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ffmpeg/libavcodec/eatgq.c

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/*
* Electronic Arts TGQ Video Decoder
* Copyright (c) 2007-2008 Peter Ross <pross@xvid.org>
*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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 Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* Electronic Arts TGQ Video Decoder
* @author Peter Ross <pross@xvid.org>
*
* Technical details here:
* http://wiki.multimedia.cx/index.php?title=Electronic_Arts_TGQ
*/
#include "avcodec.h"
#define BITSTREAM_READER_LE
#include "get_bits.h"
#include "bytestream.h"
#include "dsputil.h"
#include "aandcttab.h"
typedef struct TgqContext {
AVCodecContext *avctx;
DSPContext dsp;
AVFrame frame;
int width,height;
ScanTable scantable;
int qtable[64];
DECLARE_ALIGNED(16, DCTELEM, block)[6][64];
GetByteContext gb;
} TgqContext;
static av_cold int tgq_decode_init(AVCodecContext *avctx){
TgqContext *s = avctx->priv_data;
s->avctx = avctx;
if(avctx->idct_algo==FF_IDCT_AUTO)
avctx->idct_algo=FF_IDCT_EA;
ff_dsputil_init(&s->dsp, avctx);
ff_init_scantable(s->dsp.idct_permutation, &s->scantable, ff_zigzag_direct);
avctx->time_base = (AVRational){1, 15};
avctx->pix_fmt = PIX_FMT_YUV420P;
return 0;
}
static void tgq_decode_block(TgqContext *s, DCTELEM block[64], GetBitContext *gb){
uint8_t *perm = s->scantable.permutated;
int i,j,value;
block[0] = get_sbits(gb,8) * s->qtable[0];
for(i=1; i<64; ) {
switch(show_bits(gb,3)) {
case 4:
block[perm[i++]] = 0;
case 0:
block[perm[i++]] = 0;
skip_bits(gb,3);
break;
case 5:
case 1:
skip_bits(gb,2);
value = get_bits(gb,6);
for(j=0; j<value; j++)
block[perm[i++]] = 0;
break;
case 6:
skip_bits(gb,3);
block[perm[i]] = -s->qtable[perm[i]];
i++;
break;
case 2:
skip_bits(gb,3);
block[perm[i]] = s->qtable[perm[i]];
i++;
break;
case 7: // 111b
case 3: // 011b
skip_bits(gb,2);
if (show_bits(gb,6)==0x3F) {
skip_bits(gb, 6);
block[perm[i]] = get_sbits(gb,8)*s->qtable[perm[i]];
}else{
block[perm[i]] = get_sbits(gb,6)*s->qtable[perm[i]];
}
i++;
break;
}
}
block[0] += 128<<4;
}
static void tgq_idct_put_mb(TgqContext *s, DCTELEM (*block)[64], int mb_x, int mb_y){
int linesize= s->frame.linesize[0];
uint8_t *dest_y = s->frame.data[0] + (mb_y * 16* linesize ) + mb_x * 16;
uint8_t *dest_cb = s->frame.data[1] + (mb_y * 8 * s->frame.linesize[1]) + mb_x * 8;
uint8_t *dest_cr = s->frame.data[2] + (mb_y * 8 * s->frame.linesize[2]) + mb_x * 8;
s->dsp.idct_put(dest_y , linesize, block[0]);
s->dsp.idct_put(dest_y + 8, linesize, block[1]);
s->dsp.idct_put(dest_y + 8*linesize , linesize, block[2]);
s->dsp.idct_put(dest_y + 8*linesize + 8, linesize, block[3]);
if(!(s->avctx->flags&CODEC_FLAG_GRAY)){
s->dsp.idct_put(dest_cb, s->frame.linesize[1], block[4]);
s->dsp.idct_put(dest_cr, s->frame.linesize[2], block[5]);
}
}
static inline void tgq_dconly(TgqContext *s, unsigned char *dst, int dst_stride, int dc){
int level = av_clip_uint8((dc*s->qtable[0] + 2056)>>4);
int j;
for(j=0;j<8;j++)
memset(dst+j*dst_stride, level, 8);
}
static void tgq_idct_put_mb_dconly(TgqContext *s, int mb_x, int mb_y, const int8_t *dc)
{
int linesize= s->frame.linesize[0];
uint8_t *dest_y = s->frame.data[0] + (mb_y * 16* linesize ) + mb_x * 16;
uint8_t *dest_cb = s->frame.data[1] + (mb_y * 8 * s->frame.linesize[1]) + mb_x * 8;
uint8_t *dest_cr = s->frame.data[2] + (mb_y * 8 * s->frame.linesize[2]) + mb_x * 8;
