+{
+    switch (mode) {
+    case VERT_PRED:
+        if (!mb_x && mb_y) {
+            *copy_buf = 1;
+            return mode;
+        }
+        /* fall-through */
+    case DIAG_DOWN_LEFT_PRED:
+    case VERT_LEFT_PRED:
+        return !mb_y ? DC_127_PRED : mode;
+    case HOR_PRED:
+        if (!mb_y) {
+            *copy_buf = 1;
+            return mode;
+        }
+        /* fall-through */
+    case HOR_UP_PRED:
+        return !mb_x ? DC_129_PRED : mode;
+    case TM_VP8_PRED:
+        return check_tm_pred4x4_mode(mode, mb_x, mb_y);
+    case DC_PRED: // 4x4 DC doesn't use the same "H.264-style" exceptions as 16x16/8x8 DC
+    case DIAG_DOWN_RIGHT_PRED:
+    case VERT_RIGHT_PRED:
+    case HOR_DOWN_PRED:
+        if (!mb_y || !mb_x)
+            *copy_buf = 1;
+        return mode;
+    }
+    return mode;
+}
+
+static av_always_inline
+void intra_predict(VP8Context *s, VP8ThreadData *td, uint8_t *dst[3],
+                   VP8Macroblock *mb, int mb_x, int mb_y)
+{
+    AVCodecContext *avctx = s->avctx;
+    int x, y, mode, nnz;
+    uint32_t tr;
+
+    // for the first row, we need to run xchg_mb_border to init the top edge to 127
+    // otherwise, skip it if we aren't going to deblock
+    if (!(avctx->flags & CODEC_FLAG_EMU_EDGE && !mb_y) && (s->deblock_filter || !mb_y) && td->thread_nr == 0)
+        xchg_mb_border(s->top_border[mb_x+1], dst[0], dst[1], dst[2],
+                       s->linesize, s->uvlinesize, mb_x, mb_y, s->mb_width,
+                       s->filter.simple, 1);
+
+    if (mb->mode < MODE_I4x4) {
+        if (avctx->flags & CODEC_FLAG_EMU_EDGE) { // tested
+            mode = check_intra_pred8x8_mode_emuedge(mb->mode, mb_x, mb_y);
+        } else {
+            mode = check_intra_pred8x8_mode(mb->mode, mb_x, mb_y);
+        }
+        s->hpc.pred16x16[mode](dst[0], s->linesize);
+    } else {
+        uint8_t *ptr = dst[0];
+        uint8_t *intra4x4 = mb->intra4x4_pred_mode_mb;
+        uint8_t tr_top[4] = { 127, 127, 127, 127 };
+
+        // all blocks on the right edge of the macroblock use bottom edge
+        // the top macroblock for their topright edge
+        uint8_t *tr_right = ptr - s->linesize + 16;
+
+        // if we're on the right edge of the frame, said edge is extended
+        // from the top macroblock
+        if (!(!mb_y && avctx->flags & CODEC_FLAG_EMU_EDGE) &&
+            mb_x == s->mb_width-1) {
+            tr = tr_right[-1]*0x01010101u;
+            tr_right = (uint8_t *)&tr;
+        }
+
+        if (mb->skip)
+            AV_ZERO128(td->non_zero_count_cache);
+
+        for (y = 0; y < 4; y++) {
+            uint8_t *topright = ptr + 4 - s->linesize;
+            for (x = 0; x < 4; x++) {
+                int copy = 0, linesize = s->linesize;
+                uint8_t *dst = ptr+4*x;
+                DECLARE_ALIGNED(4, uint8_t, copy_dst)[5*8];
+
+                if ((y == 0 || x == 3) && mb_y == 0 && avctx->flags & CODEC_FLAG_EMU_EDGE) {
+                    topright = tr_top;
+                } else if (x == 3)
+                    topright = tr_right;
+
+                if (avctx->flags & CODEC_FLAG_EMU_EDGE) { // mb_x+x or mb_y+y is a hack but works
+                    mode = check_intra_pred4x4_mode_emuedge(intra4x4[x], mb_x + x, mb_y + y, &copy);
+                    if (copy) {
+                        dst = copy_dst + 12;
+                        linesize = 8;
+                        if (!(mb_y + y)) {
+                            copy_dst[3] = 127U;
+                            AV_WN32A(copy_dst+4, 127U * 0x01010101U);
+                        } else {
+                            AV_COPY32(copy_dst+4, ptr+4*x-s->linesize);
+                            if (!(mb_x + x)) {
+                                copy_dst[3] = 129U;
+                            } else {
+                                copy_dst[3] = ptr[4*x-s->linesize-1];
+                            }
+                        }
+                        if (!(mb_x + x)) {
+                            copy_dst[11] =
+                            copy_dst[19] =
+                            copy_dst[27] =
+                            copy_dst[35] = 129U;
+                        } else {
+                            copy_dst[11] = ptr[4*x              -1];
+                            copy_dst[19] = ptr[4*x+s->linesize  -1];
+                            copy_dst[27] = ptr[4*x+s->linesize*2-1];
+                            copy_dst[35] = ptr[4*x+s->linesize*3-1];
+                        }
+                    }
+                } else {
+                    mode = intra4x4[x];
+                }
+                s->hpc.pred4x4[mode](dst, topright, linesize);
+                if (copy) {
+                    AV_COPY32(ptr+4*x              , copy_dst+12);
+                    AV_COPY32(ptr+4*x+s->linesize  , copy_dst+20);
+                    AV_COPY32(ptr+4*x+s->linesize*2, copy_dst+28);
+                    AV_COPY32(ptr+4*x+s->linesize*3, copy_dst+36);
+                }
+
+                nnz = td->non_zero_count_cache[y][x];
+                if (nnz) {
+                    if (nnz == 1)
+                        s->vp8dsp.vp8_idct_dc_add(ptr+4*x, td->block[y][x], s->linesize);
+                    else
+                        s->vp8dsp.vp8_idct_add(ptr+4*x, td->block[y][x], s->linesize);
+                }
+                topright += 4;
+            }
+
+            ptr   += 4*s->linesize;
+            intra4x4 += 4;
+        }
+    }
+
+    if (avctx->flags & CODEC_FLAG_EMU_EDGE) {
+        mode = check_intra_pred8x8_mode_emuedge(mb->chroma_pred_mode, mb_x, mb_y);
+    } else {
+        mode = check_intra_pred8x8_mode(mb->chroma_pred_mode, mb_x, mb_y);
+    }
+    s->hpc.pred8x8[mode](dst[1], s->uvlinesize);
+    s->hpc.pred8x8[mode](dst[2], s->uvlinesize);
+
+    if (!(avctx->flags & CODEC_FLAG_EMU_EDGE && !mb_y) && (s->deblock_filter || !mb_y) && td->thread_nr == 0)
+        xchg_mb_border(s->top_border[mb_x+1], dst[0], dst[1], dst[2],
+                       s->linesize, s->uvlinesize, mb_x, mb_y, s->mb_width,
+                       s->filter.simple, 0);
+}
+
+static const uint8_t subpel_idx[3][8] = {
+    { 0, 1, 2, 1, 2, 1, 2, 1 }, // nr. of left extra pixels,
+                                // also function pointer index
+    { 0, 3, 5, 3, 5, 3, 5, 3 }, // nr. of extra pixels required
+    { 0, 2, 3, 2, 3, 2, 3, 2 }, // nr. of right extra pixels
+};
+
+/**
+ * luma MC function
+ *
+ * @param s VP8 decoding context
+ * @param dst target buffer for block data at block position
