chasing indexing error

1 files changed, 0 insertions, 1027 deletions

diff --git a/ffmpeg/libavcodec/4xm.c b/ffmpeg/libavcodec/4xm.c
deleted file mode 100644
index eb07cc3..0000000
--- a/ffmpeg/libavcodec/4xm.c
+++ /dev/null
@@ -1,1027 +0,0 @@
-/*
- * 4XM codec
- * Copyright (c) 2003 Michael Niedermayer
- *
- * 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
- */
-
-/**
- * @file
- * 4XM codec.
- */
-
-#include "libavutil/avassert.h"
-#include "libavutil/frame.h"
-#include "libavutil/intreadwrite.h"
-#include "avcodec.h"
-#include "bytestream.h"
-#include "dsputil.h"
-#include "get_bits.h"
-#include "internal.h"
-
-
-#define BLOCK_TYPE_VLC_BITS 5
-#define ACDC_VLC_BITS 9
-
-#define CFRAME_BUFFER_COUNT 100
-
-static const uint8_t block_type_tab[2][4][8][2] = {
-    {
-        {    // { 8, 4, 2 } x { 8, 4, 2}
-            { 0, 1 }, { 2, 2 }, { 6, 3 }, { 14, 4 }, { 30, 5 }, { 31, 5 }, { 0, 0 }
-        }, { // { 8, 4 } x 1
-            { 0, 1 }, { 0, 0 }, { 2, 2 }, { 6, 3 }, { 14, 4 }, { 15, 4 }, { 0, 0 }
-        }, { // 1 x { 8, 4 }
-            { 0, 1 }, { 2, 2 }, { 0, 0 }, { 6, 3 }, { 14, 4 }, { 15, 4 }, { 0, 0 }
-        }, { // 1 x 2, 2 x 1
-            { 0, 1 }, { 0, 0 }, { 0, 0 }, { 2, 2 }, { 6, 3 }, { 14, 4 }, { 15, 4 }
-        }
-    }, {
-        {   // { 8, 4, 2 } x { 8, 4, 2}
-            { 1, 2 }, { 4, 3 }, { 5, 3 }, { 0, 2 }, { 6, 3 }, { 7, 3 }, { 0, 0 }
-        }, {// { 8, 4 } x 1
-            { 1, 2 }, { 0, 0 }, { 2, 2 }, { 0, 2 }, { 6, 3 }, { 7, 3 }, { 0, 0 }
-        }, {// 1 x { 8, 4 }
-            { 1, 2 }, { 2, 2 }, { 0, 0 }, { 0, 2 }, { 6, 3 }, { 7, 3 }, { 0, 0 }
-        }, {// 1 x 2, 2 x 1
-            { 1, 2 }, { 0, 0 }, { 0, 0 }, { 0, 2 }, { 2, 2 }, { 6, 3 }, { 7, 3 }
-      }
-    }
-};
-
-static const uint8_t size2index[4][4] = {
-    { -1, 3, 1, 1 },
-    {  3, 0, 0, 0 },
-    {  2, 0, 0, 0 },
-    {  2, 0, 0, 0 },
-};
-
-static const int8_t mv[256][2] = {
-    {   0,   0 }, {   0,  -1 }, {  -1,   0 }, {   1,   0 }, {   0,   1 }, {  -1,  -1 }, {   1,  -1 }, {  -1,   1 },
-    {   1,   1 }, {   0,  -2 }, {  -2,   0 }, {   2,   0 }, {   0,   2 }, {  -1,  -2 }, {   1,  -2 }, {  -2,  -1 },
-    {   2,  -1 }, {  -2,   1 }, {   2,   1 }, {  -1,   2 }, {   1,   2 }, {  -2,  -2 }, {   2,  -2 }, {  -2,   2 },
-    {   2,   2 }, {   0,  -3 }, {  -3,   0 }, {   3,   0 }, {   0,   3 }, {  -1,  -3 }, {   1,  -3 }, {  -3,  -1 },
-    {   3,  -1 }, {  -3,   1 }, {   3,   1 }, {  -1,   3 }, {   1,   3 }, {  -2,  -3 }, {   2,  -3 }, {  -3,  -2 },
-    {   3,  -2 }, {  -3,   2 }, {   3,   2 }, {  -2,   3 }, {   2,   3 }, {   0,  -4 }, {  -4,   0 }, {   4,   0 },
-    {   0,   4 }, {  -1,  -4 }, {   1,  -4 }, {  -4,  -1 }, {   4,  -1 }, {   4,   1 }, {  -1,   4 }, {   1,   4 },
-    {  -3,  -3 }, {  -3,   3 }, {   3,   3 }, {  -2,  -4 }, {  -4,  -2 }, {   4,  -2 }, {  -4,   2 }, {  -2,   4 },
-    {   2,   4 }, {  -3,  -4 }, {   3,  -4 }, {   4,  -3 }, {  -5,   0 }, {  -4,   3 }, {  -3,   4 }, {   3,   4 },
-    {  -1,  -5 }, {  -5,  -1 }, {  -5,   1 }, {  -1,   5 }, {  -2,  -5 }, {   2,  -5 }, {   5,  -2 }, {   5,   2 },
-    {  -4,  -4 }, {  -4,   4 }, {  -3,  -5 }, {  -5,  -3 }, {  -5,   3 }, {   3,   5 }, {  -6,   0 }, {   0,   6 },
-    {  -6,  -1 }, {  -6,   1 }, {   1,   6 }, {   2,  -6 }, {  -6,   2 }, {   2,   6 }, {  -5,  -4 }, {   5,   4 },
-    {   4,   5 }, {  -6,  -3 }, {   6,   3 }, {  -7,   0 }, {  -1,  -7 }, {   5,  -5 }, {  -7,   1 }, {  -1,   7 },
-    {   4,  -6 }, {   6,   4 }, {  -2,  -7 }, {  -7,   2 }, {  -3,  -7 }, {   7,  -3 }, {   3,   7 }, {   6,  -5 },
-    {   0,  -8 }, {  -1,  -8 }, {  -7,  -4 }, {  -8,   1 }, {   4,   7 }, {   2,  -8 }, {  -2,   8 }, {   6,   6 },
-    {  -8,   3 }, {   5,  -7 }, {  -5,   7 }, {   8,  -4 }, {   0,  -9 }, {  -9,  -1 }, {   1,   9 }, {   7,  -6 },
-    {  -7,   6 }, {  -5,  -8 }, {  -5,   8 }, {  -9,   3 }, {   9,  -4 }, {   7,  -7 }, {   8,  -6 }, {   6,   8 },
-    {  10,   1 }, { -10,   2 }, {   9,  -5 }, {  10,  -3 }, {  -8,  -7 }, { -10,  -4 }, {   6,  -9 }, { -11,   0 },
-    {  11,   1 }, { -11,  -2 }, {  -2,  11 }, {   7,  -9 }, {  -7,   9 }, {  10,   6 }, {  -4,  11 }, {   8,  -9 },
-    {   8,   9 }, {   5,  11 }, {   7, -10 }, {  12,  -3 }, {  11,   6 }, {  -9,  -9 }, {   8,  10 }, {   5,  12 },
