ffmpeg/libavcodec/h263dec.c

761 lines
25 KiB
C

/*
* H.263 decoder
* Copyright (c) 2001 Fabrice Bellard
* Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
*
* 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
* H.263 decoder.
*/
#define UNCHECKED_BITSTREAM_READER 1
#include "libavutil/cpu.h"
#include "internal.h"
#include "avcodec.h"
#include "dsputil.h"
#include "mpegvideo.h"
#include "h263.h"
#include "h263_parser.h"
#include "mpeg4video_parser.h"
#include "msmpeg4.h"
#include "vdpau_internal.h"
#include "thread.h"
#include "flv.h"
#include "mpeg4video.h"
//#define DEBUG
//#define PRINT_FRAME_TIME
av_cold int ff_h263_decode_init(AVCodecContext *avctx)
{
MpegEncContext *s = avctx->priv_data;
s->avctx = avctx;
s->out_format = FMT_H263;
s->width = avctx->coded_width;
s->height = avctx->coded_height;
s->workaround_bugs= avctx->workaround_bugs;
// set defaults
ff_MPV_decode_defaults(s);
s->quant_precision=5;
s->decode_mb= ff_h263_decode_mb;
s->low_delay= 1;
avctx->pix_fmt= avctx->get_format(avctx, avctx->codec->pix_fmts);
s->unrestricted_mv= 1;
/* select sub codec */
switch(avctx->codec->id) {
case CODEC_ID_H263:
s->unrestricted_mv= 0;
avctx->chroma_sample_location = AVCHROMA_LOC_CENTER;
break;
case CODEC_ID_MPEG4:
break;
case CODEC_ID_MSMPEG4V1:
s->h263_pred = 1;
s->msmpeg4_version=1;
break;
case CODEC_ID_MSMPEG4V2:
s->h263_pred = 1;
s->msmpeg4_version=2;
break;
case CODEC_ID_MSMPEG4V3:
s->h263_pred = 1;
s->msmpeg4_version=3;
break;
case CODEC_ID_WMV1:
s->h263_pred = 1;
s->msmpeg4_version=4;
break;
case CODEC_ID_WMV2:
s->h263_pred = 1;
s->msmpeg4_version=5;
break;
case CODEC_ID_VC1:
case CODEC_ID_WMV3:
case CODEC_ID_VC1IMAGE:
case CODEC_ID_WMV3IMAGE:
s->h263_pred = 1;
s->msmpeg4_version=6;
avctx->chroma_sample_location = AVCHROMA_LOC_LEFT;
break;
case CODEC_ID_H263I:
break;
case CODEC_ID_FLV1:
s->h263_flv = 1;
break;
default:
return -1;
}
s->codec_id= avctx->codec->id;
avctx->hwaccel= ff_find_hwaccel(avctx->codec->id, avctx->pix_fmt);
/* for h263, we allocate the images after having read the header */
if (avctx->codec->id != CODEC_ID_H263 && avctx->codec->id != CODEC_ID_MPEG4)
if (ff_MPV_common_init(s) < 0)
return -1;
ff_h263_decode_init_vlc(s);
return 0;
}
av_cold int ff_h263_decode_end(AVCodecContext *avctx)
{
MpegEncContext *s = avctx->priv_data;
ff_MPV_common_end(s);
return 0;
}
/**
* Return the number of bytes consumed for building the current frame.
*/
static int get_consumed_bytes(MpegEncContext *s, int buf_size){
int pos= (get_bits_count(&s->gb)+7)>>3;
if(s->divx_packed || s->avctx->hwaccel){
//we would have to scan through the whole buf to handle the weird reordering ...
return buf_size;
}else if(s->flags&CODEC_FLAG_TRUNCATED){
pos -= s->parse_context.last_index;
if(pos<0) pos=0; // padding is not really read so this might be -1
return pos;
}else{
if(pos==0) pos=1; //avoid infinite loops (i doubt that is needed but ...)