+ * @param ref reference picture buffer at origin (0, 0)
+ * @param mv motion vector (relative to block position) to get pixel data from
+ * @param x_off horizontal position of block from origin (0, 0)
+ * @param y_off vertical position of block from origin (0, 0)
+ * @param block_w width of block (16, 8 or 4)
+ * @param block_h height of block (always same as block_w)
+ * @param width width of src/dst plane data
+ * @param height height of src/dst plane data
+ * @param linesize size of a single line of plane data, including padding
+ * @param mc_func motion compensation function pointers (bilinear or sixtap MC)
+ */
+static av_always_inline
+void vp8_mc_luma(VP8Context *s, VP8ThreadData *td, uint8_t *dst,
+                 ThreadFrame *ref, const VP56mv *mv,
+                 int x_off, int y_off, int block_w, int block_h,
+                 int width, int height, int linesize,
+                 vp8_mc_func mc_func[3][3])
+{
+    uint8_t *src = ref->f->data[0];
+
+    if (AV_RN32A(mv)) {
+
+        int mx = (mv->x << 1)&7, mx_idx = subpel_idx[0][mx];
+        int my = (mv->y << 1)&7, my_idx = subpel_idx[0][my];
+
+        x_off += mv->x >> 2;
+        y_off += mv->y >> 2;
+
+        // edge emulation
+        ff_thread_await_progress(ref, (3 + y_off + block_h + subpel_idx[2][my]) >> 4, 0);
+        src += y_off * linesize + x_off;
+        if (x_off < mx_idx || x_off >= width  - block_w - subpel_idx[2][mx] ||
+            y_off < my_idx || y_off >= height - block_h - subpel_idx[2][my]) {
+            s->vdsp.emulated_edge_mc(td->edge_emu_buffer, src - my_idx * linesize - mx_idx, linesize,
+                                     block_w + subpel_idx[1][mx], block_h + subpel_idx[1][my],
+                                     x_off - mx_idx, y_off - my_idx, width, height);
+            src = td->edge_emu_buffer + mx_idx + linesize * my_idx;
+        }
+        mc_func[my_idx][mx_idx](dst, linesize, src, linesize, block_h, mx, my);
+    } else {
+        ff_thread_await_progress(ref, (3 + y_off + block_h) >> 4, 0);
+        mc_func[0][0](dst, linesize, src + y_off * linesize + x_off, linesize, block_h, 0, 0);
+    }
+}
+
+/**
+ * chroma MC function
+ *
+ * @param s VP8 decoding context
+ * @param dst1 target buffer for block data at block position (U plane)
+ * @param dst2 target buffer for block data at block position (V plane)
+ * @param ref reference picture buffer at origin (0, 0)
+ * @param mv motion vector (relative to block position) to get pixel data from
+ * @param x_off horizontal position of block from origin (0, 0)
+ * @param y_off vertical position of block from origin (0, 0)
+ * @param block_w width of block (16, 8 or 4)
+ * @param block_h height of block (always same as block_w)
+ * @param width width of src/dst plane data
+ * @param height height of src/dst plane data
+ * @param linesize size of a single line of plane data, including padding
+ * @param mc_func motion compensation function pointers (bilinear or sixtap MC)
+ */
+static av_always_inline
+void vp8_mc_chroma(VP8Context *s, VP8ThreadData *td, uint8_t *dst1, uint8_t *dst2,
+                   ThreadFrame *ref, const VP56mv *mv, int x_off, int y_off,
+                   int block_w, int block_h, int width, int height, int linesize,
+                   vp8_mc_func mc_func[3][3])
+{
+    uint8_t *src1 = ref->f->data[1], *src2 = ref->f->data[2];
+
+    if (AV_RN32A(mv)) {
+        int mx = mv->x&7, mx_idx = subpel_idx[0][mx];
+        int my = mv->y&7, my_idx = subpel_idx[0][my];
+
+        x_off += mv->x >> 3;
+        y_off += mv->y >> 3;
+
+        // edge emulation
+        src1 += y_off * linesize + x_off;
+        src2 += y_off * linesize + x_off;
+        ff_thread_await_progress(ref, (3 + y_off + block_h + subpel_idx[2][my]) >> 3, 0);
+        if (x_off < mx_idx || x_off >= width  - block_w - subpel_idx[2][mx] ||
+            y_off < my_idx || y_off >= height - block_h - subpel_idx[2][my]) {
+            s->vdsp.emulated_edge_mc(td->edge_emu_buffer, src1 - my_idx * linesize - mx_idx, linesize,
+                                     block_w + subpel_idx[1][mx], block_h + subpel_idx[1][my],
+                                     x_off - mx_idx, y_off - my_idx, width, height);
+            src1 = td->edge_emu_buffer + mx_idx + linesize * my_idx;
+            mc_func[my_idx][mx_idx](dst1, linesize, src1, linesize, block_h, mx, my);
+
+            s->vdsp.emulated_edge_mc(td->edge_emu_buffer, src2 - my_idx * linesize - mx_idx, linesize,
+                                     block_w + subpel_idx[1][mx], block_h + subpel_idx[1][my],
+                                     x_off - mx_idx, y_off - my_idx, width, height);
+            src2 = td->edge_emu_buffer + mx_idx + linesize * my_idx;
+            mc_func[my_idx][mx_idx](dst2, linesize, src2, linesize, block_h, mx, my);
+        } else {
+            mc_func[my_idx][mx_idx](dst1, linesize, src1, linesize, block_h, mx, my);
+            mc_func[my_idx][mx_idx](dst2, linesize, src2, linesize, block_h, mx, my);
+        }
+    } else {
+        ff_thread_await_progress(ref, (3 + y_off + block_h) >> 3, 0);
+        mc_func[0][0](dst1, linesize, src1 + y_off * linesize + x_off, linesize, block_h, 0, 0);
+        mc_func[0][0](dst2, linesize, src2 + y_off * linesize + x_off, linesize, block_h, 0, 0);
+    }
+}
+
+static av_always_inline
+void vp8_mc_part(VP8Context *s, VP8ThreadData *td, uint8_t *dst[3],
+                 ThreadFrame *ref_frame, int x_off, int y_off,
+                 int bx_off, int by_off,
+                 int block_w, int block_h,
+                 int width, int height, VP56mv *mv)
+{
+    VP56mv uvmv = *mv;
+
+    /* Y */
+    vp8_mc_luma(s, td, dst[0] + by_off * s->linesize + bx_off,
+                ref_frame, mv, x_off + bx_off, y_off + by_off,
+                block_w, block_h, width, height, s->linesize,
+                s->put_pixels_tab[block_w == 8]);
+
+    /* U/V */
+    if (s->profile == 3) {
+        uvmv.x &= ~7;
+        uvmv.y &= ~7;
+    }
+    x_off   >>= 1; y_off   >>= 1;
+    bx_off  >>= 1; by_off  >>= 1;
+    width   >>= 1; height  >>= 1;
+    block_w >>= 1; block_h >>= 1;
+    vp8_mc_chroma(s, td, dst[1] + by_off * s->uvlinesize + bx_off,
+                  dst[2] + by_off * s->uvlinesize + bx_off, ref_frame,
+                  &uvmv, x_off + bx_off, y_off + by_off,
+                  block_w, block_h, width, height, s->uvlinesize,
+                  s->put_pixels_tab[1 + (block_w == 4)]);
+}
+
+/* Fetch pixels for estimated mv 4 macroblocks ahead.
