Electronic Arts Madcow decoder

Originally committed as revision 19178 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 318 insertions, 0 deletions

diff --git a/libavcodec/eamad.c b/libavcodec/eamad.c
new file mode 100644
index 0000000000..b4e6c42d57
--- /dev/null
+++ b/libavcodec/eamad.c
@@ -0,0 +1,318 @@
+/*
+ * Electronic Arts Madcow Video Decoder
+ * Copyright (c) 2007-2009 Peter Ross
+ *
+ * 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 St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+/**
+ * @file libavcodec/eamad.c
+ * Electronic Arts Madcow Video Decoder
+ * by Peter Ross <pross@xvid.org>
+ *
+ * Technical details here:
+ * http://wiki.multimedia.cx/index.php?title=Electronic_Arts_MAD
+ */
+
+#include "avcodec.h"
+#include "get_bits.h"
+#include "dsputil.h"
+#include "aandcttab.h"
+#include "mpeg12.h"
+#include "mpeg12data.h"
+
+#define EA_PREAMBLE_SIZE    8
+#define MADk_TAG MKTAG('M', 'A', 'D', 'k')    /* MAD i-frame */
+#define MADm_TAG MKTAG('M', 'A', 'D', 'm')    /* MAD p-frame */
+#define MADe_TAG MKTAG('M', 'A', 'D', 'e')    /* MAD lqp-frame */
+
+typedef struct MadContext {
+    MpegEncContext s;
+    AVFrame frame;
+    AVFrame last_frame;
+    void *bitstream_buf;
+    unsigned int bitstream_buf_size;
+    DECLARE_ALIGNED_16(DCTELEM, block[64]);
+} MadContext;
+
+static void bswap16_buf(uint16_t *dst, const uint16_t *src, int count)
+{
+    int i;
+    for (i=0; i<count; i++)
+        dst[i] = bswap_16(src[i]);
+}
+
+static av_cold int decode_init(AVCodecContext *avctx)
+{
+    MadContext *t = avctx->priv_data;
+    MpegEncContext *s = &t->s;
+    s->avctx = avctx;
+    avctx->pix_fmt = PIX_FMT_YUV420P;
+    if (avctx->idct_algo == FF_IDCT_AUTO)
+        avctx->idct_algo = FF_IDCT_EA;
+    dsputil_init(&s->dsp, avctx);
+    ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable, ff_zigzag_direct);
+    ff_mpeg12_init_vlcs();
+    return 0;
+}
+
+static inline void comp(unsigned char *dst, int dst_stride,
+                        unsigned char *src, int src_stride, int add)
+{
+    int j, i;
+    for (j=0; j<8; j++)
+        for (i=0; i<8; i++)
+            dst[j*dst_stride + i] = av_clip_uint8(src[j*src_stride + i] + add);
+}
+
+static inline void comp_block(MadContext *t, int mb_x, int mb_y,
+                              int j, int mv_x, int mv_y, int add)
+{
+    MpegEncContext *s = &t->s;
+    if (j < 4) {
+        comp(t->frame.data[0] + (mb_y*16 + ((j&2)<<2))*t->frame.linesize[0] + mb_x*16 + ((j&1)<<3),
+             t->frame.linesize[0],
+             t->last_frame.data[0] + (mb_y*16 + ((j&2)<<2) + mv_y)*t->last_frame.linesize[0] + mb_x*16 + ((j&1)<<3) + mv_x,
+             t->last_frame.linesize[0], add);
+    } else if (!(s->avctx->flags & CODEC_FLAG_GRAY)) {
+        int index = j - 3;
+        comp(t->frame.data[index] + (mb_y*8)*t->frame.linesize[index] + mb_x * 8,
+             t->frame.linesize[index],
+             t->last_frame.data[index] + (mb_y * 8 + (mv_y/2))*t->last_frame.linesize[index] + mb_x * 8 + (mv_x/2),
+             t->last_frame.linesize[index], add);
+    }
+}
+
+static inline void idct_put(MadContext *t, DCTELEM *block, int mb_x, int mb_y, int j)
+{
+    MpegEncContext *s = &t->s;
+    if (j < 4) {
+        s->dsp.idct_put(
+            t->frame.data[0] + (mb_y*16 + ((j&2)<<2))*t->frame.linesize[0] + mb_x*16 + ((j&1)<<3),
