ffmpeg/libavcodec/hevc_sei.c

130 lines
4.3 KiB
C

/*
* HEVC Supplementary Enhancement Information messages
*
* Copyright (C) 2012 - 2013 Guillaume Martres
* Copyright (C) 2012 - 2013 Gildas Cocherel
* Copyright (C) 2013 Vittorio Giovara
*
* 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
*/
#include "hevc.h"
#include "golomb.h"
static void decode_nal_sei_decoded_picture_hash(HEVCContext *s, int payload_size)
{
int cIdx, i;
uint8_t hash_type;
//uint16_t picture_crc;
//uint32_t picture_checksum;
GetBitContext *gb = &s->HEVClc->gb;
hash_type = get_bits(gb, 8);
for( cIdx = 0; cIdx < 3/*((s->sps->chroma_format_idc == 0) ? 1 : 3)*/; cIdx++ ) {
if ( hash_type == 0 ) {
s->is_md5 = 1;
for( i = 0; i < 16; i++) {
s->md5[cIdx][i] = get_bits(gb, 8);
}
} else if( hash_type == 1 ) {
// picture_crc = get_bits(gb, 16);
skip_bits(gb, 16);
} else if( hash_type == 2 ) {
// picture_checksum = get_bits(gb, 32);
skip_bits(gb, 32);
}
}
}
static void decode_nal_sei_frame_packing_arrangement(HEVCLocalContext *lc)
{
GetBitContext *gb = &lc->gb;
int cancel, type, quincunx;
get_ue_golomb(gb); // frame_packing_arrangement_id
cancel = get_bits1(gb); // frame_packing_cancel_flag
if ( cancel == 0 )
{
type = get_bits(gb, 7); // frame_packing_arrangement_type
quincunx = get_bits1(gb); // quincunx_sampling_flag
skip_bits(gb, 6); // content_interpretation_type
// the following skips spatial_flipping_flag frame0_flipped_flag
// field_views_flag current_frame_is_frame0_flag
// frame0_self_contained_flag frame1_self_contained_flag
skip_bits(gb, 6);
if ( quincunx == 0 && type != 5 )
skip_bits(gb, 16); // frame[01]_grid_position_[xy]
skip_bits(gb, 8); // frame_packing_arrangement_reserved_byte
skip_bits1(gb); // frame_packing_arrangement_persistance_flag
}
skip_bits1(gb); // upsampled_aspect_ratio_flag
}
static int decode_nal_sei_message(HEVCContext *s)
{
GetBitContext *gb = &s->HEVClc->gb;
int payload_type = 0;
int payload_size = 0;
int byte = 0xFF;
av_log(s->avctx, AV_LOG_DEBUG, "Decoding SEI\n");
while (byte == 0xFF) {
byte = get_bits(gb, 8);
payload_type += byte;
}
byte = 0xFF;
while (byte == 0xFF) {
byte = get_bits(gb, 8);
payload_size += byte;
}
if (s->nal_unit_type == NAL_SEI_PREFIX) {
if (payload_type == 256 /*&& s->decode_checksum_sei*/)
decode_nal_sei_decoded_picture_hash(s, payload_size);
else if (payload_type == 45)
decode_nal_sei_frame_packing_arrangement(s->HEVClc);
else {
av_log(s->avctx, AV_LOG_DEBUG, "Skipped PREFIX SEI %d\n", payload_type);
skip_bits(gb, 8*payload_size);
}
} else { /* nal_unit_type == NAL_SEI_SUFFIX */
if (payload_type == 132 /* && s->decode_checksum_sei */)
decode_nal_sei_decoded_picture_hash(s, payload_size);
else {
av_log(s->avctx, AV_LOG_DEBUG, "Skipped SUFFIX SEI %d\n", payload_type);
skip_bits(gb, 8*payload_size);
}
}
return 0;
}
static int more_rbsp_data(GetBitContext *gb)
{
return get_bits_left(gb) > 0 && show_bits(gb, 8) != 0x80;
}
int ff_hevc_decode_nal_sei(HEVCContext *s)
{
do {
decode_nal_sei_message(s);
} while (more_rbsp_data(&s->HEVClc->gb));
return 0;
}