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/*
* 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 libavcodec/h264-sei.c
* 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(&s->gb, h->sps.cpb_removal_delay_length);
h->sei_dpb_output_delay = get_bits(&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(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(&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(&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_count(&s->gb) + 16 < s->gb.size_in_bits){
int size, type;
type=0;
do{
type+= show_bits(&s->gb, 8);
}while(get_bits(&s->gb, 8) == 255);
size=0;
do{
size+= show_bits(&s->gb, 8);
}while(get_bits(&s->gb, 8) == 255);
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;
}
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