if(pos+10>buf_size) pos=buf_size; // oops ;)
return pos;
}
}
static int decode_slice(MpegEncContext *s){
const int part_mask= s->partitioned_frame ? (ER_AC_END|ER_AC_ERROR) : 0x7F;
const int mb_size= 16>>s->avctx->lowres;
s->last_resync_gb= s->gb;
s->first_slice_line= 1;
s->resync_mb_x= s->mb_x;
s->resync_mb_y= s->mb_y;
ff_set_qscale(s, s->qscale);
if (s->avctx->hwaccel) {
const uint8_t *start= s->gb.buffer + get_bits_count(&s->gb)/8;
const uint8_t *end = ff_h263_find_resync_marker(start + 1, s->gb.buffer_end);
skip_bits_long(&s->gb, 8*(end - start));
return s->avctx->hwaccel->decode_slice(s->avctx, start, end - start);
}
if(s->partitioned_frame){
const int qscale= s->qscale;
if(CONFIG_MPEG4_DECODER && s->codec_id==CODEC_ID_MPEG4){
if(ff_mpeg4_decode_partitions(s) < 0)
return -1;
}
/* restore variables which were modified */
s->first_slice_line=1;
s->mb_x= s->resync_mb_x;
s->mb_y= s->resync_mb_y;
ff_set_qscale(s, qscale);
}
for(; s->mb_y < s->mb_height; s->mb_y++) {
/* per-row end of slice checks */
if(s->msmpeg4_version){
if(s->resync_mb_y + s->slice_height == s->mb_y){
ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x-1, s->mb_y, ER_MB_END);
return 0;
}
}
if(s->msmpeg4_version==1){
s->last_dc[0]=
s->last_dc[1]=
s->last_dc[2]= 128;
}
ff_init_block_index(s);
for(; s->mb_x < s->mb_width; s->mb_x++) {
int ret;
ff_update_block_index(s);
if(s->resync_mb_x == s->mb_x && s->resync_mb_y+1 == s->mb_y){
s->first_slice_line=0;
}
/* DCT & quantize */
s->mv_dir = MV_DIR_FORWARD;
s->mv_type = MV_TYPE_16X16;
// s->mb_skipped = 0;
//printf("%d %d %06X\n", ret, get_bits_count(&s->gb), show_bits(&s->gb, 24));
ret= s->decode_mb(s, s->block);
if (s->pict_type!=AV_PICTURE_TYPE_B)
ff_h263_update_motion_val(s);
if(ret<0){
const int xy= s->mb_x + s->mb_y*s->mb_stride;
if(ret==SLICE_END){
ff_MPV_decode_mb(s, s->block);
if(s->loop_filter)
ff_h263_loop_filter(s);
//printf("%d %d %d %06X\n", s->mb_x, s->mb_y, s->gb.size*8 - get_bits_count(&s->gb), show_bits(&s->gb, 24));
ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, ER_MB_END&part_mask);
s->padding_bug_score--;
if(++s->mb_x >= s->mb_width){
s->mb_x=0;
ff_draw_horiz_band(s, s->mb_y*mb_size, mb_size);
ff_MPV_report_decode_progress(s);
s->mb_y++;
}
return 0;
}else if(ret==SLICE_NOEND){
av_log(s->avctx, AV_LOG_ERROR, "Slice mismatch at MB: %d\n", xy);
ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x+1, s->mb_y, ER_MB_END&part_mask);
return -1;
}
av_log(s->avctx, AV_LOG_ERROR, "Error at MB: %d\n", xy);
ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, ER_MB_ERROR&part_mask);
return -1;
}
ff_MPV_decode_mb(s, s->block);
if(s->loop_filter)
ff_h263_loop_filter(s);
}
ff_draw_horiz_band(s, s->mb_y*mb_size, mb_size);
ff_MPV_report_decode_progress(s);
s->mb_x= 0;
}
assert(s->mb_x==0 && s->mb_y==s->mb_height);
if(s->codec_id==CODEC_ID_MPEG4
&& (s->workaround_bugs&FF_BUG_AUTODETECT)
&& get_bits_left(&s->gb) >= 48
