New AudioUnit output module for iOS based on the Mac counterpart code

configure.ac

@@ -3531,6 +3531,19 @@ then
     ], [ AC_MSG_ERROR([cannot find CoreAudio headers]) ])
 fi
 
+dnl
+dnl  iOS CoreAudio plugin
+dnl
+AC_ARG_ENABLE(ios-audio,
+  [  --enable-ios-audio       Audio module for iOS (default disabled)])
+if test "${enable_ios_audio}" = "yes"
+then
+  AC_CHECK_HEADERS(AudioUnit/AudioUnit.h,
+    [ VLC_ADD_PLUGIN([audiounit_ios])
+      VLC_ADD_LIBS([audiounit_ios],[-Wl,-framework,CoreAudio,-framework,AudioUnit,-framework,AudioToolbox,-framework,CoreServices])
+    ], [ AC_MSG_ERROR([cannot find AudioUnit headers]) ])
+fi
+
 dnl
 dnl  AudioQueue plugin
 dnl

extras/package/ios/build.sh

@@ -265,6 +265,7 @@ ${VLCROOT}/configure \
     --disable-macosx-eyetv \
     --disable-macosx-vlc-app \
     --enable-audioqueue \
+    --enable-ios-audio \
     --enable-ios-vout \
     --enable-ios-vout2 \
     --disable-shared \

modules/audio_output/Modules.am

 SOURCES_waveout = waveout.c windows_audio_common.h
 SOURCES_auhal = TPCircularBuffer.h TPCircularBuffer.c auhal.c
+SOURCES_audiounit_ios = TPCircularBuffer.h TPCircularBuffer.c audiounit_ios.c
 SOURCES_audioqueue = audioqueue.c
 