+ * Optimized for 64-byte cache lines.  Inspired by ffh264 prefetch_motion. */
+static av_always_inline void prefetch_motion(VP8Context *s, VP8Macroblock *mb, int mb_x, int mb_y, int mb_xy, int ref)
+{
+    /* Don't prefetch refs that haven't been used very often this frame. */
+    if (s->ref_count[ref-1] > (mb_xy >> 5)) {
+        int x_off = mb_x << 4, y_off = mb_y << 4;
+        int mx = (mb->mv.x>>2) + x_off + 8;
+        int my = (mb->mv.y>>2) + y_off;
+        uint8_t **src= s->framep[ref]->tf.f->data;
+        int off= mx + (my + (mb_x&3)*4)*s->linesize + 64;
+        /* For threading, a ff_thread_await_progress here might be useful, but
+         * it actually slows down the decoder. Since a bad prefetch doesn't
+         * generate bad decoder output, we don't run it here. */
+        s->vdsp.prefetch(src[0]+off, s->linesize, 4);
+        off= (mx>>1) + ((my>>1) + (mb_x&7))*s->uvlinesize + 64;
+        s->vdsp.prefetch(src[1]+off, src[2]-src[1], 2);
+    }
+}
+
+/**
+ * Apply motion vectors to prediction buffer, chapter 18.
+ */
+static av_always_inline
+void inter_predict(VP8Context *s, VP8ThreadData *td, uint8_t *dst[3],
+                   VP8Macroblock *mb, int mb_x, int mb_y)
+{
+    int x_off = mb_x << 4, y_off = mb_y << 4;
+    int width = 16*s->mb_width, height = 16*s->mb_height;
+    ThreadFrame *ref = &s->framep[mb->ref_frame]->tf;
+    VP56mv *bmv = mb->bmv;
+
+    switch (mb->partitioning) {
+    case VP8_SPLITMVMODE_NONE:
+        vp8_mc_part(s, td, dst, ref, x_off, y_off,
+                    0, 0, 16, 16, width, height, &mb->mv);
+        break;
+    case VP8_SPLITMVMODE_4x4: {
+        int x, y;
+        VP56mv uvmv;
+
+        /* Y */
+        for (y = 0; y < 4; y++) {
+            for (x = 0; x < 4; x++) {
+                vp8_mc_luma(s, td, dst[0] + 4*y*s->linesize + x*4,
+                            ref, &bmv[4*y + x],
+                            4*x + x_off, 4*y + y_off, 4, 4,
+                            width, height, s->linesize,
+                            s->put_pixels_tab[2]);
+            }
+        }
+
+        /* U/V */
+        x_off >>= 1; y_off >>= 1; width >>= 1; height >>= 1;
+        for (y = 0; y < 2; y++) {
+            for (x = 0; x < 2; x++) {
+                uvmv.x = mb->bmv[ 2*y    * 4 + 2*x  ].x +
+                         mb->bmv[ 2*y    * 4 + 2*x+1].x +
+                         mb->bmv[(2*y+1) * 4 + 2*x  ].x +
+                         mb->bmv[(2*y+1) * 4 + 2*x+1].x;
+                uvmv.y = mb->bmv[ 2*y    * 4 + 2*x  ].y +
+                         mb->bmv[ 2*y    * 4 + 2*x+1].y +
+                         mb->bmv[(2*y+1) * 4 + 2*x  ].y +
+                         mb->bmv[(2*y+1) * 4 + 2*x+1].y;
+                uvmv.x = (uvmv.x + 2 + (uvmv.x >> (INT_BIT-1))) >> 2;
+                uvmv.y = (uvmv.y + 2 + (uvmv.y >> (INT_BIT-1))) >> 2;
+                if (s->profile == 3) {
+                    uvmv.x &= ~7;
+                    uvmv.y &= ~7;
+                }
+                vp8_mc_chroma(s, td, dst[1] + 4*y*s->uvlinesize + x*4,
+                              dst[2] + 4*y*s->uvlinesize + x*4, ref, &uvmv,
+                              4*x + x_off, 4*y + y_off, 4, 4,
+                              width, height, s->uvlinesize,
+                              s->put_pixels_tab[2]);
+            }
+        }
+        break;
+    }
+    case VP8_SPLITMVMODE_16x8:
+        vp8_mc_part(s, td, dst, ref, x_off, y_off,
+                    0, 0, 16, 8, width, height, &bmv[0]);
+        vp8_mc_part(s, td, dst, ref, x_off, y_off,
+                    0, 8, 16, 8, width, height, &bmv[1]);
+        break;
+    case VP8_SPLITMVMODE_8x16:
+        vp8_mc_part(s, td, dst, ref, x_off, y_off,
+                    0, 0, 8, 16, width, height, &bmv[0]);
+        vp8_mc_part(s, td, dst, ref, x_off, y_off,
+                    8, 0, 8, 16, width, height, &bmv[1]);
+        break;
+    case VP8_SPLITMVMODE_8x8:
+        vp8_mc_part(s, td, dst, ref, x_off, y_off,
+                    0, 0, 8, 8, width, height, &bmv[0]);
+        vp8_mc_part(s, td, dst, ref, x_off, y_off,
+                    8, 0, 8, 8, width, height, &bmv[1]);
+        vp8_mc_part(s, td, dst, ref, x_off, y_off,
+                    0, 8, 8, 8, width, height, &bmv[2]);
+        vp8_mc_part(s, td, dst, ref, x_off, y_off,
+                    8, 8, 8, 8, width, height, &bmv[3]);
+        break;
+    }
+}
+
+static av_always_inline void idct_mb(VP8Context *s, VP8ThreadData *td,
+                                     uint8_t *dst[3], VP8Macroblock *mb)
+{
+    int x, y, ch;
+
+    if (mb->mode != MODE_I4x4) {
+        uint8_t *y_dst = dst[0];
+        for (y = 0; y < 4; y++) {
+            uint32_t nnz4 = AV_RL32(td->non_zero_count_cache[y]);
+            if (nnz4) {
+                if (nnz4&~0x01010101) {
+                    for (x = 0; x < 4; x++) {
+                        if ((uint8_t)nnz4 == 1)
+                            s->vp8dsp.vp8_idct_dc_add(y_dst+4*x, td->block[y][x], s->linesize);
+                        else if((uint8_t)nnz4 > 1)
+                            s->vp8dsp.vp8_idct_add(y_dst+4*x, td->block[y][x], s->linesize);
+                        nnz4 >>= 8;
+                        if (!nnz4)
+                            break;
+                    }
+                } else {
+                    s->vp8dsp.vp8_idct_dc_add4y(y_dst, td->block[y], s->linesize);
+                }
+            }
+            y_dst += 4*s->linesize;
+        }
+    }
+
+    for (ch = 0; ch < 2; ch++) {