&& show_bits(&s->gb, 24)==0x4010
&& !s->data_partitioning)
s->padding_bug_score+=32;
/* try to detect the padding bug */
if( s->codec_id==CODEC_ID_MPEG4
&& (s->workaround_bugs&FF_BUG_AUTODETECT)
&& get_bits_left(&s->gb) >=0
&& get_bits_left(&s->gb) < 137
// && !s->resync_marker
&& !s->data_partitioning){
const int bits_count= get_bits_count(&s->gb);
const int bits_left = s->gb.size_in_bits - bits_count;
if(bits_left==0){
s->padding_bug_score+=16;
} else if(bits_left != 1){
int v= show_bits(&s->gb, 8);
v|= 0x7F >> (7-(bits_count&7));
if(v==0x7F && bits_left<=8)
s->padding_bug_score--;
else if(v==0x7F && ((get_bits_count(&s->gb)+8)&8) && bits_left<=16)
s->padding_bug_score+= 4;
else
s->padding_bug_score++;
}
}
if(s->workaround_bugs&FF_BUG_AUTODETECT){
if(s->padding_bug_score > -2 && !s->data_partitioning /*&& (s->divx_version>=0 || !s->resync_marker)*/)
s->workaround_bugs |= FF_BUG_NO_PADDING;
else
s->workaround_bugs &= ~FF_BUG_NO_PADDING;
}
// handle formats which don't have unique end markers
if(s->msmpeg4_version || (s->workaround_bugs&FF_BUG_NO_PADDING)){ //FIXME perhaps solve this more cleanly
int left= get_bits_left(&s->gb);
int max_extra=7;
/* no markers in M$ crap */
if(s->msmpeg4_version && s->pict_type==AV_PICTURE_TYPE_I)
max_extra+= 17;
/* buggy padding but the frame should still end approximately at the bitstream end */
if((s->workaround_bugs&FF_BUG_NO_PADDING) && (s->err_recognition&(AV_EF_BUFFER|AV_EF_AGGRESSIVE)))
max_extra+= 48;
else if((s->workaround_bugs&FF_BUG_NO_PADDING))
max_extra+= 256*256*256*64;
if(left>max_extra){
av_log(s->avctx, AV_LOG_ERROR, "discarding %d junk bits at end, next would be %X\n", left, show_bits(&s->gb, 24));
}
else if(left<0){
av_log(s->avctx, AV_LOG_ERROR, "overreading %d bits\n", -left);
}else
ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x-1, s->mb_y, ER_MB_END);
return 0;
}
av_log(s->avctx, AV_LOG_ERROR, "slice end not reached but screenspace end (%d left %06X, score= %d)\n",
get_bits_left(&s->gb),
show_bits(&s->gb, 24), s->padding_bug_score);
ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, ER_MB_END&part_mask);
return -1;
}
int ff_h263_decode_frame(AVCodecContext *avctx,
void *data, int *data_size,
AVPacket *avpkt)
{
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
MpegEncContext *s = avctx->priv_data;
int ret;
AVFrame *pict = data;
#ifdef PRINT_FRAME_TIME
uint64_t time= rdtsc();
#endif
s->flags= avctx->flags;
s->flags2= avctx->flags2;
/* no supplementary picture */
if (buf_size == 0) {
/* special case for last picture */
if (s->low_delay==0 && s->next_picture_ptr) {
*pict = s->next_picture_ptr->f;
s->next_picture_ptr= NULL;
*data_size = sizeof(AVFrame);
}
return 0;
}
if(s->flags&CODEC_FLAG_TRUNCATED){
int next;
if(CONFIG_MPEG4_DECODER && s->codec_id==CODEC_ID_MPEG4){
next= ff_mpeg4_find_frame_end(&s->parse_context, buf, buf_size);
}else if(CONFIG_H263_DECODER && s->codec_id==CODEC_ID_H263){
