yading@10: /*
yading@10:  * Electronic Arts TGV Video Decoder
yading@10:  * Copyright (c) 2007-2008 Peter Ross
yading@10:  *
yading@10:  * This file is part of FFmpeg.
yading@10:  *
yading@10:  * FFmpeg is free software; you can redistribute it and/or
yading@10:  * modify it under the terms of the GNU Lesser General Public
yading@10:  * License as published by the Free Software Foundation; either
yading@10:  * version 2.1 of the License, or (at your option) any later version.
yading@10:  *
yading@10:  * FFmpeg is distributed in the hope that it will be useful,
yading@10:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@10:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@10:  * Lesser General Public License for more details.
yading@10:  *
yading@10:  * You should have received a copy of the GNU Lesser General Public
yading@10:  * License along with FFmpeg; if not, write to the Free Software
yading@10:  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
yading@10:  */
yading@10: 
yading@10: /**
yading@10:  * @file
yading@10:  * Electronic Arts TGV Video Decoder
yading@10:  * by Peter Ross (pross@xvid.org)
yading@10:  *
yading@10:  * Technical details here:
yading@10:  * http://wiki.multimedia.cx/index.php?title=Electronic_Arts_TGV
yading@10:  */
yading@10: 
yading@10: #include "avcodec.h"
yading@10: #define BITSTREAM_READER_LE
yading@10: #include "get_bits.h"
yading@10: #include "internal.h"
yading@10: #include "libavutil/imgutils.h"
yading@10: #include "libavutil/mem.h"
yading@10: 
yading@10: #define EA_PREAMBLE_SIZE    8
yading@10: #define kVGT_TAG MKTAG('k', 'V', 'G', 'T')
yading@10: 
yading@10: typedef struct TgvContext {
yading@10:     AVCodecContext *avctx;
yading@10:     AVFrame last_frame;
yading@10:     uint8_t *frame_buffer;
yading@10:     int width,height;
yading@10:     uint32_t palette[AVPALETTE_COUNT];
yading@10: 
yading@10:     int (*mv_codebook)[2];
yading@10:     uint8_t (*block_codebook)[16];
yading@10:     int num_mvs;           ///< current length of mv_codebook
yading@10:     int num_blocks_packed; ///< current length of block_codebook
yading@10: } TgvContext;
yading@10: 
yading@10: static av_cold int tgv_decode_init(AVCodecContext *avctx)
yading@10: {
yading@10:     TgvContext *s = avctx->priv_data;
yading@10:     s->avctx         = avctx;
yading@10:     avctx->time_base = (AVRational){1, 15};
yading@10:     avctx->pix_fmt   = AV_PIX_FMT_PAL8;
yading@10:     avcodec_get_frame_defaults(&s->last_frame);
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: /**
yading@10:  * Unpack buffer
yading@10:  * @return 0 on success, -1 on critical buffer underflow
yading@10:  */
yading@10: static int unpack(const uint8_t *src, const uint8_t *src_end,
yading@10:                   uint8_t *dst, int width, int height)
yading@10: {
yading@10:     uint8_t *dst_end = dst + width*height;
yading@10:     int size, size1, size2, offset, run;
yading@10:     uint8_t *dst_start = dst;
yading@10: 
yading@10:     if (src[0] & 0x01)
yading@10:         src += 5;
yading@10:     else
yading@10:         src += 2;
yading@10: 
yading@10:     if (src_end - src < 3)
yading@10:         return AVERROR_INVALIDDATA;
yading@10:     size = AV_RB24(src);
yading@10:     src += 3;
yading@10: 
yading@10:     while (size > 0 && src < src_end) {
yading@10: 
yading@10:         /* determine size1 and size2 */
yading@10:         size1 = (src[0] & 3);
yading@10:         if (src[0] & 0x80) {  // 1
yading@10:             if (src[0] & 0x40 ) {  // 11
yading@10:                 if (src[0] & 0x20) {  // 111
yading@10:                     if (src[0] < 0xFC)  // !(111111)
yading@10:                         size1 = (((src[0] & 31) + 1) << 2);
yading@10:                     src++;