+        uint32_t nnz4 = AV_RL32(td->non_zero_count_cache[4+ch]);
+        if (nnz4) {
+            uint8_t *ch_dst = dst[1+ch];
+            if (nnz4&~0x01010101) {
+                for (y = 0; y < 2; y++) {
+                    for (x = 0; x < 2; x++) {
+                        if ((uint8_t)nnz4 == 1)
+                            s->vp8dsp.vp8_idct_dc_add(ch_dst+4*x, td->block[4+ch][(y<<1)+x], s->uvlinesize);
+                        else if((uint8_t)nnz4 > 1)
+                            s->vp8dsp.vp8_idct_add(ch_dst+4*x, td->block[4+ch][(y<<1)+x], s->uvlinesize);
+                        nnz4 >>= 8;
+                        if (!nnz4)
+                            goto chroma_idct_end;
+                    }
+                    ch_dst += 4*s->uvlinesize;
+                }
+            } else {
+                s->vp8dsp.vp8_idct_dc_add4uv(ch_dst, td->block[4+ch], s->uvlinesize);
+            }
+        }
+chroma_idct_end: ;
+    }
+}
+
+static av_always_inline void filter_level_for_mb(VP8Context *s, VP8Macroblock *mb, VP8FilterStrength *f )
+{
+    int interior_limit, filter_level;
+
+    if (s->segmentation.enabled) {
+        filter_level = s->segmentation.filter_level[mb->segment];
+        if (!s->segmentation.absolute_vals)
+            filter_level += s->filter.level;
+    } else
+        filter_level = s->filter.level;
+
+    if (s->lf_delta.enabled) {
+        filter_level += s->lf_delta.ref[mb->ref_frame];
+        filter_level += s->lf_delta.mode[mb->mode];
+    }
+
+    filter_level = av_clip_uintp2(filter_level, 6);
+
+    interior_limit = filter_level;
+    if (s->filter.sharpness) {
+        interior_limit >>= (s->filter.sharpness + 3) >> 2;
+        interior_limit = FFMIN(interior_limit, 9 - s->filter.sharpness);
+    }
+    interior_limit = FFMAX(interior_limit, 1);
+
+    f->filter_level = filter_level;
+    f->inner_limit = interior_limit;
+    f->inner_filter = !mb->skip || mb->mode == MODE_I4x4 || mb->mode == VP8_MVMODE_SPLIT;
+}
+
+static av_always_inline void filter_mb(VP8Context *s, uint8_t *dst[3], VP8FilterStrength *f, int mb_x, int mb_y)
+{
+    int mbedge_lim, bedge_lim, hev_thresh;
+    int filter_level = f->filter_level;
+    int inner_limit = f->inner_limit;
+    int inner_filter = f->inner_filter;
+    int linesize = s->linesize;
+    int uvlinesize = s->uvlinesize;
+    static const uint8_t hev_thresh_lut[2][64] = {
+        { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1,
+          2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+          3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
+          3, 3, 3, 3 },
+        { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1,
+          1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+          2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+          2, 2, 2, 2 }
+    };
+
+    if (!filter_level)
+        return;
+
+     bedge_lim = 2*filter_level + inner_limit;
+    mbedge_lim = bedge_lim + 4;
+
+    hev_thresh = hev_thresh_lut[s->keyframe][filter_level];
+
+    if (mb_x) {
+        s->vp8dsp.vp8_h_loop_filter16y(dst[0],     linesize,
+                                       mbedge_lim, inner_limit, hev_thresh);
+        s->vp8dsp.vp8_h_loop_filter8uv(dst[1],     dst[2],      uvlinesize,
+                                       mbedge_lim, inner_limit, hev_thresh);
+    }
+
+    if (inner_filter) {
+        s->vp8dsp.vp8_h_loop_filter16y_inner(dst[0]+ 4, linesize, bedge_lim,
+                                             inner_limit, hev_thresh);
+        s->vp8dsp.vp8_h_loop_filter16y_inner(dst[0]+ 8, linesize, bedge_lim,
+                                             inner_limit, hev_thresh);
+        s->vp8dsp.vp8_h_loop_filter16y_inner(dst[0]+12, linesize, bedge_lim,
+                                             inner_limit, hev_thresh);
+        s->vp8dsp.vp8_h_loop_filter8uv_inner(dst[1] + 4, dst[2] + 4,
+                                             uvlinesize,  bedge_lim,
+                                             inner_limit, hev_thresh);
+    }
+
+    if (mb_y) {
+        s->vp8dsp.vp8_v_loop_filter16y(dst[0],     linesize,
+                                       mbedge_lim, inner_limit, hev_thresh);
+        s->vp8dsp.vp8_v_loop_filter8uv(dst[1],     dst[2],      uvlinesize,
+                                       mbedge_lim, inner_limit, hev_thresh);
+    }
+
+    if (inner_filter) {
+        s->vp8dsp.vp8_v_loop_filter16y_inner(dst[0]+ 4*linesize,
+                                             linesize,    bedge_lim,
+                                             inner_limit, hev_thresh);
+        s->vp8dsp.vp8_v_loop_filter16y_inner(dst[0]+ 8*linesize,
+                                             linesize,    bedge_lim,
+                                             inner_limit, hev_thresh);
+        s->vp8dsp.vp8_v_loop_filter16y_inner(dst[0]+12*linesize,
+                                             linesize,    bedge_lim,
+                                             inner_limit, hev_thresh);
+        s->vp8dsp.vp8_v_loop_filter8uv_inner(dst[1] + 4 * uvlinesize,
+                                             dst[2] + 4 * uvlinesize,
+                                             uvlinesize,  bedge_lim,
+                                             inner_limit, hev_thresh);
+    }
+}
+
+static av_always_inline void filter_mb_simple(VP8Context *s, uint8_t *dst, VP8FilterStrength *f, int mb_x, int mb_y)
+{
+    int mbedge_lim, bedge_lim;
+    int filter_level = f->filter_level;
