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/*****************************************************************
* gmerlin-avdecoder - a general purpose multimedia decoding library
*
* Copyright (c) 2001 - 2012 Members of the Gmerlin project
* gmerlin-general@lists.sourceforge.net
* http://gmerlin.sourceforge.net
*
* 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 <string.h>
#include <avdec_private.h>
#include <a52_header.h>
#define BGAV_A52_CHANNEL 0
#define BGAV_A52_MONO 1
#define BGAV_A52_STEREO 2
#define BGAV_A52_3F 3
#define BGAV_A52_2F1R 4
#define BGAV_A52_3F1R 5
#define BGAV_A52_2F2R 6
#define BGAV_A52_3F2R 7
#define BGAV_A52_CHANNEL1 8
#define BGAV_A52_CHANNEL2 9
#define BGAV_A52_DOLBY 10
#define LEVEL_3DB 0.7071067811865476
#define LEVEL_45DB 0.5946035575013605
#define LEVEL_6DB 0.5
#define FRAME_SAMPLES 1536
static const uint8_t halfrate[12] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3};
static const int rate[] = { 32, 40, 48, 56, 64, 80, 96, 112,
128, 160, 192, 224, 256, 320, 384, 448,
512, 576, 640};
static const uint8_t lfeon[8] = {0x10, 0x10, 0x04, 0x04, 0x04, 0x01, 0x04, 0x01};
static const float clev[4] = {LEVEL_3DB, LEVEL_45DB, LEVEL_6DB, LEVEL_45DB};
static const float slev[4] = {LEVEL_3DB, LEVEL_6DB, 0, LEVEL_6DB};
int bgav_a52_header_read(bgav_a52_header_t * ret, uint8_t * buf)
{
int half;
int frmsizecod;
int bitrate;
int cmixlev;
int smixlev;
memset(ret, 0, sizeof(*ret));
if ((buf[0] != 0x0b) || (buf[1] != 0x77)) /* syncword */
{
return 0;
}
if (buf[5] >= 0x60) /* bsid >= 12 */
{
return 0;
}
half = halfrate[buf[5] >> 3];
/* acmod, dsurmod and lfeon */
ret->acmod = buf[6] >> 5;
/* cmixlev and surmixlev */
if((ret->acmod & 0x01) && (ret->acmod != 0x01))
{
cmixlev = (buf[6] & 0x18) >> 3;
}
else
cmixlev = -1;
if(ret->acmod & 0x04)
{
if((cmixlev) == -1)
smixlev = (buf[6] & 0x18) >> 3;
else
smixlev = (buf[6] & 0x06) >> 1;
}
else
smixlev = -1;
if(smixlev >= 0)
ret->smixlev = slev[smixlev];
if(cmixlev >= 0)
ret->cmixlev = clev[cmixlev];
if((buf[6] & 0xf8) == 0x50)
ret->dolby = 1;
if(buf[6] & lfeon[ret->acmod])
ret->lfe = 1;
frmsizecod = buf[4] & 63;
if (frmsizecod >= 38)
return 0;
bitrate = rate[frmsizecod >> 1];
ret->bitrate = (bitrate * 1000) >> half;
switch (buf[4] & 0xc0)
{
case 0:
ret->samplerate = 48000 >> half;
ret->total_bytes = 4 * bitrate;
break;
case 0x40:
ret->samplerate = 44100 >> half;
ret->total_bytes = 2 * (320 * bitrate / 147 + (frmsizecod & 1));
break;
case 0x80:
ret->samplerate = 32000 >> half;
ret->total_bytes = 6 * bitrate;
break;
default:
return 0;
}
return 1;
}
void bgav_a52_header_dump(bgav_a52_header_t * h)
{
bgav_dprintf("A52 header:\n");
bgav_dprintf(" Frame bytes: %d\n", h->total_bytes);
bgav_dprintf(" Samplerate: %d\n", h->samplerate);
bgav_dprintf(" acmod: 0x%0x\n", h->acmod);
if(h->smixlev >= 0.0)
bgav_dprintf(" smixlev: %f\n", h->smixlev);
if(h->cmixlev >= 0.0)
bgav_dprintf(" cmixlev: %f\n", h->cmixlev);
}
void bgav_a52_header_get_format(const bgav_a52_header_t * h,
gavl_audio_format_t * format)
{
format->samplerate = h->samplerate;
format->samples_per_frame = FRAME_SAMPLES;
if(h->lfe)
{
format->num_channels = 1;
format->channel_locations[0] = GAVL_CHID_LFE;
}
else
format->num_channels = 0;
switch(h->acmod)
{
case BGAV_A52_CHANNEL:
case BGAV_A52_STEREO:
format->channel_locations[format->num_channels] =
GAVL_CHID_FRONT_LEFT;
format->channel_locations[format->num_channels+1] =
GAVL_CHID_FRONT_RIGHT;
format->num_channels += 2;
break;
case BGAV_A52_MONO:
format->channel_locations[format->num_channels] =
GAVL_CHID_FRONT_CENTER;
format->num_channels += 1;
break;
case BGAV_A52_3F:
format->channel_locations[format->num_channels] =
GAVL_CHID_FRONT_LEFT;
format->channel_locations[format->num_channels+1] =
GAVL_CHID_FRONT_CENTER;
format->channel_locations[format->num_channels+2] =
GAVL_CHID_FRONT_RIGHT;
format->num_channels += 3;
break;
case BGAV_A52_2F1R:
format->channel_locations[format->num_channels] =
GAVL_CHID_FRONT_LEFT;
format->channel_locations[format->num_channels+1] =
GAVL_CHID_FRONT_RIGHT;
format->channel_locations[format->num_channels+2] =
GAVL_CHID_REAR_CENTER;
format->num_channels += 3;
break;
case BGAV_A52_3F1R:
format->channel_locations[format->num_channels] =
GAVL_CHID_FRONT_LEFT;
format->channel_locations[format->num_channels+1] =
GAVL_CHID_FRONT_CENTER;
format->channel_locations[format->num_channels+2] =
GAVL_CHID_FRONT_RIGHT;
format->channel_locations[format->num_channels+3] =
GAVL_CHID_REAR_CENTER;
format->num_channels += 4;
break;
case BGAV_A52_2F2R:
format->channel_locations[format->num_channels] =
GAVL_CHID_FRONT_LEFT;
format->channel_locations[format->num_channels+1] =
GAVL_CHID_FRONT_RIGHT;
format->channel_locations[format->num_channels+2] =
GAVL_CHID_REAR_LEFT;
format->channel_locations[format->num_channels+3] =
GAVL_CHID_REAR_RIGHT;
format->num_channels += 4;
break;
case BGAV_A52_3F2R:
format->channel_locations[format->num_channels] =
GAVL_CHID_FRONT_LEFT;
format->channel_locations[format->num_channels+1] =
GAVL_CHID_FRONT_CENTER;
format->channel_locations[format->num_channels+2] =
GAVL_CHID_FRONT_RIGHT;
format->channel_locations[format->num_channels+3] =
GAVL_CHID_REAR_LEFT;
format->channel_locations[format->num_channels+4] =
GAVL_CHID_REAR_RIGHT;
format->num_channels += 5;
break;
}
if(gavl_front_channels(format) == 3)
format->center_level = h->cmixlev;
if(gavl_rear_channels(format))
format->rear_level = h->smixlev;
}
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