+/*****************************************************************************
+ * intf.c : audio output API towards the interface modules
+ *****************************************************************************
+ * Copyright (C) 2002 VideoLAN
+ * $Id: intf.c,v 1.1 2002/09/16 20:46:38 massiot Exp $
+ *
+ * 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"
+
+/*
+ * Volume management
+ *
+ * The hardware volume cannot be set if the output module gets deleted, so
+ * we must take the mixer lock. The software volume cannot be set while the
+ * mixer is running, so we need the mixer lock (too).
+ *
+ * Here is a schematic of the i_volume range :
+ *
+ * |------------------+------------------------------------+--------------|
+ * 0 pi_low_soft pi_high_soft 1024
+ *
+ * Between pi_low_soft and pi_high_soft, the volume is done in hardware
+ * by the output module. Outside, the output module will change
+ * p_aout->mixer.i_multiplier (done in software). This scaling may result
+ * in cropping errors and should be avoided as much as possible.
+ *
+ * It is legal to have *pi_low_soft == *pi_high_soft, and do everything in
+ * software. In that case, it is recommended to use *pi_low_soft == 256,
+ * along with the utility functions provided in this file.
+ *
+ * It is also legal to have *pi_low_soft == 0 and *pi_high_soft == 1024, and
+ * completely avoid software scaling. However, some streams (esp. A/52)
+ * are encoded with a very low volume and users may complain.
+ */
+
+/*****************************************************************************
+ * aout_VolumeGet : get the volume of the output device
+ *****************************************************************************/
+int aout_VolumeGet( aout_instance_t * p_aout, audio_volume_t * pi_volume )
+{
+ int i_result;
+
+ vlc_mutex_lock( &p_aout->mixer_lock );
+
+ if ( p_aout->i_nb_inputs == 0 )
+ {
+ /* The output module is destroyed. */
+ vlc_mutex_unlock( &p_aout->mixer_lock );
+ msg_Err( p_aout, "VolumeGet called without output module" );
+ return -1;
+ }
+
+ i_result = p_aout->output.pf_volume_get( p_aout, pi_volume );
+
+ vlc_mutex_lock( &p_aout->mixer_lock );
+ return i_result;
+}
+
+/*****************************************************************************
+ * aout_VolumeSet : set the volume of the output device
+ *****************************************************************************/
+int aout_VolumeSet( aout_instance_t * p_aout, audio_volume_t i_volume )
+{
+ int i_result;
+
+ vlc_mutex_lock( &p_aout->mixer_lock );
+
+ if ( p_aout->i_nb_inputs == 0 )
+ {
+ /* The output module is destroyed. */
+ vlc_mutex_unlock( &p_aout->mixer_lock );
+ msg_Err( p_aout, "VolumeSet called without output module" );
+ return -1;
+ }
+
+ i_result = p_aout->output.pf_volume_set( p_aout, i_volume );
+
+ vlc_mutex_lock( &p_aout->mixer_lock );
+ return i_result;
+}
+
+/*****************************************************************************
+ * aout_VolumeInfos : get the boundaries pi_low_soft and pi_high_soft
+ *****************************************************************************/
+int aout_VolumeInfos( aout_instance_t * p_aout, audio_volume_t * pi_low_soft,
+ audio_volume_t * pi_high_soft )
+{
+ int i_result;
+
+ vlc_mutex_lock( &p_aout->mixer_lock );
+
+ if ( p_aout->i_nb_inputs == 0 )
+ {
+ /* The output module is destroyed. */
+ vlc_mutex_unlock( &p_aout->mixer_lock );
+ msg_Err( p_aout, "VolumeInfos called without output module" );
+ return -1;
+ }
+
+ i_result = p_aout->output.pf_volume_infos( p_aout, pi_low_soft,
+ pi_high_soft );
+
+ vlc_mutex_lock( &p_aout->mixer_lock );
+ return i_result;
+}
+
+/*****************************************************************************
+ * aout_VolumeUp : raise the output volume
+ *****************************************************************************
+ * If pi_volume != NULL, *pi_volume will contain the volume at the end of the
+ * function.
