[vlc-devel] [PATCH 3/3] android/audio: add AAudio

[Rémi Denis-Courmont]

Le torstaina 3. joulukuuta 2020, 19.16.04 EET Thomas Guillem a écrit :
> https://developer.android.com/ndk/guides/audio/aaudio/aaudio
> 
> AAudio is a native PCM-only audio API starting Android 8.0 (but enabled
> in VLC starting Android 9.0 due to some bugs).
> 
> Having tested it with few device. The latency reported by this new API is
> correct and without any irregularity, contrary to the
> AudioTrack.getTimeStamp() API that is very broken.
> 
> Plus side, a huge gain of performance due to the absence of JNI
> C->JAVA->C++. ---
>  modules/audio_output/Makefile.am      |   1 +
>  modules/audio_output/android/aaudio.c | 625 ++++++++++++++++++++++++++
>  modules/audio_output/android/device.c |   5 +
>  modules/audio_output/android/device.h |   3 +
>  4 files changed, 634 insertions(+)
>  create mode 100644 modules/audio_output/android/aaudio.c
> 
> diff --git a/modules/audio_output/Makefile.am
> b/modules/audio_output/Makefile.am index 35b11e7e3aa..f4d38d9ff68 100644
> --- a/modules/audio_output/Makefile.am
> +++ b/modules/audio_output/Makefile.am
> @@ -3,6 +3,7 @@ aout_LTLIBRARIES =
> 
>  libandroid_audio_plugin_la_SOURCES = audio_output/android/audiotrack.c \
>  	audio_output/android/opensles.c \
> +	audio_output/android/aaudio.c \
>  	audio_output/android/device.c audio_output/android/device.h \
>  	video_output/android/utils.c video_output/android/utils.h
>  libandroid_audio_plugin_la_LIBADD = $(LIBDL) $(LIBM)
> diff --git a/modules/audio_output/android/aaudio.c
> b/modules/audio_output/android/aaudio.c new file mode 100644
> index 00000000000..15c3c193b3f
> --- /dev/null
> +++ b/modules/audio_output/android/aaudio.c
> @@ -0,0 +1,625 @@
> +/**************************************************************************
> *** + * aaudio.c: Android AAudio audio stream module
> +
> ***************************************************************************
> ** + * Copyright © 2018-2020 VLC authors, VideoLAN and VideoLabs
> + *
> + * Authors: Romain Vimont <rom1v at videolabs.io>
> + *          Thomas Guillem <thomas at gllm.fr>
> + *
> + * 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. +
> ***************************************************************************
> **/ +
> +#ifdef HAVE_CONFIG_H
> +# include "config.h"
> +#endif
> +
> +#include <vlc_common.h>
> +#include <vlc_plugin.h>
> +#include <vlc_aout.h>
> +#include <assert.h>
> +#include <dlfcn.h>
> +
> +#include "device.h"
> +
> +#include <aaudio/AAudio.h>
> +
> +struct sys
> +{
> +    AAudioStream *as;
> +
> +    jobject dp;
> +    float volume;
> +    bool muted;
> +
> +    audio_sample_format_t fmt;
> +    int64_t frames_written;
> +    int64_t frames_flush_pos;
> +    bool error;
> +};
> +
> +/* dlopen/dlsym symbols */
> +static struct {
> +    void *handle;
> +    aaudio_result_t       (*AAudio_createStreamBuilder)(AAudioStreamBuilder
> **); +    const char          
> *(*AAudio_convertResultToText)(aaudio_result_t); +    void                 
> (*AAudioStreamBuilder_setFormat)(AAudioStreamBuilder *, aaudio_format_t); +
>    void                 
> (*AAudioStreamBuilder_setChannelCount)(AAudioStreamBuilder *, int32_t); +  
>  void                 
> (*AAudioStreamBuilder_setBufferCapacityInFrames)(AAudioStreamBuilder *,
> int32_t); +    void                 
> (*AAudioStreamBuilder_setPerformanceMode)(AAudioStreamBuilder *,
> aaudio_performance_mode_t); +    void                 
> (*AAudioStreamBuilder_setSessionId)(AAudioStreamBuilder *,
> aaudio_session_id_t); +    void                 
> (*AAudioStreamBuilder_setUsage)(AAudioStreamBuilder *, aaudio_usage_t); +  
>  aaudio_result_t      
> (*AAudioStreamBuilder_openStream)(AAudioStreamBuilder *, AAudioStream **);
> +    void                 
> (*AAudioStreamBuilder_delete)(AAudioStreamBuilder *); +    aaudio_result_t 
>      (*AAudioStream_requestStart)(AAudioStream *); +    aaudio_result_t    
>   (*AAudioStream_requestStop)(AAudioStream *); +    aaudio_result_t      
> (*AAudioStream_requestPause)(AAudioStream *); +    aaudio_result_t      
> (*AAudioStream_requestFlush)(AAudioStream *); +    int32_t              
> (*AAudioStream_getSampleRate)(AAudioStream *); +    aaudio_result_t      
> (*AAudioStream_getTimestamp)(AAudioStream *, clockid_t, +                  
>                                     int64_t *framePosition, int64_t
> *timeNanoseconds); +    aaudio_result_t      
> (*AAudioStream_write)(AAudioStream *, void *, int32_t numFrames, int64_t
> timeoutNanoseconds); +    aaudio_result_t      
> (*AAudioStream_close)(AAudioStream *);
> +    aaudio_stream_state_t (*AAudioStream_getState)(AAudioStream *);
> +    aaudio_result_t       (*AAudioStream_waitForStateChange)(AAudioStream
> *, aaudio_stream_state_t current_state, aaudio_stream_state_t *nextState,
> int64_t timeoutNanoseconds); +    aaudio_session_id_t  
> (*AAudioStream_getSessionId)(AAudioStream *); +} vt;

Weak symbols would probably be a lot simpler than dlsym() calls here.

-- 
レミ・デニ-クールモン
http://www.remlab.net/