yading@10:                     size2 = 0;
yading@10:                 } else {  // 110
yading@10:                     offset = ((src[0] & 0x10) << 12) + AV_RB16(&src[1]) + 1;
yading@10:                     size2  = ((src[0] & 0xC) << 6) + src[3] + 5;
yading@10:                     src   += 4;
yading@10:                 }
yading@10:             } else {  // 10
yading@10:                 size1  = ((src[1] & 0xC0) >> 6);
yading@10:                 offset = (AV_RB16(&src[1]) & 0x3FFF) + 1;
yading@10:                 size2  = (src[0] & 0x3F) + 4;
yading@10:                 src   += 3;
yading@10:             }
yading@10:         } else {  // 0
yading@10:             offset = ((src[0] & 0x60) << 3) + src[1] + 1;
yading@10:             size2  = ((src[0] & 0x1C) >> 2) + 3;
yading@10:             src   += 2;
yading@10:         }
yading@10: 
yading@10: 
yading@10:         /* fetch strip from src */
yading@10:         if (size1 > src_end - src)
yading@10:             break;
yading@10: 
yading@10:         if (size1 > 0) {
yading@10:             size -= size1;
yading@10:             run   = FFMIN(size1, dst_end - dst);
yading@10:             memcpy(dst, src, run);
yading@10:             dst += run;
yading@10:             src += run;
yading@10:         }
yading@10: 
yading@10:         if (size2 > 0) {
yading@10:             if (dst - dst_start < offset)
yading@10:                 return 0;
yading@10:             size -= size2;
yading@10:             run   = FFMIN(size2, dst_end - dst);
yading@10:             av_memcpy_backptr(dst, offset, run);
yading@10:             dst += run;
yading@10:         }
yading@10:     }
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: /**
yading@10:  * Decode inter-frame
yading@10:  * @return 0 on success, -1 on critical buffer underflow
yading@10:  */
yading@10: static int tgv_decode_inter(TgvContext *s, AVFrame *frame,
yading@10:                             const uint8_t *buf, const uint8_t *buf_end)
yading@10: {
yading@10:     int num_mvs;
yading@10:     int num_blocks_raw;
yading@10:     int num_blocks_packed;
yading@10:     int vector_bits;
yading@10:     int i,j,x,y;
yading@10:     GetBitContext gb;
yading@10:     int mvbits;
yading@10:     const uint8_t *blocks_raw;
yading@10: 
yading@10:     if(buf_end - buf < 12)
yading@10:         return AVERROR_INVALIDDATA;
yading@10: 
yading@10:     num_mvs           = AV_RL16(&buf[0]);
yading@10:     num_blocks_raw    = AV_RL16(&buf[2]);
yading@10:     num_blocks_packed = AV_RL16(&buf[4]);
yading@10:     vector_bits       = AV_RL16(&buf[6]);
yading@10:     buf += 12;
yading@10: 
yading@10:     if (vector_bits > MIN_CACHE_BITS || !vector_bits) {
yading@10:         av_log(s->avctx, AV_LOG_ERROR,
yading@10:                "Invalid value for motion vector bits: %d\n", vector_bits);
yading@10:         return AVERROR_INVALIDDATA;
yading@10:     }
yading@10: 
yading@10:     /* allocate codebook buffers as necessary */
yading@10:     if (num_mvs > s->num_mvs) {
yading@10:         s->mv_codebook = av_realloc(s->mv_codebook, num_mvs*2*sizeof(int));
yading@10:         s->num_mvs = num_mvs;
yading@10:     }
yading@10: 
yading@10:     if (num_blocks_packed > s->num_blocks_packed) {
yading@10:         s->block_codebook = av_realloc(s->block_codebook, num_blocks_packed*16);
yading@10:         s->num_blocks_packed = num_blocks_packed;
yading@10:     }
yading@10: 
yading@10:     /* read motion vectors */
yading@10:     mvbits = (num_mvs * 2 * 10 + 31) & ~31;
yading@10: 
yading@10:     if (buf_end - buf < (mvbits>>3) + 16*num_blocks_raw + 8*num_blocks_packed)
yading@10:         return AVERROR_INVALIDDATA;
yading@10: 
yading@10:     init_get_bits(&gb, buf, mvbits);
yading@10:     for (i = 0; i < num_mvs; i++) {
