Android: add native AudioTrack aout module

Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>
Signed-off-by: Rafaël Carré <funman@videolan.org>

modules/audio_output/Modules.am

@@ -3,6 +3,13 @@ SOURCES_auhal = auhal.c packet.c
 SOURCES_audioqueue = audioqueue.c packet.c
 SOURCES_opensles_android = opensles_android.c
 
+libandroid_audiotrack_plugin_la_SOURCES = android_audiotrack.c
+libandroid_audiotrack_plugin_la_CFLAGS = $(AM_CFLAGS)
+libandroid_audiotrack_plugin_la_LIBADD = $(AM_LIBADD) -ldl
+if HAVE_ANDROID
+libvlc_LTLIBRARIES += libandroid_audiotrack_plugin.la
+endif
+
 libadummy_plugin_la_SOURCES = adummy.c
 libadummy_plugin_la_CFLAGS = $(AM_CFLAGS)
 libadummy_plugin_la_LIBADD = $(AM_LIBADD)

modules/audio_output/audiotrack.c

+/*****************************************************************************
+ * audiotrack.c: Android native AudioTrack audio output module
+ *****************************************************************************
+ * Copyright © 2012 VLC authors and VideoLAN
+ *
+ * Authors: Ming Hu <tewilove@gmail.com>
+ *
+ * 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 <dlfcn.h>
+#include <assert.h>
+
+#define SIZE_OF_AUDIOTRACK 256
+
+/* From AudioSystem.h */
+#define MUSIC 3
+
+enum pcm_sub_format {
+    PCM_SUB_16_BIT          = 0x1, // must be 1 for backward compatibility
+    PCM_SUB_8_BIT           = 0x2  // must be 2 for backward compatibility
+};
+
+enum audio_format {
+    PCM                 = 0x00000000, // must be 0 for backward compatibility
+    PCM_16_BIT          = (PCM|PCM_SUB_16_BIT),
+    PCM_8_BIT           = (PCM|PCM_SUB_8_BIT)
+};
+
+enum audio_channels {
+    CHANNEL_OUT_FRONT_LEFT            = 0x4,
+    CHANNEL_OUT_FRONT_RIGHT           = 0x8,
+    CHANNEL_OUT_FRONT_CENTER          = 0x10,
+    CHANNEL_OUT_LOW_FREQUENCY         = 0x20,
+    CHANNEL_OUT_BACK_LEFT             = 0x40,
+    CHANNEL_OUT_BACK_RIGHT            = 0x80,
+    CHANNEL_OUT_FRONT_LEFT_OF_CENTER  = 0x100,
+    CHANNEL_OUT_FRONT_RIGHT_OF_CENTER = 0x200,
+    CHANNEL_OUT_BACK_CENTER           = 0x400,
+    CHANNEL_OUT_MONO = CHANNEL_OUT_FRONT_LEFT,
+    CHANNEL_OUT_STEREO = (CHANNEL_OUT_FRONT_LEFT | CHANNEL_OUT_FRONT_RIGHT)
+};
+
+// _ZN7android11AudioSystem19getOutputFrameCountEPii
+typedef int (*AudioSystem_getOutputFrameCount)(int *, int);
+// _ZN7android11AudioSystem16getOutputLatencyEPji
+typedef int (*AudioSystem_getOutputLatency)(unsigned int *, int);
+// _ZN7android11AudioSystem21getOutputSamplingRateEPii
+typedef int (*AudioSystem_getOutputSamplingRate)(int *, int);
+
+// _ZN7android10AudioTrack16getMinFrameCountEPiij
+typedef int (*AudioTrack_getMinFrameCount)(int *, int, unsigned int);
+
+// _ZN7android10AudioTrackC1EijiiijPFviPvS1_ES1_ii
+typedef void (*AudioTrack_ctor)(void *, int, unsigned int, int, int, int, unsigned int, void (*)(int, void *, void *), void *, int, int);
+// _ZN7android10AudioTrackC1EijiiijPFviPvS1_ES1_i
+typedef void (*AudioTrack_ctor_legacy)(void *, int, unsigned int, int, int, int, unsigned int, void (*)(int, void *, void *), void *, int);
+// _ZN7android10AudioTrackD1Ev
+typedef void (*AudioTrack_dtor)(void *);
+// _ZNK7android10AudioTrack9initCheckEv
