+/*****************************************************************************
+ * aout_pcm.c: PCM audio output functions
+ *****************************************************************************
+ * Copyright (C) 1999-2002 VideoLAN
+ * $Id: aout_pcm.c,v 1.1 2002/02/24 22:06:50 sam Exp $
+ *
+ * Authors: Michel Kaempf <maxx@via.ecp.fr>
+ * Cyril Deguet <asmax@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 <stdio.h> /* "intf_msg.h" */
+#include <stdlib.h> /* calloc(), malloc(), free() */
+#include <string.h>
+
+#include <videolan/vlc.h>
+
+#include "audio_output.h"
+#include "aout_pcm.h"
+
+/* Biggest difference allowed between scheduled playing date and actual date
+ (in microseconds) */
+#define MAX_DELTA 10000
+
+/*****************************************************************************
+ * Local prototypes
+ *****************************************************************************/
+static void FillBuffer( aout_thread_t * p_aout, aout_fifo_t * p_fifo );
+static int NextFrame ( aout_thread_t * p_aout, aout_fifo_t * p_fifo,
+ mtime_t aout_date );
+
+ /*****************************************************************************
+ * Functions
+ *****************************************************************************/
+void aout_PCMThread( aout_thread_t * p_aout )
+{
+ int i_fifo;
+ int i_buffer, i_buffer_limit, i_bytes;
+
+ /* As the s32_buffer was created with calloc(), we don't have to set this
+ * memory to zero and we can immediately jump into the thread's loop */
+ while ( ! p_aout->b_die )
+ {
+ vlc_mutex_lock( &p_aout->fifos_lock );
+ for ( i_fifo = 0; i_fifo < AOUT_MAX_FIFOS; i_fifo++ )
+ {
+ if( p_aout->fifo[i_fifo].b_die )
+ {
+ aout_FreeFifo( &p_aout->fifo[i_fifo] );
+ }
+ else
+ {
+ FillBuffer( p_aout, &p_aout->fifo[i_fifo] );
+ }
+ }
+ vlc_mutex_unlock( &p_aout->fifos_lock );
+
+ i_buffer_limit = p_aout->i_units * p_aout->i_channels;
+
+ switch ( p_aout->i_format )
+ {
+ case AOUT_FMT_U8:
+ for ( i_buffer = 0; i_buffer < i_buffer_limit; i_buffer++ )
+ {
+ ((u8*)p_aout->buffer)[i_buffer] = (u8)(
+ (p_aout->s32_buffer[i_buffer] / AOUT_MAX_FIFOS / 256 + 128)
+ * p_aout->i_volume / 256);
+ p_aout->s32_buffer[i_buffer] = 0;
+ }
+ break;
+
+ case AOUT_FMT_S8:
+ for ( i_buffer = 0; i_buffer < i_buffer_limit; i_buffer++ )
+ {
+ ((s8*)p_aout->buffer)[i_buffer] = (s8)(
+ p_aout->s32_buffer[i_buffer] / AOUT_MAX_FIFOS / 256
+ * p_aout->i_volume / 256);
+ p_aout->s32_buffer[i_buffer] = 0;
+ }
+ break;
+
+ case AOUT_FMT_U16_LE:
+ case AOUT_FMT_U16_BE:
+ for ( i_buffer = 0; i_buffer < i_buffer_limit; i_buffer++ )
+ {
+ ((u16*)p_aout->buffer)[i_buffer] = (u16)(
+ (p_aout->s32_buffer[i_buffer] / AOUT_MAX_FIFOS + 128)
+ * p_aout->i_volume / 256);
+ p_aout->s32_buffer[i_buffer] = 0;
+ }
+ break;
+
+ case AOUT_FMT_S16_LE:
+ case AOUT_FMT_S16_BE:
+ for ( i_buffer = 0; i_buffer < i_buffer_limit; i_buffer++ )
+ {
+ ((s16*)p_aout->buffer)[i_buffer] = (s16)(
+ p_aout->s32_buffer[i_buffer] / AOUT_MAX_FIFOS
+ * p_aout->i_volume / 256);
+ p_aout->s32_buffer[i_buffer] = 0;
+ }
+ break;
+ }
+
+ i_bytes = p_aout->pf_getbufinfo( p_aout, i_buffer_limit );
+
+ switch ( p_aout->i_format )
+ {