tgq_dconly(s,dest_y , linesize, dc[0]);
tgq_dconly(s,dest_y + 8, linesize, dc[1]);
tgq_dconly(s,dest_y + 8*linesize , linesize, dc[2]);
tgq_dconly(s,dest_y + 8*linesize + 8, linesize, dc[3]);
if(!(s->avctx->flags&CODEC_FLAG_GRAY)) {
tgq_dconly(s,dest_cb, s->frame.linesize[1], dc[4]);
tgq_dconly(s,dest_cr, s->frame.linesize[2], dc[5]);
}
}
static void tgq_decode_mb(TgqContext *s, int mb_y, int mb_x){
int mode;
int i;
int8_t dc[6];
mode = bytestream2_get_byte(&s->gb);
if (mode>12) {
GetBitContext gb;
init_get_bits(&gb, s->gb.buffer, FFMIN(s->gb.buffer_end - s->gb.buffer, mode) * 8);
for(i=0; i<6; i++)
tgq_decode_block(s, s->block[i], &gb);
tgq_idct_put_mb(s, s->block, mb_x, mb_y);
bytestream2_skip(&s->gb, mode);
}else{
if (mode==3) {
memset(dc, bytestream2_get_byte(&s->gb), 4);
dc[4] = bytestream2_get_byte(&s->gb);
dc[5] = bytestream2_get_byte(&s->gb);
}else if (mode==6) {
bytestream2_get_buffer(&s->gb, dc, 6);
}else if (mode==12) {
for (i = 0; i < 6; i++) {
dc[i] = bytestream2_get_byte(&s->gb);
bytestream2_skip(&s->gb, 1);
}
}else{
av_log(s->avctx, AV_LOG_ERROR, "unsupported mb mode %i\n", mode);
}
tgq_idct_put_mb_dconly(s, mb_x, mb_y, dc);
}
}
static void tgq_calculate_qtable(TgqContext *s, int quant){
int i,j;
const int a = (14*(100-quant))/100 + 1;
const int b = (11*(100-quant))/100 + 4;
for(j=0;j<8;j++)
for(i=0;i<8;i++)
if (s->avctx->idct_algo==FF_IDCT_EA)
s->qtable[j*8+i] = ((a*(j+i)/(7+7) + b)*ff_inv_aanscales[j*8+i])>>(14-4);
else
s->qtable[j*8+i] = (a*(j+i)/(7+7) + b)<<3;
}
static int tgq_decode_frame(AVCodecContext *avctx,
void *data, int *data_size,
AVPacket *avpkt){
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
TgqContext *s = avctx->priv_data;
int x,y;
int big_endian = AV_RL32(&buf[4]) > 0x000FFFFF;
if (buf_size < 16) {
av_log(avctx, AV_LOG_WARNING, "truncated header\n");
return -1;
}
bytestream2_init(&s->gb, buf + 8, buf_size - 8);
if (big_endian) {
s->width = bytestream2_get_be16u(&s->gb);
s->height = bytestream2_get_be16u(&s->gb);
} else {
s->width = bytestream2_get_le16u(&s->gb);
s->height = bytestream2_get_le16u(&s->gb);
}
if (s->avctx->width!=s->width || s->avctx->height!=s->height) {
avcodec_set_dimensions(s->avctx, s->width, s->height);
if (s->frame.data[0])
avctx->release_buffer(avctx, &s->frame);
}
tgq_calculate_qtable(s, bytestream2_get_byteu(&s->gb));
bytestream2_skip(&s->gb, 3);
if (!s->frame.data[0]) {
s->frame.key_frame = 1;
s->frame.pict_type = AV_PICTURE_TYPE_I;
s->frame.buffer_hints = FF_BUFFER_HINTS_VALID;
if (avctx->get_buffer(avctx, &s->frame)) {
av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
return -1;
}
}
for (y = 0; y < FFALIGN(avctx->height, 16) >> 4; y++)
for (x = 0; x < FFALIGN(avctx->width, 16) >> 4; x++)
tgq_decode_mb(s, y, x);
*data_size = sizeof(AVFrame);
*(AVFrame*)data = s->frame;
return avpkt->size;
}
static av_cold int tgq_decode_end(AVCodecContext *avctx){
TgqContext *s = avctx->priv_data;
if (s->frame.data[0])
s->avctx->release_buffer(avctx, &s->frame);
return 0;
}
AVCodec ff_eatgq_decoder = {
.name = "eatgq",
.type = AVMEDIA_TYPE_VIDEO,
.id = CODEC_ID_TGQ,
.priv_data_size = sizeof(TgqContext),
.init = tgq_decode_init,
.close = tgq_decode_end,
.decode = tgq_decode_frame,
.capabilities = CODEC_CAP_DR1,
.long_name = NULL_IF_CONFIG_SMALL("Electronic Arts TGQ video"),
};
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