+    int inner_limit = f->inner_limit;
+    int inner_filter = f->inner_filter;
+    int linesize = s->linesize;
+
+    if (!filter_level)
+        return;
+
+     bedge_lim = 2*filter_level + inner_limit;
+    mbedge_lim = bedge_lim + 4;
+
+    if (mb_x)
+        s->vp8dsp.vp8_h_loop_filter_simple(dst, linesize, mbedge_lim);
+    if (inner_filter) {
+        s->vp8dsp.vp8_h_loop_filter_simple(dst+ 4, linesize, bedge_lim);
+        s->vp8dsp.vp8_h_loop_filter_simple(dst+ 8, linesize, bedge_lim);
+        s->vp8dsp.vp8_h_loop_filter_simple(dst+12, linesize, bedge_lim);
+    }
+
+    if (mb_y)
+        s->vp8dsp.vp8_v_loop_filter_simple(dst, linesize, mbedge_lim);
+    if (inner_filter) {
+        s->vp8dsp.vp8_v_loop_filter_simple(dst+ 4*linesize, linesize, bedge_lim);
+        s->vp8dsp.vp8_v_loop_filter_simple(dst+ 8*linesize, linesize, bedge_lim);
+        s->vp8dsp.vp8_v_loop_filter_simple(dst+12*linesize, linesize, bedge_lim);
+    }
+}
+
+#define MARGIN (16 << 2)
+static void vp8_decode_mv_mb_modes(AVCodecContext *avctx, VP8Frame *curframe,
+                                   VP8Frame *prev_frame)
+{
+    VP8Context *s = avctx->priv_data;
+    int mb_x, mb_y;
+
+    s->mv_min.y = -MARGIN;
+    s->mv_max.y = ((s->mb_height - 1) << 6) + MARGIN;
+    for (mb_y = 0; mb_y < s->mb_height; mb_y++) {
+        VP8Macroblock *mb = s->macroblocks_base + ((s->mb_width+1)*(mb_y + 1) + 1);
+        int mb_xy = mb_y*s->mb_width;
+
+        AV_WN32A(s->intra4x4_pred_mode_left, DC_PRED*0x01010101);
+
+        s->mv_min.x = -MARGIN;
+        s->mv_max.x = ((s->mb_width - 1) << 6) + MARGIN;
+        for (mb_x = 0; mb_x < s->mb_width; mb_x++, mb_xy++, mb++) {
+            if (mb_y == 0)
+                AV_WN32A((mb-s->mb_width-1)->intra4x4_pred_mode_top, DC_PRED*0x01010101);
+            decode_mb_mode(s, mb, mb_x, mb_y, curframe->seg_map->data + mb_xy,
+                           prev_frame && prev_frame->seg_map ?
+                           prev_frame->seg_map->data + mb_xy : NULL, 1);
+            s->mv_min.x -= 64;
+            s->mv_max.x -= 64;
+        }
+        s->mv_min.y -= 64;
+        s->mv_max.y -= 64;
+    }
+}
+
+#if HAVE_THREADS
+#define check_thread_pos(td, otd, mb_x_check, mb_y_check)\
+    do {\
+        int tmp = (mb_y_check << 16) | (mb_x_check & 0xFFFF);\
+        if (otd->thread_mb_pos < tmp) {\
+            pthread_mutex_lock(&otd->lock);\
+            td->wait_mb_pos = tmp;\
+            do {\
+                if (otd->thread_mb_pos >= tmp)\
+                    break;\
+                pthread_cond_wait(&otd->cond, &otd->lock);\
+            } while (1);\
+            td->wait_mb_pos = INT_MAX;\
+            pthread_mutex_unlock(&otd->lock);\
+        }\
+    } while(0);
+
+#define update_pos(td, mb_y, mb_x)\
+    do {\
+    int pos              = (mb_y << 16) | (mb_x & 0xFFFF);\
+    int sliced_threading = (avctx->active_thread_type == FF_THREAD_SLICE) && (num_jobs > 1);\
+    int is_null          = (next_td == NULL) || (prev_td == NULL);\
+    int pos_check        = (is_null) ? 1 :\
+                            (next_td != td && pos >= next_td->wait_mb_pos) ||\
+                            (prev_td != td && pos >= prev_td->wait_mb_pos);\
+    td->thread_mb_pos = pos;\
+    if (sliced_threading && pos_check) {\
+        pthread_mutex_lock(&td->lock);\
+        pthread_cond_broadcast(&td->cond);\
+        pthread_mutex_unlock(&td->lock);\
+    }\
+    } while(0);
+#else
+#define check_thread_pos(td, otd, mb_x_check, mb_y_check)
+#define update_pos(td, mb_y, mb_x)
+#endif
+
+static void vp8_decode_mb_row_no_filter(AVCodecContext *avctx, void *tdata,
+                                        int jobnr, int threadnr)
+{
+    VP8Context *s = avctx->priv_data;
+    VP8ThreadData *prev_td, *next_td, *td = &s->thread_data[threadnr];
+    int mb_y = td->thread_mb_pos>>16;
+    int i, y, mb_x, mb_xy = mb_y*s->mb_width;
+    int num_jobs = s->num_jobs;
+    VP8Frame *curframe = s->curframe, *prev_frame = s->prev_frame;
+    VP56RangeCoder *c = &s->coeff_partition[mb_y & (s->num_coeff_partitions-1)];
+    VP8Macroblock *mb;
+    uint8_t *dst[3] = {
+        curframe->tf.f->data[0] + 16*mb_y*s->linesize,
+        curframe->tf.f->data[1] +  8*mb_y*s->uvlinesize,
+        curframe->tf.f->data[2] +  8*mb_y*s->uvlinesize
+    };
+    if (mb_y == 0) prev_td = td;
+    else           prev_td = &s->thread_data[(jobnr + num_jobs - 1)%num_jobs];
+    if (mb_y == s->mb_height-1) next_td = td;
+    else                        next_td = &s->thread_data[(jobnr + 1)%num_jobs];
+    if (s->mb_layout == 1)
+        mb = s->macroblocks_base + ((s->mb_width+1)*(mb_y + 1) + 1);
+    else {
+        mb = s->macroblocks + (s->mb_height - mb_y - 1)*2;
+        memset(mb - 1, 0, sizeof(*mb)); // zero left macroblock
+        AV_WN32A(s->intra4x4_pred_mode_left, DC_PRED*0x01010101);
+    }
+
+    memset(td->left_nnz, 0, sizeof(td->left_nnz));
+    // left edge of 129 for intra prediction
+    if (!(avctx->flags & CODEC_FLAG_EMU_EDGE)) {
+        for (i = 0; i < 3; i++)
+            for (y = 0; y < 16>>!!i; y++)
+                dst[i][y*curframe->tf.f->linesize[i]-1] = 129;
+        if (mb_y == 1) {
+            s->top_border[0][15] = s->top_border[0][23] = s->top_border[0][31] = 129;
+        }
+    }
+
+    s->mv_min.x = -MARGIN;
+    s->mv_max.x = ((s->mb_width  - 1) << 6) + MARGIN;
+
+    for (mb_x = 0; mb_x < s->mb_width; mb_x++, mb_xy++, mb++) {
+        // Wait for previous thread to read mb_x+2, and reach mb_y-1.
