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ffmpeg/libavcodec/eatgv.c

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/*
* 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
* Electronic Arts TGV Video Decoder
* by Peter Ross (pross@xvid.org)
*
* Technical details here:
* http://wiki.multimedia.cx/index.php?title=Electronic_Arts_TGV
*/
#include "libavutil/imgutils.h"
#include "libavutil/mem.h"
#define BITSTREAM_READER_LE
#include "avcodec.h"
#include "get_bits.h"
#include "codec_internal.h"
#include "internal.h"
#define EA_PREAMBLE_SIZE 8
#define kVGT_TAG MKTAG('k', 'V', 'G', 'T')
typedef struct TgvContext {
AVCodecContext *avctx;
AVFrame *last_frame;
uint8_t *frame_buffer;
int width,height;
uint32_t palette[AVPALETTE_COUNT];
int (*mv_codebook)[2];
uint8_t (*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->framerate = (AVRational){ 15, 1 };
avctx->pix_fmt = AV_PIX_FMT_PAL8;
s->last_frame = av_frame_alloc();
if (!s->last_frame)
return AVERROR(ENOMEM);
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,
uint8_t *dst, int width, int height)
{
uint8_t *dst_end = dst + width*height;
int size, size1, size2, offset, run;
uint8_t *dst_start = dst;
if (src[0] & 0x01)
src += 5;
else
src += 2;
if (src_end - src < 3)
return AVERROR_INVALIDDATA;
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, AVFrame *frame,
const uint8_t *buf, const uint8_t *buf_end)
{
int num_mvs;
int num_blocks_raw;
int num_blocks_packed;
int vector_bits;
int i,j,x,y;
GetBitContext gb;
int mvbits;
const uint8_t *blocks_raw;
if(buf_end - buf < 12)
return AVERROR_INVALIDDATA;
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;
if (vector_bits > MIN_CACHE_BITS || !vector_bits) {
av_log(s->avctx, AV_LOG_ERROR,
"Invalid value for motion vector bits: %d\n", vector_bits);
return AVERROR_INVALIDDATA;
}
/* allocate codebook buffers as necessary */
if (num_mvs > s->num_mvs) {
int err = av_reallocp_array(&s->mv_codebook, num_mvs, sizeof(*s->mv_codebook));
if (err < 0) {
s->num_mvs = 0;
return err;
}
s->num_mvs = num_mvs;
}
if (num_blocks_packed > s->num_blocks_packed) {
int err;
if ((err = av_reallocp(&s->block_codebook, num_blocks_packed * 16)) < 0) {
s->num_blocks_packed = 0;
return err;
}
s->num_blocks_packed = num_blocks_packed;
}
/* read motion vectors */
mvbits = (num_mvs * 2 * 10 + 31) & ~31;
if (buf_end - buf < (mvbits>>3) + 16*num_blocks_raw + 8*num_blocks_packed)
return AVERROR_INVALIDDATA;
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)];
}
if (get_bits_left(&gb) < vector_bits *
(s->avctx->height / 4) * (s->avctx->width / 4))
return AVERROR_INVALIDDATA;
/* 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 uint8_t *src;
ptrdiff_t src_stride;
if (vector < num_mvs) {
int mx = x * 4 + s->mv_codebook[vector][0];
int my = y * 4 + s->mv_codebook[vector][1];
if (mx < 0 || mx + 4 > s->avctx->width ||
my < 0 || my + 4 > s->avctx->height) {
av_log(s->avctx, AV_LOG_ERROR, "MV %d %d out of picture\n", mx, my);
continue;
}
src = s->last_frame->data[0] + mx + my * s->last_frame->linesize[0];
src_stride = s->last_frame->linesize[0];
} 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++)
frame->data[0][(y * 4 + j) * frame->linesize[0] + (x * 4 + i)] =
src[j * src_stride + i];
}
return 0;
}
static int tgv_decode_frame(AVCodecContext *avctx, AVFrame *frame,
int *got_frame, AVPacket *avpkt)
{
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
TgvContext *s = avctx->priv_data;
const uint8_t *buf_end = buf + buf_size;
int chunk_type, ret;
if (buf_end - buf < EA_PREAMBLE_SIZE)
return AVERROR_INVALIDDATA;
chunk_type = AV_RL32(&buf[0]);
buf += EA_PREAMBLE_SIZE;
if (chunk_type == kVGT_TAG) {
int pal_count, i;
if(buf_end - buf < 12) {
av_log(avctx, AV_LOG_WARNING, "truncated header\n");
return AVERROR_INVALIDDATA;
}
s->width = AV_RL16(&buf[0]);
s->height = AV_RL16(&buf[2]);
if (s->avctx->width != s->width || s->avctx->height != s->height) {
av_freep(&s->frame_buffer);
av_frame_unref(s->last_frame);
if ((ret = ff_set_dimensions(s->avctx, s->width, s->height)) < 0)
return ret;
}
pal_count = AV_RL16(&buf[6]);
buf += 12;
for(i = 0; i < pal_count && i < AVPALETTE_COUNT && buf_end - buf >= 3; i++) {
s->palette[i] = 0xFFU << 24 | AV_RB24(buf);
buf += 3;
}
if (buf_end - buf < 5) {
return AVERROR_INVALIDDATA;
}
}
if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
return ret;
memcpy(frame->data[1], s->palette, AVPALETTE_SIZE);
if (chunk_type == kVGT_TAG) {
int y;
frame->key_frame = 1;
frame->pict_type = AV_PICTURE_TYPE_I;
if (!s->frame_buffer &&
!(s->frame_buffer = av_mallocz(s->width * s->height)))
return AVERROR(ENOMEM);
if (unpack(buf, buf_end, s->frame_buffer, s->avctx->width, s->avctx->height) < 0) {
av_log(avctx, AV_LOG_WARNING, "truncated intra frame\n");
return AVERROR_INVALIDDATA;
}
for (y = 0; y < s->height; y++)
memcpy(frame->data[0] + y * frame->linesize[0],
s->frame_buffer + y * s->width,
s->width);
} else {
if (!s->last_frame->data[0]) {
av_log(avctx, AV_LOG_WARNING, "inter frame without corresponding intra frame\n");
return buf_size;
}
frame->key_frame = 0;
frame->pict_type = AV_PICTURE_TYPE_P;
if (tgv_decode_inter(s, frame, buf, buf_end) < 0) {
av_log(avctx, AV_LOG_WARNING, "truncated inter frame\n");
return AVERROR_INVALIDDATA;
}
}
av_frame_unref(s->last_frame);
if ((ret = av_frame_ref(s->last_frame, frame)) < 0)
return ret;
*got_frame = 1;
return buf_size;
}
static av_cold int tgv_decode_end(AVCodecContext *avctx)
{
TgvContext *s = avctx->priv_data;
av_frame_free(&s->last_frame);
av_freep(&s->frame_buffer);
av_freep(&s->mv_codebook);
av_freep(&s->block_codebook);
return 0;
}
const FFCodec ff_eatgv_decoder = {
.p.name = "eatgv",
.p.long_name = NULL_IF_CONFIG_SMALL("Electronic Arts TGV video"),
.p.type = AVMEDIA_TYPE_VIDEO,
.p.id = AV_CODEC_ID_TGV,
.priv_data_size = sizeof(TgvContext),
.init = tgv_decode_init,
.close = tgv_decode_end,
FF_CODEC_DECODE_CB(tgv_decode_frame),
.p.capabilities = AV_CODEC_CAP_DR1,
.caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
};
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