modules/audio_output/audioqueue.c

   1 /*****************************************************************************
   2  * audioqueue.c : AudioQueue audio output plugin for vlc
   3  *****************************************************************************
   4  * Copyright (C) 2010 VideoLAN and AUTHORS
   5  *
   6  * Authors: Romain Goyet <romain.goyet@likid.org>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  21  *****************************************************************************/
  22
  23 /*****************************************************************************
  24  * Preamble
  25  *****************************************************************************/
  26 #include <unistd.h>                                      /* write(), close() */
  27
  28 #ifdef HAVE_CONFIG_H
  29 # include "config.h"
  30 #endif
  31
  32 #include <vlc_common.h>
  33 #include <vlc_plugin.h>
  34 #include <vlc_aout.h>
  35
  36 #include <AudioToolBox/AudioToolBox.h>
  37
  38 #define FRAME_SIZE 2048
  39 #define NUMBER_OF_BUFFERS 3
  40
  41 /*****************************************************************************
  42  * aout_sys_t: AudioQueue audio output method descriptor
  43  *****************************************************************************
  44  * This structure is part of the audio output thread descriptor.
  45  * It describes the specific properties of an audio device.
  46  *****************************************************************************/
  47 struct aout_sys_t
  48 {
  49     AudioQueueRef audioQueue;
  50 };
  51
  52 /*****************************************************************************
  53  * Local prototypes
  54  *****************************************************************************/
  55 static int  Open               ( vlc_object_t * );
  56 static void Close              ( vlc_object_t * );
  57 static void Play               ( aout_instance_t * );
  58 static void AudioQueueCallback (void *, AudioQueueRef, AudioQueueBufferRef);
  59
  60 /*****************************************************************************
  61  * Module descriptor
  62  *****************************************************************************/
  63 vlc_module_begin ()
  64     set_shortname( "AudioQueue" )
  65     set_description( N_("AudioQueue (iOS / Mac OS) audio output") )
  66     set_capability( "audio output", 40 )
  67     set_category( CAT_AUDIO )
  68     set_subcategory( SUBCAT_AUDIO_AOUT )
  69     add_shortcut( "audioqueue" )
  70     set_callbacks( Open, Close )
  71 vlc_module_end ()
  72
  73 /*****************************************************************************
  74  * Open: open the audio device
  75  *****************************************************************************/
  76
  77 static int Open ( vlc_object_t *p_this )
  78 {
  79     aout_instance_t *p_aout = (aout_instance_t *)p_this;
  80     struct aout_sys_t *p_sys = malloc(sizeof(aout_sys_t));
  81     p_aout->output.p_sys = p_sys;
  82
  83     OSStatus status = 0;
  84
  85     // Setup the audio device.
  86     AudioStreamBasicDescription deviceFormat;
  87     deviceFormat.mSampleRate = 44100;
  88     deviceFormat.mFormatID = kAudioFormatLinearPCM;
  89     deviceFormat.mFormatFlags = kLinearPCMFormatFlagIsSignedInteger; // Signed integer, little endian
  90     deviceFormat.mBytesPerPacket = 4;
  91     deviceFormat.mFramesPerPacket = 1;
  92     deviceFormat.mBytesPerFrame = 4;
  93     deviceFormat.mChannelsPerFrame = 2;
  94     deviceFormat.mBitsPerChannel = 16;
  95     deviceFormat.mReserved = 0;
  96
  97     // Create a new output AudioQueue for the device.
  98     status = AudioQueueNewOutput(&deviceFormat,         // Format
  99                                  AudioQueueCallback,    // Callback
 100                                  p_aout,                // User data, passed to the callback
 101                                  CFRunLoopGetMain(),    // RunLoop
 102                                  kCFRunLoopDefaultMode, // RunLoop mode
 103                                  0,                     // Flags ; must be zero (per documentation)...
 104                                  &(p_sys->audioQueue)); // Output
 105
 106     // This will be used for boosting the audio without the need of a mixer (floating-point conversion is expensive on ARM)
 107     // AudioQueueSetParameter(p_sys->audioQueue, kAudioQueueParam_Volume, 12.0); // Defaults to 1.0
 108
 109     msg_Dbg(p_aout, "New AudioQueue output created (status = %i)", status);
 110
 111     // Allocate buffers for the AudioQueue, and pre-fill them.
 112     for (int i = 0; i < NUMBER_OF_BUFFERS; ++i) {
 113         AudioQueueBufferRef buffer = NULL;
 114         status = AudioQueueAllocateBuffer(p_sys->audioQueue, FRAME_SIZE * 4, &buffer);
 115         AudioQueueCallback(NULL, p_sys->audioQueue, buffer);
 116     }
 117
 118     /* Volume is entirely done in software. */
 119     aout_VolumeSoftInit( p_aout );
 120
 121     p_aout->output.output.i_format = VLC_CODEC_S16L;
 122     p_aout->output.output.i_physical_channels = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT;
 123     p_aout->output.output.i_rate = 44100;
 124     p_aout->output.i_nb_samples = FRAME_SIZE;
 125     p_aout->output.pf_play = Play;
 126
 127     msg_Dbg(p_aout, "Starting AudioQueue (status = %i)", status);
 128     status = AudioQueueStart(p_sys->audioQueue, NULL);
 129
 130     return VLC_SUCCESS;
 131 }
 132
 133 /*****************************************************************************
 134  * Play: play a sound samples buffer
 135  *****************************************************************************/
 136 static void Play( aout_instance_t * p_aout )
 137 {
 138     VLC_UNUSED(p_aout);
 139 }
 140
 141 /*****************************************************************************
 142  * Close: close the audio device
 143  *****************************************************************************/
 144 static void Close ( vlc_object_t *p_this )
 145 {
 146     aout_instance_t *p_aout = (aout_instance_t *)p_this;
 147     struct aout_sys_t * p_sys = p_aout->output.p_sys;
 148
 149     msg_Dbg(p_aout, "Stopping AudioQueue");
 150     AudioQueueStop(p_sys->audioQueue, false);
 151     msg_Dbg(p_aout, "Disposing of AudioQueue");
 152     AudioQueueDispose(p_sys->audioQueue, false);
 153     free (p_sys);
 154 }
 155
 156 void AudioQueueCallback(void * inUserData, AudioQueueRef inAQ, AudioQueueBufferRef inBuffer) {
 157     aout_instance_t * p_aout = (aout_instance_t *)inUserData;
 158     aout_buffer_t *   p_buffer = NULL;
 159
 160     if (p_aout) {
 161         vlc_mutex_lock( &p_aout->output_fifo_lock );
 162         p_buffer = aout_FifoPop( p_aout, &p_aout->output.fifo );
 163         vlc_mutex_unlock( &p_aout->output_fifo_lock );
 164     }
 165
 166     if ( p_buffer != NULL ) {
 167         vlc_memcpy( inBuffer->mAudioData, p_buffer->p_buffer, p_buffer->i_buffer );
 168         inBuffer->mAudioDataByteSize = p_buffer->i_buffer;
 169         aout_BufferFree( p_buffer );
 170     } else {
 171         vlc_memset( inBuffer->mAudioData, 0, inBuffer->mAudioDataBytesCapacity );
 172         inBuffer->mAudioDataByteSize = inBuffer->mAudioDataBytesCapacity;
 173     }
 174     AudioQueueEnqueueBuffer(inAQ, inBuffer, 0, NULL);
 175 }