Revision 4c4dc3c77b9dc7e51eb365be3172909ede4df92a authored by Marty Rosenberg on 27 May 2014, 13:40:35 UTC, committed by Marty Rosenberg on 27 May 2014, 13:40:35 UTC
1 parent 70cc08d
cubeb_audiotrack.c
/*
* Copyright © 2013 Mozilla Foundation
*
* This program is made available under an ISC-style license. See the
* accompanying file LICENSE for details.
*/
#if !defined(NDEBUG)
#define NDEBUG
#endif
#include <assert.h>
#include <pthread.h>
#include <stdlib.h>
#include <time.h>
#include <dlfcn.h>
#include "android/log.h"
#include "cubeb/cubeb.h"
#include "cubeb-internal.h"
#include "android/audiotrack_definitions.h"
#ifndef ALOG
#if defined(DEBUG) || defined(FORCE_ALOG)
#define ALOG(args...) __android_log_print(ANDROID_LOG_INFO, "Gecko - Cubeb" , ## args)
#else
#define ALOG(args...)
#endif
#endif
/**
* A lot of bytes for safety. It should be possible to bring this down a bit. */
#define SIZE_AUDIOTRACK_INSTANCE 256
/**
* call dlsym to get the symbol |mangled_name|, handle the error and store the
* pointer in |pointer|. Because depending on Android version, we want different
* symbols, not finding a symbol is not an error. */
#define DLSYM_DLERROR(mangled_name, pointer, lib) \
do { \
pointer = dlsym(lib, mangled_name); \
if (!pointer) { \
ALOG("error while loading %stm: %stm\n", mangled_name, dlerror()); \
} else { \
ALOG("%stm: OK", mangled_name); \
} \
} while(0);
static struct cubeb_ops const audiotrack_ops;
void audiotrack_destroy(cubeb * context);
void audiotrack_stream_destroy(cubeb_stream * stream);
struct AudioTrack {
/* only available on ICS and later. The second int paramter is in fact of type audio_stream_type_t. */
/* static */ status_t (*get_min_frame_count)(int* frame_count, int stream_type, uint32_t rate);
/* if we have a recent ctor, but can't find the above symbol, we
* can get the minimum frame count with this signature, and we are
* running gingerbread. */
/* static */ status_t (*get_min_frame_count_gingerbread)(int* frame_count, int stream_type, uint32_t rate);
/* if this symbol is not availble, and the next one is, we know
* we are on a Froyo (Android 2.2) device. */
void* (*ctor)(void* instance, int, unsigned int, int, int, int, unsigned int, void (*)(int, void*, void*), void*, int, int);
void* (*ctor_froyo)(void* instance, int, unsigned int, int, int, int, unsigned int, void (*)(int, void*, void*), void*, int);
void* (*dtor)(void* instance);
void (*start)(void* instance);
void (*pause)(void* instance);
uint32_t (*latency)(void* instance);
status_t (*check)(void* instance);
status_t (*get_position)(void* instance, uint32_t* position);
/* only used on froyo. */
/* static */ int (*get_output_frame_count)(int* frame_count, int stream);
/* static */ int (*get_output_latency)(uint32_t* latency, int stream);
/* static */ int (*get_output_samplingrate)(int* samplerate, int stream);
status_t (*set_marker_position)(void* instance, unsigned int);
};
struct cubeb {
struct cubeb_ops const * ops;
void * library;
struct AudioTrack klass;
};
struct cubeb_stream {
cubeb * context;
cubeb_stream_params params;
cubeb_data_callback data_callback;
cubeb_state_callback state_callback;
void * instance;
void * user_ptr;
/* Number of frames that have been passed to the AudioTrack callback */
long unsigned written;
int draining;
};
static void
audiotrack_refill(int event, void* user, void* info)
{
cubeb_stream * stream = user;
switch (event) {
case EVENT_MORE_DATA: {
long got = 0;
struct Buffer * b = (struct Buffer*)info;
if (stream->draining) {
return;
}
got = stream->data_callback(stream, stream->user_ptr, b->raw, b->frameCount);