+            t->frame.linesize[0], block);
+    } else if (!(s->avctx->flags & CODEC_FLAG_GRAY)) {
+        int index = j - 3;
+        s->dsp.idct_put(
+            t->frame.data[index] + (mb_y*8)*t->frame.linesize[index] + mb_x*8,
+            t->frame.linesize[index], block);
+    }
+}
+
+static inline void decode_block_intra(MadContext * t, DCTELEM * block)
+{
+    MpegEncContext *s = &t->s;
+    int level, i, j, run;
+    RLTable *rl = &ff_rl_mpeg1;
+    const uint8_t *scantable = s->intra_scantable.permutated;
+    int16_t *quant_matrix = s->intra_matrix;
+
+    block[0] = (128 + get_sbits(&s->gb, 8)) * quant_matrix[0];
+
+    /* The RL decoder is derived from mpeg1_decode_block_intra;
+       Escaped level and run values a decoded differently */
+    {
+        OPEN_READER(re, &s->gb);
+        /* now quantify & encode AC coefficients */
+        for (;;) {
+            UPDATE_CACHE(re, &s->gb);
+            GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
+
+            if (level == 127) {
+                break;
+            } else if (level != 0) {
+                i += run;
+                j = scantable[i];
+                level = (level*quant_matrix[j]) >> 4;
+                level = (level-1)|1;
+                level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
+                LAST_SKIP_BITS(re, &s->gb, 1);
+            } else {
+                /* escape */
+                UPDATE_CACHE(re, &s->gb);
+                level = SHOW_SBITS(re, &s->gb, 10); SKIP_BITS(re, &s->gb, 10);
+
+                UPDATE_CACHE(re, &s->gb);
+                run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
+
+                i += run;
+                j = scantable[i];
+                if (level < 0) {
+                    level = -level;
+                    level = (level*quant_matrix[j]) >> 4;
+                    level = (level-1)|1;
+                    level = -level;
+                } else {
+                    level = (level*quant_matrix[j]) >> 4;
+                    level = (level-1)|1;
+                }
+            }
+            if (i > 63) {
+                av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
+                return;
+            }
+
+            block[j] = level;
+        }
+        CLOSE_READER(re, &s->gb);
+    }
+}
+
+static int decode_motion(GetBitContext *gb)
+{
+    int value = 0;
+    if (get_bits1(gb)) {
+        if (get_bits1(gb))
+            value = -17;
+        value += get_bits(gb, 4) + 1;
+    }
+    return value;
+}
+
+static void decode_mb(MadContext *t, int inter)
+{
+    MpegEncContext *s = &t->s;
+    int mv_map = 0;
+    int mv_x, mv_y;
+    int j;
+
+    if (inter) {
+        int v = decode210(&s->gb);
+        if (v < 2) {
+            mv_map = v ? get_bits(&s->gb, 6) : 63;
+            mv_x = decode_motion(&s->gb);
+            mv_y = decode_motion(&s->gb);
+        } else {
+            mv_map = 0;
+        }
+    }
+
+    for (j=0; j<6; j++) {
+        if (mv_map & (1<<j)) {  // mv_x and mv_y are guarded by mv_map
+            int add = 2*decode_motion(&s->gb);
+            comp_block(t, s->mb_x, s->mb_y, j, mv_x, mv_y, add);
+        } else {
+            s->dsp.clear_block(t->block);
+            decode_block_intra(t, t->block);
