Electronic Arts TGV decoder

Originally committed as revision 14642 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 340 insertions, 0 deletions

diff --git a/libavcodec/eatgv.c b/libavcodec/eatgv.c
new file mode 100644
index 0000000000..a8787bb873
--- /dev/null
+++ b/libavcodec/eatgv.c
@@ -0,0 +1,340 @@
+/*
+ * Electronic Arts TGV Video Decoder
+ * Copyright (c) 2007-2008 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 eatgv.c
+ * Electronic Arts TGV Video Decoder
+ * by Peter Ross (suxen_drol at hotmail dot com)
+ *
+ * Technical details here:
+ * http://wiki.multimedia.cx/index.php?title=Electronic_Arts_TGV
+ */
+
+#include "avcodec.h"
+#define ALT_BITSTREAM_READER_LE
+#include "bitstream.h"
+#include <libavutil/lzo.h>
+
+#define EA_PREAMBLE_SIZE    8
+#define kVGT_TAG MKTAG('k', 'V', 'G', 'T')
+
+typedef struct TgvContext {
+    AVCodecContext *avctx;
+    AVFrame frame;
+    AVFrame last_frame;
+    int width,height;
+    unsigned int palette[AVPALETTE_COUNT];
+
+    int (*mv_codebook)[2];
+    unsigned char (*block_codebook)[16];
+    int num_mvs;           ///< current length of mv_codebook
+    int num_blocks_packed; ///< current length of block_codebook
+} TgvContext;
+
+static av_cold int tgv_decode_init(AVCodecContext *avctx){
+    TgvContext *s = avctx->priv_data;
+    s->avctx = avctx;
+    avctx->time_base = (AVRational){1, 15};
+    avctx->pix_fmt = PIX_FMT_PAL8;
+    return 0;
+}
+
+/**
+ * Unpack buffer
+ * @return 0 on success, -1 on critical buffer underflow
+ */
+static int unpack(const uint8_t *src, const uint8_t *src_end, unsigned char *dst, int width, int height) {
+    unsigned char *dst_end = dst + width*height;
+    int size,size1,size2,offset,run;
+    unsigned char *dst_start = dst;
+
+    if (src[0] & 0x01)
+        src += 5;
+    else
+        src += 2;
+
+    if (src+3>src_end)
+        return -1;
+    size = AV_RB24(src);
+    src += 3;
+
+    while(size>0 && src<src_end) {
+
+        /* determine size1 and size2 */
+        size1 = (src[0] & 3);
+        if ( src[0] & 0x80 ) {  // 1
+            if (src[0] & 0x40 ) {  // 11
+                if ( src[0] & 0x20 ) {  // 111
+                    if ( src[0] < 0xFC )  // !(111111)
+                        size1 = (((src[0] & 31) + 1) << 2);
+                    src++;
+                    size2 = 0;
+                } else {  // 110
+                    offset = ((src[0] & 0x10) << 12) + AV_RB16(&src[1]) + 1;
+                    size2 = ((src[0] & 0xC) << 6) + src[3] + 5;
+                    src += 4;
+                }
+            } else {  // 10
+                size1 = ( ( src[1] & 0xC0) >> 6 );
+                offset = (AV_RB16(&src[1]) & 0x3FFF) + 1;
+                size2 = (src[0] & 0x3F) + 4;
+                src += 3;
+            }
+        } else {  // 0
+            offset = ((src[0] & 0x60) << 3) + src[1] + 1;
+            size2 = ((src[0] & 0x1C) >> 2) + 3;
+            src += 2;
+        }
+
+
+        /* fetch strip from src */
+        if (size1>src_end-src)
+            break;
+
+        if (size1>0) {
+            size -= size1;
+            run = FFMIN(size1, dst_end-dst);
+            memcpy(dst, src, run);
+            dst += run;
+            src += run;
+        }
+
+        if (size2>0) {
+            if (dst-dst_start<offset)
+                return 0;
