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/*
* Copyright (c) 2007 Ian Caulfield
*
* 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 <stdint.h>
#include "libavutil/channel_layout.h"
#include "get_bits.h"
#include "mlp_parse.h"
#include "mlp.h"
static const uint8_t mlp_quants[16] = {
16, 20, 24, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
};
static const uint8_t mlp_channels[32] = {
1, 2, 3, 4, 3, 4, 5, 3, 4, 5, 4, 5, 6, 4, 5, 4,
5, 6, 5, 5, 6, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
};
static const uint64_t mlp_layout[32] = {
AV_CH_LAYOUT_MONO,
AV_CH_LAYOUT_STEREO,
AV_CH_LAYOUT_2_1,
AV_CH_LAYOUT_QUAD,
AV_CH_LAYOUT_STEREO|AV_CH_LOW_FREQUENCY,
AV_CH_LAYOUT_2_1|AV_CH_LOW_FREQUENCY,
AV_CH_LAYOUT_QUAD|AV_CH_LOW_FREQUENCY,
AV_CH_LAYOUT_SURROUND,
AV_CH_LAYOUT_4POINT0,
AV_CH_LAYOUT_5POINT0_BACK,
AV_CH_LAYOUT_SURROUND|AV_CH_LOW_FREQUENCY,
AV_CH_LAYOUT_4POINT0|AV_CH_LOW_FREQUENCY,
AV_CH_LAYOUT_5POINT1_BACK,
AV_CH_LAYOUT_4POINT0,
AV_CH_LAYOUT_5POINT0_BACK,
AV_CH_LAYOUT_SURROUND|AV_CH_LOW_FREQUENCY,
AV_CH_LAYOUT_4POINT0|AV_CH_LOW_FREQUENCY,
AV_CH_LAYOUT_5POINT1_BACK,
AV_CH_LAYOUT_QUAD|AV_CH_LOW_FREQUENCY,
AV_CH_LAYOUT_5POINT0_BACK,
AV_CH_LAYOUT_5POINT1_BACK,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};
static int mlp_get_major_sync_size(const uint8_t * buf, int bufsize)
{
int has_extension, extensions = 0;
int size = 28;
if (bufsize < 28)
return -1;
if (AV_RB32(buf) == 0xf8726fba) {
has_extension = buf[25] & 1;
if (has_extension) {
extensions = buf[26] >> 4;
size += 2 + extensions * 2;
}
}
return size;
}
/** Read a major sync info header - contains high level information about
* the stream - sample rate, channel arrangement etc. Most of this
* information is not actually necessary for decoding, only for playback.
* gb must be a freshly initialized GetBitContext with no bits read.
*/
int ff_mlp_read_major_sync(void *log, MLPHeaderInfo *mh, GetBitContext *gb)
{
int ratebits, channel_arrangement, header_size;
uint16_t checksum;
av_assert1(get_bits_count(gb) == 0);
header_size = mlp_get_major_sync_size(gb->buffer, gb->size_in_bits >> 3);
if (header_size < 0 || gb->size_in_bits < header_size << 3) {
av_log(log, AV_LOG_ERROR, "packet too short, unable to read major sync\n");
return -1;
}
checksum = ff_mlp_checksum16(gb->buffer, header_size - 2);
if (checksum != AV_RL16(gb->buffer+header_size-2)) {
av_log(log, AV_LOG_ERROR, "major sync info header checksum error\n");
return AVERROR_INVALIDDATA;
}
if (get_bits(gb, 24) != 0xf8726f) /* Sync words */
return AVERROR_INVALIDDATA;
mh->stream_type = get_bits(gb, 8);
mh->header_size = header_size;
if (mh->stream_type == 0xbb) {
mh->group1_bits = mlp_quants[get_bits(gb, 4)];
mh->group2_bits = mlp_quants[get_bits(gb, 4)];
ratebits = get_bits(gb, 4);
mh->group1_samplerate = mlp_samplerate(ratebits);
mh->group2_samplerate = mlp_samplerate(get_bits(gb, 4));
skip_bits(gb, 11);
mh->channel_arrangement=
channel_arrangement = get_bits(gb, 5);
mh->channels_mlp = mlp_channels[channel_arrangement];
mh->channel_layout_mlp = mlp_layout[channel_arrangement];
} else if (mh->stream_type == 0xba) {
mh->group1_bits = 24; // TODO: Is this information actually conveyed anywhere?
mh->group2_bits = 0;
ratebits = get_bits(gb, 4);
mh->group1_samplerate = mlp_samplerate(ratebits);
mh->group2_samplerate = 0;
skip_bits(gb, 4);
mh->channel_modifier_thd_stream0 = get_bits(gb, 2);
mh->channel_modifier_thd_stream1 = get_bits(gb, 2);
mh->channel_arrangement=
channel_arrangement = get_bits(gb, 5);
mh->channels_thd_stream1 = truehd_channels(channel_arrangement);
mh->channel_layout_thd_stream1 = truehd_layout(channel_arrangement);
mh->channel_modifier_thd_stream2 = get_bits(gb, 2);
channel_arrangement = get_bits(gb, 13);
mh->channels_thd_stream2 = truehd_channels(channel_arrangement);
mh->channel_layout_thd_stream2 = truehd_layout(channel_arrangement);
} else
return AVERROR_INVALIDDATA;
mh->access_unit_size = 40 << (ratebits & 7);
mh->access_unit_size_pow2 = 64 << (ratebits & 7);
skip_bits_long(gb, 48);
mh->is_vbr = get_bits1(gb);
mh->peak_bitrate = (get_bits(gb, 15) * mh->group1_samplerate + 8) >> 4;
mh->num_substreams = get_bits(gb, 4);
skip_bits_long(gb, 4 + (header_size - 17) * 8);
return 0;
}
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