stream->written += got;
if (got != (long)b->frameCount) {
uint32_t p;
stream->draining = 1;
/* set a marker so we are notified when the are done draining, that is,
* when every frame has been played by android. */
stream->context->klass.set_marker_position(stream->instance, stream->written);
}
break;
}
case EVENT_UNDERRUN:
ALOG("underrun in cubeb backend.");
break;
case EVENT_LOOP_END:
assert(0 && "We don't support the loop feature of audiotrack.");
break;
case EVENT_MARKER:
assert(stream->draining);
stream->state_callback(stream, stream->user_ptr, CUBEB_STATE_DRAINED);
break;
case EVENT_NEW_POS:
assert(0 && "We don't support the setPositionUpdatePeriod feature of audiotrack.");
break;
case EVENT_BUFFER_END:
assert(0 && "Should not happen.");
break;
}
}
/* We are running on froyo if we found the right AudioTrack constructor */
static int
audiotrack_version_is_froyo(cubeb * ctx)
{
return ctx->klass.ctor_froyo != NULL;
}
/* We are running on gingerbread if we found the gingerbread signature for
* getMinFrameCount */
static int
audiotrack_version_is_gingerbread(cubeb * ctx)
{
return ctx->klass.get_min_frame_count_gingerbread != NULL;
}
int
audiotrack_get_min_frame_count(cubeb * ctx, cubeb_stream_params * params, int * min_frame_count)
{
status_t status;
/* Recent Android have a getMinFrameCount method. On Froyo, we have to compute it by hand. */
if (audiotrack_version_is_froyo(ctx)) {
int samplerate, frame_count, latency, min_buffer_count;
status = ctx->klass.get_output_frame_count(&frame_count, params->stream_type);
if (status) {
ALOG("error getting the output frame count.");
return CUBEB_ERROR;
}
status = ctx->klass.get_output_latency((uint32_t*)&latency, params->stream_type);
if (status) {
ALOG("error getting the output frame count.");
return CUBEB_ERROR;
}
status = ctx->klass.get_output_samplingrate(&samplerate, params->stream_type);
if (status) {
ALOG("error getting the output frame count.");
return CUBEB_ERROR;
}
/* Those numbers were found reading the Android source. It is the minimum
* numbers that will be accepted by the AudioTrack class, hence yielding the
* best latency possible.
* See https://android.googlesource.com/platform/frameworks/base/+/android-2.2.3_r2.1/media/libmedia/AudioTrack.cpp
* around line 181 for Android 2.2 */
min_buffer_count = latency / ((1000 * frame_count) / samplerate);
min_buffer_count = min_buffer_count < 2 ? min_buffer_count : 2;
*min_frame_count = (frame_count * params->rate * min_buffer_count) / samplerate;
return CUBEB_OK;
}
/* Recent Android have a getMinFrameCount method. */
if (!audiotrack_version_is_gingerbread(ctx)) {
status = ctx->klass.get_min_frame_count(min_frame_count, params->stream_type, params->rate);
} else {
status = ctx->klass.get_min_frame_count_gingerbread(min_frame_count, params->stream_type, params->rate);
}
if (status != 0) {
ALOG("error getting the min frame count");
return CUBEB_ERROR;
}
return CUBEB_OK;
}
int
audiotrack_init(cubeb ** context, char const * context_name)
{
cubeb * ctx;
struct AudioTrack* c;
assert(context);
*context = NULL;
ctx = calloc(1, sizeof(*ctx));
assert(ctx);
/* If we use an absolute path here ("/system/lib/libmedia.so"), and on Android
* 2.2, the dlopen succeeds, all the dlsym succeed, but a segfault happens on
* the first call to a dlsym'ed function. Somehow this does not happen when
* using only the name of the library. */
ctx->library = dlopen("libmedia.so", RTLD_LAZY);
if (!ctx->library) {
ALOG("dlopen error: %s.", dlerror());
free(ctx);
return CUBEB_ERROR;
}
/* Recent Android first, then Froyo. */
DLSYM_DLERROR("_ZN7android10AudioTrackC1EijiiijPFviPvS1_ES1_ii", ctx->klass.ctor, ctx->library);