yading@10:         s->mv_codebook[i][0] = get_sbits(&gb, 10);
yading@10:         s->mv_codebook[i][1] = get_sbits(&gb, 10);
yading@10:     }
yading@10:     buf += mvbits >> 3;
yading@10: 
yading@10:     /* note ptr to uncompressed blocks */
yading@10:     blocks_raw = buf;
yading@10:     buf       += num_blocks_raw * 16;
yading@10: 
yading@10:     /* read compressed blocks */
yading@10:     init_get_bits(&gb, buf, (buf_end - buf) << 3);
yading@10:     for (i = 0; i < num_blocks_packed; i++) {
yading@10:         int tmp[4];
yading@10:         for (j = 0; j < 4; j++)
yading@10:             tmp[j] = get_bits(&gb, 8);
yading@10:         for (j = 0; j < 16; j++)
yading@10:             s->block_codebook[i][15-j] = tmp[get_bits(&gb, 2)];
yading@10:     }
yading@10: 
yading@10:     if (get_bits_left(&gb) < vector_bits *
yading@10:         (s->avctx->height / 4) * (s->avctx->width / 4))
yading@10:         return AVERROR_INVALIDDATA;
yading@10: 
yading@10:     /* read vectors and build frame */
yading@10:     for (y = 0; y < s->avctx->height / 4; y++)
yading@10:         for (x = 0; x < s->avctx->width / 4; x++) {
yading@10:             unsigned int vector = get_bits(&gb, vector_bits);
yading@10:             const uint8_t *src;
yading@10:             int src_stride;
yading@10: 
yading@10:             if (vector < num_mvs) {
yading@10:                 int mx = x * 4 + s->mv_codebook[vector][0];
yading@10:                 int my = y * 4 + s->mv_codebook[vector][1];
yading@10: 
yading@10:                 if (mx < 0 || mx + 4 > s->avctx->width ||
yading@10:                     my < 0 || my + 4 > s->avctx->height) {
yading@10:                     av_log(s->avctx, AV_LOG_ERROR, "MV %d %d out of picture\n", mx, my);
yading@10:                     continue;
yading@10:                 }
yading@10: 
yading@10:                 src = s->last_frame.data[0] + mx + my * s->last_frame.linesize[0];
yading@10:                 src_stride = s->last_frame.linesize[0];
yading@10:             } else {
yading@10:                 int offset = vector - num_mvs;
yading@10:                 if (offset < num_blocks_raw)
yading@10:                     src = blocks_raw + 16*offset;
yading@10:                 else if (offset - num_blocks_raw < num_blocks_packed)
yading@10:                     src = s->block_codebook[offset - num_blocks_raw];
yading@10:                 else
yading@10:                     continue;
yading@10:                 src_stride = 4;
yading@10:             }
yading@10: 
yading@10:             for (j = 0; j < 4; j++)
yading@10:                 for (i = 0; i < 4; i++)
yading@10:                     frame->data[0][(y * 4 + j) * frame->linesize[0] + (x * 4 + i)] =
yading@10:                         src[j * src_stride + i];
yading@10:     }
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static int tgv_decode_frame(AVCodecContext *avctx,
yading@10:                             void *data, int *got_frame,
yading@10:                             AVPacket *avpkt)
yading@10: {
yading@10:     const uint8_t *buf     = avpkt->data;
yading@10:     int buf_size           = avpkt->size;
yading@10:     TgvContext *s          = avctx->priv_data;
yading@10:     const uint8_t *buf_end = buf + buf_size;
yading@10:     AVFrame *frame         = data;
yading@10:     int chunk_type, ret;
yading@10: 
yading@10:     if (buf_end - buf < EA_PREAMBLE_SIZE)
yading@10:         return AVERROR_INVALIDDATA;
yading@10: 
yading@10:     chunk_type = AV_RL32(&buf[0]);
yading@10:     buf       += EA_PREAMBLE_SIZE;
yading@10: 
yading@10:     if (chunk_type == kVGT_TAG) {
yading@10:         int pal_count, i;
yading@10:         if(buf_end - buf < 12) {
yading@10:             av_log(avctx, AV_LOG_WARNING, "truncated header\n");
