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/*
* 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 Libav.
*
* Libav 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.
*
* Libav 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 Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "golomb.h"
#include "hevc.h"
static void decode_nal_sei_decoded_picture_hash(HEVCContext *s)
{
int cIdx, i;
GetBitContext *gb = &s->HEVClc.gb;
uint8_t hash_type = get_bits(gb, 8);
for (cIdx = 0; cIdx < 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(HEVCContext *s)
{
GetBitContext *gb = &s->HEVClc.gb;
get_ue_golomb(gb); // frame_packing_arrangement_id
s->sei_frame_packing_present = !get_bits1(gb);
if (s->sei_frame_packing_present) {
s->frame_packing_arrangement_type = get_bits(gb, 7);
s->quincunx_subsampling = get_bits1(gb);
s->content_interpretation_type = get_bits(gb, 6);
// 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 (!s->quincunx_subsampling && s->frame_packing_arrangement_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 void decode_nal_sei_display_orientation(HEVCContext *s)
{
GetBitContext *gb = &s->HEVClc.gb;
s->sei_display_orientation_present = !get_bits1(gb);
if (s->sei_display_orientation_present) {
s->sei_hflip = get_bits1(gb); // hor_flip
s->sei_vflip = get_bits1(gb); // ver_flip
s->sei_anticlockwise_rotation = get_bits(gb, 16);
skip_bits1(gb); // display_orientation_persistence_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)
decode_nal_sei_decoded_picture_hash(s);
else if (payload_type == 45)
decode_nal_sei_frame_packing_arrangement(s);
else if (payload_type == 47)
decode_nal_sei_display_orientation(s);
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)
decode_nal_sei_decoded_picture_hash(s);
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;
}
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