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ffmpeg/libavcodec/mdec.c

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/*
* Sony PlayStation MDEC (Motion DECoder)
* Copyright (c) 2003 Michael Niedermayer
*
* based upon code from Sebastian Jedruszkiewicz <elf@frogger.rules.pl>
*
* 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 Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* Sony PlayStation MDEC (Motion DECoder)
* This is very similar to intra-only MPEG-1.
*/
#include "avcodec.h"
#include "dsputil.h"
#include "mpegvideo.h"
#include "mpeg12.h"
#include "thread.h"
typedef struct MDECContext{
AVCodecContext *avctx;
DSPContext dsp;
AVFrame picture;
GetBitContext gb;
ScanTable scantable;
int version;
int qscale;
int last_dc[3];
int mb_width;
int mb_height;
int mb_x, mb_y;
DECLARE_ALIGNED(16, DCTELEM, block)[6][64];
uint8_t *bitstream_buffer;
unsigned int bitstream_buffer_size;
int block_last_index[6];
} MDECContext;
//very similar to MPEG-1
static inline int mdec_decode_block_intra(MDECContext *a, DCTELEM *block, int n)
{
int level, diff, i, j, run;
int component;
RLTable *rl = &ff_rl_mpeg1;
uint8_t * const scantable= a->scantable.permutated;
const uint16_t *quant_matrix= ff_mpeg1_default_intra_matrix;
const int qscale= a->qscale;
/* DC coefficient */
if(a->version==2){
block[0]= 2*get_sbits(&a->gb, 10) + 1024;
}else{
component = (n <= 3 ? 0 : n - 4 + 1);
diff = decode_dc(&a->gb, component);
if (diff >= 0xffff)
return -1;
a->last_dc[component]+= diff;
block[0] = a->last_dc[component]<<3;
}
i = 0;
{
OPEN_READER(re, &a->gb);
/* now quantify & encode AC coefficients */
for(;;) {
UPDATE_CACHE(re, &a->gb);
GET_RL_VLC(level, run, re, &a->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*qscale*quant_matrix[j])>>3;
level = (level ^ SHOW_SBITS(re, &a->gb, 1)) - SHOW_SBITS(re, &a->gb, 1);
LAST_SKIP_BITS(re, &a->gb, 1);
} else {
/* escape */
run = SHOW_UBITS(re, &a->gb, 6)+1; LAST_SKIP_BITS(re, &a->gb, 6);
UPDATE_CACHE(re, &a->gb);
level = SHOW_SBITS(re, &a->gb, 10); SKIP_BITS(re, &a->gb, 10);
i += run;
j = scantable[i];
if(level<0){
level= -level;
level= (level*qscale*quant_matrix[j])>>3;
level= (level-1)|1;
level= -level;
}else{
level= (level*qscale*quant_matrix[j])>>3;
level= (level-1)|1;
}
}
if (i > 63){
av_log(a->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", a->mb_x, a->mb_y);
return -1;
}
block[j] = level;
}
CLOSE_READER(re, &a->gb);
}
a->block_last_index[n] = i;
return 0;
}
static inline int decode_mb(MDECContext *a, DCTELEM block[6][64]){
int i;
const int block_index[6]= {5,4,0,1,2,3};
a->dsp.clear_blocks(block[0]);
for(i=0; i<6; i++){
if( mdec_decode_block_intra(a, block[ block_index[i] ], block_index[i]) < 0 ||
get_bits_left(&a->gb) < 0)
return -1;
}
return 0;
}
static inline void idct_put(MDECContext *a, int mb_x, int mb_y){
DCTELEM (*block)[64]= a->block;
int linesize= a->picture.linesize[0];
uint8_t *dest_y = a->picture.data[0] + (mb_y * 16* linesize ) + mb_x * 16;
uint8_t *dest_cb = a->picture.data[1] + (mb_y * 8 * a->picture.linesize[1]) + mb_x * 8;
uint8_t *dest_cr = a->picture.data[2] + (mb_y * 8 * a->picture.linesize[2]) + mb_x * 8;
a->dsp.idct_put(dest_y , linesize, block[0]);
a->dsp.idct_put(dest_y + 8, linesize, block[1]);
a->dsp.idct_put(dest_y + 8*linesize , linesize, block[2]);