-    { -11,   7 }, {  13,   2 }, {   6, -12 }, {  10,   9 }, { -11,   8 }, {  -7,  12 }, {   0,  14 }, {  14,  -2 },
-    {  -9,  11 }, {  -6,  13 }, { -14,  -4 }, {  -5, -14 }, {   5,  14 }, { -15,  -1 }, { -14,  -6 }, {   3, -15 },
-    {  11, -11 }, {  -7,  14 }, {  -5,  15 }, {   8, -14 }, {  15,   6 }, {   3,  16 }, {   7, -15 }, { -16,   5 },
-    {   0,  17 }, { -16,  -6 }, { -10,  14 }, { -16,   7 }, {  12,  13 }, { -16,   8 }, { -17,   6 }, { -18,   3 },
-    {  -7,  17 }, {  15,  11 }, {  16,  10 }, {   2, -19 }, {   3, -19 }, { -11, -16 }, { -18,   8 }, { -19,  -6 },
-    {   2, -20 }, { -17, -11 }, { -10, -18 }, {   8,  19 }, { -21,  -1 }, { -20,   7 }, {  -4,  21 }, {  21,   5 },
-    {  15,  16 }, {   2, -22 }, { -10, -20 }, { -22,   5 }, {  20, -11 }, {  -7, -22 }, { -12,  20 }, {  23,  -5 },
-    {  13, -20 }, {  24,  -2 }, { -15,  19 }, { -11,  22 }, {  16,  19 }, {  23, -10 }, { -18, -18 }, {  -9, -24 },
-    {  24, -10 }, {  -3,  26 }, { -23,  13 }, { -18, -20 }, {  17,  21 }, {  -4,  27 }, {  27,   6 }, {   1, -28 },
-    { -11,  26 }, { -17, -23 }, {   7,  28 }, {  11, -27 }, {  29,   5 }, { -23, -19 }, { -28, -11 }, { -21,  22 },
-    { -30,   7 }, { -17,  26 }, { -27,  16 }, {  13,  29 }, {  19, -26 }, {  10, -31 }, { -14, -30 }, {  20, -27 },
-    { -29,  18 }, { -16, -31 }, { -28, -22 }, {  21, -30 }, { -25,  28 }, {  26, -29 }, {  25, -32 }, { -32, -32 }
-};
-
-/* This is simply the scaled down elementwise product of the standard JPEG
- * quantizer table and the AAN premul table. */
-static const uint8_t dequant_table[64] = {
-    16, 15, 13, 19, 24, 31, 28, 17,
-    17, 23, 25, 31, 36, 63, 45, 21,
-    18, 24, 27, 37, 52, 59, 49, 20,
-    16, 28, 34, 40, 60, 80, 51, 20,
-    18, 31, 48, 66, 68, 86, 56, 21,
-    19, 38, 56, 59, 64, 64, 48, 20,
-    27, 48, 55, 55, 56, 51, 35, 15,
-    20, 35, 34, 32, 31, 22, 15,  8,
-};
-
-static VLC block_type_vlc[2][4];
-
-
-typedef struct CFrameBuffer {
-    unsigned int allocated_size;
-    unsigned int size;
-    int id;
-    uint8_t *data;
-} CFrameBuffer;
-
-typedef struct FourXContext {
-    AVCodecContext *avctx;
-    DSPContext dsp;
-    AVFrame *current_picture, *last_picture;
-    GetBitContext pre_gb;          ///< ac/dc prefix
-    GetBitContext gb;
-    GetByteContext g;
-    GetByteContext g2;
-    int mv[256];
-    VLC pre_vlc;
-    int last_dc;
-    DECLARE_ALIGNED(16, int16_t, block)[6][64];
-    void *bitstream_buffer;
-    unsigned int bitstream_buffer_size;
-    int version;
-    CFrameBuffer cfrm[CFRAME_BUFFER_COUNT];
-} FourXContext;
-
-
-#define FIX_1_082392200  70936
-#define FIX_1_414213562  92682
-#define FIX_1_847759065 121095
-#define FIX_2_613125930 171254
-
-#define MULTIPLY(var, const) (((var) * (const)) >> 16)
-
-static void idct(int16_t block[64])
-{
-    int tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
-    int tmp10, tmp11, tmp12, tmp13;
-    int z5, z10, z11, z12, z13;
-    int i;
-    int temp[64];
-
-    for (i = 0; i < 8; i++) {
-        tmp10 = block[8 * 0 + i] + block[8 * 4 + i];
-        tmp11 = block[8 * 0 + i] - block[8 * 4 + i];
-
-        tmp13 = block[8 * 2 + i] + block[8 * 6 + i];
-        tmp12 = MULTIPLY(block[8 * 2 + i] - block[8 * 6 + i], FIX_1_414213562) - tmp13;
-
-        tmp0 = tmp10 + tmp13;
-        tmp3 = tmp10 - tmp13;
-        tmp1 = tmp11 + tmp12;
-        tmp2 = tmp11 - tmp12;
-
-        z13 = block[8 * 5 + i] + block[8 * 3 + i];
-        z10 = block[8 * 5 + i] - block[8 * 3 + i];
-        z11 = block[8 * 1 + i] + block[8 * 7 + i];
-        z12 = block[8 * 1 + i] - block[8 * 7 + i];
-
-        tmp7  =          z11 + z13;
-        tmp11 = MULTIPLY(z11 - z13, FIX_1_414213562);
-
-        z5    = MULTIPLY(z10 + z12, FIX_1_847759065);
-        tmp10 = MULTIPLY(z12,  FIX_1_082392200) - z5;
-        tmp12 = MULTIPLY(z10, -FIX_2_613125930) + z5;
-
-        tmp6 = tmp12 - tmp7;
-        tmp5 = tmp11 - tmp6;
-        tmp4 = tmp10 + tmp5;
-
-        temp[8 * 0 + i] = tmp0 + tmp7;
-        temp[8 * 7 + i] = tmp0 - tmp7;
-        temp[8 * 1 + i] = tmp1 + tmp6;
-        temp[8 * 6 + i] = tmp1 - tmp6;
-        temp[8 * 2 + i] = tmp2 + tmp5;
-        temp[8 * 5 + i] = tmp2 - tmp5;
-        temp[8 * 4 + i] = tmp3 + tmp4;
-        temp[8 * 3 + i] = tmp3 - tmp4;
-    }
-
-    for (i = 0; i < 8 * 8; i += 8) {
-        tmp10 = temp[0 + i] + temp[4 + i];