next= ff_h263_find_frame_end(&s->parse_context, buf, buf_size);
}else{
av_log(s->avctx, AV_LOG_ERROR, "this codec does not support truncated bitstreams\n");
return -1;
}
if( ff_combine_frame(&s->parse_context, next, (const uint8_t **)&buf, &buf_size) < 0 )
return buf_size;
}
retry:
if(s->divx_packed && s->bitstream_buffer_size){
int i;
for(i=0; i<buf_size-3; i++){
if(buf[i]==0 && buf[i+1]==0 && buf[i+2]==1){
if(buf[i+3]==0xB0){
av_log(s->avctx, AV_LOG_WARNING, "Discarding excessive bitstream in packed xvid\n");
s->bitstream_buffer_size=0;
}
break;
}
}
}
if(s->bitstream_buffer_size && (s->divx_packed || buf_size<20)){ //divx 5.01+/xvid frame reorder
init_get_bits(&s->gb, s->bitstream_buffer, s->bitstream_buffer_size*8);
}else
init_get_bits(&s->gb, buf, buf_size*8);
s->bitstream_buffer_size=0;
if (!s->context_initialized) {
if (ff_MPV_common_init(s) < 0) //we need the idct permutaton for reading a custom matrix
return -1;
}
/* We need to set current_picture_ptr before reading the header,
* otherwise we cannot store anyting in there */
if (s->current_picture_ptr == NULL || s->current_picture_ptr->f.data[0]) {
int i= ff_find_unused_picture(s, 0);
if (i < 0)
return i;
s->current_picture_ptr= &s->picture[i];
}
/* let's go :-) */
if (CONFIG_WMV2_DECODER && s->msmpeg4_version==5) {
ret= ff_wmv2_decode_picture_header(s);
} else if (CONFIG_MSMPEG4_DECODER && s->msmpeg4_version) {
ret = ff_msmpeg4_decode_picture_header(s);
} else if (CONFIG_MPEG4_DECODER && s->h263_pred) {
if(s->avctx->extradata_size && s->picture_number==0){
GetBitContext gb;
init_get_bits(&gb, s->avctx->extradata, s->avctx->extradata_size*8);
ret = ff_mpeg4_decode_picture_header(s, &gb);
}
ret = ff_mpeg4_decode_picture_header(s, &s->gb);
} else if (CONFIG_H263I_DECODER && s->codec_id == CODEC_ID_H263I) {
ret = ff_intel_h263_decode_picture_header(s);
} else if (CONFIG_FLV_DECODER && s->h263_flv) {
ret = ff_flv_decode_picture_header(s);
} else {
ret = ff_h263_decode_picture_header(s);
}
if(ret==FRAME_SKIPPED) return get_consumed_bytes(s, buf_size);
/* skip if the header was thrashed */
if (ret < 0){
av_log(s->avctx, AV_LOG_ERROR, "header damaged\n");
return -1;
}
avctx->has_b_frames= !s->low_delay;
if(s->xvid_build==-1 && s->divx_version==-1 && s->lavc_build==-1){
if(s->stream_codec_tag == AV_RL32("XVID") ||
s->codec_tag == AV_RL32("XVID") || s->codec_tag == AV_RL32("XVIX") ||
s->codec_tag == AV_RL32("RMP4") ||
s->codec_tag == AV_RL32("SIPP")
)
s->xvid_build= 0;
#if 0
if(s->codec_tag == AV_RL32("DIVX") && s->vo_type==0 && s->vol_control_parameters==1
&& s->padding_bug_score > 0 && s->low_delay) // XVID with modified fourcc
s->xvid_build= 0;
#endif
}
if(s->xvid_build==-1 && s->divx_version==-1 && s->lavc_build==-1){
if(s->codec_tag == AV_RL32("DIVX") && s->vo_type==0 && s->vol_control_parameters==0)
s->divx_version= 400; //divx 4
}
if(s->xvid_build>=0 && s->divx_version>=0){
s->divx_version=
s->divx_build= -1;
