Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP
Fetching contributors…

Cannot retrieve contributors at this time

216 lines (183 sloc) 7.659 kb
/*
* H.26L/H.264/AVC/JVT/14496-10/... sei decoding
* Copyright (c) 2003 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.264 / AVC / MPEG4 part10 sei decoding.
* @author Michael Niedermayer <michaelni@gmx.at>
*/
#include "internal.h"
#include "avcodec.h"
#include "h264.h"
#include "golomb.h"
//#undef NDEBUG
#include <assert.h>
static const uint8_t sei_num_clock_ts_table[9]={
1, 1, 1, 2, 2, 3, 3, 2, 3
};
void ff_h264_reset_sei(H264Context *h) {
h->sei_recovery_frame_cnt = -1;
h->sei_dpb_output_delay = 0;
h->sei_cpb_removal_delay = -1;
h->sei_buffering_period_present = 0;
}
static int decode_picture_timing(H264Context *h){
MpegEncContext * const s = &h->s;
if(h->sps.nal_hrd_parameters_present_flag || h->sps.vcl_hrd_parameters_present_flag){
h->sei_cpb_removal_delay = get_bits_long(&s->gb, h->sps.cpb_removal_delay_length);
h->sei_dpb_output_delay = get_bits_long(&s->gb, h->sps.dpb_output_delay_length);
}
if(h->sps.pic_struct_present_flag){
unsigned int i, num_clock_ts;
h->sei_pic_struct = get_bits(&s->gb, 4);
h->sei_ct_type = 0;
if (h->sei_pic_struct > SEI_PIC_STRUCT_FRAME_TRIPLING)
return -1;
num_clock_ts = sei_num_clock_ts_table[h->sei_pic_struct];
for (i = 0 ; i < num_clock_ts ; i++){
if(get_bits(&s->gb, 1)){ /* clock_timestamp_flag */
unsigned int full_timestamp_flag;
h->sei_ct_type |= 1<<get_bits(&s->gb, 2);
skip_bits(&s->gb, 1); /* nuit_field_based_flag */
skip_bits(&s->gb, 5); /* counting_type */
full_timestamp_flag = get_bits(&s->gb, 1);
skip_bits(&s->gb, 1); /* discontinuity_flag */
skip_bits(&s->gb, 1); /* cnt_dropped_flag */
skip_bits(&s->gb, 8); /* n_frames */
if(full_timestamp_flag){
skip_bits(&s->gb, 6); /* seconds_value 0..59 */
skip_bits(&s->gb, 6); /* minutes_value 0..59 */
skip_bits(&s->gb, 5); /* hours_value 0..23 */
}else{
if(get_bits(&s->gb, 1)){ /* seconds_flag */
skip_bits(&s->gb, 6); /* seconds_value range 0..59 */
if(get_bits(&s->gb, 1)){ /* minutes_flag */
skip_bits(&s->gb, 6); /* minutes_value 0..59 */
if(get_bits(&s->gb, 1)) /* hours_flag */
skip_bits(&s->gb, 5); /* hours_value 0..23 */
}
}
}
if(h->sps.time_offset_length > 0)
skip_bits(&s->gb, h->sps.time_offset_length); /* time_offset */
}
}
if(s->avctx->debug & FF_DEBUG_PICT_INFO)
av_log(s->avctx, AV_LOG_DEBUG, "ct_type:%X pic_struct:%d\n", h->sei_ct_type, h->sei_pic_struct);
}
return 0;
}
static int decode_unregistered_user_data(H264Context *h, int size){
MpegEncContext * const s = &h->s;
uint8_t user_data[16+256];
int e, build, i;
if(size<16)
return -1;
for(i=0; i<sizeof(user_data)-1 && i<size; i++){
user_data[i]= get_bits(&s->gb, 8);
}
user_data[i]= 0;
e= sscanf(user_data+16, "x264 - core %d"/*%s - H.264/MPEG-4 AVC codec - Copyleft 2005 - http://www.videolan.org/x264.html*/, &build);
if(e==1 && build>0)
h->x264_build= build;
if(e==1 && build==1 && !strncmp(user_data+16, "x264 - core 0000", 16))
h->x264_build = 67;
if(s->avctx->debug & FF_DEBUG_BUGS)
av_log(s->avctx, AV_LOG_DEBUG, "user data:\"%s\"\n", user_data+16);
for(; i<size; i++)
skip_bits(&s->gb, 8);
return 0;
}
static int decode_recovery_point(H264Context *h){
MpegEncContext * const s = &h->s;
h->sei_recovery_frame_cnt = get_ue_golomb(&s->gb);
skip_bits(&s->gb, 4); /* 1b exact_match_flag, 1b broken_link_flag, 2b changing_slice_group_idc */
return 0;
}
static int decode_buffering_period(H264Context *h){
MpegEncContext * const s = &h->s;
unsigned int sps_id;
int sched_sel_idx;
SPS *sps;
sps_id = get_ue_golomb_31(&s->gb);
if(sps_id > 31 || !h->sps_buffers[sps_id]) {
av_log(h->s.avctx, AV_LOG_ERROR, "non-existing SPS %d referenced in buffering period\n", sps_id);
return -1;
}
sps = h->sps_buffers[sps_id];
// NOTE: This is really so duplicated in the standard... See H.264, D.1.1
if (sps->nal_hrd_parameters_present_flag) {
for (sched_sel_idx = 0; sched_sel_idx < sps->cpb_cnt; sched_sel_idx++) {
h->initial_cpb_removal_delay[sched_sel_idx] = get_bits_long(&s->gb, sps->initial_cpb_removal_delay_length);
skip_bits(&s->gb, sps->initial_cpb_removal_delay_length); // initial_cpb_removal_delay_offset
}
}
if (sps->vcl_hrd_parameters_present_flag) {
for (sched_sel_idx = 0; sched_sel_idx < sps->cpb_cnt; sched_sel_idx++) {
h->initial_cpb_removal_delay[sched_sel_idx] = get_bits_long(&s->gb, sps->initial_cpb_removal_delay_length);
skip_bits(&s->gb, sps->initial_cpb_removal_delay_length); // initial_cpb_removal_delay_offset
}
}
h->sei_buffering_period_present = 1;
return 0;
}
int ff_h264_decode_sei(H264Context *h){
MpegEncContext * const s = &h->s;
while (get_bits_left(&s->gb) > 16) {
int size, type;
type=0;
do{
if (get_bits_left(&s->gb) < 8)
return -1;
type+= show_bits(&s->gb, 8);
}while(get_bits(&s->gb, 8) == 255);
size=0;
do{
if (get_bits_left(&s->gb) < 8)
return -1;
size+= show_bits(&s->gb, 8);
}while(get_bits(&s->gb, 8) == 255);
if(s->avctx->debug&FF_DEBUG_STARTCODE)
av_log(h->s.avctx, AV_LOG_DEBUG, "SEI %d len:%d\n", type, size);
switch(type){
case SEI_TYPE_PIC_TIMING: // Picture timing SEI
if(decode_picture_timing(h) < 0)
return -1;
break;
case SEI_TYPE_USER_DATA_UNREGISTERED:
if(decode_unregistered_user_data(h, size) < 0)
return -1;
break;
case SEI_TYPE_RECOVERY_POINT:
if(decode_recovery_point(h) < 0)
return -1;
break;
case SEI_BUFFERING_PERIOD:
if(decode_buffering_period(h) < 0)
return -1;
break;
default:
skip_bits(&s->gb, 8*size);
}
//FIXME check bits here
align_get_bits(&s->gb);
}
return 0;
}
Jump to Line
Something went wrong with that request. Please try again.