[Android] [PATCH 4/4] android: add native AudioTrack aout module

Rafaël Carré funman at videolan.org
Mon Mar 5 00:04:59 CET 2012


From: tewilove <tewilove at gmail.com>

---
 configure.ac                        |   12 ++
 extras/package/android/configure.sh |    1 +
 modules/audio_output/Modules.am     |    1 +
 modules/audio_output/audiotrack.c   |  232 +++++++++++++++++++++++++++++++++++
 4 files changed, 246 insertions(+), 0 deletions(-)
 create mode 100644 modules/audio_output/audiotrack.c

diff --git a/configure.ac b/configure.ac
index 2a74fe6..dc93774 100644
--- a/configure.ac
+++ b/configure.ac
@@ -3500,6 +3500,18 @@ if test "${HAVE_ANDROID}" = "1"; then
 fi
 
 dnl
+dnl  android AudioTrack module
+dnl
+AC_ARG_ENABLE(android-audiotrack,
+  [  --enable-android-audiotrack   Android native AudioTrack audio output module (default disabled)])
+if test "${enable_android_audiotrack}" = "yes"; then
+  if test "${HAVE_ANDROID}" = "1"; then
+     VLC_ADD_PLUGIN([android_audiotrack])
+     VLC_ADD_LDFLAGS([android_audiotrack], [-ldl])
+  fi
+fi
+
+dnl
 dnl libsamplerate plugin
 dnl
 PKG_ENABLE_MODULES_VLC([SAMPLERATE], [], [samplerate], [Resampler with libsamplerate], [auto])
diff --git a/extras/package/android/configure.sh b/extras/package/android/configure.sh
index 3c65fb4..920598b 100755
--- a/extras/package/android/configure.sh
+++ b/extras/package/android/configure.sh
@@ -47,6 +47,7 @@ sh $VLC_SOURCEDIR/configure --host=arm-linux-androideabi --build=x86_64-unknown-
                 --enable-avcodec \
                 --enable-opensles \
                 --enable-android-surface \
+                --enable-android-audiotrack \
                 --enable-debug \
                 --enable-mkv \
                 --enable-taglib \
diff --git a/modules/audio_output/Modules.am b/modules/audio_output/Modules.am
index 1c571ee..fcdd5e4 100644
--- a/modules/audio_output/Modules.am
+++ b/modules/audio_output/Modules.am
@@ -5,6 +5,7 @@ SOURCES_auhal = auhal.c
 SOURCES_jack = jack.c
 SOURCES_audioqueue = audioqueue.c
 SOURCES_opensles_android = opensles_android.c
+SOURCES_android_audiotrack = audiotrack.c
 
