You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 

372 lines
12 KiB

/*****************************************************************************
* mpegaudio.c
*****************************************************************************
* Copyright (C) 2001, 2002 VideoLAN
* $Id: mpegaudio.c,v 1.2 2002/12/18 01:34:44 fenrir Exp $
*
* Authors: Laurent Aimar <fenrir@via.ecp.fr>
* Eric Petit <titer@videolan.org>
*
* 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, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
*****************************************************************************/
/*****************************************************************************
* Preamble
*****************************************************************************/
#include <vlc/vlc.h>
#include <vlc/aout.h>
#include <vlc/decoder.h>
#include <vlc/input.h>
#include <vlc/sout.h>
#include <stdlib.h> /* malloc(), free() */
#include <string.h> /* strdup() */
#include "codecs.h" /* WAVEFORMATEX BITMAPINFOHEADER */
/*****************************************************************************
* Local prototypes
*****************************************************************************/
typedef struct packetizer_s
{
/* Input properties */
decoder_fifo_t *p_fifo;
bit_stream_t bit_stream;
/* Output properties */
sout_input_t *p_sout_input;
sout_packet_format_t output_format;
uint64_t i_samplescount;
uint32_t i_samplespersecond;
} packetizer_t;
static int Open ( vlc_object_t * );
static int Run ( decoder_fifo_t * );
static int InitThread ( packetizer_t * );
static void PacketizeThread ( packetizer_t * );
static void EndThread ( packetizer_t * );
#define FREE( p ) if( p ) free( p ); p = NULL
/*****************************************************************************
* Module descriptor
*****************************************************************************/
vlc_module_begin();
set_description( _("MPEG-I/II audio packetizer") );
set_capability( "packetizer", 50 );
set_callbacks( Open, NULL );
vlc_module_end();
static int mpegaudio_bitrate[2][3][16] =
{
{
/* v1 l1 */
{ 0, 32, 64, 96, 128, 160, 192, 224, 256, 288, 320, 352, 384, 416, 448, 0},
/* v1 l2 */
{ 0, 32, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384, 0},
/* v1 l3 */
{ 0, 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 0}
},
{
/* v2 l1 */
{ 0, 32, 48, 56, 64, 80, 96, 112, 128, 144, 160, 176, 192, 224, 256, 0},
/* v2 l2 */
{ 0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160, 0},
/* v2 l3 */
{ 0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160, 0}
}
};
static int mpegaudio_samplerate[2][4] = /* version 1 then 2 */
{
{ 44100, 48000, 32000, 0 },
{ 22050, 24000, 16000, 0 }
};
/*****************************************************************************
* OpenDecoder: probe the packetizer and return score
*****************************************************************************
* Tries to launch a decoder and return score so that the interface is able
* to choose.
*****************************************************************************/
static int Open( vlc_object_t *p_this )
{
decoder_fifo_t *p_fifo = (decoder_fifo_t*) p_this;
if( p_fifo->i_fourcc != VLC_FOURCC( 'm', 'p', 'g', 'a') )
{
return VLC_EGENERIC;
}
p_fifo->pf_run = Run;
return VLC_SUCCESS;
}
/*****************************************************************************
* RunDecoder: this function is called just after the thread is created
*****************************************************************************/
static int Run( decoder_fifo_t *p_fifo )
{
packetizer_t *p_pack;
int b_error;
msg_Info( p_fifo, "Running mpegaudio packetizer" );
if( !( p_pack = malloc( sizeof( packetizer_t ) ) ) )
{
msg_Err( p_fifo, "out of memory" );
DecoderError( p_fifo );
return( -1 );
}
memset( p_pack, 0, sizeof( packetizer_t ) );
p_pack->p_fifo = p_fifo;
if( InitThread( p_pack ) != 0 )
{
DecoderError( p_fifo );
return( -1 );
}
while( ( !p_pack->p_fifo->b_die )&&( !p_pack->p_fifo->b_error ) )
{
PacketizeThread( p_pack );
}
if( ( b_error = p_pack->p_fifo->b_error ) )
{
DecoderError( p_pack->p_fifo );
}
EndThread( p_pack );
FREE( p_pack );
if( b_error )
{
return( -1 );
}
return( 0 );
}
/*****************************************************************************
* InitThread: initialize data before entering main loop
*****************************************************************************/
static int InitThread( packetizer_t *p_pack )
{
p_pack->output_format.i_cat = AUDIO_ES;
p_pack->output_format.i_fourcc = p_pack->p_fifo->i_fourcc;
p_pack->output_format.p_format = NULL;
p_pack->p_sout_input = NULL;
p_pack->i_samplescount = 0;