+ case AOUT_FMT_U8:
+ case AOUT_FMT_S8:
+ p_aout->date = mdate() + ((((mtime_t)((i_bytes + 4 *
+ p_aout->i_latency) / p_aout->i_channels)) * 1000000) /
+ ((mtime_t)p_aout->i_rate)) + p_main->i_desync;
+
+ p_aout->pf_play( p_aout, (byte_t *)p_aout->buffer,
+ i_buffer_limit );
+ break;
+
+ case AOUT_FMT_U16_LE:
+ case AOUT_FMT_U16_BE:
+ case AOUT_FMT_S16_LE:
+ case AOUT_FMT_S16_BE:
+ p_aout->date = mdate() + ((((mtime_t)((i_bytes + 4 *
+ p_aout->i_latency) / (2 * p_aout->i_channels))) * 1000000) /
+ ((mtime_t)p_aout->i_rate)) + p_main->i_desync;
+
+ p_aout->pf_play( p_aout, (byte_t *)p_aout->buffer,
+ i_buffer_limit * 2 );
+ break;
+ }
+
+ if ( i_bytes > i_buffer_limit )
+ {
+ msleep( p_aout->i_msleep );
+ }
+ }
+
+ vlc_mutex_lock( &p_aout->fifos_lock );
+ for ( i_fifo = 0; i_fifo < AOUT_MAX_FIFOS; i_fifo++ )
+ {
+ aout_FreeFifo( &p_aout->fifo[i_fifo] );
+ }
+ vlc_mutex_unlock( &p_aout->fifos_lock );
+}
+
+/* Following functions are local */
+
+/*****************************************************************************
+ * InitializeIncrement: change i_x/i_y to i_a+i_b/i_c
+ *****************************************************************************/
+static __inline__ void InitializeIncrement( aout_increment_t * p_inc,
+ int i_x, int i_y )
+{
+ p_inc->i_r = -i_y;
+ p_inc->i_a = 0;
+
+ while ( i_x >= i_y )
+ {
+ p_inc->i_a++;
+ i_x -= i_y;
+ }
+
+ p_inc->i_b = i_x;
+ p_inc->i_c = i_y;
+}
+
+/*****************************************************************************
+ * UpdateIncrement
+ *****************************************************************************/
+static __inline__ void UpdateIncrement( aout_increment_t * p_inc,
+ int * pi_integer )
+{
+ if( (p_inc->i_r += p_inc->i_b) >= 0 )
+ {
+ *pi_integer += p_inc->i_a + 1;
+ p_inc->i_r -= p_inc->i_c;
+ }
+ else
+ {
+ *pi_integer += p_inc->i_a;
+ }
+}
+
+/*****************************************************************************
+ * FillBuffer: Read data from decoder fifo, and put it in S32_buffer
+ *****************************************************************************/
+static void FillBuffer( aout_thread_t * p_aout, aout_fifo_t * p_fifo )
+{
+ int i_buffer = 0;
+ int i_buffer_limit, i_units;
+
+ switch ( p_fifo->i_format )
+ {
+ case AOUT_FIFO_PCM:
+
+ i_units = p_aout->i_units;
+
+ /* While there are empty frames in the buffer, fill them */
+ while ( i_units > 0 )
+ {
+ /* If there is no next frame, wait for one */
+ if( !p_fifo->b_next_frame )
+ {
+ if( NextFrame(p_aout, p_fifo, p_aout->date +
+ ((((mtime_t)(i_buffer >> 1)) * 1000000) /
+ ((mtime_t)p_aout->i_rate))) )
+ {
+ break;
+ }
+ }
+
+ i_buffer_limit = p_aout->i_units * p_aout->i_channels;
+
+ while ( i_buffer < i_buffer_limit )
+ {
+ /* FIXME: make this more generic */
+ if( p_aout->i_channels == 2 )
+ {
+ p_aout->s32_buffer[i_buffer++] +=
+ (s32)( ((s16 *)p_fifo->buffer)[2*p_fifo->i_unit] );
+ p_aout->s32_buffer[i_buffer++] +=
+ (s32)( ((s16 *)p_fifo->buffer)[2*p_fifo->i_unit+1] );
+ }
+ else if( p_aout->i_channels == 1 )
+ {
+ p_aout->s32_buffer[i_buffer++] +=
+ (s32)( ((s16 *)p_fifo->buffer)[p_fifo->i_unit] );
+ }
+ else
+ {
+ intf_ErrMsg( "aout error: unsupported number of channels" );