 libadummy_plugin_la_SOURCES = adummy.c
 libadummy_plugin_la_CFLAGS = $(AM_CFLAGS)
diff --git a/modules/audio_output/audiotrack.c b/modules/audio_output/audiotrack.c
new file mode 100644
index 0000000..4457781
--- /dev/null
+++ b/modules/audio_output/audiotrack.c
@@ -0,0 +1,232 @@
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <vlc_common.h>
+#include <vlc_plugin.h>
+#include <vlc_aout.h>
+
+#include <dlfcn.h>
+
+// _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 *);
+
+struct aout_sys_t {
+    int type;
+    uint32_t rate;
+    int channel;
+    int format;
+    int size;
+    void *libmedia;
+    void *AudioTrack;
+};
+
+static AudioSystem_getOutputFrameCount as_getOutputFrameCount = NULL;
+static AudioSystem_getOutputLatency as_getOutputLatency = NULL;
+static AudioSystem_getOutputSamplingRate as_getOutputSamplingRate = NULL;
+static AudioTrack_getMinFrameCount at_getMinFrameCount = NULL;
+static AudioTrack_ctor at_ctor = NULL;
+static AudioTrack_ctor_legacy at_ctor_legacy = NULL;
+static AudioTrack_dtor at_dtor = NULL;
+static AudioTrack_initCheck at_initCheck = NULL;
+static AudioTrack_start at_start = NULL;
+static AudioTrack_stop at_stop = NULL;
+static AudioTrack_write at_write = NULL;
+static AudioTrack_flush at_flush = NULL;
+
+static void *InitLibrary();
+
+static int  Open(vlc_object_t *);
+static void Close(vlc_object_t *);
+static void Play(audio_output_t *, block_t *);
+
+vlc_module_begin ()
+    set_shortname("AudioTrack")
+    set_description(N_("Android AudioTrack audio output"))
+    set_capability("audio output", 25)
+    set_category(CAT_AUDIO)
+    set_subcategory(SUBCAT_AUDIO_AOUT)
+    add_shortcut("android")
+    set_callbacks(Open, Close)
+vlc_module_end ()
+
+void *InitLibrary() {
+    void *p_library;
+
+    p_library = dlopen("libmedia.so", RTLD_NOW);
+    if (!p_library)
+        return NULL;
+    as_getOutputFrameCount = (AudioSystem_getOutputFrameCount)(dlsym(p_library, "_ZN7android11AudioSystem19getOutputFrameCountEPii"));
+    as_getOutputLatency = (AudioSystem_getOutputLatency)(dlsym(p_library, "_ZN7android11AudioSystem16getOutputLatencyEPji"));
+    as_getOutputSamplingRate = (AudioSystem_getOutputSamplingRate)(dlsym(p_library, "_ZN7android11AudioSystem21getOutputSamplingRateEPii"));
+    at_getMinFrameCount = (AudioTrack_getMinFrameCount)(dlsym(p_library, "_ZN7android10AudioTrack16getMinFrameCountEPiij"));
+    at_ctor = (AudioTrack_ctor)(dlsym(p_library, "_ZN7android10AudioTrackC1EijiiijPFviPvS1_ES1_ii"));
+    at_ctor_legacy = (AudioTrack_ctor_legacy)(dlsym(p_library, "_ZN7android10AudioTrackC1EijiiijPFviPvS1_ES1_i"));
+    at_dtor = (AudioTrack_dtor)(dlsym(p_library, "_ZN7android10AudioTrackD1Ev"));
+    at_initCheck = (AudioTrack_initCheck)(dlsym(p_library, "_ZNK7android10AudioTrack9initCheckEv"));
+    at_start = (AudioTrack_start)(dlsym(p_library, "_ZN7android10AudioTrack5startEv"));
+    at_stop = (AudioTrack_stop)(dlsym(p_library, "_ZN7android10AudioTrack4stopEv"));
+    at_write = (AudioTrack_write)(dlsym(p_library, "_ZN7android10AudioTrack5writeEPKvj"));
+    at_flush = (AudioTrack_flush)(dlsym(p_library, "_ZN7android10AudioTrack5flushEv"));
+    // need the first 3 or the last 1
+    if (!((as_getOutputFrameCount && as_getOutputLatency && as_getOutputSamplingRate) || at_getMinFrameCount)) {
+        dlclose(p_library);
+        return NULL;
+    }
+    // need all in the list
+    if (!((at_ctor || at_ctor_legacy) && at_dtor && at_initCheck && at_start && at_stop && at_write && at_flush)) {
+        dlclose(p_library);
+        return NULL;
+    }
+    return p_library;
+}
+
+static int Open(vlc_object_t *p_this) {
+    struct aout_sys_t *p_sys;
+    void *p_library;
+    audio_output_t *p_aout = (audio_output_t*)(p_this);
+    int status;
+    int afSampleRate, afFrameCount, afLatency, minBufCount, minFrameCount;
+    int type, channel, rate, format, size;
+
+    p_library = InitLibrary();
+    if (!p_library) {