+            size -= size2;
+            run = FFMIN(size2, dst_end-dst);
+            av_memcpy_backptr(dst, offset, run);
+            dst += run;
+        }
+    }
+
+    return 0;
+}
+
+/**
+ * Decode inter-frame
+ * @return 0 on success, -1 on critical buffer underflow
+ */
+static int tgv_decode_inter(TgvContext * s, const uint8_t *buf, const uint8_t *buf_end){
+    unsigned char *frame0_end = s->last_frame.data[0] + s->avctx->width*s->last_frame.linesize[0];
+    int num_mvs;
+    int num_blocks_raw;
+    int num_blocks_packed;
+    int vector_bits;
+    int i,j,x,y;
+    GetBitContext gb;
+    int mvbits;
+    const unsigned char *blocks_raw;
+
+    if(buf+12>buf_end)
+        return -1;
+
+    num_mvs           = AV_RL16(&buf[0]);
+    num_blocks_raw    = AV_RL16(&buf[2]);
+    num_blocks_packed = AV_RL16(&buf[4]);
+    vector_bits       = AV_RL16(&buf[6]);
+    buf += 12;
+
+    /* allocate codebook buffers as neccessary */
+    if (num_mvs > s->num_mvs) {
+        s->mv_codebook = av_realloc(s->mv_codebook, num_mvs*2*sizeof(int));
+        s->num_mvs = num_mvs;
+    }
+
+    if (num_blocks_packed > s->num_blocks_packed) {
+        s->block_codebook = av_realloc(s->block_codebook, num_blocks_packed*16*sizeof(unsigned char));
+        s->num_blocks_packed = num_blocks_packed;
+    }
+
+    /* read motion vectors */
+    mvbits = (num_mvs*2*10+31) & ~31;
+
+    if (buf+(mvbits>>3)+16*num_blocks_raw+8*num_blocks_packed>buf_end)
+        return -1;
+
+    init_get_bits(&gb, buf, mvbits);
+    for (i=0; i<num_mvs; i++) {
+        s->mv_codebook[i][0] = get_sbits(&gb, 10);
+        s->mv_codebook[i][1] = get_sbits(&gb, 10);
+    }
+    buf += mvbits>>3;
+
+    /* note ptr to uncompressed blocks */
+    blocks_raw = buf;
+    buf += num_blocks_raw*16;
+
+    /* read compressed blocks */
+    init_get_bits(&gb, buf, (buf_end-buf)<<3);
+    for (i=0; i<num_blocks_packed; i++) {
+        int tmp[4];
+        for(j=0; j<4; j++)
+            tmp[j] = get_bits(&gb, 8);
+        for(j=0; j<16; j++)
+            s->block_codebook[i][15-j] = tmp[get_bits(&gb, 2)];
+    }
+
+    /* read vectors and build frame */
+    for(y=0; y<s->avctx->height/4; y++)
+    for(x=0; x<s->avctx->width/4; x++) {
+        unsigned int vector = get_bits(&gb, vector_bits);
+        const unsigned char *src;
+        int src_stride;
+
+        if (vector < num_mvs) {
+            src = s->last_frame.data[0] +
+                  (y*4 + s->mv_codebook[vector][1])*s->last_frame.linesize[0] +
+                   x*4 + s->mv_codebook[vector][0];
+            src_stride = s->last_frame.linesize[0];
+            if (src+3*src_stride+3>=frame0_end)
+                continue;
+        }else{
+            int offset = vector - num_mvs;
+            if (offset<num_blocks_raw)
+                src = blocks_raw + 16*offset;
+            else if (offset-num_blocks_raw<num_blocks_packed)
+                src = s->block_codebook[offset-num_blocks_raw];
+            else
+                continue;
+            src_stride = 4;
+        }
+
+        for(j=0; j<4; j++)
+        for(i=0; i<4; i++)
+            s->frame.data[0][ (y*4+j)*s->frame.linesize[0] + (x*4+i)  ] =
+               src[j*src_stride + i];
+    }
+
+    return 0;
+}
+
+/** release AVFrame buffers if allocated */
+static void cond_release_buffer(AVFrame *pic)
+{
