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/*
* TAK common code
* Copyright (c) 2012 Paul B Mahol
*
* 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 "libavutil/bswap.h"
#include "libavutil/crc.h"
#include "libavutil/intreadwrite.h"
#define BITSTREAM_READER_LE
#include "tak.h"
static const uint16_t frame_duration_type_quants[] = {
3, 4, 6, 8, 4096, 8192, 16384, 512, 1024, 2048,
};
static int tak_get_nb_samples(int sample_rate, enum TAKFrameSizeType type)
{
int nb_samples, max_nb_samples;
if (type <= TAK_FST_250ms) {
nb_samples = sample_rate * frame_duration_type_quants[type] >>
TAK_FRAME_DURATION_QUANT_SHIFT;
max_nb_samples = 16384;
} else if (type < FF_ARRAY_ELEMS(frame_duration_type_quants)) {
nb_samples = frame_duration_type_quants[type];
max_nb_samples = sample_rate *
frame_duration_type_quants[TAK_FST_250ms] >>
TAK_FRAME_DURATION_QUANT_SHIFT;
} else {
return AVERROR_INVALIDDATA;
}
if (nb_samples <= 0 || nb_samples > max_nb_samples)
return AVERROR_INVALIDDATA;
return nb_samples;
}
static int crc_init = 0;
#if CONFIG_SMALL
#define CRC_TABLE_SIZE 257
#else
#define CRC_TABLE_SIZE 1024
#endif
static AVCRC crc_24[CRC_TABLE_SIZE];
av_cold void ff_tak_init_crc(void)
{
if (!crc_init) {
av_crc_init(crc_24, 0, 24, 0x864CFBU, sizeof(crc_24));
crc_init = 1;
}
}
int ff_tak_check_crc(const uint8_t *buf, unsigned int buf_size)
{
uint32_t crc, CRC;
if (buf_size < 4)
return AVERROR_INVALIDDATA;
buf_size -= 3;
CRC = av_bswap32(AV_RL24(buf + buf_size)) >> 8;
crc = av_crc(crc_24, 0xCE04B7U, buf, buf_size);
if (CRC != crc)
return AVERROR_INVALIDDATA;
return 0;
}
void avpriv_tak_parse_streaminfo(GetBitContext *gb, TAKStreamInfo *s)
{
uint64_t channel_mask = 0;
int frame_type, i;
s->codec = get_bits(gb, TAK_ENCODER_CODEC_BITS);
skip_bits(gb, TAK_ENCODER_PROFILE_BITS);
frame_type = get_bits(gb, TAK_SIZE_FRAME_DURATION_BITS);
s->samples = get_bits64(gb, TAK_SIZE_SAMPLES_NUM_BITS);
s->data_type = get_bits(gb, TAK_FORMAT_DATA_TYPE_BITS);
s->sample_rate = get_bits(gb, TAK_FORMAT_SAMPLE_RATE_BITS) +
TAK_SAMPLE_RATE_MIN;
s->bps = get_bits(gb, TAK_FORMAT_BPS_BITS) +
TAK_BPS_MIN;
s->channels = get_bits(gb, TAK_FORMAT_CHANNEL_BITS) +
TAK_CHANNELS_MIN;
if (get_bits1(gb)) {
skip_bits(gb, TAK_FORMAT_VALID_BITS);
if (get_bits1(gb)) {
for (i = 0; i < s->channels; i++) {
int value = get_bits(gb, TAK_FORMAT_CH_LAYOUT_BITS);
if (value > 0 && value <= 18)
channel_mask |= 1 << (value - 1);
}
}
}
s->ch_layout = channel_mask;
s->frame_samples = tak_get_nb_samples(s->sample_rate, frame_type);
}
int ff_tak_decode_frame_header(AVCodecContext *avctx, GetBitContext *gb,
TAKStreamInfo *ti, int log_level_offset)
{
if (get_bits(gb, TAK_FRAME_HEADER_SYNC_ID_BITS) != TAK_FRAME_HEADER_SYNC_ID) {
av_log(avctx, AV_LOG_ERROR + log_level_offset, "missing sync id\n");
return AVERROR_INVALIDDATA;
}
ti->flags = get_bits(gb, TAK_FRAME_HEADER_FLAGS_BITS);
ti->frame_num = get_bits(gb, TAK_FRAME_HEADER_NO_BITS);
if (ti->flags & TAK_FRAME_FLAG_IS_LAST) {
ti->last_frame_samples = get_bits(gb, TAK_FRAME_HEADER_SAMPLE_COUNT_BITS) + 1;
skip_bits(gb, 2);
} else {
ti->last_frame_samples = 0;
}
if (ti->flags & TAK_FRAME_FLAG_HAS_INFO) {
avpriv_tak_parse_streaminfo(gb, ti);
if (get_bits(gb, 6))
skip_bits(gb, 25);
align_get_bits(gb);
}
skip_bits(gb, 24);
return 0;
}
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