nengel@2: /*
nengel@2:  * H.26L/H.264/AVC/JVT/14496-10/... sei decoding
nengel@2:  * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
nengel@2:  *
nengel@2:  * This file is part of FFmpeg.
nengel@2:  *
nengel@2:  * FFmpeg is free software; you can redistribute it and/or
nengel@2:  * modify it under the terms of the GNU Lesser General Public
nengel@2:  * License as published by the Free Software Foundation; either
nengel@2:  * version 2.1 of the License, or (at your option) any later version.
nengel@2:  *
nengel@2:  * FFmpeg is distributed in the hope that it will be useful,
nengel@2:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
nengel@2:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
nengel@2:  * Lesser General Public License for more details.
nengel@2:  *
nengel@2:  * You should have received a copy of the GNU Lesser General Public
nengel@2:  * License along with FFmpeg; if not, write to the Free Software
nengel@2:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
nengel@2:  */
nengel@2: 
nengel@2: /**
nengel@2:  * @file
nengel@2:  * H.264 / AVC / MPEG4 part10 sei decoding.
nengel@2:  * @author Michael Niedermayer <michaelni@gmx.at>
nengel@2:  */
nengel@2: 
nengel@2: #include "avcodec.h"
nengel@2: #include "h264_types.h"
nengel@2: #include "golomb.h"
nengel@2: 
nengel@2: //#undef NDEBUG
nengel@2: #include <assert.h>
nengel@2: 
nengel@2: static const uint8_t sei_num_clock_ts_table[9]={
nengel@2:     1,  1,  1,  2,  2,  3,  3,  2,  3
nengel@2: };
nengel@2: 
nengel@2: void ff_h264_reset_sei(NalContext *n) {
nengel@2:     n->sei_recovery_frame_cnt       = -1;
nengel@2:     n->sei_dpb_output_delay         =  0;
nengel@2:     n->sei_cpb_removal_delay        = -1;
nengel@2:     n->sei_buffering_period_present =  0;
nengel@2: }
nengel@2: 
nengel@2: static int decode_picture_timing(NalContext *n, GetBitContext *gb){
nengel@2:     if(n->sps.nal_hrd_parameters_present_flag || n->sps.vcl_hrd_parameters_present_flag){
nengel@2:         n->sei_cpb_removal_delay = get_bits(gb, n->sps.cpb_removal_delay_length);
nengel@2:         n->sei_dpb_output_delay = get_bits(gb, n->sps.dpb_output_delay_length);
nengel@2:     }
nengel@2:     if(n->sps.pic_struct_present_flag){
nengel@2:         unsigned int i, num_clock_ts;
nengel@2:         n->sei_pic_struct = get_bits(gb, 4);
nengel@2:         n->sei_ct_type    = 0;
nengel@2: 
nengel@2:         if (n->sei_pic_struct > SEI_PIC_STRUCT_FRAME_TRIPLING)
nengel@2:             return -1;
nengel@2: 
nengel@2:         num_clock_ts = sei_num_clock_ts_table[n->sei_pic_struct];
nengel@2: 
nengel@2:         for (i = 0 ; i < num_clock_ts ; i++){
nengel@2:             if(get_bits(gb, 1)){                  /* clock_timestamp_flag */
nengel@2:                 unsigned int full_timestamp_flag;
nengel@2:                 n->sei_ct_type |= 1<<get_bits(gb, 2);
nengel@2:                 skip_bits(gb, 1);                 /* nuit_field_based_flag */
nengel@2:                 skip_bits(gb, 5);                 /* counting_type */
nengel@2:                 full_timestamp_flag = get_bits(gb, 1);
nengel@2:                 skip_bits(gb, 1);                 /* discontinuity_flag */
nengel@2:                 skip_bits(gb, 1);                 /* cnt_dropped_flag */
nengel@2:                 skip_bits(gb, 8);                 /* n_frames */
nengel@2:                 if(full_timestamp_flag){
nengel@2:                     skip_bits(gb, 6);             /* seconds_value 0..59 */
nengel@2:                     skip_bits(gb, 6);             /* minutes_value 0..59 */
nengel@2:                     skip_bits(gb, 5);             /* hours_value 0..23 */
nengel@2:                 }else{
nengel@2:                     if(get_bits(gb, 1)){          /* seconds_flag */
nengel@2:                         skip_bits(gb, 6);         /* seconds_value range 0..59 */
nengel@2:                         if(get_bits(gb, 1)){      /* minutes_flag */
nengel@2:                             skip_bits(gb, 6);     /* minutes_value 0..59 */
nengel@2:                             if(get_bits(gb, 1))   /* hours_flag */
nengel@2:                                 skip_bits(gb, 5); /* hours_value 0..23 */
nengel@2:                         }
nengel@2:                     }
nengel@2:                 }