if (!ctx->klass.ctor) {
DLSYM_DLERROR("_ZN7android10AudioTrackC1EijiiijPFviPvS1_ES1_i", ctx->klass.ctor_froyo, ctx->library);
assert(ctx->klass.ctor_froyo);
}
DLSYM_DLERROR("_ZN7android10AudioTrackD1Ev", ctx->klass.dtor, ctx->library);
DLSYM_DLERROR("_ZNK7android10AudioTrack7latencyEv", ctx->klass.latency, ctx->library);
DLSYM_DLERROR("_ZNK7android10AudioTrack9initCheckEv", ctx->klass.check, ctx->library);
DLSYM_DLERROR("_ZN7android11AudioSystem21getOutputSamplingRateEPii", ctx->klass.get_output_samplingrate, ctx->library);
/* |getMinFrameCount| is not available on Froyo, and is available on
* gingerbread and ICS with a different signature. */
if (audiotrack_version_is_froyo(ctx)) {
DLSYM_DLERROR("_ZN7android11AudioSystem19getOutputFrameCountEPii", ctx->klass.get_output_frame_count, ctx->library);
DLSYM_DLERROR("_ZN7android11AudioSystem16getOutputLatencyEPji", ctx->klass.get_output_latency, ctx->library);
} else {
DLSYM_DLERROR("_ZN7android10AudioTrack16getMinFrameCountEPi19audio_stream_type_tj", ctx->klass.get_min_frame_count, ctx->library);
if (!ctx->klass.get_min_frame_count) {
DLSYM_DLERROR("_ZN7android10AudioTrack16getMinFrameCountEPiij", ctx->klass.get_min_frame_count_gingerbread, ctx->library);
}
}
DLSYM_DLERROR("_ZN7android10AudioTrack5startEv", ctx->klass.start, ctx->library);
DLSYM_DLERROR("_ZN7android10AudioTrack5pauseEv", ctx->klass.pause, ctx->library);
DLSYM_DLERROR("_ZN7android10AudioTrack11getPositionEPj", ctx->klass.get_position, ctx->library);
DLSYM_DLERROR("_ZN7android10AudioTrack17setMarkerPositionEj", ctx->klass.set_marker_position, ctx->library);
/* check that we have a combination of symbol that makes sense */
c = &ctx->klass;
if(!((c->ctor || c->ctor_froyo) && /* at least on ctor. */
c->dtor && c->latency && c->check &&
/* at least one way to get the minimum frame count to request. */
((c->get_output_frame_count && c->get_output_latency && c->get_output_samplingrate) ||
c->get_min_frame_count ||
c->get_min_frame_count_gingerbread) &&
c->start && c->pause && c->get_position && c->set_marker_position)) {
ALOG("Could not find all the symbols we need.");
audiotrack_destroy(ctx);
return CUBEB_ERROR;
}
ctx->ops = &audiotrack_ops;
*context = ctx;
return CUBEB_OK;
}
char const *
audiotrack_get_backend_id(cubeb * context)
{
return "audiotrack";
}
static int
audiotrack_get_max_channel_count(cubeb * ctx, uint32_t * max_channels)
{
assert(ctx && max_channels);
/* The android mixer handles up to two channels, see
http://androidxref.com/4.2.2_r1/xref/frameworks/av/services/audioflinger/AudioFlinger.h#67 */
*max_channels = 2;
return CUBEB_OK;
}
static int
audiotrack_get_min_latency(cubeb * ctx, cubeb_stream_params params, uint32_t * latency_ms)
{
/* We always use the lowest latency possible when using this backend (see
* audiotrack_stream_init), so this value is not going to be used. */
int rv;
rv = audiotrack_get_min_frame_count(ctx, ¶ms, latency_ms);
if (rv != CUBEB_OK) {
return CUBEB_ERROR;
}
/* Convert to milliseconds. */
*latency_ms = *latency_ms * 1000 / params.rate;
return CUBEB_OK;
}
static int
audiotrack_get_preferred_sample_rate(cubeb * ctx, uint32_t * rate)
{
status_t rv;
rv = ctx->klass.get_output_samplingrate(rate, 3 /* MUSIC */);
return rv == 0 ? CUBEB_OK : CUBEB_ERROR;
}
void
audiotrack_destroy(cubeb * context)
{
assert(context);
dlclose(context->library);
free(context);
}
int
audiotrack_stream_init(cubeb * ctx, cubeb_stream ** stream, char const * stream_name,
cubeb_stream_params stream_params, unsigned int latency,
cubeb_data_callback data_callback,