-        tmp11 = temp[0 + i] - temp[4 + i];
-
-        tmp13 = temp[2 + i] + temp[6 + i];
-        tmp12 = MULTIPLY(temp[2 + i] - temp[6 + i], FIX_1_414213562) - tmp13;
-
-        tmp0 = tmp10 + tmp13;
-        tmp3 = tmp10 - tmp13;
-        tmp1 = tmp11 + tmp12;
-        tmp2 = tmp11 - tmp12;
-
-        z13 = temp[5 + i] + temp[3 + i];
-        z10 = temp[5 + i] - temp[3 + i];
-        z11 = temp[1 + i] + temp[7 + i];
-        z12 = temp[1 + i] - temp[7 + i];
-
-        tmp7  = z11 + z13;
-        tmp11 = MULTIPLY(z11 - z13, FIX_1_414213562);
-
-        z5    = MULTIPLY(z10 + z12, FIX_1_847759065);
-        tmp10 = MULTIPLY(z12,  FIX_1_082392200) - z5;
-        tmp12 = MULTIPLY(z10, -FIX_2_613125930) + z5;
-
-        tmp6 = tmp12 - tmp7;
-        tmp5 = tmp11 - tmp6;
-        tmp4 = tmp10 + tmp5;
-
-        block[0 + i] = (tmp0 + tmp7) >> 6;
-        block[7 + i] = (tmp0 - tmp7) >> 6;
-        block[1 + i] = (tmp1 + tmp6) >> 6;
-        block[6 + i] = (tmp1 - tmp6) >> 6;
-        block[2 + i] = (tmp2 + tmp5) >> 6;
-        block[5 + i] = (tmp2 - tmp5) >> 6;
-        block[4 + i] = (tmp3 + tmp4) >> 6;
-        block[3 + i] = (tmp3 - tmp4) >> 6;
-    }
-}
-
-static av_cold void init_vlcs(FourXContext *f)
-{
-    static VLC_TYPE table[2][4][32][2];
-    int i, j;
-
-    for (i = 0; i < 2; i++) {
-        for (j = 0; j < 4; j++) {
-            block_type_vlc[i][j].table           = table[i][j];
-            block_type_vlc[i][j].table_allocated = 32;
-            init_vlc(&block_type_vlc[i][j], BLOCK_TYPE_VLC_BITS, 7,
-                     &block_type_tab[i][j][0][1], 2, 1,
-                     &block_type_tab[i][j][0][0], 2, 1,
-                     INIT_VLC_USE_NEW_STATIC);
-        }
-    }
-}
-
-static void init_mv(FourXContext *f, int linesize)
-{
-    int i;
-
-    for (i = 0; i < 256; i++) {
-        if (f->version > 1)
-            f->mv[i] = mv[i][0] + mv[i][1] * linesize / 2;
-        else
-            f->mv[i] = (i & 15) - 8 + ((i >> 4) - 8) * linesize / 2;
-    }
-}
-
-#if HAVE_BIGENDIAN
-#define LE_CENTRIC_MUL(dst, src, scale, dc)             \
-    {                                                   \
-        unsigned tmpval = AV_RN32(src);                 \
-        tmpval = (tmpval << 16) | (tmpval >> 16);       \
-        tmpval = tmpval * (scale) + (dc);               \
-        tmpval = (tmpval << 16) | (tmpval >> 16);       \
-        AV_WN32A(dst, tmpval);                          \
-    }
-#else
-#define LE_CENTRIC_MUL(dst, src, scale, dc)              \
-    {                                                    \
-        unsigned tmpval = AV_RN32(src) * (scale) + (dc); \
-        AV_WN32A(dst, tmpval);                           \
-    }
-#endif
-
-static inline void mcdc(uint16_t *dst, const uint16_t *src, int log2w,
-                        int h, int stride, int scale, unsigned dc)
-{
-    int i;
-    dc *= 0x10001;
-
-    switch (log2w) {
-    case 0:
-        for (i = 0; i < h; i++) {
-            dst[0] = scale * src[0] + dc;
-            if (scale)
-                src += stride;
-            dst += stride;
-        }
-        break;
-    case 1:
-        for (i = 0; i < h; i++) {
-            LE_CENTRIC_MUL(dst, src, scale, dc);
-            if (scale)
-                src += stride;
-            dst += stride;
-        }
-        break;
-    case 2:
-        for (i = 0; i < h; i++) {
-            LE_CENTRIC_MUL(dst, src, scale, dc);
-            LE_CENTRIC_MUL(dst + 2, src + 2, scale, dc);
-            if (scale)
-                src += stride;
-            dst += stride;
-        }
-        break;
-    case 3:
-        for (i = 0; i < h; i++) {
-            LE_CENTRIC_MUL(dst,     src,     scale, dc);
-            LE_CENTRIC_MUL(dst + 2, src + 2, scale, dc);
-            LE_CENTRIC_MUL(dst + 4, src + 4, scale, dc);
-            LE_CENTRIC_MUL(dst + 6, src + 6, scale, dc);
-            if (scale)
-                src += stride;
-            dst += stride;
-        }
-        break;
-    default:
-        av_assert0(0);
-    }
-}
-
-static int decode_p_block(FourXContext *f, uint16_t *dst, uint16_t *src,
-                          int log2w, int log2h, int stride)
-{
-    const int index = size2index[log2h][log2w];
-    const int h     = 1 << log2h;
-    int code        = get_vlc2(&f->gb,
