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/*****************************************************************
* gmerlin-avdecoder - a general purpose multimedia decoding library
*
* Copyright (c) 2001 - 2024 Members of the Gmerlin project
* http://github.com/bplaum
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
* *****************************************************************/
#include <avdec_private.h>
#include <adts_header.h>
#define IS_ADTS(h) ((h[0] == 0xff) && \
((h[1] & 0xf0) == 0xf0) && \
((h[1] & 0x06) == 0x00))
static const int adts_samplerates[] =
{96000,88200,64000,48000,44100,
32000,24000,22050,16000,12000,
11025,8000,7350,0,0,0};
int bgav_adts_header_read(const uint8_t * data,
bgav_adts_header_t * ret)
{
if(!IS_ADTS(data))
return 0;
if(data[1] & 0x08)
ret->mpeg_version = 2;
else
ret->mpeg_version = 4;
ret->protection_absent = data[1] & 0x01;
ret->profile = (data[2] & 0xC0) >> 6;
ret->samplerate_index = (data[2]&0x3C)>>2;
ret->samplerate = adts_samplerates[ret->samplerate_index];
ret->channel_configuration = ((data[2]&0x01)<<2)|((data[3]&0xC0)>>6);
ret->frame_bytes = ((((unsigned int)data[3] & 0x3)) << 11)
| (((unsigned int)data[4]) << 3) | (data[5] >> 5);
ret->num_blocks = (data[6] & 0x03) + 1;
return 1;
}
void bgav_adts_header_dump(const bgav_adts_header_t * adts)
{
gavl_dprintf( "ADTS\n");
gavl_dprintf( " MPEG Version: %d\n", adts->mpeg_version);
gavl_dprintf( " Profile: ");
if(adts->mpeg_version == 2)
{
switch(adts->profile)
{
case 0:
gavl_dprintf( "MPEG-2 AAC Main profile\n");
break;
case 1:
gavl_dprintf( "MPEG-2 AAC Low Complexity profile (LC)\n");
break;
case 2:
gavl_dprintf( "MPEG-2 AAC Scalable Sample Rate profile (SSR)\n");
break;
case 3:
gavl_dprintf( "MPEG-2 AAC (reserved)\n");
break;
}
}
else
{
switch(adts->profile)
{
case 0:
gavl_dprintf( "MPEG-4 AAC Main profile\n");
break;
case 1:
gavl_dprintf( "MPEG-4 AAC Low Complexity profile (LC)\n");
break;
case 2:
gavl_dprintf( "MPEG-4 AAC Scalable Sample Rate profile (SSR)\n");
break;
case 3:
gavl_dprintf( "MPEG-4 AAC Long Term Prediction (LTP)\n");
break;
}
}
gavl_dprintf( " Samplerate: %d\n", adts->samplerate);
gavl_dprintf( " Channel configuration: %d\n", adts->channel_configuration);
gavl_dprintf( " Frame bytes: %d\n", adts->frame_bytes);
gavl_dprintf( " Num blocks: %d\n", adts->num_blocks);
gavl_dprintf( " Protection absent: %d\n", adts->protection_absent);
}
void bgav_adts_header_get_format(const bgav_adts_header_t * adts,
gavl_audio_format_t * format)
{
if(adts->profile == 2)
format->samples_per_frame = 960;
else
format->samples_per_frame = 1024;
format->samplerate = adts->samplerate;
switch(adts->channel_configuration)
{
case 1:
format->num_channels = 1;
format->channel_locations[0] = GAVL_CHID_FRONT_CENTER;
break;
case 2:
format->num_channels = 2;
format->channel_locations[0] = GAVL_CHID_FRONT_LEFT;
format->channel_locations[1] = GAVL_CHID_FRONT_RIGHT;
break;
case 3:
format->num_channels = 3;
format->channel_locations[0] = GAVL_CHID_FRONT_CENTER;
format->channel_locations[1] = GAVL_CHID_FRONT_LEFT;
format->channel_locations[2] = GAVL_CHID_FRONT_RIGHT;
break;
case 4:
format->num_channels = 4;
format->channel_locations[0] = GAVL_CHID_FRONT_CENTER;
format->channel_locations[1] = GAVL_CHID_FRONT_LEFT;
format->channel_locations[2] = GAVL_CHID_FRONT_RIGHT;
format->channel_locations[3] = GAVL_CHID_REAR_CENTER;
break;
case 5:
format->num_channels = 5;
format->channel_locations[0] = GAVL_CHID_FRONT_CENTER;
format->channel_locations[1] = GAVL_CHID_FRONT_LEFT;
format->channel_locations[2] = GAVL_CHID_FRONT_RIGHT;
format->channel_locations[3] = GAVL_CHID_REAR_LEFT;
format->channel_locations[4] = GAVL_CHID_REAR_RIGHT;
break;
case 6:
format->num_channels = 6;
format->channel_locations[0] = GAVL_CHID_FRONT_CENTER;
format->channel_locations[1] = GAVL_CHID_FRONT_LEFT;
format->channel_locations[2] = GAVL_CHID_FRONT_RIGHT;
format->channel_locations[3] = GAVL_CHID_REAR_LEFT;
format->channel_locations[4] = GAVL_CHID_REAR_RIGHT;
format->channel_locations[5] = GAVL_CHID_LFE;
break;
}
}
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