yading@10:             return AVERROR_INVALIDDATA;
yading@10:         }
yading@10: 
yading@10:         s->width  = AV_RL16(&buf[0]);
yading@10:         s->height = AV_RL16(&buf[2]);
yading@10:         if (s->avctx->width != s->width || s->avctx->height != s->height) {
yading@10:             avcodec_set_dimensions(s->avctx, s->width, s->height);
yading@10:             av_freep(&s->frame_buffer);
yading@10:             av_frame_unref(&s->last_frame);
yading@10:         }
yading@10: 
yading@10:         pal_count = AV_RL16(&buf[6]);
yading@10:         buf += 12;
yading@10:         for(i = 0; i < pal_count && i < AVPALETTE_COUNT && buf_end - buf >= 3; i++) {
yading@10:             s->palette[i] = 0xFFU << 24 | AV_RB24(buf);
yading@10:             buf += 3;
yading@10:         }
yading@10:     }
yading@10: 
yading@10:     if ((ret = av_image_check_size(s->width, s->height, 0, avctx)) < 0)
yading@10:         return ret;
yading@10: 
yading@10:     if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
yading@10:         return ret;
yading@10: 
yading@10:     memcpy(frame->data[1], s->palette, AVPALETTE_SIZE);
yading@10: 
yading@10:     if (chunk_type == kVGT_TAG) {
yading@10:         int y;
yading@10:         frame->key_frame = 1;
yading@10:         frame->pict_type = AV_PICTURE_TYPE_I;
yading@10: 
yading@10:         if (!s->frame_buffer &&
yading@10:             !(s->frame_buffer = av_malloc(s->width * s->height)))
yading@10:             return AVERROR(ENOMEM);
yading@10: 
yading@10:         if (unpack(buf, buf_end, s->frame_buffer, s->avctx->width, s->avctx->height) < 0) {
yading@10:             av_log(avctx, AV_LOG_WARNING, "truncated intra frame\n");
yading@10:             return AVERROR_INVALIDDATA;
yading@10:         }
yading@10:         for (y = 0; y < s->height; y++)
yading@10:             memcpy(frame->data[0]  + y * frame->linesize[0],
yading@10:                    s->frame_buffer + y * s->width,
yading@10:                    s->width);
yading@10:     } else {
yading@10:         if (!s->last_frame.data[0]) {
yading@10:             av_log(avctx, AV_LOG_WARNING, "inter frame without corresponding intra frame\n");
yading@10:             return buf_size;
yading@10:         }
yading@10:         frame->key_frame = 0;
yading@10:         frame->pict_type = AV_PICTURE_TYPE_P;
yading@10:         if (tgv_decode_inter(s, frame, buf, buf_end) < 0) {
yading@10:             av_log(avctx, AV_LOG_WARNING, "truncated inter frame\n");
yading@10:             return AVERROR_INVALIDDATA;
yading@10:         }
yading@10:     }
yading@10: 
yading@10:     av_frame_unref(&s->last_frame);
yading@10:     if ((ret = av_frame_ref(&s->last_frame, frame)) < 0)
yading@10:         return ret;
yading@10: 
yading@10:     *got_frame = 1;
yading@10: 
yading@10:     return buf_size;
yading@10: }
yading@10: 
yading@10: static av_cold int tgv_decode_end(AVCodecContext *avctx)
yading@10: {
yading@10:     TgvContext *s = avctx->priv_data;
yading@10:     av_frame_unref(&s->last_frame);
yading@10:     av_freep(&s->frame_buffer);
yading@10:     av_free(s->mv_codebook);
yading@10:     av_free(s->block_codebook);
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: AVCodec ff_eatgv_decoder = {
yading@10:     .name           = "eatgv",
yading@10:     .type           = AVMEDIA_TYPE_VIDEO,
yading@10:     .id             = AV_CODEC_ID_TGV,
yading@10:     .priv_data_size = sizeof(TgvContext),
yading@10:     .init           = tgv_decode_init,
yading@10:     .close          = tgv_decode_end,
yading@10:     .decode         = tgv_decode_frame,
yading@10:     .long_name      = NULL_IF_CONFIG_SMALL("Electronic Arts TGV video"),
yading@10:     .capabilities   = CODEC_CAP_DR1,
yading@10: };