+        if (prev_td != td) {
+            if (threadnr != 0) {
+                check_thread_pos(td, prev_td, mb_x+1, mb_y-1);
+            } else {
+                check_thread_pos(td, prev_td, (s->mb_width+3) + (mb_x+1), mb_y-1);
+            }
+        }
+
+        s->vdsp.prefetch(dst[0] + (mb_x&3)*4*s->linesize + 64, s->linesize, 4);
+        s->vdsp.prefetch(dst[1] + (mb_x&7)*s->uvlinesize + 64, dst[2] - dst[1], 2);
+
+        if (!s->mb_layout)
+            decode_mb_mode(s, mb, mb_x, mb_y, curframe->seg_map->data + mb_xy,
+                           prev_frame && prev_frame->seg_map ?
+                           prev_frame->seg_map->data + mb_xy : NULL, 0);
+
+        prefetch_motion(s, mb, mb_x, mb_y, mb_xy, VP56_FRAME_PREVIOUS);
+
+        if (!mb->skip)
+            decode_mb_coeffs(s, td, c, mb, s->top_nnz[mb_x], td->left_nnz);
+
+        if (mb->mode <= MODE_I4x4)
+            intra_predict(s, td, dst, mb, mb_x, mb_y);
+        else
+            inter_predict(s, td, dst, mb, mb_x, mb_y);
+
+        prefetch_motion(s, mb, mb_x, mb_y, mb_xy, VP56_FRAME_GOLDEN);
+
+        if (!mb->skip) {
+            idct_mb(s, td, dst, mb);
+        } else {
+            AV_ZERO64(td->left_nnz);
+            AV_WN64(s->top_nnz[mb_x], 0);   // array of 9, so unaligned
+
+            // Reset DC block predictors if they would exist if the mb had coefficients
+            if (mb->mode != MODE_I4x4 && mb->mode != VP8_MVMODE_SPLIT) {
+                td->left_nnz[8]     = 0;
+                s->top_nnz[mb_x][8] = 0;
+            }
+        }
+
+        if (s->deblock_filter)
+            filter_level_for_mb(s, mb, &td->filter_strength[mb_x]);
+
+        if (s->deblock_filter && num_jobs != 1 && threadnr == num_jobs-1) {
+            if (s->filter.simple)
+                backup_mb_border(s->top_border[mb_x+1], dst[0], NULL, NULL, s->linesize, 0, 1);
+            else
+                backup_mb_border(s->top_border[mb_x+1], dst[0], dst[1], dst[2], s->linesize, s->uvlinesize, 0);
+        }
+
+        prefetch_motion(s, mb, mb_x, mb_y, mb_xy, VP56_FRAME_GOLDEN2);
+
+        dst[0] += 16;
+        dst[1] += 8;
+        dst[2] += 8;
+        s->mv_min.x -= 64;
+        s->mv_max.x -= 64;
+
+        if (mb_x == s->mb_width+1) {
+            update_pos(td, mb_y, s->mb_width+3);
+        } else {
+            update_pos(td, mb_y, mb_x);
+        }
+    }
+}
+
+static void vp8_filter_mb_row(AVCodecContext *avctx, void *tdata,
+                              int jobnr, int threadnr)
+{
+    VP8Context *s = avctx->priv_data;
+    VP8ThreadData *td = &s->thread_data[threadnr];
+    int mb_x, mb_y = td->thread_mb_pos>>16, num_jobs = s->num_jobs;
+    AVFrame *curframe = s->curframe->tf.f;
+    VP8Macroblock *mb;
+    VP8ThreadData *prev_td, *next_td;
+    uint8_t *dst[3] = {
+        curframe->data[0] + 16*mb_y*s->linesize,
+        curframe->data[1] +  8*mb_y*s->uvlinesize,
+        curframe->data[2] +  8*mb_y*s->uvlinesize
+    };
+
+    if (s->mb_layout == 1)
+        mb = s->macroblocks_base + ((s->mb_width+1)*(mb_y + 1) + 1);
+    else
+        mb = s->macroblocks + (s->mb_height - mb_y - 1)*2;
+
+    if (mb_y == 0) prev_td = td;
+    else           prev_td = &s->thread_data[(jobnr + num_jobs - 1)%num_jobs];
+    if (mb_y == s->mb_height-1) next_td = td;
+    else                        next_td = &s->thread_data[(jobnr + 1)%num_jobs];
+
+    for (mb_x = 0; mb_x < s->mb_width; mb_x++, mb++) {
+        VP8FilterStrength *f = &td->filter_strength[mb_x];
+        if (prev_td != td) {
+            check_thread_pos(td, prev_td, (mb_x+1) + (s->mb_width+3), mb_y-1);
+        }
+        if (next_td != td)
+            if (next_td != &s->thread_data[0]) {
+                check_thread_pos(td, next_td, mb_x+1, mb_y+1);
+            }
+
+        if (num_jobs == 1) {
+            if (s->filter.simple)
+                backup_mb_border(s->top_border[mb_x+1], dst[0], NULL, NULL, s->linesize, 0, 1);
+            else
+                backup_mb_border(s->top_border[mb_x+1], dst[0], dst[1], dst[2], s->linesize, s->uvlinesize, 0);
+        }
+
+        if (s->filter.simple)
+            filter_mb_simple(s, dst[0], f, mb_x, mb_y);
+        else
+            filter_mb(s, dst, f, mb_x, mb_y);
+        dst[0] += 16;
+        dst[1] += 8;
+        dst[2] += 8;
+
+        update_pos(td, mb_y, (s->mb_width+3) + mb_x);
+    }
+}
+
+static int vp8_decode_mb_row_sliced(AVCodecContext *avctx, void *tdata,
+                                    int jobnr, int threadnr)
+{
+    VP8Context *s = avctx->priv_data;
+    VP8ThreadData *td = &s->thread_data[jobnr];
+    VP8ThreadData *next_td = NULL, *prev_td = NULL;
+    VP8Frame *curframe = s->curframe;
+    int mb_y, num_jobs = s->num_jobs;
+    td->thread_nr = threadnr;
+    for (mb_y = jobnr; mb_y < s->mb_height; mb_y += num_jobs) {
+        if (mb_y >= s->mb_height) break;
+        td->thread_mb_pos = mb_y<<16;
+        vp8_decode_mb_row_no_filter(avctx, tdata, jobnr, threadnr);