+ }
+
+ UpdateIncrement(&p_fifo->unit_increment, &p_fifo->i_unit);
+
+ if( p_fifo->i_unit >= p_fifo->i_unit_limit )
+ {
+ p_fifo->i_unit -= p_fifo->i_unit_limit;
+ }
+ }
+
+ if( p_fifo->i_units > i_units )
+ {
+ p_fifo->i_units -= i_units;
+ break;
+ }
+ else
+ {
+ i_units -= p_fifo->i_units;
+
+ vlc_mutex_lock( &p_fifo->data_lock );
+ p_fifo->i_start_frame = p_fifo->i_next_frame;
+ /* p_fifo->b_start_frame = 1; */
+ p_fifo->i_next_frame = AOUT_FIFO_INC( p_fifo->i_next_frame );
+ p_fifo->b_next_frame = 0;
+ vlc_cond_signal( &p_fifo->data_wait );
+ vlc_mutex_unlock( &p_fifo->data_lock );
+
+ }
+ }
+ break;
+
+ default:
+ break;
+ }
+}
+
+static int NextFrame( aout_thread_t * p_aout, aout_fifo_t * p_fifo,
+ mtime_t aout_date )
+{
+ int i_units, i_units_dist, i_rate;
+ u64 i_delta;
+
+ /* We take the lock */
+ vlc_mutex_lock( &p_fifo->data_lock );
+
+ /* Are we looking for a dated start frame ? */
+ if ( !p_fifo->b_start_frame )
+ {
+ while ( p_fifo->i_start_frame != p_fifo->i_end_frame )
+ {
+ if ( p_fifo->date[p_fifo->i_start_frame] != LAST_MDATE )
+ {
+ p_fifo->b_start_frame = 1;
+ p_fifo->i_next_frame = AOUT_FIFO_INC( p_fifo->i_start_frame );
+ p_fifo->i_unit = p_fifo->i_start_frame *
+ (p_fifo->i_frame_size / p_fifo->i_channels);
+ break;
+ }
+ p_fifo->i_start_frame = AOUT_FIFO_INC( p_fifo->i_start_frame );
+ }
+
+ if ( p_fifo->i_start_frame == p_fifo->i_end_frame )
+ {
+ vlc_mutex_unlock( &p_fifo->data_lock );
+ return( -1 );
+ }
+ }
+
+ /* We are looking for the next dated frame */
+ /* FIXME : is the output fifo full ?? -- pretty unlikely given its size */
+ while ( !p_fifo->b_next_frame )
+ {
+ while ( p_fifo->i_next_frame != p_fifo->i_end_frame )
+ {
+ if ( p_fifo->date[p_fifo->i_next_frame] != LAST_MDATE )
+ {
+ p_fifo->b_next_frame = 1;
+ break;
+ }
+ p_fifo->i_next_frame = AOUT_FIFO_INC( p_fifo->i_next_frame );
+ }
+
+ while ( p_fifo->i_next_frame == p_fifo->i_end_frame )
+ {
+ vlc_cond_wait( &p_fifo->data_wait, &p_fifo->data_lock );
+ if ( p_fifo->b_die )
+ {
+ vlc_mutex_unlock( &p_fifo->data_lock );
+ return( -1 );
+ }
+ }
+ }
+
+ i_units = ((p_fifo->i_next_frame - p_fifo->i_start_frame) & AOUT_FIFO_SIZE)
+ * (p_fifo->i_frame_size / p_fifo->i_channels);
+
+ i_delta = aout_date - p_fifo->date[p_fifo->i_start_frame];
+
+ /* Resample if delta is too long */
+ if( abs(i_delta) > MAX_DELTA )
+ {
+ i_rate = p_fifo->i_rate + (i_delta / 256);
+ }
+ else
+ {
+ i_rate = p_fifo->i_rate;
+ }
+
+ InitializeIncrement( &p_fifo->unit_increment, i_rate, p_aout->i_rate );
+
+ /* Calculate how many units we're going to write */
+ i_units_dist = p_fifo->i_unit - p_fifo->i_start_frame
+ * (p_fifo->i_frame_size / p_fifo->i_channels);
+
+ /* Manage the fifo wrapping */
+ if( i_units_dist > p_fifo->i_unit_limit / 2 )
+ {
+ i_units -= (i_units_dist - p_fifo->i_unit_limit);
+ }
+ else if( i_units_dist < - p_fifo->i_unit_limit / 2 )
+ {
+ i_units -= (i_units_dist + p_fifo->i_unit_limit);
+ }
+ else
+ {
+ i_units -= i_units_dist;
+ }
+
+ p_fifo->i_units = 1 + ( i_units * p_aout->i_rate / i_rate );
+
+ /* We release the lock before leaving */
+ vlc_mutex_unlock( &p_fifo->data_lock );
+ return( 0 );
+}
+