-                               block_type_vlc[1 - (f->version > 1)][index].table,
-                               BLOCK_TYPE_VLC_BITS, 1);
-    uint16_t *start = (uint16_t *)f->last_picture->data[0];
-    uint16_t *end   = start + stride * (f->avctx->height - h + 1) - (1 << log2w);
-    int ret;
-    int scale   = 1;
-    unsigned dc = 0;
-
-    av_assert0(code >= 0 && code <= 6 && log2w >= 0);
-
-    if (code == 1) {
-        log2h--;
-        if ((ret = decode_p_block(f, dst, src, log2w, log2h, stride)) < 0)
-            return ret;
-        return decode_p_block(f, dst + (stride << log2h),
-                              src + (stride << log2h),
-                              log2w, log2h, stride);
-    } else if (code == 2) {
-        log2w--;
-        if ((ret = decode_p_block(f, dst , src, log2w, log2h, stride)) < 0)
-            return ret;
-        return decode_p_block(f, dst + (1 << log2w),
-                              src + (1 << log2w),
-                              log2w, log2h, stride);
-    } else if (code == 6) {
-        if (bytestream2_get_bytes_left(&f->g2) < 4) {
-            av_log(f->avctx, AV_LOG_ERROR, "wordstream overread\n");
-            return AVERROR_INVALIDDATA;
-        }
-        if (log2w) {
-            dst[0]      = bytestream2_get_le16u(&f->g2);
-            dst[1]      = bytestream2_get_le16u(&f->g2);
-        } else {
-            dst[0]      = bytestream2_get_le16u(&f->g2);
-            dst[stride] = bytestream2_get_le16u(&f->g2);
-        }
-        return 0;
-    }
-
-    if ((code&3)==0 && bytestream2_get_bytes_left(&f->g) < 1) {
-        av_log(f->avctx, AV_LOG_ERROR, "bytestream overread\n");
-        return AVERROR_INVALIDDATA;
-    }
-
-    if (code == 0) {
-        src  += f->mv[bytestream2_get_byte(&f->g)];
-    } else if (code == 3 && f->version >= 2) {
-        return 0;
-    } else if (code == 4) {
-        src  += f->mv[bytestream2_get_byte(&f->g)];
-        if (bytestream2_get_bytes_left(&f->g2) < 2){
-            av_log(f->avctx, AV_LOG_ERROR, "wordstream overread\n");
-            return AVERROR_INVALIDDATA;
-        }
-        dc    = bytestream2_get_le16(&f->g2);
-    } else if (code == 5) {
-        if (bytestream2_get_bytes_left(&f->g2) < 2){
-            av_log(f->avctx, AV_LOG_ERROR, "wordstream overread\n");
-            return AVERROR_INVALIDDATA;
-        }
-        av_assert0(start <= src && src <= end);
-        scale = 0;
-        dc    = bytestream2_get_le16(&f->g2);
-    }
-
-    if (start > src || src > end) {
-        av_log(f->avctx, AV_LOG_ERROR, "mv out of pic\n");
-        return AVERROR_INVALIDDATA;
-    }
-
-    mcdc(dst, src, log2w, h, stride, scale, dc);
-
-    return 0;
-}
-
-static int decode_p_frame(FourXContext *f, AVFrame *frame,
-                          const uint8_t *buf, int length)
-{
-    int x, y;
-    const int width  = f->avctx->width;
-    const int height = f->avctx->height;
-    uint16_t *dst    = (uint16_t *)frame->data[0];
-    const int stride =             frame->linesize[0] >> 1;
-    uint16_t *src;
-    unsigned int bitstream_size, bytestream_size, wordstream_size, extra,
-                 bytestream_offset, wordstream_offset;
-    int ret;
-
-    if (!f->last_picture->data[0]) {
-        if ((ret = ff_get_buffer(f->avctx, f->last_picture,
-                                 AV_GET_BUFFER_FLAG_REF)) < 0) {
-            return ret;
-        }
-        for (y=0; y<f->avctx->height; y++)
-            memset(f->last_picture->data[0] + y*f->last_picture->linesize[0], 0, 2*f->avctx->width);
-    }
-
-    src = (uint16_t *)f->last_picture->data[0];
-
-    if (f->version > 1) {
-        extra           = 20;
-        if (length < extra)
-            return AVERROR_INVALIDDATA;
-        bitstream_size  = AV_RL32(buf + 8);
-        wordstream_size = AV_RL32(buf + 12);
-        bytestream_size = AV_RL32(buf + 16);
-    } else {
-        extra           = 0;
-        bitstream_size  = AV_RL16(buf - 4);
-        wordstream_size = AV_RL16(buf - 2);
-        bytestream_size = FFMAX(length - bitstream_size - wordstream_size, 0);
-    }
-
-    if (bitstream_size > length || bitstream_size >= INT_MAX/8 ||
-        bytestream_size > length - bitstream_size ||
-        wordstream_size > length - bytestream_size - bitstream_size ||
-        extra > length - bytestream_size - bitstream_size - wordstream_size) {