+        if (s->deblock_filter)
+            vp8_filter_mb_row(avctx, tdata, jobnr, threadnr);
+        update_pos(td, mb_y, INT_MAX & 0xFFFF);
+
+        s->mv_min.y -= 64;
+        s->mv_max.y -= 64;
+
+        if (avctx->active_thread_type == FF_THREAD_FRAME)
+            ff_thread_report_progress(&curframe->tf, mb_y, 0);
+    }
+
+    return 0;
+}
+
+static int vp8_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
+                            AVPacket *avpkt)
+{
+    VP8Context *s = avctx->priv_data;
+    int ret, i, referenced, num_jobs;
+    enum AVDiscard skip_thresh;
+    VP8Frame *av_uninit(curframe), *prev_frame;
+
+    if ((ret = decode_frame_header(s, avpkt->data, avpkt->size)) < 0)
+        goto err;
+
+    prev_frame = s->framep[VP56_FRAME_CURRENT];
+
+    referenced = s->update_last || s->update_golden == VP56_FRAME_CURRENT
+                                || s->update_altref == VP56_FRAME_CURRENT;
+
+    skip_thresh = !referenced ? AVDISCARD_NONREF :
+                    !s->keyframe ? AVDISCARD_NONKEY : AVDISCARD_ALL;
+
+    if (avctx->skip_frame >= skip_thresh) {
+        s->invisible = 1;
+        memcpy(&s->next_framep[0], &s->framep[0], sizeof(s->framep[0]) * 4);
+        goto skip_decode;
+    }
+    s->deblock_filter = s->filter.level && avctx->skip_loop_filter < skip_thresh;
+
+    // release no longer referenced frames
+    for (i = 0; i < 5; i++)
+        if (s->frames[i].tf.f->data[0] &&
+            &s->frames[i] != prev_frame &&
+            &s->frames[i] != s->framep[VP56_FRAME_PREVIOUS] &&
+            &s->frames[i] != s->framep[VP56_FRAME_GOLDEN] &&
+            &s->frames[i] != s->framep[VP56_FRAME_GOLDEN2])
+            vp8_release_frame(s, &s->frames[i]);
+
+    // find a free buffer
+    for (i = 0; i < 5; i++)
+        if (&s->frames[i] != prev_frame &&
+            &s->frames[i] != s->framep[VP56_FRAME_PREVIOUS] &&
+            &s->frames[i] != s->framep[VP56_FRAME_GOLDEN] &&
+            &s->frames[i] != s->framep[VP56_FRAME_GOLDEN2]) {
+            curframe = s->framep[VP56_FRAME_CURRENT] = &s->frames[i];
+            break;
+        }
+    if (i == 5) {
+        av_log(avctx, AV_LOG_FATAL, "Ran out of free frames!\n");
+        abort();
+    }
+    if (curframe->tf.f->data[0])
+        vp8_release_frame(s, curframe);
+
+    // Given that arithmetic probabilities are updated every frame, it's quite likely
+    // that the values we have on a random interframe are complete junk if we didn't
+    // start decode on a keyframe. So just don't display anything rather than junk.
+    if (!s->keyframe && (!s->framep[VP56_FRAME_PREVIOUS] ||
+                         !s->framep[VP56_FRAME_GOLDEN] ||
+                         !s->framep[VP56_FRAME_GOLDEN2])) {
+        av_log(avctx, AV_LOG_WARNING, "Discarding interframe without a prior keyframe!\n");
+        ret = AVERROR_INVALIDDATA;
+        goto err;
+    }
+
+    curframe->tf.f->key_frame = s->keyframe;
+    curframe->tf.f->pict_type = s->keyframe ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
+    if ((ret = vp8_alloc_frame(s, curframe, referenced)) < 0)
+        goto err;
+
+    // check if golden and altref are swapped
+    if (s->update_altref != VP56_FRAME_NONE) {
+        s->next_framep[VP56_FRAME_GOLDEN2]  = s->framep[s->update_altref];
+    } else {
+        s->next_framep[VP56_FRAME_GOLDEN2]  = s->framep[VP56_FRAME_GOLDEN2];
+    }
+    if (s->update_golden != VP56_FRAME_NONE) {
+        s->next_framep[VP56_FRAME_GOLDEN]   = s->framep[s->update_golden];
+    } else {
+        s->next_framep[VP56_FRAME_GOLDEN]   = s->framep[VP56_FRAME_GOLDEN];
+    }
+    if (s->update_last) {
+        s->next_framep[VP56_FRAME_PREVIOUS] = curframe;
+    } else {
+        s->next_framep[VP56_FRAME_PREVIOUS] = s->framep[VP56_FRAME_PREVIOUS];
+    }
+    s->next_framep[VP56_FRAME_CURRENT]      = curframe;
+
+    ff_thread_finish_setup(avctx);
+
+    s->linesize   = curframe->tf.f->linesize[0];
+    s->uvlinesize = curframe->tf.f->linesize[1];
+
+    if (!s->thread_data[0].edge_emu_buffer)
+        for (i = 0; i < MAX_THREADS; i++)
+            s->thread_data[i].edge_emu_buffer = av_malloc(21*s->linesize);
+
+    memset(s->top_nnz, 0, s->mb_width*sizeof(*s->top_nnz));
+    /* Zero macroblock structures for top/top-left prediction from outside the frame. */
+    if (!s->mb_layout)
+        memset(s->macroblocks + s->mb_height*2 - 1, 0, (s->mb_width+1)*sizeof(*s->macroblocks));
+    if (!s->mb_layout && s->keyframe)
+        memset(s->intra4x4_pred_mode_top, DC_PRED, s->mb_width*4);
+
+    // top edge of 127 for intra prediction
+    if (!(avctx->flags & CODEC_FLAG_EMU_EDGE)) {
+        s->top_border[0][15] = s->top_border[0][23] = 127;
+        s->top_border[0][31] = 127;
+        memset(s->top_border[1], 127, s->mb_width*sizeof(*s->top_border));
+    }
+    memset(s->ref_count, 0, sizeof(s->ref_count));
+
+
+    // Make sure the previous frame has read its segmentation map,
+    // if we re-use the same map.