 libopensles_android_plugin_la_SOURCES = opensles_android.c

modules/audio_output/audiounit_ios.c

+/*****************************************************************************
+ * audiounit_ios.c: AudioUnit output plugin for iOS
+ *****************************************************************************
+ * Copyright (C) 2012 - 2013 VLC authors and VideoLAN
+ * $Id$
+ *
+ * Authors: Felix Paul Kühne <fkuehne at videolan dot org>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ *****************************************************************************/
+
+#pragma mark includes
+
+#ifdef HAVE_CONFIG_H
+# import "config.h"
+#endif
+
+#import <vlc_common.h>
+#import <vlc_plugin.h>
+#import <vlc_aout.h>
+
+#import <AudioUnit/AudioUnit.h>
+#import <CoreAudio/CoreAudioTypes.h>
+#import <AudioToolbox/AudioToolbox.h>
+#import <mach/mach_time.h>
+
+#import "TPCircularBuffer.h"
+
+#pragma mark -
+#pragma mark private declarations
+
+#define STREAM_FORMAT_MSG(pre, sfm) \
+    pre "[%f][%4.4s][%u][%u][%u][%u][%u][%u]", \
+    sfm.mSampleRate, (char *)&sfm.mFormatID, \
+    (unsigned int)sfm.mFormatFlags, (unsigned int)sfm.mBytesPerPacket, \
+    (unsigned int)sfm.mFramesPerPacket, (unsigned int)sfm.mBytesPerFrame, \
+    (unsigned int)sfm.mChannelsPerFrame, (unsigned int)sfm.mBitsPerChannel
+
+#define kBufferLength 2048 * 8 * 8 * 4
+
+/*****************************************************************************
+ * aout_sys_t: private audio output method descriptor
+ *****************************************************************************
+ * This structure is part of the audio output thread descriptor.
+ * It describes the CoreAudio specific properties of an output thread.
+ *****************************************************************************/
+struct aout_sys_t
+{
+    uint8_t                     chans_to_reorder;   /* do we need channel reordering */
+    uint8_t                     chan_table[AOUT_CHAN_MAX];
+
+    UInt32                      i_numberOfChannels;
+    TPCircularBuffer            circular_buffer;    /* circular buffer to swap the audio data */
+
+    /* AUHAL specific */
+    AudioComponent              au_component;       /* The AudioComponent we use */
+    AudioUnit                   au_unit;            /* The AudioUnit we use */
+
+    int                         i_rate;             /* media sample rate */
+    mtime_t                     i_played_length;    /* how much did we play already */
+    mtime_t                     i_last_sample_time; /* last sample time played by the AudioUnit */
+    mtime_t                     i_first_time_stamp;
+    bool                        b_got_first_sample;
+
+    vlc_mutex_t                 lock;
+};
+
+#pragma mark -
+#pragma mark local prototypes & module descriptor
+
+static int      Open                    (vlc_object_t *);
+static void     Close                   (vlc_object_t *);
+static int      Start                   (audio_output_t *, audio_sample_format_t *);
+static int      StartAnalog             (audio_output_t *, audio_sample_format_t *);
+static void     Stop                    (audio_output_t *);
+
+static void     Play                    (audio_output_t *, block_t *);
+static void     Pause                   (audio_output_t *, bool, mtime_t);
+static void     Flush                   (audio_output_t *, bool);
+static int      TimeGet                 (audio_output_t *, mtime_t *);
+static OSStatus RenderCallback    (vlc_object_t *, AudioUnitRenderActionFlags *, const AudioTimeStamp *,
+                                         UInt32 , UInt32, AudioBufferList *);
+vlc_module_begin ()
+    set_shortname("audiounit_ios")
+    set_description(N_("AudioUnit output for iOS"))
+    set_capability("audio output", 101)
+    set_category(CAT_AUDIO)
+    set_subcategory(SUBCAT_AUDIO_AOUT)
+    set_callbacks(Open, Close)
+vlc_module_end ()
+
+#pragma mark -
+#pragma mark initialization
+
+static int Open(vlc_object_t *obj)
+{
+    audio_output_t *aout = (audio_output_t *)obj;
+    aout_sys_t *sys = malloc(sizeof (*sys));
+
+    if (unlikely(sys == NULL))
+        return VLC_ENOMEM;
+
+    vlc_mutex_init(&sys->lock);
+
+    aout->sys = sys;
+    aout->start = Start;
+    aout->stop = Stop;
+
+    return VLC_SUCCESS;
+}
+
+static void Close(vlc_object_t *obj)
+{
+    audio_output_t *aout = (audio_output_t *)obj;
+    aout_sys_t *sys = aout->sys;
+
+    vlc_mutex_destroy(&sys->lock);
+
+    free(sys);
+}
+
+static int Start(audio_output_t *p_aout, audio_sample_format_t *restrict fmt)
+{
+    struct aout_sys_t *p_sys = NULL;
+
+    p_sys = p_aout->sys;
+    p_sys->au_component = NULL;
+    p_sys->au_unit = NULL;
+
+    aout_FormatPrint(p_aout, "VLC is looking for:", fmt);
+
+    if (StartAnalog(p_aout, fmt)) {
+        msg_Dbg(p_aout, "analog AudioUnit output successfully opened");