-        av_log(f->avctx, AV_LOG_ERROR, "lengths %d %d %d %d\n", bitstream_size, bytestream_size, wordstream_size,
-        bitstream_size+ bytestream_size+ wordstream_size - length);
-        return AVERROR_INVALIDDATA;
-    }
-
-    av_fast_padded_malloc(&f->bitstream_buffer, &f->bitstream_buffer_size,
-                          bitstream_size);
-    if (!f->bitstream_buffer)
-        return AVERROR(ENOMEM);
-    f->dsp.bswap_buf(f->bitstream_buffer, (const uint32_t*)(buf + extra),
-                     bitstream_size / 4);
-    init_get_bits(&f->gb, f->bitstream_buffer, 8 * bitstream_size);
-
-    wordstream_offset = extra + bitstream_size;
-    bytestream_offset = extra + bitstream_size + wordstream_size;
-    bytestream2_init(&f->g2, buf + wordstream_offset,
-                     length - wordstream_offset);
-    bytestream2_init(&f->g, buf + bytestream_offset,
-                     length - bytestream_offset);
-
-    init_mv(f, frame->linesize[0]);
-
-    for (y = 0; y < height; y += 8) {
-        for (x = 0; x < width; x += 8)
-            if ((ret = decode_p_block(f, dst + x, src + x, 3, 3, stride)) < 0)
-                return ret;
-        src += 8 * stride;
-        dst += 8 * stride;
-    }
-
-    return 0;
-}
-
-/**
- * decode block and dequantize.
- * Note this is almost identical to MJPEG.
- */
-static int decode_i_block(FourXContext *f, int16_t *block)
-{
-    int code, i, j, level, val;
-
-    if (get_bits_left(&f->gb) < 2){
-        av_log(f->avctx, AV_LOG_ERROR, "%d bits left before decode_i_block()\n", get_bits_left(&f->gb));
-        return -1;
-    }
-
-    /* DC coef */
-    val = get_vlc2(&f->pre_gb, f->pre_vlc.table, ACDC_VLC_BITS, 3);
-    if (val >> 4) {
-        av_log(f->avctx, AV_LOG_ERROR, "error dc run != 0\n");
-        return AVERROR_INVALIDDATA;
-    }
-
-    if (val)
-        val = get_xbits(&f->gb, val);
-
-    val        = val * dequant_table[0] + f->last_dc;
-    f->last_dc = block[0] = val;
-    /* AC coefs */
-    i = 1;
-    for (;;) {
-        code = get_vlc2(&f->pre_gb, f->pre_vlc.table, ACDC_VLC_BITS, 3);
-
-        /* EOB */
-        if (code == 0)
-            break;
-        if (code == 0xf0) {
-            i += 16;
-        } else {
-            if (code & 0xf) {
-                level = get_xbits(&f->gb, code & 0xf);
-            } else {
-                av_log(f->avctx, AV_LOG_ERROR, "0 coeff\n");
-                return AVERROR_INVALIDDATA;
-            }
-            i    += code >> 4;
-            if (i >= 64) {
-                av_log(f->avctx, AV_LOG_ERROR, "run %d oveflow\n", i);
-                return 0;
-            }
-
-            j = ff_zigzag_direct[i];
-            block[j] = level * dequant_table[j];
-            i++;
-            if (i >= 64)
-                break;
-        }
-    }
-
-    return 0;
-}
-
-static inline void idct_put(FourXContext *f, AVFrame *frame, int x, int y)
-{
-    int16_t (*block)[64] = f->block;
-    int stride           = frame->linesize[0] >> 1;
-    int i;
-    uint16_t *dst = ((uint16_t*)frame->data[0]) + y * stride + x;
-
-    for (i = 0; i < 4; i++) {
-        block[i][0] += 0x80 * 8 * 8;
-        idct(block[i]);
-    }
-
-    if (!(f->avctx->flags & CODEC_FLAG_GRAY)) {
-        for (i = 4; i < 6; i++)
-            idct(block[i]);
-    }
-
-    /* Note transform is:
-     * y  = ( 1b + 4g + 2r) / 14
-     * cb = ( 3b - 2g - 1r) / 14
-     * cr = (-1b - 4g + 5r) / 14 */
-    for (y = 0; y < 8; y++) {
-        for (x = 0; x < 8; x++) {
-            int16_t *temp = block[(x >> 2) + 2 * (y >> 2)] +
-                            2 * (x & 3) + 2 * 8 * (y & 3); // FIXME optimize
-            int cb = block[4][x + 8 * y];
-            int cr = block[5][x + 8 * y];
-            int cg = (cb + cr) >> 1;
-            int y;
-
-            cb += cb;
-
-            y               = temp[0];
-            dst[0]          = ((y + cb) >> 3) + (((y - cg) & 0xFC) << 3) + (((y + cr) & 0xF8) << 8);
-            y               = temp[1];
-            dst[1]          = ((y + cb) >> 3) + (((y - cg) & 0xFC) << 3) + (((y + cr) & 0xF8) << 8);
-            y               = temp[8];
-            dst[stride]     = ((y + cb) >> 3) + (((y - cg) & 0xFC) << 3) + (((y + cr) & 0xF8) << 8);
-            y               = temp[9];