+    if (pic->data[0]) {
+        av_freep(&pic->data[0]);
+        av_free(pic->data[1]);
+    }
+}
+
+static int tgv_decode_frame(AVCodecContext *avctx,
+                            void *data, int *data_size,
+                            const uint8_t *buf, int buf_size)
+{
+    TgvContext *s = avctx->priv_data;
+    const uint8_t *buf_end = buf + buf_size;
+    int chunk_type;
+
+    chunk_type = AV_RL32(&buf[0]);
+    buf += EA_PREAMBLE_SIZE;
+
+    if (chunk_type==kVGT_TAG) {
+        int pal_count, i;
+        if(buf+12>buf_end) {
+            av_log(avctx, AV_LOG_WARNING, "truncated header\n");
+            return -1;
+        }
+
+        s->width  = AV_RL16(&buf[0]);
+        s->height = AV_RL16(&buf[2]);
+        if (s->avctx->width!=s->width || s->avctx->height!=s->height) {
+            avcodec_set_dimensions(s->avctx, s->width, s->height);
+            cond_release_buffer(&s->frame);
+            cond_release_buffer(&s->last_frame);
+        }
+
+        pal_count = AV_RL16(&buf[6]);
+        buf += 12;
+        for(i=0; i<pal_count && i<AVPALETTE_COUNT && buf+2<buf_end; i++) {
+            s->palette[i] = AV_RB24(buf);
+            buf += 3;
+        }
+    }
+
+    if (avcodec_check_dimensions(avctx, s->width, s->height))
+        return -1;
+
+    /* shuffle */
+    FFSWAP(AVFrame, s->frame, s->last_frame);
+    if (!s->frame.data[0]) {
+        s->frame.reference = 1;
+        s->frame.buffer_hints = FF_BUFFER_HINTS_VALID;
+        s->frame.linesize[0] = s->width;
+
+        /* allocate additional 12 bytes to accomodate av_memcpy_backptr() OUTBUF_PADDED optimisation */
+        s->frame.data[0] = av_malloc(s->width*s->height + 12);
+        if (!s->frame.data[0])
+            return AVERROR_NOMEM;
+        s->frame.data[1] = av_malloc(AVPALETTE_SIZE);
+        if (!s->frame.data[1]) {
+            av_freep(&s->frame.data[0]);
+            return AVERROR_NOMEM;
+        }
+    }
+    memcpy(s->frame.data[1], s->palette, AVPALETTE_SIZE);
+
+    if(chunk_type==kVGT_TAG) {
+        s->frame.key_frame = 1;
+        s->frame.pict_type = FF_I_TYPE;
+        if (unpack(buf, buf_end, s->frame.data[0], s->avctx->width, s->avctx->height)<0) {
+            av_log(avctx, AV_LOG_WARNING, "truncated intra frame\n");
+            return -1;
+        }
+    }else{
+        if (!s->last_frame.data[0]) {
+            av_log(avctx, AV_LOG_WARNING, "inter frame without corresponding intra frame\n");
+            return buf_size;
+        }
+        s->frame.key_frame = 0;
+        s->frame.pict_type = FF_P_TYPE;
+        if (tgv_decode_inter(s, buf, buf_end)<0) {
+            av_log(avctx, AV_LOG_WARNING, "truncated inter frame\n");
+            return -1;
+        }
+    }
+
+    *data_size = sizeof(AVFrame);
+    *(AVFrame*)data = s->frame;
+
+    return buf_size;
+}
+
+static av_cold int tgv_decode_end(AVCodecContext *avctx)
+{
+    TgvContext *s = avctx->priv_data;
+    cond_release_buffer(&s->frame);
+    cond_release_buffer(&s->last_frame);
+    av_free(s->mv_codebook);
+    av_free(s->block_codebook);
+    return 0;
+}
+
+AVCodec eatgv_decoder = {
+    "eatgv",
+    CODEC_TYPE_VIDEO,
+    CODEC_ID_TGV,
+    sizeof(TgvContext),
+    tgv_decode_init,
+    NULL,
+    tgv_decode_end,
+    tgv_decode_frame,
+    .long_name = NULL_IF_CONFIG_SMALL("Electronic Arts TGV Video"),
+};