output.c
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上传日期:2009-03-27
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- /*****************************************************************************
- * output.c : internal management of output streams for the audio output
- *****************************************************************************
- * Copyright (C) 2002-2004 VideoLAN
- * $Id: output.c 8485 2004-08-21 13:54:36Z asmax $
- *
- * Authors: Christophe Massiot <massiot@via.ecp.fr>
- *
- * 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 <stdlib.h> /* calloc(), malloc(), free() */
- #include <string.h>
- #include <vlc/vlc.h>
- #include "audio_output.h"
- #include "aout_internal.h"
- /*****************************************************************************
- * aout_OutputNew : allocate a new output and rework the filter pipeline
- *****************************************************************************
- * This function is entered with the mixer lock.
- *****************************************************************************/
- int aout_OutputNew( aout_instance_t * p_aout,
- audio_sample_format_t * p_format )
- {
- /* Retrieve user defaults. */
- int i_rate = config_GetInt( p_aout, "aout-rate" );
- vlc_value_t val, text;
- /* kludge to avoid a fpu error when rate is 0... */
- if( i_rate == 0 ) i_rate = -1;
- memcpy( &p_aout->output.output, p_format, sizeof(audio_sample_format_t) );
- if ( i_rate != -1 )
- p_aout->output.output.i_rate = i_rate;
- aout_FormatPrepare( &p_aout->output.output );
- vlc_mutex_lock( &p_aout->output_fifo_lock );
- /* Find the best output plug-in. */
- p_aout->output.p_module = module_Need( p_aout, "audio output", "$aout", 0);
- if ( p_aout->output.p_module == NULL )
- {
- msg_Err( p_aout, "no suitable aout module" );
- vlc_mutex_unlock( &p_aout->output_fifo_lock );
- return -1;
- }
- if ( var_Type( p_aout, "audio-channels" ) ==
- (VLC_VAR_INTEGER | VLC_VAR_HASCHOICE) )
- {
- /* The user may have selected a different channels configuration. */
- var_Get( p_aout, "audio-channels", &val );
- if ( val.i_int == AOUT_VAR_CHAN_RSTEREO )
- {
- p_aout->output.output.i_original_channels |=
- AOUT_CHAN_REVERSESTEREO;
- }
- else if ( val.i_int == AOUT_VAR_CHAN_STEREO )
- {
- p_aout->output.output.i_original_channels =
- AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT;
- }
- else if ( val.i_int == AOUT_VAR_CHAN_LEFT )
- {
- p_aout->output.output.i_original_channels = AOUT_CHAN_LEFT;
- }
- else if ( val.i_int == AOUT_VAR_CHAN_RIGHT )
- {
- p_aout->output.output.i_original_channels = AOUT_CHAN_RIGHT;
- }
- else if ( val.i_int == AOUT_VAR_CHAN_DOLBYS )
- {
- p_aout->output.output.i_original_channels
- = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_DOLBYSTEREO;
- }
- }
- else if ( p_aout->output.output.i_physical_channels == AOUT_CHAN_CENTER
- && (p_aout->output.output.i_original_channels
- & AOUT_CHAN_PHYSMASK) == (AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT) )
- {
- /* Mono - create the audio-channels variable. */
- var_Create( p_aout, "audio-channels",
- VLC_VAR_INTEGER | VLC_VAR_HASCHOICE );
- text.psz_string = _("Audio Channels");
- var_Change( p_aout, "audio-channels", VLC_VAR_SETTEXT, &text, NULL );
- val.i_int = AOUT_VAR_CHAN_STEREO; text.psz_string = _("Stereo");
- var_Change( p_aout, "audio-channels", VLC_VAR_ADDCHOICE, &val, &text );
- val.i_int = AOUT_VAR_CHAN_LEFT; text.psz_string = _("Left");
- var_Change( p_aout, "audio-channels", VLC_VAR_ADDCHOICE, &val, &text );
- val.i_int = AOUT_VAR_CHAN_RIGHT; text.psz_string = _("Right");
- var_Change( p_aout, "audio-channels", VLC_VAR_ADDCHOICE, &val, &text );
- if ( p_aout->output.output.i_original_channels & AOUT_CHAN_DUALMONO )
- {
- /* Go directly to the left channel. */
- p_aout->output.output.i_original_channels = AOUT_CHAN_LEFT;
- val.i_int = AOUT_VAR_CHAN_LEFT;
- var_Set( p_aout, "audio-channels", val );
- }
- var_AddCallback( p_aout, "audio-channels", aout_ChannelsRestart,
- NULL );
- }
- else if ( p_aout->output.output.i_physical_channels ==