p_pack->i_samplespersecond = 0;
if( InitBitstream( &p_pack->bit_stream, p_pack->p_fifo,
NULL, NULL ) != VLC_SUCCESS )
{
msg_Err( p_pack->p_fifo, "cannot initialize bitstream" );
return -1;
}
return( 0 );
}
/*****************************************************************************
* PacketizeThread: packetize an unit (here copy a complete pes)
*****************************************************************************/
static void PacketizeThread( packetizer_t *p_pack )
{
sout_buffer_t *p_sout_buffer;
size_t i_size;
uint32_t i_sync, i_header;
int i_version, i_layer;
int i_channels, i_samplerate, i_bitrate;
int i_samplesperframe, i_framelength;
int i_skip = 0;
/* search a valid start code */
for( ;; )
{
int i_crc, i_bitrate_index, i_samplerate_index;
int i_padding, i_extention, i_mode, i_modeext, i_copyright;
int i_original, i_emphasis;
RealignBits( &p_pack->bit_stream );
while( ShowBits( &p_pack->bit_stream, 12 ) != 0x0fff &&
!p_pack->p_fifo->b_die && !p_pack->p_fifo->b_error )
{
//msg_Warn( p_pack->p_fifo, "trash..." );
RemoveBits( &p_pack->bit_stream, 8 );
i_skip++;
}
if( p_pack->p_fifo->b_die || p_pack->p_fifo->b_error )
{
return;
}
i_sync = GetBits( &p_pack->bit_stream, 12 );
i_header = ShowBits( &p_pack->bit_stream, 20 );
i_version = 1 - GetBits( &p_pack->bit_stream, 1 );
i_layer = 3 - GetBits( &p_pack->bit_stream, 2 );
i_crc = 1 - GetBits( &p_pack->bit_stream, 1 );
i_bitrate_index = GetBits( &p_pack->bit_stream, 4 );
i_samplerate_index = GetBits( &p_pack->bit_stream, 2 );
i_padding = GetBits( &p_pack->bit_stream, 1 );
i_extention = GetBits( &p_pack->bit_stream, 1 );
i_mode = GetBits( &p_pack->bit_stream, 2 );
i_modeext = GetBits( &p_pack->bit_stream, 2 );
i_copyright = GetBits( &p_pack->bit_stream, 1 );
i_original = GetBits( &p_pack->bit_stream, 1 );
i_emphasis = GetBits( &p_pack->bit_stream, 2 );
if( i_layer != 3 &&
i_bitrate_index > 0x00 && i_bitrate_index < 0x0f &&
i_samplerate_index != 0x03 &&
i_emphasis != 0x02 )
{
i_channels = ( i_mode == 3 ) ? 1 : 2;
i_bitrate = mpegaudio_bitrate[i_version][i_layer][i_bitrate_index];
i_samplerate = mpegaudio_samplerate[i_version][i_samplerate_index];
switch( i_layer )
{
case 0:
i_framelength = ( ( i_version ? 6000 : 12000 ) *
i_bitrate / i_samplerate + i_padding ) * 4;
break;
case 1:
case 2:
i_framelength = ( i_version ? 72000 : 144000 ) *
i_bitrate / i_samplerate + i_padding;
break;
default:
i_framelength = 0;
}
switch( i_layer )
{
case 0:
i_samplesperframe = 384;
break;
case 1:
i_samplesperframe = 1152;
break;
case 2:
i_samplesperframe = i_version ? 576 : 1152;
break;
default:
i_samplesperframe = 0;
}
break;
}
}
if( !p_pack->p_sout_input )
{
/* add a input for the stream ouput */
WAVEFORMATEX *p_wf;
p_wf = malloc( sizeof( WAVEFORMATEX ) );
p_pack->output_format.p_format = (void*)p_wf;
p_wf->wFormatTag = WAVE_FORMAT_MPEG;
p_wf->nChannels = i_channels;
p_wf->nSamplesPerSec = i_samplerate;
p_wf->nAvgBytesPerSec = 0;
p_wf->nBlockAlign = 1;
p_wf->wBitsPerSample = 0;
p_wf->cbSize = 0; // FIXME there are more field for mpegaudio
p_pack->p_sout_input =
sout_InputNew( p_pack->p_fifo,
&p_pack->output_format );
if( !p_pack->p_sout_input )
{
msg_Err( p_pack->p_fifo,
"cannot add a new stream" );
p_pack->p_fifo->b_error = 1;
return;
}
msg_Dbg( p_pack->p_fifo,
"v:%d l:%d channels:%d samplerate:%d bitrate:%d size:%d",
i_version, i_layer, i_channels, i_samplerate,
i_bitrate, i_framelength );
}
i_size = __MAX( i_framelength, 4 );
// msg_Dbg( p_pack->p_fifo, "frame length %d b", i_size );
p_sout_buffer =
sout_BufferNew( p_pack->p_sout_input->p_sout, i_size );
if( !p_sout_buffer )
{
p_pack->p_fifo->b_error = 1;
return;
}
p_sout_buffer->p_buffer[0] = ( i_sync >> 4 )&0xff;
p_sout_buffer->p_buffer[1] =
( ( i_sync << 4 )&0xf0 ) | ( ( i_header >> 16 )&0x0f );
p_sout_buffer->p_buffer[2] = ( i_header >> 8 )&0xff;
p_sout_buffer->p_buffer[3] = ( i_header )&0xff;
p_sout_buffer->i_bitrate = i_bitrate;
p_sout_buffer->i_pts =
p_sout_buffer->i_dts =
(uint64_t)1000000 *
(uint64_t)p_pack->i_samplescount /
(uint64_t)i_samplerate;
p_sout_buffer->i_length =
(uint64_t)1000000 *
(uint64_t)i_samplesperframe /
(uint64_t)i_samplerate;
p_pack->i_samplescount += i_samplesperframe;
/* we are already aligned */
GetChunk( &p_pack->bit_stream,
p_sout_buffer->p_buffer + 4,
i_size - 4 );
sout_InputSendBuffer( p_pack->p_sout_input,
p_sout_buffer );
}
/*****************************************************************************
* EndThread : packetizer thread destruction
*****************************************************************************/
static void EndThread ( packetizer_t *p_pack)
{
if( p_pack->p_sout_input )
{
sout_InputDelete( p_pack->p_sout_input );
}
}