-            dst[1 + stride] = ((y + cb) >> 3) + (((y - cg) & 0xFC) << 3) + (((y + cr) & 0xF8) << 8);
-            dst            += 2;
-        }
-        dst += 2 * stride - 2 * 8;
-    }
-}
-
-static int decode_i_mb(FourXContext *f)
-{
-    int ret;
-    int i;
-
-    f->dsp.clear_blocks(f->block[0]);
-
-    for (i = 0; i < 6; i++)
-        if ((ret = decode_i_block(f, f->block[i])) < 0)
-            return ret;
-
-    return 0;
-}
-
-static const uint8_t *read_huffman_tables(FourXContext *f,
-                                          const uint8_t * const buf,
-                                          int buf_size)
-{
-    int frequency[512] = { 0 };
-    uint8_t flag[512];
-    int up[512];
-    uint8_t len_tab[257];
-    int bits_tab[257];
-    int start, end;
-    const uint8_t *ptr = buf;
-    const uint8_t *ptr_end = buf + buf_size;
-    int j;
-
-    memset(up, -1, sizeof(up));
-
-    start = *ptr++;
-    end   = *ptr++;
-    for (;;) {
-        int i;
-
-        if (ptr_end - ptr < FFMAX(end - start + 1, 0) + 1) {
-            av_log(f->avctx, AV_LOG_ERROR, "invalid data in read_huffman_tables\n");
-            return NULL;
-        }
-
-        for (i = start; i <= end; i++)
-            frequency[i] = *ptr++;
-        start = *ptr++;
-        if (start == 0)
-            break;
-
-        end = *ptr++;
-    }
-    frequency[256] = 1;
-
-    while ((ptr - buf) & 3)
-        ptr++; // 4byte align
-
-    if (ptr > ptr_end) {
-        av_log(f->avctx, AV_LOG_ERROR, "ptr overflow in read_huffman_tables\n");
-        return NULL;
-    }
-
-    for (j = 257; j < 512; j++) {
-        int min_freq[2] = { 256 * 256, 256 * 256 };
-        int smallest[2] = { 0, 0 };
-        int i;
-        for (i = 0; i < j; i++) {
-            if (frequency[i] == 0)
-                continue;
-            if (frequency[i] < min_freq[1]) {
-                if (frequency[i] < min_freq[0]) {
-                    min_freq[1] = min_freq[0];
-                    smallest[1] = smallest[0];
-                    min_freq[0] = frequency[i];
-                    smallest[0] = i;
-                } else {
-                    min_freq[1] = frequency[i];
-                    smallest[1] = i;
-                }
-            }
-        }
-        if (min_freq[1] == 256 * 256)
-            break;
-
-        frequency[j]           = min_freq[0] + min_freq[1];
-        flag[smallest[0]]      = 0;
-        flag[smallest[1]]      = 1;
-        up[smallest[0]]        =
-        up[smallest[1]]        = j;
-        frequency[smallest[0]] = frequency[smallest[1]] = 0;
-    }
-
-    for (j = 0; j < 257; j++) {
-        int node, len = 0, bits = 0;
-
-        for (node = j; up[node] != -1; node = up[node]) {
-            bits += flag[node] << len;
-            len++;
-            if (len > 31)
-                // can this happen at all ?
-                av_log(f->avctx, AV_LOG_ERROR,
-                       "vlc length overflow\n");
-        }
-
-        bits_tab[j] = bits;
-        len_tab[j]  = len;
-    }
-
-    if (init_vlc(&f->pre_vlc, ACDC_VLC_BITS, 257, len_tab, 1, 1,
-                 bits_tab, 4, 4, 0))
-        return NULL;
-
-    return ptr;
-}
-
-static int mix(int c0, int c1)
-{
-    int blue  =  2 * (c0 & 0x001F) + (c1 & 0x001F);
-    int green = (2 * (c0 & 0x03E0) + (c1 & 0x03E0)) >> 5;
-    int red   =  2 * (c0 >> 10)    + (c1 >> 10);
-    return red / 3 * 1024 + green / 3 * 32 + blue / 3;
-}
-
-static int decode_i2_frame(FourXContext *f, AVFrame *frame, const uint8_t *buf, int length)
-{
-    int x, y, x2, y2;
-    const int width  = f->avctx->width;
-    const int height = f->avctx->height;
-    const int mbs    = (FFALIGN(width, 16) >> 4) * (FFALIGN(height, 16) >> 4);
-    uint16_t *dst    = (uint16_t*)frame->data[0];
-    const int stride =            frame->linesize[0]>>1;
-    const uint8_t *buf_end = buf + length;
-    GetByteContext g3;
-
-    if (length < mbs * 8) {
-        av_log(f->avctx, AV_LOG_ERROR, "packet size too small\n");
-        return AVERROR_INVALIDDATA;
-    }
-    bytestream2_init(&g3, buf, length);
-
-    for (y = 0; y < height; y += 16) {
-        for (x = 0; x < width; x += 16) {
-            unsigned int color[4] = { 0 }, bits;
-            if (buf_end - buf < 8)
-                return -1;
-            // warning following is purely guessed ...