+    if (prev_frame && s->segmentation.enabled && !s->segmentation.update_map)
+        ff_thread_await_progress(&prev_frame->tf, 1, 0);
+
+    if (s->mb_layout == 1)
+        vp8_decode_mv_mb_modes(avctx, curframe, prev_frame);
+
+    if (avctx->active_thread_type == FF_THREAD_FRAME)
+        num_jobs = 1;
+    else
+        num_jobs = FFMIN(s->num_coeff_partitions, avctx->thread_count);
+    s->num_jobs   = num_jobs;
+    s->curframe   = curframe;
+    s->prev_frame = prev_frame;
+    s->mv_min.y   = -MARGIN;
+    s->mv_max.y   = ((s->mb_height - 1) << 6) + MARGIN;
+    for (i = 0; i < MAX_THREADS; i++) {
+        s->thread_data[i].thread_mb_pos = 0;
+        s->thread_data[i].wait_mb_pos = INT_MAX;
+    }
+    avctx->execute2(avctx, vp8_decode_mb_row_sliced, s->thread_data, NULL, num_jobs);
+
+    ff_thread_report_progress(&curframe->tf, INT_MAX, 0);
+    memcpy(&s->framep[0], &s->next_framep[0], sizeof(s->framep[0]) * 4);
+
+skip_decode:
+    // if future frames don't use the updated probabilities,
+    // reset them to the values we saved
+    if (!s->update_probabilities)
+        s->prob[0] = s->prob[1];
+
+    if (!s->invisible) {
+        if ((ret = av_frame_ref(data, curframe->tf.f)) < 0)
+            return ret;
+        *got_frame      = 1;
+    }
+
+    return avpkt->size;
+err:
+    memcpy(&s->next_framep[0], &s->framep[0], sizeof(s->framep[0]) * 4);
+    return ret;
+}
+
+static av_cold int vp8_decode_free(AVCodecContext *avctx)
+{
+    VP8Context *s = avctx->priv_data;
+    int i;
+
+    vp8_decode_flush_impl(avctx, 1);
+    for (i = 0; i < FF_ARRAY_ELEMS(s->frames); i++)
+        av_frame_free(&s->frames[i].tf.f);
+
+    return 0;
+}
+
+static av_cold int vp8_init_frames(VP8Context *s)
+{
+    int i;
+    for (i = 0; i < FF_ARRAY_ELEMS(s->frames); i++) {
+        s->frames[i].tf.f = av_frame_alloc();
+        if (!s->frames[i].tf.f)
+            return AVERROR(ENOMEM);
+    }
+    return 0;
+}
+
+static av_cold int vp8_decode_init(AVCodecContext *avctx)
+{
+    VP8Context *s = avctx->priv_data;
+    int ret;
+
+    s->avctx = avctx;
+    avctx->pix_fmt = AV_PIX_FMT_YUV420P;
+    avctx->internal->allocate_progress = 1;
+
+    ff_videodsp_init(&s->vdsp, 8);
+    ff_h264_pred_init(&s->hpc, AV_CODEC_ID_VP8, 8, 1);
+    ff_vp8dsp_init(&s->vp8dsp);
+
+    if ((ret = vp8_init_frames(s)) < 0) {
+        vp8_decode_free(avctx);
+        return ret;
+    }
+
+    return 0;
+}
+
+static av_cold int vp8_decode_init_thread_copy(AVCodecContext *avctx)
+{
+    VP8Context *s = avctx->priv_data;
+    int ret;
+
+    s->avctx = avctx;
+
+    if ((ret = vp8_init_frames(s)) < 0) {
+        vp8_decode_free(avctx);
+        return ret;
+    }
+
+    return 0;
+}
+
+#define REBASE(pic) \
+    pic ? pic - &s_src->frames[0] + &s->frames[0] : NULL
+
+static int vp8_decode_update_thread_context(AVCodecContext *dst, const AVCodecContext *src)
+{
+    VP8Context *s = dst->priv_data, *s_src = src->priv_data;
+    int i;
+
+    if (s->macroblocks_base &&
+        (s_src->mb_width != s->mb_width || s_src->mb_height != s->mb_height)) {
+        free_buffers(s);
+        s->mb_width  = s_src->mb_width;
+        s->mb_height = s_src->mb_height;
+    }
+
+    s->prob[0] = s_src->prob[!s_src->update_probabilities];
+    s->segmentation = s_src->segmentation;
+    s->lf_delta = s_src->lf_delta;
+    memcpy(s->sign_bias, s_src->sign_bias, sizeof(s->sign_bias));
+
+    for (i = 0; i < FF_ARRAY_ELEMS(s_src->frames); i++) {
+        if (s_src->frames[i].tf.f->data[0]) {
+            int ret = vp8_ref_frame(s, &s->frames[i], &s_src->frames[i]);
+            if (ret < 0)
+                return ret;
+        }
+    }
+
+    s->framep[0] = REBASE(s_src->next_framep[0]);
+    s->framep[1] = REBASE(s_src->next_framep[1]);
+    s->framep[2] = REBASE(s_src->next_framep[2]);
+    s->framep[3] = REBASE(s_src->next_framep[3]);
+
+    return 0;
+}
+
+AVCodec ff_vp8_decoder = {
+    .name                  = "vp8",
+    .type                  = AVMEDIA_TYPE_VIDEO,
+    .id                    = AV_CODEC_ID_VP8,
+    .priv_data_size        = sizeof(VP8Context),
+    .init                  = vp8_decode_init,
+    .close                 = vp8_decode_free,
+    .decode                = vp8_decode_frame,
+    .capabilities          = CODEC_CAP_DR1 | CODEC_CAP_FRAME_THREADS | CODEC_CAP_SLICE_THREADS,
+    .flush                 = vp8_decode_flush,
+    .long_name             = NULL_IF_CONFIG_SMALL("On2 VP8"),
+    .init_thread_copy      = ONLY_IF_THREADS_ENABLED(vp8_decode_init_thread_copy),
+    .update_thread_context = ONLY_IF_THREADS_ENABLED(vp8_decode_update_thread_context),
+};