+            idct_put(t, t->block, s->mb_x, s->mb_y, j);
+        }
+    }
+}
+
+static void calc_intra_matrix(MadContext *t, int qscale)
+{
+    MpegEncContext *s = &t->s;
+    int i;
+
+    if (s->avctx->idct_algo == FF_IDCT_EA) {
+        s->intra_matrix[0] = (ff_inv_aanscales[0]*ff_mpeg1_default_intra_matrix[0]) >> 11;
+        for (i=1; i<64; i++)
+            s->intra_matrix[i] = (ff_inv_aanscales[i]*ff_mpeg1_default_intra_matrix[i]*qscale + 32) >> 10;
+    } else {
+        s->intra_matrix[0] = ff_mpeg1_default_intra_matrix[0];
+        for (i=1; i<64; i++)
+            s->intra_matrix[i] = (ff_mpeg1_default_intra_matrix[i]*qscale) << 1;
+    }
+}
+
+static int decode_frame(AVCodecContext *avctx,
+                        void *data, int *data_size,
+                        AVPacket *avpkt)
+{
+    const uint8_t *buf = avpkt->data;
+    int buf_size       = avpkt->size;
+    const uint8_t *buf_end = buf+buf_size;
+    MadContext *t     = avctx->priv_data;
+    MpegEncContext *s = &t->s;
+    int chunk_type;
+    int inter;
+
+    if (buf_size < 17) {
+        av_log(avctx, AV_LOG_ERROR, "Input buffer too small\n");
+        *data_size = 0;
+        return -1;
+    }
+
+    chunk_type = AV_RL32(&buf[0]);
+    inter = (chunk_type == MADm_TAG || chunk_type == MADe_TAG);
+    buf += 8;
+
+    av_reduce(&avctx->time_base.num, &avctx->time_base.den,
+              AV_RL16(&buf[6]), 1000, 1<<30);
+
+    s->width  = AV_RL16(&buf[8]);
+    s->height = AV_RL16(&buf[10]);
+    calc_intra_matrix(t, buf[13]);
+    buf += 16;
+
+    if (avctx->width != s->width || avctx->height != s->height) {
+        if (avcodec_check_dimensions(avctx, s->width, s->height) < 0)
+            return -1;
+        avcodec_set_dimensions(avctx, s->width, s->height);
+        if (t->frame.data[0])
+            avctx->release_buffer(avctx, &t->frame);
+    }
+
+    t->frame.reference = 1;
+    if (!t->frame.data[0]) {
+        if (avctx->get_buffer(avctx, &t->frame) < 0) {
+            av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
+            return -1;
+        }
+    }
+
+    av_fast_malloc(&t->bitstream_buf, &t->bitstream_buf_size, (buf_end-buf) + FF_INPUT_BUFFER_PADDING_SIZE);
+    if (!t->bitstream_buf)
+        return AVERROR(ENOMEM);
+    bswap16_buf(t->bitstream_buf, (const uint16_t*)buf, (buf_end-buf)/2);
+    init_get_bits(&s->gb, t->bitstream_buf, 8*(buf_end-buf));
+
+    for (s->mb_y=0; s->mb_y < (avctx->height+15)/16; s->mb_y++)
+        for (s->mb_x=0; s->mb_x < (avctx->width +15)/16; s->mb_x++)
+            decode_mb(t, inter);
+
+    *data_size = sizeof(AVFrame);
+    *(AVFrame*)data = t->frame;
+
+    if (chunk_type != MADe_TAG)
+        FFSWAP(AVFrame, t->frame, t->last_frame);
+
+    return buf_size;
+}
+
+static av_cold int decode_end(AVCodecContext *avctx)
+{
+    MadContext *t = avctx->priv_data;
+    if (t->frame.data[0])
+        avctx->release_buffer(avctx, &t->frame);
+    if (t->last_frame.data[0])
+        avctx->release_buffer(avctx, &t->last_frame);
+    av_free(t->bitstream_buf);
+    return 0;
+}
+
+AVCodec eamad_decoder = {
+    "eamad",
+    CODEC_TYPE_VIDEO,
+    CODEC_ID_MAD,
+    sizeof(MadContext),
+    decode_init,
+    NULL,
+    decode_end,
+    decode_frame,
+    CODEC_CAP_DR1,
+    .long_name = NULL_IF_CONFIG_SMALL("Electronic Arts Madcow Video")
+};