ssize_t A2dpAudioInterface::A2dpAudioStreamOut::write(const void* buffer, size_t bytes)
{
Mutex::Autolock lock(mLock);
size_t remaining = bytes;
status_t status = -1;
if (!mBluetoothEnabled || mClosing || mSuspended) {
LOGV("A2dpAudioStreamOut::write(), but bluetooth disabled \
mBluetoothEnabled %d, mClosing %d, mSuspended %d",
mBluetoothEnabled, mClosing, mSuspended);
goto Error;
}
status = init();
if (status < 0)
goto Error;
while (remaining > 0) {
status = a2dp_write(mData, buffer, remaining);
if (status <= 0) {
LOGE("a2dp_write failed err: %d\n", status);
goto Error;
}
remaining -= status;
buffer = ((char *)buffer) + status;
}
mStandby = false;
return bytes;
Error:
// Simulate audio output timing in case of error
usleep(((bytes * 1000 )/ frameSize() / sampleRate()) * 1000);
return status;
}
static void *_out_buf_thread_func(void *context)
{
struct astream_out *out = (struct astream_out *)context;
pthread_mutex_lock(&out->buf_lock);
while(!out->buf_thread_exit) {
size_t frames;
frames = _out_frames_ready_locked(out);
while (frames && !out->buf_thread_exit) {
int retries = MAX_WRITE_RETRIES;
uint64_t now;
uint32_t elapsed_us;
while (frames > 0 && !out->buf_thread_exit) {
int ret;
uint32_t buffer_duration_us;
/* PCM format is always 16bit stereo */
size_t bytes = frames * sizeof(uint32_t);
if (bytes > out->buffer_size) {
bytes = out->buffer_size;
}
pthread_mutex_lock(&out->lock);
if (out->standby) {
/* abort and clear all pending frames if standby requested */
pthread_mutex_unlock(&out->lock);
frames = _out_frames_ready_locked(out);
_out_inc_rd_idx_locked(out, frames);
goto wait;
}
/* indicate to out_standby_stream_locked() that a2dp_write() is active */
out->write_busy = true;
pthread_mutex_unlock(&out->lock);
pthread_mutex_unlock(&out->buf_lock);
ret = a2dp_write(out->data, out->buf + out->buf_rd_idx, bytes);
/* clear write_busy condition */
pthread_mutex_lock(&out->buf_lock);
pthread_mutex_lock(&out->lock);
out->write_busy = false;
pthread_cond_signal(&out->write_cond);
pthread_mutex_unlock(&out->lock);
if (ret < 0) {
LOGE("%s: a2dp_write failed (%d)\n", __func__, ret);
/* skip pending frames in case of write error */
_out_inc_rd_idx_locked(out, frames);
break;
} else if (ret == 0) {
if (retries-- == 0) {
/* skip pending frames in case of multiple time out */
_out_inc_rd_idx_locked(out, frames);
break;
}
continue;
}
ret /= sizeof(uint32_t);
_out_inc_rd_idx_locked(out, ret);
frames -= ret;
/* XXX: PLEASE FIX ME!!!! */
/* if A2DP sink runs abnormally fast, sleep a little so that
* audioflinger mixer thread does no spin and starve other threads. */
/* NOTE: It is likely that the A2DP headset is being disconnected */
now = system_time();
elapsed_us = (now - out->last_write_time) / 1000UL;
buffer_duration_us = ((ret * 1000) / out->sample_rate) * 1000;
if (elapsed_us < (buffer_duration_us / 4)) {
LOGV("A2DP sink runs too fast");
usleep(buffer_duration_us - elapsed_us);
}
out->last_write_time = now;
}
frames = _out_frames_ready_locked(out);
}
wait:
if (!out->buf_thread_exit) {
pthread_cond_wait(&out->buf_cond, &out->buf_lock);
}
}
pthread_mutex_unlock(&out->buf_lock);
return NULL;
}