+        msg_Err(VLC_OBJECT(p_this), "Could not initialize libmedia.so!");
+        return VLC_EGENERIC;
+    }
+    p_sys = (struct aout_sys_t*)malloc(sizeof(aout_sys_t));
+    if (p_sys == NULL)
+        return VLC_ENOMEM;
+    p_sys->libmedia = p_library;
+    // AudioSystem::MUSIC = 3
+    type = 3;
+    p_sys->type = type;
+    // 4000 <= frequency <= 48000
+    if (p_aout->format.i_rate < 4000)
+        p_aout->format.i_rate = 4000;
+    if (p_aout->format.i_rate > 48000)
+        p_aout->format.i_rate = 48000;
+    rate = p_aout->format.i_rate;
+    p_sys->rate = rate;
+    // U8/S16 only
+    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;
+    // AudioSystem::PCM_16_BIT = 1
+    // AudioSystem::PCM_8_BIT = 2
+    format = (p_aout->format.i_format == VLC_CODEC_S16L) ? 1 : 2;
+    p_sys->format = format;
+    // TODO: android supports more channels
+    channel = aout_FormatNbChannels(&p_aout->format);
+    if (channel > 2) {
+        channel = 2;
+        p_aout->format.i_physical_channels = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT;
+    }
+    // AudioSystem::CHANNEL_OUT_STEREO = 12
+    // AudioSystem::CHANNEL_OUT_MONO = 4
+    channel = (channel == 2) ? 12 : 4;
+    p_sys->channel = channel;
+    // use the minium value
+    if (!at_getMinFrameCount) {
+        status = as_getOutputSamplingRate(&afSampleRate, type);
+        status ^= as_getOutputFrameCount(&afFrameCount, type);
+        status ^= as_getOutputLatency((uint32_t*)(&afLatency), type);
+        if (status != 0) {
+            free(p_sys);
+            return VLC_EGENERIC;
+        }
+        minBufCount = afLatency / ((1000 * afFrameCount) / afSampleRate);
+        if (minBufCount < 2)
+            minBufCount = 2;
+        minFrameCount = (afFrameCount * rate * minBufCount) / afSampleRate;
+        p_aout->format.i_bytes_per_frame = minFrameCount;
+    }
+    else {
+        status = at_getMinFrameCount(&p_aout->format.i_bytes_per_frame, type, rate);
+        if (status != 0) {
+            free(p_sys);
+            return VLC_EGENERIC;
+        }
+    }
+    p_aout->format.i_bytes_per_frame <<= 1;
+    p_sys->size = p_aout->format.i_bytes_per_frame;
+    // sizeof(AudioTrack) == 0x58 (not sure) on 2.2.1, this should be enough
+    p_sys->AudioTrack = malloc(256);
+    if (!p_sys->AudioTrack) {
+        free(p_sys);
+        return VLC_ENOMEM;
+    }
+    // higher than android 2.2
+    if (at_ctor)
+        at_ctor(p_sys->AudioTrack, p_sys->type, p_sys->rate, p_sys->format, p_sys->channel, p_sys->size, 0, NULL, NULL, 0, 0);
+    // higher than android 1.6
+    else if (at_ctor_legacy)
+        at_ctor_legacy(p_sys->AudioTrack, p_sys->type, p_sys->rate, p_sys->format, p_sys->channel, p_sys->size, 0, NULL, NULL, 0);
+    status = at_initCheck(p_sys->AudioTrack);
+    // android 1.6
+    if (status != 0) {
+        p_sys->channel = (p_sys->channel == 12) ? 2 : 1;
+        at_ctor_legacy(p_sys->AudioTrack, p_sys->type, p_sys->rate, p_sys->format, p_sys->channel, p_sys->size, 0, NULL, NULL, 0);
+        status = at_initCheck(p_sys->AudioTrack);
+    }
+    if (status != 0) {
+        msg_Err(p_aout, "Cannot create AudioTrack!");
+        free(p_sys->AudioTrack);
+        free(p_sys);
+        return VLC_EGENERIC;
+    }
+
+    p_aout->sys = p_sys;
+    p_aout->pf_play = Play;
+
+    at_start(p_sys->AudioTrack);
+
+    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;
+
+    at_stop(p_sys->AudioTrack);
+    at_flush(p_sys->AudioTrack);
+    at_dtor(p_sys->AudioTrack);
+    free(p_sys->AudioTrack);
+    free(p_sys);
+}
+
+static void Play(audio_output_t *p_aout, block_t *p_buffer) {
+    aout_sys_t *p_sys = p_aout->sys;
+
+    int length = 0;
+    while (length < p_buffer->i_buffer) {
+        length += at_write(p_sys->AudioTrack, (char*)(p_buffer->p_buffer) + length, p_buffer->i_buffer - length);
+    }
+
+    aout_BufferFree(p_buffer);
+}
+
-- 
1.7.9


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