+        p_aout->play = Play;
+        p_aout->flush = Flush;
+        p_aout->time_get = TimeGet;
+        p_aout->pause = Pause;
+        return VLC_SUCCESS;
+    }
+
+    /* If we reach this, this aout has failed */
+    msg_Err(p_aout, "opening AudioUnit output failed");
+    return VLC_EGENERIC;
+}
+
+/*
+ * StartAnalog: open and setup a HAL AudioUnit to do PCM audio output
+ */
+static int StartAnalog(audio_output_t *p_aout, audio_sample_format_t *fmt)
+{
+    struct aout_sys_t           *p_sys = p_aout->sys;
+    UInt32                      i_param_size = 0;
+    AudioComponentDescription   desc;
+    AURenderCallbackStruct      callback;
+    p_aout->sys->chans_to_reorder = 0;
+    OSStatus status;
+
+    /* Lets go find our Component */
+    desc.componentType = kAudioUnitType_Output;
+    desc.componentSubType = kAudioUnitSubType_RemoteIO;
+    desc.componentManufacturer = kAudioUnitManufacturer_Apple;
+    desc.componentFlags = 0;
+    desc.componentFlagsMask = 0;
+
+    p_sys->au_component = AudioComponentFindNext(NULL, &desc);
+    if (p_sys->au_component == NULL) {
+        msg_Warn(p_aout, "we cannot find our audio component");
+        return false;
+    }
+
+    status = AudioComponentInstanceNew(p_sys->au_component, &p_sys->au_unit);
+    if (status != noErr) {
+        msg_Warn(p_aout, "we cannot open our audio component (%li)", status);
+        return false;
+    }
+
+    UInt32 flag = 1;
+    status = AudioUnitSetProperty(p_sys->au_unit,
+                                  kAudioOutputUnitProperty_EnableIO,
+                                  kAudioUnitScope_Output,
+                                  0,
+                                  &flag,
+                                  sizeof(flag));
+    if (status != noErr)
+        msg_Warn(p_aout, "failed to set IO mode (%li)", status);
+
+    /* Get the current format */
+    AudioStreamBasicDescription streamDescription;
+    streamDescription.mSampleRate = fmt->i_rate;
+    fmt->i_format = VLC_CODEC_FL32;
+    streamDescription.mFormatID = kAudioFormatLinearPCM;
+    streamDescription.mFormatFlags = kAudioFormatFlagsNativeFloatPacked; // FL32
+    streamDescription.mChannelsPerFrame = 2;
+    streamDescription.mFramesPerPacket = 1;
+    streamDescription.mBitsPerChannel = 32;
+    streamDescription.mBytesPerFrame = streamDescription.mBitsPerChannel * streamDescription.mChannelsPerFrame / 8;
+    streamDescription.mBytesPerPacket = streamDescription.mBytesPerFrame * streamDescription.mFramesPerPacket;
+    i_param_size = sizeof(streamDescription);
+    p_sys->i_rate = fmt->i_rate;
+
+    /* Set the desired format */
+    i_param_size = sizeof(AudioStreamBasicDescription);
+    status = AudioUnitSetProperty(p_sys->au_unit,
+                                  kAudioUnitProperty_StreamFormat,
+                                  kAudioUnitScope_Input,
+                                  0,
+                                  &streamDescription,
+                                  i_param_size);
+    if (status != noErr) {
+        msg_Err(p_aout, "failed to set stream format (%li)", status);
+        return false;
+    }
+    msg_Dbg(p_aout, STREAM_FORMAT_MSG("we set the AU format: " , streamDescription));
+
+    /* Retrieve actual format */
+    status = AudioUnitGetProperty(p_sys->au_unit,
+                                  kAudioUnitProperty_StreamFormat,
+                                  kAudioUnitScope_Input,
+                                  0,
+                                  &streamDescription,
+                                  &i_param_size);
+    if (status != noErr)
+        msg_Warn(p_aout, "failed to verify stream format (%li)", status);
+    msg_Dbg(p_aout, STREAM_FORMAT_MSG("the actual set AU format is " , streamDescription));
+
+    /* Do the last VLC aout setups */
+    aout_FormatPrepare(fmt);
+
+    /* set the IOproc callback */
+    callback.inputProc = (AURenderCallback) RenderCallback;
+    callback.inputProcRefCon = p_aout;
+
+    status = AudioUnitSetProperty(p_sys->au_unit,
+                            kAudioUnitProperty_SetRenderCallback,
+                            kAudioUnitScope_Input,
+                            0, &callback, sizeof(callback));
+    if (status != noErr) {
+        msg_Err(p_aout, "render callback setup failed (%li)", status);
+        return false;
+    }
+
+    /* AU initiliaze */
+    status = AudioUnitInitialize(p_sys->au_unit);
+    if (status != noErr) {
+        msg_Err(p_aout, "failed to init AudioUnit (%li)", status);
+        return false;
+    }
+
+    /* setup circular buffer */
+    TPCircularBufferInit(&p_sys->circular_buffer, kBufferLength);
+
+    p_sys->b_got_first_sample = false;
+    p_sys->i_played_length = 0;
+    p_sys->i_last_sample_time = 0;
+    p_sys->i_first_time_stamp = 0;
+
+    return true;
+}
+
+static void Stop(audio_output_t *p_aout)
+{