+ *****************************************************************************/
+int aout_VolumeUp( aout_instance_t * p_aout, int i_nb_steps,
+ audio_volume_t * pi_volume )
+{
+ int i_result;
+ audio_volume_t i_volume;
+
+ vlc_mutex_lock( &p_aout->mixer_lock );
+
+ if ( p_aout->i_nb_inputs == 0 )
+ {
+ /* The output module is destroyed. */
+ vlc_mutex_unlock( &p_aout->mixer_lock );
+ msg_Err( p_aout, "VolumeUp called without output module" );
+ return -1;
+ }
+
+ if ( p_aout->output.pf_volume_get( p_aout, &i_volume ) )
+ {
+ vlc_mutex_unlock( &p_aout->mixer_lock );
+ return -1;
+ }
+
+ i_volume += AOUT_VOLUME_STEP * i_nb_steps;
+ if ( i_volume > 1024 ) i_volume = 1024;
+
+ i_result = p_aout->output.pf_volume_set( p_aout, i_volume );
+
+ vlc_mutex_lock( &p_aout->mixer_lock );
+
+ if ( pi_volume != NULL ) *pi_volume = i_volume;
+ return i_result;
+}
+
+/*****************************************************************************
+ * aout_VolumeDown : lower the output volume
+ *****************************************************************************
+ * If pi_volume != NULL, *pi_volume will contain the volume at the end of the
+ * function.
+ *****************************************************************************/
+int aout_VolumeDown( aout_instance_t * p_aout, int i_nb_steps,
+ audio_volume_t * pi_volume )
+{
+ int i_result;
+ audio_volume_t i_volume;
+
+ vlc_mutex_lock( &p_aout->mixer_lock );
+
+ if ( p_aout->i_nb_inputs == 0 )
+ {
+ /* The output module is destroyed. */
+ vlc_mutex_unlock( &p_aout->mixer_lock );
+ msg_Err( p_aout, "VolumeUp called without output module" );
+ return -1;
+ }
+
+ if ( p_aout->output.pf_volume_get( p_aout, &i_volume ) )
+ {
+ vlc_mutex_unlock( &p_aout->mixer_lock );
+ return -1;
+ }
+
+ if ( i_volume < AOUT_VOLUME_STEP * i_nb_steps )
+ i_volume = 0;
+ else
+ i_volume -= AOUT_VOLUME_STEP * i_nb_steps;
+
+ i_result = p_aout->output.pf_volume_set( p_aout, i_volume );
+
+ vlc_mutex_lock( &p_aout->mixer_lock );
+
+ if ( pi_volume != NULL ) *pi_volume = i_volume;
+ return i_result;
+}
+
+/*
+ * The next functions are not supposed to be called by the interface, but
+ * are placeholders for software-only scaling.
+ */
+
+/* Meant to be called by the output plug-in's Open(). */
+void aout_VolumeSoftInit( aout_instance_t * p_aout )
+{
+ p_aout->output.i_volume = AOUT_VOLUME_DEFAULT;
+}
+
+/* Placeholder for pf_volume_infos(). */
+int aout_VolumeSoftInfos( aout_instance_t * p_aout,
+ audio_volume_t * pi_low_soft,
+ audio_volume_t * pi_high_soft )
+{
+ *pi_low_soft = *pi_high_soft = AOUT_VOLUME_DEFAULT;
+ return 0;
+}
+
+/* Placeholder for pf_volume_get(). */
+int aout_VolumeSoftGet( aout_instance_t * p_aout,
+ audio_volume_t * pi_volume )
+{
+ *pi_volume = p_aout->output.i_volume;
+ return 0;
+}
+
+
+/* Placeholder for pf_volume_set(). */
+int aout_VolumeSoftSet( aout_instance_t * p_aout,
+ audio_volume_t i_volume )
+{
+ aout_MixerMultiplierSet( p_aout, (float)(i_volume / AOUT_VOLUME_DEFAULT) );
+ return 0;
+}
+