- (AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT)
- && (p_aout->output.output.i_original_channels &
- (AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT)) )
- {
- /* Stereo - create the audio-channels variable. */
- var_Create( p_aout, "audio-channels",
- VLC_VAR_INTEGER | VLC_VAR_HASCHOICE );
- text.psz_string = _("Audio Channels");
- var_Change( p_aout, "audio-channels", VLC_VAR_SETTEXT, &text, NULL );
- if ( p_aout->output.output.i_original_channels & AOUT_CHAN_DOLBYSTEREO )
- {
- val.i_int = AOUT_VAR_CHAN_DOLBYS;
- text.psz_string = _("Dolby Surround");
- }
- else
- {
- val.i_int = AOUT_VAR_CHAN_STEREO;
- text.psz_string = _("Stereo");
- }
- var_Change( p_aout, "audio-channels", VLC_VAR_ADDCHOICE, &val, &text );
- val.i_int = AOUT_VAR_CHAN_LEFT; text.psz_string = _("Left");
- var_Change( p_aout, "audio-channels", VLC_VAR_ADDCHOICE, &val, &text );
- val.i_int = AOUT_VAR_CHAN_RIGHT; text.psz_string = _("Right");
- var_Change( p_aout, "audio-channels", VLC_VAR_ADDCHOICE, &val, &text );
- val.i_int = AOUT_VAR_CHAN_RSTEREO; text.psz_string=_("Reverse stereo");
- var_Change( p_aout, "audio-channels", VLC_VAR_ADDCHOICE, &val, &text );
- if ( p_aout->output.output.i_original_channels & AOUT_CHAN_DUALMONO )
- {
- /* Go directly to the left channel. */
- p_aout->output.output.i_original_channels = AOUT_CHAN_LEFT;
- val.i_int = AOUT_VAR_CHAN_LEFT;
- var_Set( p_aout, "audio-channels", val );
- }
- var_AddCallback( p_aout, "audio-channels", aout_ChannelsRestart,
- NULL );
- }
- val.b_bool = VLC_TRUE;
- var_Set( p_aout, "intf-change", val );
- aout_FormatPrepare( &p_aout->output.output );
- /* Prepare FIFO. */
- aout_FifoInit( p_aout, &p_aout->output.fifo,
- p_aout->output.output.i_rate );
- vlc_mutex_unlock( &p_aout->output_fifo_lock );
- aout_FormatPrint( p_aout, "output", &p_aout->output.output );
- /* Calculate the resulting mixer output format. */
- memcpy( &p_aout->mixer.mixer, &p_aout->output.output,
- sizeof(audio_sample_format_t) );
- if ( !AOUT_FMT_NON_LINEAR(&p_aout->output.output) )
- {
- /* Non-S/PDIF mixer only deals with float32 or fixed32. */
- p_aout->mixer.mixer.i_format
- = (p_aout->p_libvlc->i_cpu & CPU_CAPABILITY_FPU) ?
- VLC_FOURCC('f','l','3','2') :
- VLC_FOURCC('f','i','3','2');
- aout_FormatPrepare( &p_aout->mixer.mixer );
- }
- else
- {
- p_aout->mixer.mixer.i_format = p_format->i_format;
- }
- aout_FormatPrint( p_aout, "mixer", &p_aout->output.output );
- /* Create filters. */
- if ( aout_FiltersCreatePipeline( p_aout, p_aout->output.pp_filters,
- &p_aout->output.i_nb_filters,
- &p_aout->mixer.mixer,
- &p_aout->output.output ) < 0 )
- {
- msg_Err( p_aout, "couldn't set an output pipeline" );
- module_Unneed( p_aout, p_aout->output.p_module );
- return -1;
- }
- /* Prepare hints for the buffer allocator. */
- p_aout->mixer.output_alloc.i_alloc_type = AOUT_ALLOC_HEAP;
- p_aout->mixer.output_alloc.i_bytes_per_sec
- = p_aout->mixer.mixer.i_bytes_per_frame
- * p_aout->mixer.mixer.i_rate
- / p_aout->mixer.mixer.i_frame_length;
- aout_FiltersHintBuffers( p_aout, p_aout->output.pp_filters,
- p_aout->output.i_nb_filters,
- &p_aout->mixer.output_alloc );
- p_aout->output.b_error = 0;
- return 0;
- }
- /*****************************************************************************
- * aout_OutputDelete : delete the output
- *****************************************************************************
- * This function is entered with the mixer lock.
- *****************************************************************************/
- void aout_OutputDelete( aout_instance_t * p_aout )
- {
- if ( p_aout->output.b_error )
- {
- return;
- }
- module_Unneed( p_aout, p_aout->output.p_module );
- aout_FiltersDestroyPipeline( p_aout, p_aout->output.pp_filters,
- p_aout->output.i_nb_filters );
- aout_FifoDestroy( p_aout, &p_aout->output.fifo );
- p_aout->output.b_error = VLC_TRUE;
- }
- /*****************************************************************************
- * aout_OutputPlay : play a buffer
- *****************************************************************************
- * This function is entered with the mixer lock.
