Commit 22c1b3b1 authored by Michel Kaempf's avatar Michel Kaempf
Browse files

* Rajout du d�but du d�codeur ac3 ;

parent b278b2a6
/*****************************************************************************
* ac3_decoder.h : ac3 decoder thread interface
* (c)1999 VideoLAN
*****************************************************************************/
#define AC3DEC_FRAME_SIZE (2*256)
/*****************************************************************************
* ac3dec_frame_t
*****************************************************************************/
typedef s16 ac3dec_frame_t[ AC3DEC_FRAME_SIZE ];
/*****************************************************************************
* ac3dec_thread_t : ac3 decoder thread descriptor
*****************************************************************************/
typedef struct ac3dec_thread_s
{
/*
* Thread properties
*/
vlc_thread_t thread_id; /* id for thread functions */
boolean_t b_die; /* `die' flag */
boolean_t b_error; /* `error' flag */
/*
* Input properties
*/
decoder_fifo_t fifo; /* stores the PES stream data */
/* The bit stream structure handles the PES stream at the bit level */
bit_stream_t bit_stream;
/*
* Decoder properties
*/
unsigned int total_bits_read;
/*
* Output properties
*/
aout_fifo_t * p_aout_fifo; /* stores the decompressed audio frames */
aout_thread_t * p_aout; /* needed to create the audio fifo */
} ac3dec_thread_t;
/*****************************************************************************
* Prototypes
*****************************************************************************/
ac3dec_thread_t * ac3dec_CreateThread( input_thread_t * p_input );
void ac3dec_DestroyThread( ac3dec_thread_t * p_ac3dec );
/*****************************************************************************
* ac3_decoder.c: ac3 decoder thread
* (c)1999 VideoLAN
*****************************************************************************/
/*****************************************************************************
* Preamble
*****************************************************************************/
#include <unistd.h> /* getpid() */
#include <stdio.h> /* "intf_msg.h" */
#include <stdlib.h> /* malloc(), free() */
#include <sys/soundcard.h> /* "audio_output.h" */
#include <sys/uio.h> /* "input.h" */
#include "common.h"
#include "config.h"
#include "mtime.h"
#include "vlc_thread.h"
#include "debug.h" /* "input_netlist.h" */
#include "intf_msg.h" /* intf_DbgMsg(), intf_ErrMsg() */
#include "input.h" /* pes_packet_t */
#include "input_netlist.h" /* input_NetlistFreePES() */
#include "decoder_fifo.h" /* DECODER_FIFO_(ISEMPTY|START|INCSTART)() */
#include "audio_output.h"
#include "ac3_decoder.h"
/*****************************************************************************
* Local prototypes
*****************************************************************************/
static int InitThread ( ac3dec_thread_t * p_adec );
static void RunThread ( ac3dec_thread_t * p_adec );
static void ErrorThread ( ac3dec_thread_t * p_adec );
static void EndThread ( ac3dec_thread_t * p_adec );
//static byte_t GetByte ( bit_stream_t * p_bit_stream );
//static void NeedBits ( bit_stream_t * p_bit_stream, int i_bits );
//static void DumpBits ( bit_stream_t * p_bit_stream, int i_bits );
//static int FindHeader ( adec_thread_t * p_adec );
/*****************************************************************************
* ac3dec_CreateThread: creates an ac3 decoder thread
*****************************************************************************/
ac3dec_thread_t * ac3dec_CreateThread( input_thread_t * p_input )
{
ac3dec_thread_t * p_ac3dec;
intf_DbgMsg("ac3dec debug: creating ac3 decoder thread\n");
/* Allocate the memory needed to store the thread's structure */
if ( (p_ac3dec = (ac3dec_thread_t *)malloc( sizeof(ac3dec_thread_t) )) == NULL )
{
intf_ErrMsg("ac3dec error: not enough memory for ac3dec_CreateThread() to create the new thread\n");
return( NULL );
}
/*
* Initialize the thread properties
*/
p_ac3dec->b_die = 0;
p_ac3dec->b_error = 0;
/*
* Initialize the input properties
*/
/* Initialize the decoder fifo's data lock and conditional variable and set
* its buffer as empty */
vlc_mutex_init( &p_ac3dec->fifo.data_lock );
vlc_cond_init( &p_ac3dec->fifo.data_wait );
p_ac3dec->fifo.i_start = 0;
p_ac3dec->fifo.i_end = 0;
/* Initialize the bit stream structure */
p_ac3dec->bit_stream.p_input = p_input;
p_ac3dec->bit_stream.p_decoder_fifo = &p_ac3dec->fifo;
p_ac3dec->bit_stream.fifo.buffer = 0;
p_ac3dec->bit_stream.fifo.i_available = 0;
/*
* Initialize the output properties
*/
p_ac3dec->p_aout = p_input->p_aout;
p_ac3dec->p_aout_fifo = NULL;
/* Spawn the ac3 decoder thread */
if ( vlc_thread_create(&p_ac3dec->thread_id, "ac3 decoder", (vlc_thread_func_t)RunThread, (void *)p_ac3dec) )
{
intf_ErrMsg( "ac3dec error: can't spawn ac3 decoder thread\n" );
free( p_ac3dec );
return( NULL );
}
intf_DbgMsg( "ac3dec debug: ac3 decoder thread (%p) created\n", p_ac3dec );