+typedef int (*AudioTrack_initCheck)(void *);
+// _ZN7android10AudioTrack5startEv
+typedef int (*AudioTrack_start)(void *);
+// _ZN7android10AudioTrack4stopEv
+typedef int (*AudioTrack_stop)(void *);
+// _ZN7android10AudioTrack5writeEPKvj
+typedef int (*AudioTrack_write)(void *, void  const*, unsigned int);
+// _ZN7android10AudioTrack5flushEv
+typedef int (*AudioTrack_flush)(void *);
+// _ZN7android10AudioTrack5pauseEv
+typedef int (*AudioTrack_pause)(void *);
+
+struct aout_sys_t {
+    void *libmedia;
+    void *AudioTrack;
+
+    AudioSystem_getOutputFrameCount as_getOutputFrameCount;
+    AudioSystem_getOutputLatency as_getOutputLatency;
+    AudioSystem_getOutputSamplingRate as_getOutputSamplingRate;
+
+    AudioTrack_getMinFrameCount at_getMinFrameCount;
+    AudioTrack_ctor at_ctor;
+    AudioTrack_ctor_legacy at_ctor_legacy;
+    AudioTrack_dtor at_dtor;
+    AudioTrack_initCheck at_initCheck;
+    AudioTrack_start at_start;
+    AudioTrack_stop at_stop;
+    AudioTrack_write at_write;
+    AudioTrack_flush at_flush;
+    AudioTrack_pause at_pause;
+};
+
+static void *InitLibrary(struct aout_sys_t *p_sys);
+
+static int  Open(vlc_object_t *);
+static void Close(vlc_object_t *);
+static void Play(audio_output_t *, block_t *);
+static void Pause (audio_output_t *, bool, mtime_t);
+
+vlc_module_begin ()
+    set_shortname("AudioTrack")
+    set_description(N_("Android AudioTrack audio output"))
+    set_capability("audio output", 225)
+    set_category(CAT_AUDIO)
+    set_subcategory(SUBCAT_AUDIO_AOUT)
+    add_shortcut("android")
+    set_callbacks(Open, Close)
+vlc_module_end ()
+
+static void *InitLibrary(struct aout_sys_t *p_sys)
+{
+    /* DL Open libmedia */
+    void *p_library;
+    p_library = dlopen("libmedia.so", RTLD_NOW|RTLD_LOCAL);
+    if (!p_library)
+        return NULL;
+
+    /* Register symbols */
+    p_sys->as_getOutputFrameCount = (AudioSystem_getOutputFrameCount)(dlsym(p_library, "_ZN7android11AudioSystem19getOutputFrameCountEPii"));
+    p_sys->as_getOutputLatency = (AudioSystem_getOutputLatency)(dlsym(p_library, "_ZN7android11AudioSystem16getOutputLatencyEPji"));
+    if(p_sys->as_getOutputLatency == NULL) {
+        /* 4.1 Jellybean prototype */
+        p_sys->as_getOutputLatency = (AudioSystem_getOutputLatency)(dlsym(p_library, "_ZN7android11AudioSystem16getOutputLatencyEPj19audio_stream_type_t"));
+    }
+    p_sys->as_getOutputSamplingRate = (AudioSystem_getOutputSamplingRate)(dlsym(p_library, "_ZN7android11AudioSystem21getOutputSamplingRateEPii"));
+    p_sys->at_getMinFrameCount = (AudioTrack_getMinFrameCount)(dlsym(p_library, "_ZN7android10AudioTrack16getMinFrameCountEPiij"));
+    if(p_sys->at_getMinFrameCount == NULL) {
+        /* 4.1 Jellybean prototype */
+        p_sys->at_getMinFrameCount = (AudioTrack_getMinFrameCount)(dlsym(p_library, "_ZN7android10AudioTrack16getMinFrameCountEPi19audio_stream_type_tj"));
+    }
+    p_sys->at_ctor = (AudioTrack_ctor)(dlsym(p_library, "_ZN7android10AudioTrackC1EijiiijPFviPvS1_ES1_ii"));
+    p_sys->at_ctor_legacy = (AudioTrack_ctor_legacy)(dlsym(p_library, "_ZN7android10AudioTrackC1EijiiijPFviPvS1_ES1_i"));
+    p_sys->at_dtor = (AudioTrack_dtor)(dlsym(p_library, "_ZN7android10AudioTrackD1Ev"));