- *****************************************************************************/
- void aout_OutputPlay( aout_instance_t * p_aout, aout_buffer_t * p_buffer )
- {
- aout_FiltersPlay( p_aout, p_aout->output.pp_filters,
- p_aout->output.i_nb_filters,
- &p_buffer );
- if( p_buffer->i_nb_bytes == 0 )
- {
- aout_BufferFree( p_buffer );
- return;
- }
- vlc_mutex_lock( &p_aout->output_fifo_lock );
- aout_FifoPush( p_aout, &p_aout->output.fifo, p_buffer );
- p_aout->output.pf_play( p_aout );
- vlc_mutex_unlock( &p_aout->output_fifo_lock );
- }
- /*****************************************************************************
- * aout_OutputNextBuffer : give the audio output plug-in the right buffer
- *****************************************************************************
- * If b_can_sleek is 1, the aout core functions won't try to resample
- * new buffers to catch up - that is we suppose that the output plug-in can
- * compensate it by itself. S/PDIF outputs should always set b_can_sleek = 1.
- * This function is entered with no lock at all :-).
- *****************************************************************************/
- aout_buffer_t * aout_OutputNextBuffer( aout_instance_t * p_aout,
- mtime_t start_date,
- vlc_bool_t b_can_sleek )
- {
- aout_buffer_t * p_buffer;
- vlc_mutex_lock( &p_aout->output_fifo_lock );
- p_buffer = p_aout->output.fifo.p_first;
- while ( p_buffer && p_buffer->start_date < mdate() - AOUT_PTS_TOLERANCE )
- {
- msg_Dbg( p_aout, "audio output is too slow ("I64Fd"), "
- "trashing "I64Fd"us", mdate() - p_buffer->start_date,
- p_buffer->end_date - p_buffer->start_date );
- p_buffer = p_buffer->p_next;
- aout_BufferFree( p_aout->output.fifo.p_first );
- p_aout->output.fifo.p_first = p_buffer;
- }
- if ( p_buffer == NULL )
- {
- p_aout->output.fifo.pp_last = &p_aout->output.fifo.p_first;
- #if 0 /* This is bad because the audio output might just be trying to fill
- * in it's internal buffers. And anyway, it's up to the audio output
- * to deal with this kind of starvation. */
- /* Set date to 0, to allow the mixer to send a new buffer ASAP */
- aout_FifoSet( p_aout, &p_aout->output.fifo, 0 );
- if ( !p_aout->output.b_starving )
- msg_Dbg( p_aout,
- "audio output is starving (no input), playing silence" );
- p_aout->output.b_starving = 1;
- #endif
- vlc_mutex_unlock( &p_aout->output_fifo_lock );
- return NULL;
- }
- /* Here we suppose that all buffers have the same duration - this is
- * generally true, and anyway if it's wrong it won't be a disaster.
- */
- if ( p_buffer->start_date > start_date
- + (p_buffer->end_date - p_buffer->start_date) )
- /*
- * + AOUT_PTS_TOLERANCE )
- * There is no reason to want that, it just worsen the scheduling of
- * an audio sample after an output starvation (ie. on start or on resume)
- * --Gibalou
- */
- {
- vlc_mutex_unlock( &p_aout->output_fifo_lock );
- if ( !p_aout->output.b_starving )
- msg_Dbg( p_aout, "audio output is starving ("I64Fd"), "
- "playing silence", p_buffer->start_date - start_date );
- p_aout->output.b_starving = 1;
- return NULL;
- }
- p_aout->output.b_starving = 0;
- if ( !b_can_sleek &&
- ( (p_buffer->start_date - start_date > AOUT_PTS_TOLERANCE)
- || (start_date - p_buffer->start_date > AOUT_PTS_TOLERANCE) ) )
- {
- /* Try to compensate the drift by doing some resampling. */
- int i;
- mtime_t difference = start_date - p_buffer->start_date;
- msg_Warn( p_aout, "output date isn't PTS date, requesting "
- "resampling ("I64Fd")", difference );
- vlc_mutex_lock( &p_aout->input_fifos_lock );
- for ( i = 0; i < p_aout->i_nb_inputs; i++ )
- {
- aout_fifo_t * p_fifo = &p_aout->pp_inputs[i]->fifo;
- aout_FifoMoveDates( p_aout, p_fifo, difference );
- }
- aout_FifoMoveDates( p_aout, &p_aout->output.fifo, difference );
- vlc_mutex_unlock( &p_aout->input_fifos_lock );
- }
- p_aout->output.fifo.p_first = p_buffer->p_next;
- if ( p_buffer->p_next == NULL )
- {
- p_aout->output.fifo.pp_last = &p_aout->output.fifo.p_first;
- }
- vlc_mutex_unlock( &p_aout->output_fifo_lock );
- return p_buffer;
- }