}
if(s->workaround_bugs&FF_BUG_AUTODETECT){
if(s->codec_tag == AV_RL32("XVIX"))
s->workaround_bugs|= FF_BUG_XVID_ILACE;
if(s->codec_tag == AV_RL32("UMP4")){
s->workaround_bugs|= FF_BUG_UMP4;
}
if(s->divx_version>=500 && s->divx_build<1814){
s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
}
if(s->divx_version>502 && s->divx_build<1814){
s->workaround_bugs|= FF_BUG_QPEL_CHROMA2;
}
if(s->xvid_build<=3U)
s->padding_bug_score= 256*256*256*64;
if(s->xvid_build<=1U)
s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
if(s->xvid_build<=12U)
s->workaround_bugs|= FF_BUG_EDGE;
if(s->xvid_build<=32U)
s->workaround_bugs|= FF_BUG_DC_CLIP;
#define SET_QPEL_FUNC(postfix1, postfix2) \
s->dsp.put_ ## postfix1 = ff_put_ ## postfix2;\
s->dsp.put_no_rnd_ ## postfix1 = ff_put_no_rnd_ ## postfix2;\
s->dsp.avg_ ## postfix1 = ff_avg_ ## postfix2;
if(s->lavc_build<4653U)
s->workaround_bugs|= FF_BUG_STD_QPEL;
if(s->lavc_build<4655U)
s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
if(s->lavc_build<4670U){
s->workaround_bugs|= FF_BUG_EDGE;
}
if(s->lavc_build<=4712U)
s->workaround_bugs|= FF_BUG_DC_CLIP;
if(s->divx_version>=0)
s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
//printf("padding_bug_score: %d\n", s->padding_bug_score);
if(s->divx_version==501 && s->divx_build==20020416)
s->padding_bug_score= 256*256*256*64;
if(s->divx_version<500U){
s->workaround_bugs|= FF_BUG_EDGE;
}
if(s->divx_version>=0)
s->workaround_bugs|= FF_BUG_HPEL_CHROMA;
#if 0
if(s->divx_version==500)
s->padding_bug_score= 256*256*256*64;
/* very ugly XVID padding bug detection FIXME/XXX solve this differently
* Let us hope this at least works.
*/
if( s->resync_marker==0 && s->data_partitioning==0 && s->divx_version==-1
&& s->codec_id==CODEC_ID_MPEG4 && s->vo_type==0)
s->workaround_bugs|= FF_BUG_NO_PADDING;
if(s->lavc_build<4609U) //FIXME not sure about the version num but a 4609 file seems ok
s->workaround_bugs|= FF_BUG_NO_PADDING;
#endif
}
if(s->workaround_bugs& FF_BUG_STD_QPEL){
SET_QPEL_FUNC(qpel_pixels_tab[0][ 5], qpel16_mc11_old_c)
SET_QPEL_FUNC(qpel_pixels_tab[0][ 7], qpel16_mc31_old_c)
SET_QPEL_FUNC(qpel_pixels_tab[0][ 9], qpel16_mc12_old_c)
SET_QPEL_FUNC(qpel_pixels_tab[0][11], qpel16_mc32_old_c)
SET_QPEL_FUNC(qpel_pixels_tab[0][13], qpel16_mc13_old_c)
SET_QPEL_FUNC(qpel_pixels_tab[0][15], qpel16_mc33_old_c)
SET_QPEL_FUNC(qpel_pixels_tab[1][ 5], qpel8_mc11_old_c)
SET_QPEL_FUNC(qpel_pixels_tab[1][ 7], qpel8_mc31_old_c)
SET_QPEL_FUNC(qpel_pixels_tab[1][ 9], qpel8_mc12_old_c)
SET_QPEL_FUNC(qpel_pixels_tab[1][11], qpel8_mc32_old_c)
SET_QPEL_FUNC(qpel_pixels_tab[1][13], qpel8_mc13_old_c)
SET_QPEL_FUNC(qpel_pixels_tab[1][15], qpel8_mc33_old_c)
}
if(avctx->debug & FF_DEBUG_BUGS)
av_log(s->avctx, AV_LOG_DEBUG, "bugs: %X lavc_build:%d xvid_build:%d divx_version:%d divx_build:%d %s\n",
s->workaround_bugs, s->lavc_build, s->xvid_build, s->divx_version, s->divx_build,
s->divx_packed ? "p" : "");