+    p_sys->at_initCheck = (AudioTrack_initCheck)(dlsym(p_library, "_ZNK7android10AudioTrack9initCheckEv"));
+    p_sys->at_start = (AudioTrack_start)(dlsym(p_library, "_ZN7android10AudioTrack5startEv"));
+    p_sys->at_stop = (AudioTrack_stop)(dlsym(p_library, "_ZN7android10AudioTrack4stopEv"));
+    p_sys->at_write = (AudioTrack_write)(dlsym(p_library, "_ZN7android10AudioTrack5writeEPKvj"));
+    p_sys->at_flush = (AudioTrack_flush)(dlsym(p_library, "_ZN7android10AudioTrack5flushEv"));
+    p_sys->at_pause = (AudioTrack_pause)(dlsym(p_library, "_ZN7android10AudioTrack5pauseEv"));
+
+    /* We need the first 3 or the last 1 */
+    if (!((p_sys->as_getOutputFrameCount && p_sys->as_getOutputLatency && p_sys->as_getOutputSamplingRate)
+        || p_sys->at_getMinFrameCount)) {
+        dlclose(p_library);
+        return NULL;
+    }
+
+    // We need all the other Symbols
+    if (!((p_sys->at_ctor || p_sys->at_ctor_legacy) && p_sys->at_dtor && p_sys->at_initCheck &&
+           p_sys->at_start && p_sys->at_stop && p_sys->at_write && p_sys->at_flush)) {
+        dlclose(p_library);
+        return NULL;
+    }
+    return p_library;
+}
+
+static int Open(vlc_object_t *p_this)
+{
+    struct aout_sys_t *p_sys;
+    audio_output_t *p_aout = (audio_output_t*)(p_this);
+
+    int status, size;
+    int afSampleRate, afFrameCount, afLatency, minBufCount, minFrameCount;
+    int stream_type, channel, rate, format;
+
+    p_sys = (struct aout_sys_t*) malloc(sizeof(aout_sys_t));
+    if (!p_sys)
+        return VLC_ENOMEM;
+
+    p_sys->libmedia = InitLibrary(p_sys);
+    if (!p_sys->libmedia) {
+        msg_Err(p_aout, "Could not initialize libmedia.so!");
+        free(p_sys);
+        return VLC_EGENERIC;
+    }
+
+    /* 4000 <= frequency <= 48000 */
+    rate = p_aout->format.i_rate;
+    if (rate < 4000)
+        rate = 4000;
+    if (rate > 48000)
+        rate = 48000;
+
+    stream_type = MUSIC;
+
+    /* We can only accept U8 and S16L */
+    if (p_aout->format.i_format != VLC_CODEC_U8 && p_aout->format.i_format != VLC_CODEC_S16L)
+        p_aout->format.i_format = VLC_CODEC_S16L;
+    format = (p_aout->format.i_format == VLC_CODEC_S16L) ? PCM_16_BIT : PCM_8_BIT;
+
+    /* TODO: android supports more channels */
+    p_aout->format.i_original_channels = aout_FormatNbChannels(&p_aout->format);
+    switch(p_aout->format.i_original_channels)
+    {
+    case 1:
+        channel = CHANNEL_OUT_MONO;
+        p_aout->format.i_physical_channels = AOUT_CHAN_CENTER;
+        break;
+    case 2:
+    default:
+        channel = CHANNEL_OUT_STEREO;
+        p_aout->format.i_physical_channels = AOUT_CHAN_STEREO;
+        break;
+    }
+
+    /* Get the minimum buffer value */
+    if (!p_sys->at_getMinFrameCount) {
+        status = p_sys->as_getOutputSamplingRate(&afSampleRate, stream_type);
+        status ^= p_sys->as_getOutputFrameCount(&afFrameCount, stream_type);
+        status ^= p_sys->as_getOutputLatency((uint32_t*)(&afLatency), stream_type);
+        if (status != 0) {
+            msg_Err(p_aout, "Could not query the AudioStream parameters");
+            dlclose(p_sys->libmedia);
+            free(p_sys);