a->dsp.idct_put(dest_y + 8*linesize + 8, linesize, block[3]);
if(!(a->avctx->flags&CODEC_FLAG_GRAY)){
a->dsp.idct_put(dest_cb, a->picture.linesize[1], block[4]);
a->dsp.idct_put(dest_cr, a->picture.linesize[2], block[5]);
}
}
static int decode_frame(AVCodecContext *avctx,
void *data, int *data_size,
AVPacket *avpkt)
{
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
MDECContext * const a = avctx->priv_data;
AVFrame *picture = data;
AVFrame * const p= &a->picture;
int i;
if(p->data[0])
ff_thread_release_buffer(avctx, p);
p->reference= 0;
if(ff_thread_get_buffer(avctx, p) < 0){
av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
return -1;
}
p->pict_type= AV_PICTURE_TYPE_I;
p->key_frame= 1;
av_fast_malloc(&a->bitstream_buffer, &a->bitstream_buffer_size, buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
if (!a->bitstream_buffer)
return AVERROR(ENOMEM);
for(i=0; i<buf_size; i+=2){
a->bitstream_buffer[i] = buf[i+1];
a->bitstream_buffer[i+1]= buf[i ];
}
init_get_bits(&a->gb, a->bitstream_buffer, buf_size*8);
/* skip over 4 preamble bytes in stream (typically 0xXX 0xXX 0x00 0x38) */
skip_bits(&a->gb, 32);
a->qscale= get_bits(&a->gb, 16);
a->version= get_bits(&a->gb, 16);
a->last_dc[0]=
a->last_dc[1]=
a->last_dc[2]= 128;
for(a->mb_x=0; a->mb_x<a->mb_width; a->mb_x++){
for(a->mb_y=0; a->mb_y<a->mb_height; a->mb_y++){
if( decode_mb(a, a->block) <0)
return -1;
idct_put(a, a->mb_x, a->mb_y);
}
}
p->quality= a->qscale * FF_QP2LAMBDA;
memset(p->qscale_table, a->qscale, a->mb_width);
*picture = a->picture;
*data_size = sizeof(AVPicture);
return (get_bits_count(&a->gb)+31)/32*4;
}
static av_cold void mdec_common_init(AVCodecContext *avctx){
MDECContext * const a = avctx->priv_data;
ff_dsputil_init(&a->dsp, avctx);
a->mb_width = (avctx->coded_width + 15) / 16;
a->mb_height = (avctx->coded_height + 15) / 16;
avcodec_get_frame_defaults(&a->picture);
avctx->coded_frame= &a->picture;
a->avctx= avctx;
}
static av_cold int decode_init(AVCodecContext *avctx){
MDECContext * const a = avctx->priv_data;
AVFrame *p= &a->picture;
mdec_common_init(avctx);
ff_mpeg12_init_vlcs();
ff_init_scantable(a->dsp.idct_permutation, &a->scantable, ff_zigzag_direct);
if( avctx->idct_algo == FF_IDCT_AUTO )
avctx->idct_algo = FF_IDCT_SIMPLE;
p->qstride= 0;
p->qscale_table= av_mallocz(a->mb_width);
avctx->pix_fmt= PIX_FMT_YUVJ420P;
return 0;
}
static av_cold int decode_init_thread_copy(AVCodecContext *avctx){
MDECContext * const a = avctx->priv_data;
AVFrame *p = &a->picture;
avctx->coded_frame= p;
a->avctx= avctx;
p->qscale_table= av_mallocz(a->mb_width);
return 0;
}
static av_cold int decode_end(AVCodecContext *avctx){
MDECContext * const a = avctx->priv_data;
if(a->picture.data[0])
avctx->release_buffer(avctx, &a->picture);
av_freep(&a->bitstream_buffer);
av_freep(&a->picture.qscale_table);
a->bitstream_buffer_size=0;
return 0;
}
AVCodec ff_mdec_decoder = {
.name = "mdec",
.type = AVMEDIA_TYPE_VIDEO,
.id = CODEC_ID_MDEC,
.priv_data_size = sizeof(MDECContext),
.init = decode_init,
.close = decode_end,
.decode = decode_frame,
.capabilities = CODEC_CAP_DR1 | CODEC_CAP_FRAME_THREADS,
.long_name = NULL_IF_CONFIG_SMALL("Sony PlayStation MDEC (Motion DECoder)"),
.init_thread_copy = ONLY_IF_THREADS_ENABLED(decode_init_thread_copy)
};
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