#if HAVE_MMX
if (s->codec_id == CODEC_ID_MPEG4 && s->xvid_build>=0 && avctx->idct_algo == FF_IDCT_AUTO && (av_get_cpu_flags() & AV_CPU_FLAG_MMX)) {
avctx->idct_algo= FF_IDCT_XVIDMMX;
ff_dct_common_init(s);
s->picture_number=0;
}
#endif
/* After H263 & mpeg4 header decode we have the height, width,*/
/* and other parameters. So then we could init the picture */
/* FIXME: By the way H263 decoder is evolving it should have */
/* an H263EncContext */
if ( s->width != avctx->coded_width
|| s->height != avctx->coded_height) {
/* H.263 could change picture size any time */
ParseContext pc= s->parse_context; //FIXME move these demuxng hack to avformat
if (HAVE_THREADS && (s->avctx->active_thread_type&FF_THREAD_FRAME)) {
av_log_missing_feature(s->avctx, "Width/height/bit depth/chroma idc changing with threads is", 0);
return -1; // width / height changed during parallelized decoding
}
s->parse_context.buffer=0;
ff_MPV_common_end(s);
s->parse_context= pc;
}
if (!s->context_initialized) {
avcodec_set_dimensions(avctx, s->width, s->height);
goto retry;
}
if((s->codec_id==CODEC_ID_H263 || s->codec_id==CODEC_ID_H263P || s->codec_id == CODEC_ID_H263I))
s->gob_index = ff_h263_get_gob_height(s);
// for skipping the frame
s->current_picture.f.pict_type = s->pict_type;
s->current_picture.f.key_frame = s->pict_type == AV_PICTURE_TYPE_I;
/* skip B-frames if we don't have reference frames */
if(s->last_picture_ptr==NULL && (s->pict_type==AV_PICTURE_TYPE_B || s->dropable)) return get_consumed_bytes(s, buf_size);
if( (avctx->skip_frame >= AVDISCARD_NONREF && s->pict_type==AV_PICTURE_TYPE_B)
|| (avctx->skip_frame >= AVDISCARD_NONKEY && s->pict_type!=AV_PICTURE_TYPE_I)
|| avctx->skip_frame >= AVDISCARD_ALL)
return get_consumed_bytes(s, buf_size);
if(s->next_p_frame_damaged){
if(s->pict_type==AV_PICTURE_TYPE_B)
return get_consumed_bytes(s, buf_size);
else
s->next_p_frame_damaged=0;
}
if((s->avctx->flags2 & CODEC_FLAG2_FAST) && s->pict_type==AV_PICTURE_TYPE_B){
s->me.qpel_put= s->dsp.put_2tap_qpel_pixels_tab;
s->me.qpel_avg= s->dsp.avg_2tap_qpel_pixels_tab;
}else if((!s->no_rounding) || s->pict_type==AV_PICTURE_TYPE_B){
s->me.qpel_put= s->dsp.put_qpel_pixels_tab;
s->me.qpel_avg= s->dsp.avg_qpel_pixels_tab;
}else{
s->me.qpel_put= s->dsp.put_no_rnd_qpel_pixels_tab;
s->me.qpel_avg= s->dsp.avg_qpel_pixels_tab;
}
if(ff_MPV_frame_start(s, avctx) < 0)
return -1;
if (!s->divx_packed) ff_thread_finish_setup(avctx);
if (CONFIG_MPEG4_VDPAU_DECODER && (s->avctx->codec->capabilities & CODEC_CAP_HWACCEL_VDPAU)) {
ff_vdpau_mpeg4_decode_picture(s, s->gb.buffer, s->gb.buffer_end - s->gb.buffer);
goto frame_end;
}
if (avctx->hwaccel) {
if (avctx->hwaccel->start_frame(avctx, s->gb.buffer, s->gb.buffer_end - s->gb.buffer) < 0)
return -1;
}
ff_er_frame_start(s);
//the second part of the wmv2 header contains the MB skip bits which are stored in current_picture->mb_type