+    struct aout_sys_t   *p_sys = p_aout->sys;
+    OSStatus status;
+
+    if (p_sys->au_unit) {
+        status = AudioOutputUnitStop(p_sys->au_unit);
+        if (status != noErr)
+            msg_Warn(p_aout, "failed to stop AudioUnit (%li)", status);
+
+        status = AudioComponentInstanceDispose(p_sys->au_unit);
+        if (status != noErr)
+            msg_Warn(p_aout, "failed to dispose Audio Component instance (%li)", status);
+    }
+
+    p_sys->i_played_length = 0;
+    p_sys->i_last_sample_time = 0;
+    p_sys->i_first_time_stamp = 0;
+
+    /* clean-up circular buffer */
+    TPCircularBufferCleanup(&p_sys->circular_buffer);
+}
+
+#pragma mark -
+#pragma mark actual playback
+
+static void Play (audio_output_t * p_aout, block_t * p_block)
+{
+    struct aout_sys_t *p_sys = p_aout->sys;
+
+    if (p_block->i_nb_samples > 0) {
+        if (!p_sys->b_got_first_sample) {
+            /* Start the AU */
+            OSStatus status = AudioOutputUnitStart(p_sys->au_unit);
+            msg_Dbg(p_aout, "audio output unit started: %li", status);
+            p_sys->b_got_first_sample = true;
+        }
+
+        /* Do the channel reordering */
+        if (p_sys->chans_to_reorder) {
+           aout_ChannelReorder(p_block->p_buffer,
+                               p_block->i_buffer,
+                               p_sys->chans_to_reorder,
+                               p_sys->chan_table,
+                               VLC_CODEC_FL32);
+        }
+
+        /* keep track of the played data */
+        p_aout->sys->i_played_length += p_block->i_length;
+
+        /* move data to buffer */
+        TPCircularBufferProduceBytes(&p_sys->circular_buffer, p_block->p_buffer, p_block->i_buffer);
+    }
+
+    block_Release(p_block);
+}
+
+static void Pause (audio_output_t *p_aout, bool pause, mtime_t date)
+{
+    struct aout_sys_t * p_sys = p_aout->sys;
+    VLC_UNUSED(date);
+
+    if (pause)
+        AudioOutputUnitStop(p_sys->au_unit);
+    else
+        AudioOutputUnitStart(p_sys->au_unit);
+}
+
+static void Flush(audio_output_t *p_aout, bool wait)
+{
+    struct aout_sys_t * p_sys = p_aout->sys;
+    VLC_UNUSED(wait);
+
+    p_sys->b_got_first_sample = false;
+
+    /* flush circular buffer */
+    AudioOutputUnitStop(p_aout->sys->au_unit);
+    TPCircularBufferClear(&p_aout->sys->circular_buffer);
+
+    p_sys->i_played_length = 0;
+    p_sys->i_last_sample_time = 0;
+    p_sys->i_first_time_stamp = 0;
+}
+
+static int TimeGet(audio_output_t *p_aout, mtime_t *delay)
+{
+    struct aout_sys_t * p_sys = p_aout->sys;
+
+    vlc_mutex_lock(&p_sys->lock);
+    mtime_t i_pos = (p_sys->i_last_sample_time - p_sys->i_first_time_stamp) * CLOCK_FREQ / p_sys->i_rate;
+    vlc_mutex_unlock(&p_sys->lock);
+
+    if (i_pos > 0) {
+        *delay = p_aout->sys->i_played_length - i_pos;
+        return 0;
+    }
+    else
+        return -1;
+}
+
+/*****************************************************************************
+ * RenderCallback: This function is called everytime the AudioUnit wants
+ * us to provide some more audio data.
+ * Don't print anything during normal playback, calling blocking function from
+ * this callback is not allowed.
+ *****************************************************************************/
+static OSStatus RenderCallback(vlc_object_t *p_obj,
+                               AudioUnitRenderActionFlags *ioActionFlags,
+                               const AudioTimeStamp *inTimeStamp,
+                               UInt32 inBusNumber,
+                               UInt32 inNumberFrames,
+                               AudioBufferList *ioData) {
+    VLC_UNUSED(ioActionFlags);
+    VLC_UNUSED(inTimeStamp);
+    VLC_UNUSED(inBusNumber);
+
+    audio_output_t * p_aout = (audio_output_t *)p_obj;
+    struct aout_sys_t * p_sys = p_aout->sys;
+
+    int bytesToCopy = ioData->mBuffers[0].mDataByteSize;
+    Float32 *targetBuffer = (Float32*)ioData->mBuffers[0].mData;
+
+    /* Pull audio from buffer */
+    int32_t availableBytes = 0;
+    Float32 *buffer = TPCircularBufferTail(&p_sys->circular_buffer, &availableBytes);
+
+    /* check if we have enough data */
+    if (!availableBytes) {
+        /* return an empty buffer so silence is played until we have data */
+        for (UInt32 j = 0; j < inNumberFrames; j++)
+            targetBuffer[j] = 0.;
+    } else {
+        memcpy(targetBuffer, buffer, __MIN(bytesToCopy, availableBytes));
+        TPCircularBufferConsume(&p_sys->circular_buffer, __MIN(bytesToCopy, availableBytes));
+        VLC_UNUSED(inNumberFrames);
+        vlc_mutex_lock(&p_sys->lock);
+        p_sys->i_last_sample_time = inTimeStamp->mSampleTime;
+        vlc_mutex_unlock(&p_sys->lock);
+        if (p_sys->i_first_time_stamp == 0)
+            p_sys->i_first_time_stamp = inTimeStamp->mSampleTime;
+    }
+
+    return noErr;
+}
+