return( p_ac3dec );
}
/*****************************************************************************
* ac3dec_DestroyThread: destroys an ac3 decoder thread
*****************************************************************************/
void ac3dec_DestroyThread( ac3dec_thread_t * p_ac3dec )
{
intf_DbgMsg( "ac3dec debug: requesting termination of ac3 decoder thread %p\n", p_ac3dec );
/* Ask thread to kill itself */
p_ac3dec->b_die = 1;
/* Make sure the decoder thread leaves the GetByte() function */
vlc_mutex_lock( &(p_ac3dec->fifo.data_lock) );
vlc_cond_signal( &(p_ac3dec->fifo.data_wait) );
vlc_mutex_unlock( &(p_ac3dec->fifo.data_lock) );
/* Waiting for the decoder thread to exit */
/* Remove this as soon as the "status" flag is implemented */
vlc_thread_join( p_ac3dec->thread_id );
}
/* Following functions are local */
/*****************************************************************************
* decode_find_sync()
*****************************************************************************/
static __inline__ int decode_find_sync( ac3dec_thread_t * p_ac3dec )
{
while ( (!p_ac3dec->b_die) && (!p_ac3dec->b_error) )
{
NeedBits( &(p_ac3dec->bit_stream), 16 );
if ( (p_ac3dec->bit_stream.fifo.buffer >> (32 - 16)) == 0x0b77 )
{
DumpBits( &(p_ac3dec->bit_stream), 16 );
p_ac3dec->total_bits_read = 16;
return( 0 );
}
DumpBits( &(p_ac3dec->bit_stream), 1 );
}
return( -1 );
}
/*****************************************************************************
* InitThread : initialize an ac3 decoder thread
*****************************************************************************/
static int InitThread( ac3dec_thread_t * p_ac3dec )
{
aout_fifo_t aout_fifo;
intf_DbgMsg( "ac3dec debug: initializing ac3 decoder thread %p\n", p_ac3dec );
/* Our first job is to initialize the bit stream structure with the
* beginning of the input stream */
vlc_mutex_lock( &p_ac3dec->fifo.data_lock );
while ( DECODER_FIFO_ISEMPTY(p_ac3dec->fifo) )
{
vlc_cond_wait( &p_ac3dec->fifo.data_wait, &p_ac3dec->fifo.data_lock );
}
p_ac3dec->bit_stream.p_ts = DECODER_FIFO_START( p_ac3dec->fifo )->p_first_ts;
p_ac3dec->bit_stream.i_byte = p_ac3dec->bit_stream.p_ts->i_payload_start;
vlc_mutex_unlock( &p_ac3dec->fifo.data_lock );
aout_fifo.i_type = AOUT_ADEC_STEREO_FIFO;
aout_fifo.b_stereo = 1;
aout_fifo.l_frame_size = AC3DEC_FRAME_SIZE;
/* Creating the audio output fifo */
if ( (p_ac3dec->p_aout_fifo = aout_CreateFifo(p_ac3dec->p_aout, &aout_fifo)) == NULL )
{
return( -1 );
}
intf_DbgMsg( "ac3dec debug: ac3 decoder thread %p initialized\n", p_ac3dec );
return( 0 );
}
/*****************************************************************************
* RunThread : ac3 decoder thread
*****************************************************************************/
static void RunThread( ac3dec_thread_t * p_ac3dec )
{
intf_DbgMsg( "ac3dec debug: running ac3 decoder thread (%p) (pid == %i)\n", p_ac3dec, getpid() );
/* Initializing the ac3 decoder thread */
if ( InitThread(p_ac3dec) )
{
p_ac3dec->b_error = 1;
}
/* ac3 decoder thread's main loop */
while ( (!p_ac3dec->b_die) && (!p_ac3dec->b_error) )
{
if ( decode_find_sync(p_ac3dec) == 0 )
{
fprintf( stderr, "ac3dec debug: decode_find_sync() == 0\n" );
}
}
/* If b_error is set, the ac3 decoder thread enters the error loop */
if ( p_ac3dec->b_error )
{
ErrorThread( p_ac3dec );
}
/* End of the ac3 decoder thread */
EndThread( p_ac3dec );
}
/*****************************************************************************
* ErrorThread : ac3 decoder's RunThread() error loop
*****************************************************************************/
static void ErrorThread( ac3dec_thread_t * p_ac3dec )
{
/* We take the lock, because we are going to read/write the start/end
* indexes of the decoder fifo */
vlc_mutex_lock( &p_ac3dec->fifo.data_lock );
/* Wait until a `die' order is sent */
while( !p_ac3dec->b_die )
{
/* Trash all received PES packets */
while( !DECODER_FIFO_ISEMPTY(p_ac3dec->fifo) )
{
input_NetlistFreePES( p_ac3dec->bit_stream.p_input, DECODER_FIFO_START(p_ac3dec->fifo) );
DECODER_FIFO_INCSTART( p_ac3dec->fifo );
}
/* Waiting for the input thread to put new PES packets in the fifo */
vlc_cond_wait( &p_ac3dec->fifo.data_wait, &p_ac3dec->fifo.data_lock );
}
/* We can release the lock before leaving */
vlc_mutex_unlock( &p_ac3dec->fifo.data_lock );
}
/*****************************************************************************
* EndThread : ac3 decoder thread destruction
*****************************************************************************/
static void EndThread( ac3dec_thread_t * p_ac3dec )
{
intf_DbgMsg( "ac3dec debug: destroying ac3 decoder thread %p\n", p_ac3dec );
/* If the audio output fifo was created, we destroy it */
if ( p_ac3dec->p_aout_fifo != NULL )
{
aout_DestroyFifo( p_ac3dec->p_aout_fifo );
}
/* Destroy descriptor */
free( p_ac3dec );
intf_DbgMsg( "ac3dec debug: ac3 decoder thread %p destroyed\n", p_ac3dec );
}
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