//which is not available before ff_MPV_frame_start()
if (CONFIG_WMV2_DECODER && s->msmpeg4_version==5){
ret = ff_wmv2_decode_secondary_picture_header(s);
if(ret<0) return ret;
if(ret==1) goto intrax8_decoded;
}
/* decode each macroblock */
s->mb_x=0;
s->mb_y=0;
ret = decode_slice(s);
while(s->mb_y<s->mb_height){
if(s->msmpeg4_version){
if(s->slice_height==0 || s->mb_x!=0 || (s->mb_y%s->slice_height)!=0 || get_bits_count(&s->gb) > s->gb.size_in_bits)
break;
}else{
int prev_x=s->mb_x, prev_y=s->mb_y;
if(ff_h263_resync(s)<0)
break;
if (prev_y * s->mb_width + prev_x < s->mb_y * s->mb_width + s->mb_x)
s->error_occurred = 1;
}
if(s->msmpeg4_version<4 && s->h263_pred)
ff_mpeg4_clean_buffers(s);
if (decode_slice(s) < 0) ret = AVERROR_INVALIDDATA;
}
if (s->msmpeg4_version && s->msmpeg4_version<4 && s->pict_type==AV_PICTURE_TYPE_I)
if(!CONFIG_MSMPEG4_DECODER || ff_msmpeg4_decode_ext_header(s, buf_size) < 0){
s->error_status_table[s->mb_num-1]= ER_MB_ERROR;
}
assert(s->bitstream_buffer_size==0);
frame_end:
/* divx 5.01+ bistream reorder stuff */
if(s->codec_id==CODEC_ID_MPEG4 && s->divx_packed){
int current_pos= s->gb.buffer == s->bitstream_buffer ? 0 : (get_bits_count(&s->gb)>>3);
int startcode_found=0;
if(buf_size - current_pos > 7){
int i;
for(i=current_pos; i<buf_size-4; i++){
if(buf[i]==0 && buf[i+1]==0 && buf[i+2]==1 && buf[i+3]==0xB6){
startcode_found=!(buf[i+4]&0x40);
break;
}
}
}
if(startcode_found){
av_fast_malloc(
&s->bitstream_buffer,
&s->allocated_bitstream_buffer_size,
buf_size - current_pos + FF_INPUT_BUFFER_PADDING_SIZE);
if (!s->bitstream_buffer)
return AVERROR(ENOMEM);
memcpy(s->bitstream_buffer, buf + current_pos, buf_size - current_pos);
s->bitstream_buffer_size= buf_size - current_pos;
}
}
intrax8_decoded:
ff_er_frame_end(s);
if (avctx->hwaccel) {
if (avctx->hwaccel->end_frame(avctx) < 0)
return -1;
}
ff_MPV_frame_end(s);
assert(s->current_picture.f.pict_type == s->current_picture_ptr->f.pict_type);
assert(s->current_picture.f.pict_type == s->pict_type);
if (s->pict_type == AV_PICTURE_TYPE_B || s->low_delay) {
*pict = s->current_picture_ptr->f;
} else if (s->last_picture_ptr != NULL) {
*pict = s->last_picture_ptr->f;
}
if(s->last_picture_ptr || s->low_delay){
*data_size = sizeof(AVFrame);
ff_print_debug_info(s, pict);
}
#ifdef PRINT_FRAME_TIME
av_log(avctx, AV_LOG_DEBUG, "%"PRId64"\n", rdtsc()-time);
#endif
return (ret && (avctx->err_recognition & AV_EF_EXPLODE))?ret:get_consumed_bytes(s, buf_size);
}
AVCodec ff_h263_decoder = {
.name = "h263",
.type = AVMEDIA_TYPE_VIDEO,
.id = CODEC_ID_H263,
.priv_data_size = sizeof(MpegEncContext),
.init = ff_h263_decode_init,
.close = ff_h263_decode_end,
.decode = ff_h263_decode_frame,
.capabilities = CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
.flush= ff_mpeg_flush,
.max_lowres= 3,
.long_name= NULL_IF_CONFIG_SMALL("H.263 / H.263-1996, H.263+ / H.263-1998 / H.263 version 2"),
.pix_fmts= ff_hwaccel_pixfmt_list_420,
};