nengel@2:                 if(n->sps.time_offset_length > 0)
nengel@2:                     skip_bits(gb, n->sps.time_offset_length); /* time_offset */
nengel@2:             }
nengel@2:         }
nengel@2:     }
nengel@2:     return 0;
nengel@2: }
nengel@2: 
nengel@2: static int decode_unregistered_user_data(GetBitContext *gb, int size){
nengel@2:     char user_data[16+256];
nengel@2:     int e, build, i;
nengel@2: 
nengel@2:     if(size<16)
nengel@2:         return -1;
nengel@2: 
nengel@2:     for(i=0; i<(int) sizeof(user_data)-1 && i<size; i++){
nengel@2:         user_data[i]= get_bits(gb, 8);
nengel@2:     }
nengel@2: 
nengel@2:     user_data[i]= 0;
nengel@2:     e= sscanf(user_data+16, "x264 - core %d"/*%s - H.264/MPEG-4 AVC codec - Copyleft 2005 - http://www.videolan.org/x264.html*/, &build);
nengel@2:     (void) e;
nengel@2:     for(; i<size; i++)
nengel@2:         skip_bits(gb, 8);
nengel@2: 
nengel@2:     return 0;
nengel@2: }
nengel@2: 
nengel@2: static int decode_recovery_point(NalContext *n, GetBitContext *gb){
nengel@2: 
nengel@2:     n->sei_recovery_frame_cnt = get_ue_golomb(gb);
nengel@2:     skip_bits(gb, 4);       /* 1b exact_match_flag, 1b broken_link_flag, 2b changing_slice_group_idc */
nengel@2: 
nengel@2:     return 0;
nengel@2: }
nengel@2: 
nengel@2: static int decode_buffering_period(NalContext *n, GetBitContext *gb){
nengel@2:     unsigned int sps_id;
nengel@2:     int sched_sel_idx;
nengel@2:     SPS *sps;
nengel@2: 
nengel@2:     sps_id = get_ue_golomb_31(gb);
nengel@2:     if(sps_id > 31 || !n->sps_buffers[sps_id]) {
nengel@2:         av_log(AV_LOG_ERROR, "non-existing SPS %d referenced in buffering period\n", sps_id);
nengel@2:         return -1;
nengel@2:     }
nengel@2:     sps = n->sps_buffers[sps_id];
nengel@2: 
nengel@2:     // NOTE: This is really so duplicated in the standard... See H.264, D.1.1
nengel@2:     if (sps->nal_hrd_parameters_present_flag) {
nengel@2:         for (sched_sel_idx = 0; sched_sel_idx < sps->cpb_cnt; sched_sel_idx++) {
nengel@2:             n->initial_cpb_removal_delay[sched_sel_idx] = get_bits(gb, sps->initial_cpb_removal_delay_length);
nengel@2:             skip_bits(gb, sps->initial_cpb_removal_delay_length); // initial_cpb_removal_delay_offset
nengel@2:         }
nengel@2:     }
nengel@2:     if (sps->vcl_hrd_parameters_present_flag) {
nengel@2:         for (sched_sel_idx = 0; sched_sel_idx < sps->cpb_cnt; sched_sel_idx++) {
nengel@2:             n->initial_cpb_removal_delay[sched_sel_idx] = get_bits(gb, sps->initial_cpb_removal_delay_length);
nengel@2:             skip_bits(gb, sps->initial_cpb_removal_delay_length); // initial_cpb_removal_delay_offset
nengel@2:         }
nengel@2:     }
nengel@2: 
nengel@2:     n->sei_buffering_period_present = 1;
nengel@2:     return 0;
nengel@2: }
nengel@2: 
nengel@2: int ff_h264_decode_sei(NalContext *n, GetBitContext *gb){
nengel@2:     while(get_bits_count(gb) + 16 < gb->size_in_bits){
nengel@2:         int size, type;
nengel@2: 
nengel@2:         type=0;
nengel@2:         do{
nengel@2:             type+= show_bits(gb, 8);
nengel@2:         }while(get_bits(gb, 8) == 255);
nengel@2: 
nengel@2:         size=0;
nengel@2:         do{
nengel@2:             size+= show_bits(gb, 8);
nengel@2:         }while(get_bits(gb, 8) == 255);
nengel@2: 
nengel@2:         switch(type){
nengel@2:         case SEI_TYPE_PIC_TIMING: // Picture timing SEI
nengel@2:             if(decode_picture_timing(n, gb) < 0)
nengel@2:                 return -1;
nengel@2:             break;
nengel@2:         case SEI_TYPE_USER_DATA_UNREGISTERED:
nengel@2:             if(decode_unregistered_user_data(gb, size) < 0)
nengel@2:                 return -1;
nengel@2:             break;
nengel@2:         case SEI_TYPE_RECOVERY_POINT:
nengel@2:             if(decode_recovery_point(n, gb) < 0)
nengel@2:                 return -1;
nengel@2:             break;
nengel@2:         case SEI_BUFFERING_PERIOD:
nengel@2:             if(decode_buffering_period(n, gb) < 0)
nengel@2:                 return -1;
nengel@2:             break;
nengel@2:         default:
nengel@2:             skip_bits(gb, 8*size);
nengel@2:         }
nengel@2: 
nengel@2:         //FIXME check bits here
nengel@2:         align_get_bits(gb);
nengel@2:     }
nengel@2: 
nengel@2:     return 0;
nengel@2: }