+            return VLC_EGENERIC;
+        }
+        minBufCount = afLatency / ((1000 * afFrameCount) / afSampleRate);
+        if (minBufCount < 2)
+            minBufCount = 2;
+        minFrameCount = (afFrameCount * rate * minBufCount) / afSampleRate;
+    }
+    else {
+        status = p_sys->at_getMinFrameCount(&minFrameCount, stream_type, rate);
+        if (status != 0) {
+            msg_Err(p_aout, "Could not query the AudioTrack parameters");
+            dlclose(p_sys->libmedia);
+            free(p_sys);
+            return VLC_EGENERIC;
+        }
+    }
+
+    size = minFrameCount * (channel == CHANNEL_OUT_STEREO ? 2 : 1) * 4;
+
+    /* Sizeof(AudioTrack) == 0x58 (not sure) on 2.2.1, this should be enough */
+    p_sys->AudioTrack = malloc(SIZE_OF_AUDIOTRACK);
+    if (!p_sys->AudioTrack) {
+        dlclose(p_sys->libmedia);
+        free(p_sys);
+        return VLC_ENOMEM;
+    }
+
+    *((uint32_t *) ((uint32_t)p_sys->AudioTrack + SIZE_OF_AUDIOTRACK - 4)) = 0xbaadbaad;
+    // Higher than android 2.2
+    if (p_sys->at_ctor)
+        p_sys->at_ctor(p_sys->AudioTrack, stream_type, rate, format, channel, size, 0, NULL, NULL, 0, 0);
+    // Higher than android 1.6
+    else if (p_sys->at_ctor_legacy)
+        p_sys->at_ctor_legacy(p_sys->AudioTrack, stream_type, rate, format, channel, size, 0, NULL, NULL, 0);
+
+    assert( (*((uint32_t *) ((uint32_t)p_sys->AudioTrack + SIZE_OF_AUDIOTRACK - 4)) == 0xbaadbaad) );
+
+    /* And Init */
+    status = p_sys->at_initCheck(p_sys->AudioTrack);
+
+    /* android 1.6 uses channel count instead of stream_type */
+    if (status != 0) {
+        channel = (channel == CHANNEL_OUT_STEREO) ? 2 : 1;
+        p_sys->at_ctor_legacy(p_sys->AudioTrack, stream_type, rate, format, channel, size, 0, NULL, NULL, 0);
+        status = p_sys->at_initCheck(p_sys->AudioTrack);
+    }
+    if (status != 0) {
+        msg_Err(p_aout, "Cannot create AudioTrack!");
+        dlclose(p_sys->libmedia);
+        free(p_sys->AudioTrack);
+        free(p_sys);
+        return VLC_EGENERIC;
+    }
+
+    p_aout->sys = p_sys;
+    p_aout->pf_play = Play;
+    p_aout->pf_pause = Pause;
+
+    p_sys->at_start(p_sys->AudioTrack);
+
+    p_aout->format.i_rate = rate;
+
+    return VLC_SUCCESS;
+}
+
+static void Close(vlc_object_t *p_this)
+{
+    audio_output_t *p_aout = (audio_output_t*)p_this;
+    aout_sys_t *p_sys = p_aout->sys;
+
+    p_sys->at_stop(p_sys->AudioTrack);
+    p_sys->at_flush(p_sys->AudioTrack);
+    p_sys->at_dtor(p_sys->AudioTrack);
+    free(p_sys->AudioTrack);
+    dlclose(p_sys->libmedia);
+    free(p_sys);
+}
+
+/* FIXME: lipsync */
+static void Play(audio_output_t *p_aout, block_t *p_buffer)
+{
+    aout_sys_t *p_sys = p_aout->sys;
+
+    size_t length = 0;
+    while (length < p_buffer->i_buffer) {
+        length += p_sys->at_write(p_sys->AudioTrack, (char*)(p_buffer->p_buffer) + length, p_buffer->i_buffer - length);
+    }
+
+    block_Release( p_buffer );
+}
+
+static void Pause(audio_output_t *p_aout, bool pause, mtime_t date)
+{
+    aout_sys_t *p_sys = p_aout->sys;
+
+    if (pause) {
+        p_sys->at_pause(p_sys->AudioTrack);
+    } else {
+        p_sys->at_start(p_sys->AudioTrack);
+    }
+}