cubeb_state_callback state_callback,
void * user_ptr)
{
cubeb_stream * stm;
int32_t channels;
int32_t min_frame_count;
assert(ctx && stream);
if (stream_params.format == CUBEB_SAMPLE_FLOAT32LE ||
stream_params.format == CUBEB_SAMPLE_FLOAT32BE) {
return CUBEB_ERROR_INVALID_FORMAT;
}
if (audiotrack_get_min_frame_count(ctx, &stream_params, &min_frame_count)) {
return CUBEB_ERROR;
}
stm = calloc(1, sizeof(*stm));
assert(stm);
stm->context = ctx;
stm->data_callback = data_callback;
stm->state_callback = state_callback;
stm->user_ptr = user_ptr;
stm->params = stream_params;
stm->instance = calloc(SIZE_AUDIOTRACK_INSTANCE, 1);
(*(uint32_t*)((intptr_t)stm->instance + SIZE_AUDIOTRACK_INSTANCE - 4)) = 0xbaadbaad;
assert(stm->instance && "cubeb: EOM");
/* gingerbread uses old channel layout enum */
if (audiotrack_version_is_froyo(ctx) || audiotrack_version_is_gingerbread(ctx)) {
channels = stm->params.channels == 2 ? AUDIO_CHANNEL_OUT_STEREO_Legacy : AUDIO_CHANNEL_OUT_MONO_Legacy;
} else {
channels = stm->params.channels == 2 ? AUDIO_CHANNEL_OUT_STEREO_ICS : AUDIO_CHANNEL_OUT_MONO_ICS;
}
if (audiotrack_version_is_froyo(ctx)) {
ctx->klass.ctor_froyo(stm->instance,
stm->params.stream_type,
stm->params.rate,
AUDIO_FORMAT_PCM_16_BIT,
channels,
min_frame_count,
0,
audiotrack_refill,
stm,
0);
} else {
ctx->klass.ctor(stm->instance,
stm->params.stream_type,
stm->params.rate,
AUDIO_FORMAT_PCM_16_BIT,
channels,
min_frame_count,
0,
audiotrack_refill,
stm,
0,
0);
}
assert((*(uint32_t*)((intptr_t)stm->instance + SIZE_AUDIOTRACK_INSTANCE - 4)) == 0xbaadbaad);
if (ctx->klass.check(stm->instance)) {
ALOG("stream not initialized properly.");
audiotrack_stream_destroy(stm);
return CUBEB_ERROR;
}
*stream = stm;
return CUBEB_OK;
}
void
audiotrack_stream_destroy(cubeb_stream * stream)
{
assert(stream->context);
stream->context->klass.dtor(stream->instance);
free(stream->instance);
stream->instance = NULL;
free(stream);
}
int
audiotrack_stream_start(cubeb_stream * stream)
{
assert(stream->instance);
stream->context->klass.start(stream->instance);
stream->state_callback(stream, stream->user_ptr, CUBEB_STATE_STARTED);
return CUBEB_OK;
}
int
audiotrack_stream_stop(cubeb_stream * stream)
{
assert(stream->instance);
stream->context->klass.pause(stream->instance);
stream->state_callback(stream, stream->user_ptr, CUBEB_STATE_STOPPED);
return CUBEB_OK;
}
int
audiotrack_stream_get_position(cubeb_stream * stream, uint64_t * position)
{
uint32_t p;
assert(stream->instance && position);
stream->context->klass.get_position(stream->instance, &p);
*position = p;
return CUBEB_OK;
}
int
audiotrack_stream_get_latency(cubeb_stream * stream, uint32_t * latency)
{
assert(stream->instance && latency);
/* Android returns the latency in ms, we want it in frames. */
*latency = stream->context->klass.latency(stream->instance);
/* with rate <= 96000, we won't overflow until 44.739 seconds of latency */
*latency = (*latency * stream->params.rate) / 1000;
return 0;
}
static struct cubeb_ops const audiotrack_ops = {
.init = audiotrack_init,
.get_backend_id = audiotrack_get_backend_id,
.get_max_channel_count = audiotrack_get_max_channel_count,
.get_min_latency = audiotrack_get_min_latency,
.get_preferred_sample_rate = audiotrack_get_preferred_sample_rate,
.destroy = audiotrack_destroy,
.stream_init = audiotrack_stream_init,
.stream_destroy = audiotrack_stream_destroy,
.stream_start = audiotrack_stream_start,
.stream_stop = audiotrack_stream_stop,
.stream_get_position = audiotrack_stream_get_position,
.stream_get_latency = audiotrack_stream_get_latency
};
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