-            color[0] = bytestream2_get_le16u(&g3);
-            color[1] = bytestream2_get_le16u(&g3);
-
-            if (color[0] & 0x8000)
-                av_log(f->avctx, AV_LOG_ERROR, "unk bit 1\n");
-            if (color[1] & 0x8000)
-                av_log(f->avctx, AV_LOG_ERROR, "unk bit 2\n");
-
-            color[2] = mix(color[0], color[1]);
-            color[3] = mix(color[1], color[0]);
-
-            bits = bytestream2_get_le32u(&g3);
-            for (y2 = 0; y2 < 16; y2++) {
-                for (x2 = 0; x2 < 16; x2++) {
-                    int index = 2 * (x2 >> 2) + 8 * (y2 >> 2);
-                    dst[y2 * stride + x2] = color[(bits >> index) & 3];
-                }
-            }
-            dst += 16;
-        }
-        dst += 16 * stride - x;
-    }
-
-    return 0;
-}
-
-static int decode_i_frame(FourXContext *f, AVFrame *frame, const uint8_t *buf, int length)
-{
-    int x, y, ret;
-    const int width  = f->avctx->width;
-    const int height = f->avctx->height;
-    const unsigned int bitstream_size = AV_RL32(buf);
-    unsigned int prestream_size;
-    const uint8_t *prestream;
-
-    if (bitstream_size > (1 << 26))
-        return AVERROR_INVALIDDATA;
-
-    if (length < bitstream_size + 12) {
-        av_log(f->avctx, AV_LOG_ERROR, "packet size too small\n");
-        return AVERROR_INVALIDDATA;
-    }
-
-    prestream_size = 4 * AV_RL32(buf + bitstream_size + 4);
-    prestream      =             buf + bitstream_size + 12;
-
-    if (prestream_size + bitstream_size + 12 != length
-        || prestream_size > (1 << 26)) {
-        av_log(f->avctx, AV_LOG_ERROR, "size mismatch %d %d %d\n",
-               prestream_size, bitstream_size, length);
-        return AVERROR_INVALIDDATA;
-    }
-
-    prestream = read_huffman_tables(f, prestream, prestream_size);
-    if (!prestream) {
-        av_log(f->avctx, AV_LOG_ERROR, "Error reading Huffman tables.\n");
-        return AVERROR_INVALIDDATA;
-    }
-
-    av_assert0(prestream <= buf + length);
-
-    init_get_bits(&f->gb, buf + 4, 8 * bitstream_size);
-
-    prestream_size = length + buf - prestream;
-
-    av_fast_padded_malloc(&f->bitstream_buffer, &f->bitstream_buffer_size,
-                          prestream_size);
-    if (!f->bitstream_buffer)
-        return AVERROR(ENOMEM);
-    f->dsp.bswap_buf(f->bitstream_buffer, (const uint32_t*)prestream,
-                     prestream_size / 4);
-    init_get_bits(&f->pre_gb, f->bitstream_buffer, 8 * prestream_size);
-
-    f->last_dc = 0 * 128 * 8 * 8;
-
-    for (y = 0; y < height; y += 16) {
-        for (x = 0; x < width; x += 16) {
-            if ((ret = decode_i_mb(f)) < 0)
-                return ret;
-
-            idct_put(f, frame, x, y);
-        }
-    }
-
-    if (get_vlc2(&f->pre_gb, f->pre_vlc.table, ACDC_VLC_BITS, 3) != 256)
-        av_log(f->avctx, AV_LOG_ERROR, "end mismatch\n");
-
-    return 0;
-}
-
-static int decode_frame(AVCodecContext *avctx, void *data,
-                        int *got_frame, AVPacket *avpkt)
-{
-    const uint8_t *buf    = avpkt->data;
-    int buf_size          = avpkt->size;
-    FourXContext *const f = avctx->priv_data;
-    AVFrame *picture      = data;
-    int i, frame_4cc, frame_size, ret;
-
-    if (buf_size < 20)
-        return AVERROR_INVALIDDATA;
-
-    av_assert0(avctx->width % 16 == 0 && avctx->height % 16 == 0);
-
-    if (buf_size < AV_RL32(buf + 4) + 8) {
-        av_log(f->avctx, AV_LOG_ERROR, "size mismatch %d %d\n",
-               buf_size, AV_RL32(buf + 4));
-        return AVERROR_INVALIDDATA;
-    }
-
-    frame_4cc = AV_RL32(buf);
-
-    if (frame_4cc == AV_RL32("cfrm")) {
-        int free_index       = -1;
-        int id, whole_size;
-        const int data_size  = buf_size - 20;
-        CFrameBuffer *cfrm;
-
-        if (f->version <= 1) {
-            av_log(f->avctx, AV_LOG_ERROR, "cfrm in version %d\n", f->version);
-            return AVERROR_INVALIDDATA;
-        }
-
-        id         = AV_RL32(buf + 12);
-        whole_size = AV_RL32(buf + 16);
-
-        if (data_size < 0 || whole_size < 0) {
-            av_log(f->avctx, AV_LOG_ERROR, "sizes invalid\n");
-            return AVERROR_INVALIDDATA;
-        }
-
-        for (i = 0; i < CFRAME_BUFFER_COUNT; i++)
-            if (f->cfrm[i].id && f->cfrm[i].id < avctx->frame_number)
-                av_log(f->avctx, AV_LOG_ERROR, "lost c frame %d\n",
-                       f->cfrm[i].id);
-
-        for (i = 0; i < CFRAME_BUFFER_COUNT; i++) {
-            if (f->cfrm[i].id == id)
-                break;
-            if (f->cfrm[i].size == 0)
-                free_index = i;
-        }
-
-        if (i >= CFRAME_BUFFER_COUNT) {
-            i             = free_index;
