adding ffmpeg specific version

1 files changed, 224 insertions, 0 deletions

diff --git a/ffmpeg1/libavcodec/mss1.c b/ffmpeg1/libavcodec/mss1.c
new file mode 100644
index 0000000..bb1858d
--- /dev/null
+++ b/ffmpeg1/libavcodec/mss1.c
@@ -0,0 +1,224 @@
+/*
+ * Microsoft Screen 1 (aka Windows Media Video V7 Screen) decoder
+ * Copyright (c) 2012 Konstantin Shishkov
+ *
+ * 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
+ * Microsoft Screen 1 (aka Windows Media Video V7 Screen) decoder
+ */
+
+#include "avcodec.h"
+#include "internal.h"
+#include "mss12.h"
+
+typedef struct MSS1Context {
+    MSS12Context   ctx;
+    AVFrame        pic;
+    SliceContext   sc;
+} MSS1Context;
+
+static void arith_normalise(ArithCoder *c)
+{
+    for (;;) {
+        if (c->high >= 0x8000) {
+            if (c->low < 0x8000) {
+                if (c->low >= 0x4000 && c->high < 0xC000) {
+                    c->value -= 0x4000;
+                    c->low   -= 0x4000;
+                    c->high  -= 0x4000;
+                } else {
+                    return;
+                }
+            } else {
+                c->value -= 0x8000;
+                c->low   -= 0x8000;
+                c->high  -= 0x8000;
+            }
+        }
+        c->value <<= 1;
+        c->low   <<= 1;
+        c->high  <<= 1;
+        c->high   |= 1;
+        c->value  |= get_bits1(c->gbc.gb);
+    }
+}
+
+ARITH_GET_BIT()
+
+static int arith_get_bits(ArithCoder *c, int bits)
+{
+    int range = c->high - c->low + 1;
+    int val   = (((c->value - c->low + 1) << bits) - 1) / range;
+    int prob  = range * val;
+
+    c->high   = ((prob + range) >> bits) + c->low - 1;
+    c->low   += prob >> bits;
+
+    arith_normalise(c);
+
+    return val;
+}
+
+static int arith_get_number(ArithCoder *c, int mod_val)
+{
+    int range = c->high - c->low + 1;
+    int val   = ((c->value - c->low + 1) * mod_val - 1) / range;
+    int prob  = range * val;
+
+    c->high   = (prob + range) / mod_val + c->low - 1;
+    c->low   += prob / mod_val;
+
+    arith_normalise(c);
+
+    return val;
+}
+
+static int arith_get_prob(ArithCoder *c, int16_t *probs)
+{
+    int range = c->high - c->low + 1;
+    int val   = ((c->value - c->low + 1) * probs[0] - 1) / range;
+    int sym   = 1;
+
+    while (probs[sym] > val)
+        sym++;
+
+    c->high = range * probs[sym - 1] / probs[0] + c->low - 1;
+    c->low += range * probs[sym]     / probs[0];
+
+    return sym;
+}
+
+ARITH_GET_MODEL_SYM()
+
+static void arith_init(ArithCoder *c, GetBitContext *gb)
+{
+    c->low           = 0;
+    c->high          = 0xFFFF;
+    c->value         = get_bits(gb, 16);
+    c->gbc.gb        = gb;
+    c->get_model_sym = arith_get_model_sym;
+    c->get_number    = arith_get_number;
+}
+
+static int decode_pal(MSS12Context *ctx, ArithCoder *acoder)
+{
+    int i, ncol, r, g, b;
+    uint32_t *pal = ctx->pal + 256 - ctx->free_colours;
+
+    if (!ctx->free_colours)
+        return 0;
+
+    ncol = arith_get_number(acoder, ctx->free_colours + 1);
+    for (i = 0; i < ncol; i++) {
+        r = arith_get_bits(acoder, 8);
+        g = arith_get_bits(acoder, 8);
+        b = arith_get_bits(acoder, 8);
+        *pal++ = (0xFFU << 24) | (r << 16) | (g << 8) | b;
+    }
+
+    return !!ncol;
+}
+
+static int mss1_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
+                             AVPacket *avpkt)
+{
+    const uint8_t *buf = avpkt->data;
+    int buf_size = avpkt->size;
+    MSS1Context *ctx = avctx->priv_data;
+    MSS12Context *c = &ctx->ctx;
+    GetBitContext gb;
+    ArithCoder acoder;
+    int pal_changed = 0;
+    int ret;
+
+    init_get_bits(&gb, buf, buf_size * 8);
+    arith_init(&acoder, &gb);
+
+    if ((ret = ff_reget_buffer(avctx, &ctx->pic)) < 0)
+        return ret;
+
+    c->pal_pic    =  ctx->pic.data[0] + ctx->pic.linesize[0] * (avctx->height - 1);
+    c->pal_stride = -ctx->pic.linesize[0];
+    c->keyframe   = !arith_get_bit(&acoder);
+    if (c->keyframe) {
+        c->corrupted = 0;
+        ff_mss12_slicecontext_reset(&ctx->sc);
+        pal_changed        = decode_pal(c, &acoder);
+        ctx->pic.key_frame = 1;
+        ctx->pic.pict_type = AV_PICTURE_TYPE_I;
+    } else {
+        if (c->corrupted)
+            return AVERROR_INVALIDDATA;
+        ctx->pic.key_frame = 0;
+        ctx->pic.pict_type = AV_PICTURE_TYPE_P;
+    }
+    c->corrupted = ff_mss12_decode_rect(&ctx->sc, &acoder, 0, 0,
+                                        avctx->width, avctx->height);
+    if (c->corrupted)
+        return AVERROR_INVALIDDATA;
+    memcpy(ctx->pic.data[1], c->pal, AVPALETTE_SIZE);
+    ctx->pic.palette_has_changed = pal_changed;
+
+    if ((ret = av_frame_ref(data, &ctx->pic)) < 0)
+        return ret;
+
+    *got_frame      = 1;
+
+    /* always report that the buffer was completely consumed */
+    return buf_size;
+}
+
+static av_cold int mss1_decode_init(AVCodecContext *avctx)
+{
+    MSS1Context * const c = avctx->priv_data;
+    int ret;
+
+    c->ctx.avctx       = avctx;
+
+    avcodec_get_frame_defaults(&c->pic);
+
+    ret = ff_mss12_decode_init(&c->ctx, 0, &c->sc, NULL);
+
+    avctx->pix_fmt = AV_PIX_FMT_PAL8;
+
+    return ret;
+}
+
+static av_cold int mss1_decode_end(AVCodecContext *avctx)
+{
+    MSS1Context * const ctx = avctx->priv_data;
+
+    av_frame_unref(&ctx->pic);
+    ff_mss12_decode_end(&ctx->ctx);
+
+    return 0;
+}
+
+AVCodec ff_mss1_decoder = {
+    .name           = "mss1",
+    .type           = AVMEDIA_TYPE_VIDEO,
+    .id             = AV_CODEC_ID_MSS1,
+    .priv_data_size = sizeof(MSS1Context),
+    .init           = mss1_decode_init,
+    .close          = mss1_decode_end,
+    .decode         = mss1_decode_frame,
+    .capabilities   = CODEC_CAP_DR1,
+    .long_name      = NULL_IF_CONFIG_SMALL("MS Screen 1"),
+};