-            f->cfrm[i].id = id;
-        }
-        cfrm = &f->cfrm[i];
-
-        if (data_size > UINT_MAX -  cfrm->size - FF_INPUT_BUFFER_PADDING_SIZE)
-            return AVERROR_INVALIDDATA;
-
-        cfrm->data = av_fast_realloc(cfrm->data, &cfrm->allocated_size,
-                                     cfrm->size + data_size + FF_INPUT_BUFFER_PADDING_SIZE);
-        // explicit check needed as memcpy below might not catch a NULL
-        if (!cfrm->data) {
-            av_log(f->avctx, AV_LOG_ERROR, "realloc failure\n");
-            return AVERROR(ENOMEM);
-        }
-
-        memcpy(cfrm->data + cfrm->size, buf + 20, data_size);
-        cfrm->size += data_size;
-
-        if (cfrm->size >= whole_size) {
-            buf        = cfrm->data;
-            frame_size = cfrm->size;
-
-            if (id != avctx->frame_number)
-                av_log(f->avctx, AV_LOG_ERROR, "cframe id mismatch %d %d\n",
-                       id, avctx->frame_number);
-
-            if (f->version <= 1)
-                return AVERROR_INVALIDDATA;
-
-            cfrm->size = cfrm->id = 0;
-            frame_4cc  = AV_RL32("pfrm");
-        } else
-            return buf_size;
-    } else {
-        buf        = buf      + 12;
-        frame_size = buf_size - 12;
-    }
-
-    FFSWAP(AVFrame*, f->current_picture, f->last_picture);
-
-    // alternatively we would have to use our own buffer management
-    avctx->flags |= CODEC_FLAG_EMU_EDGE;
-
-    if ((ret = ff_reget_buffer(avctx, f->current_picture)) < 0)
-        return ret;
-
-    if (frame_4cc == AV_RL32("ifr2")) {
-        f->current_picture->pict_type = AV_PICTURE_TYPE_I;
-        if ((ret = decode_i2_frame(f, f->current_picture, buf - 4, frame_size + 4)) < 0) {
-            av_log(f->avctx, AV_LOG_ERROR, "decode i2 frame failed\n");
-            return ret;
-        }
-    } else if (frame_4cc == AV_RL32("ifrm")) {
-        f->current_picture->pict_type = AV_PICTURE_TYPE_I;
-        if ((ret = decode_i_frame(f, f->current_picture, buf, frame_size)) < 0) {
-            av_log(f->avctx, AV_LOG_ERROR, "decode i frame failed\n");
-            return ret;
-        }
-    } else if (frame_4cc == AV_RL32("pfrm") || frame_4cc == AV_RL32("pfr2")) {
-        f->current_picture->pict_type = AV_PICTURE_TYPE_P;
-        if ((ret = decode_p_frame(f, f->current_picture, buf, frame_size)) < 0) {
-            av_log(f->avctx, AV_LOG_ERROR, "decode p frame failed\n");
-            return ret;
-        }
-    } else if (frame_4cc == AV_RL32("snd_")) {
-        av_log(avctx, AV_LOG_ERROR, "ignoring snd_ chunk length:%d\n",
-               buf_size);
-    } else {
-        av_log(avctx, AV_LOG_ERROR, "ignoring unknown chunk length:%d\n",
-               buf_size);
-    }
-
-    f->current_picture->key_frame = f->current_picture->pict_type == AV_PICTURE_TYPE_I;
-
-    if ((ret = av_frame_ref(picture, f->current_picture)) < 0)
-        return ret;
-    *got_frame = 1;
-
-    emms_c();
-
-    return buf_size;
-}
-
-static av_cold int decode_init(AVCodecContext *avctx)
-{
-    FourXContext * const f = avctx->priv_data;
-
-    if (avctx->extradata_size != 4 || !avctx->extradata) {
-        av_log(avctx, AV_LOG_ERROR, "extradata wrong or missing\n");
-        return AVERROR_INVALIDDATA;
-    }
-    if((avctx->width % 16) || (avctx->height % 16)) {
-        av_log(avctx, AV_LOG_ERROR, "unsupported width/height\n");
-        return AVERROR_INVALIDDATA;
-    }
-
-    f->version = AV_RL32(avctx->extradata) >> 16;
-    ff_dsputil_init(&f->dsp, avctx);
-    f->avctx = avctx;
-    init_vlcs(f);
-
-    if (f->version > 2)
-        avctx->pix_fmt = AV_PIX_FMT_RGB565;
-    else
-        avctx->pix_fmt = AV_PIX_FMT_BGR555;
-
-    f->current_picture = av_frame_alloc();
-    f->last_picture    = av_frame_alloc();
-    if (!f->current_picture  || !f->last_picture)
-        return AVERROR(ENOMEM);
-
-    return 0;
-}
-
-
-static av_cold int decode_end(AVCodecContext *avctx)
-{
-    FourXContext * const f = avctx->priv_data;
-    int i;
-
-    av_freep(&f->bitstream_buffer);
-    f->bitstream_buffer_size = 0;
-    for (i = 0; i < CFRAME_BUFFER_COUNT; i++) {
-        av_freep(&f->cfrm[i].data);
-        f->cfrm[i].allocated_size = 0;
-    }
-    ff_free_vlc(&f->pre_vlc);
-    av_frame_free(&f->current_picture);
-    av_frame_free(&f->last_picture);
-
-    return 0;
-}
-
-AVCodec ff_fourxm_decoder = {
-    .name           = "4xm",
-    .long_name      = NULL_IF_CONFIG_SMALL("4X Movie"),
-    .type           = AVMEDIA_TYPE_VIDEO,
-    .id             = AV_CODEC_ID_4XM,
-    .priv_data_size = sizeof(FourXContext),
-    .init           = decode_init,
-    .close          = decode_end,
-    .decode         = decode_frame,
-    .capabilities   = CODEC_CAP_DR1,
-};