status_t AudioStreamOut::open(
audio_io_handle_t handle,
audio_devices_t devices,
struct audio_config *config,
const char *address)
{
audio_stream_out_t *outStream;
int status = hwDev()->open_output_stream(
hwDev(),
handle,
devices,
flags,
config,
&outStream,
address);
ALOGV("AudioStreamOut::open(), HAL open_output_stream returned "
" %p, sampleRate %d, Format %#x, "
"channelMask %#x, status %d",
outStream,
config->sample_rate,
config->format,
config->channel_mask,
status);
if (status == NO_ERROR) {
stream = outStream;
mHalFormatIsLinearPcm = audio_is_linear_pcm(config->format);
ALOGI("AudioStreamOut::open(), mHalFormatIsLinearPcm = %d", (int)mHalFormatIsLinearPcm);
mHalFrameSize = audio_stream_out_frame_size(stream);
}
return status;
}
static size_t out_get_buffer_size(const struct audio_stream *stream)
{
const struct stream_out* out = (const struct stream_out*)stream;
size_t buffer_size =
proxy_get_period_size(&out->proxy) * audio_stream_out_frame_size(&(out->stream));
return buffer_size;
}
static ssize_t out_write(struct audio_stream_out *stream, const void* buffer,
size_t bytes)
{
/* XXX: fake timing for audio output */
usleep(bytes * 1000000 / audio_stream_out_frame_size(stream) /
out_get_sample_rate(&stream->common));
return bytes;
}
static ssize_t out_write(struct audio_stream_out *stream, const void* buffer, size_t bytes)
{
int ret;
struct stream_out *out = (struct stream_out *)stream;
pthread_mutex_lock(&out->dev->lock);
pthread_mutex_lock(&out->lock);
if (out->standby) {
ret = start_output_stream(out);
if (ret != 0) {
pthread_mutex_unlock(&out->dev->lock);
goto err;
}
out->standby = false;
}
pthread_mutex_unlock(&out->dev->lock);
alsa_device_proxy* proxy = &out->proxy;
const void * write_buff = buffer;
int num_write_buff_bytes = bytes;
const int num_device_channels = proxy_get_channel_count(proxy); /* what we told alsa */
const int num_req_channels = out->hal_channel_count; /* what we told AudioFlinger */
if (num_device_channels != num_req_channels) {
/* allocate buffer */
const size_t required_conversion_buffer_size =
bytes * num_device_channels / num_req_channels;
if (required_conversion_buffer_size > out->conversion_buffer_size) {
out->conversion_buffer_size = required_conversion_buffer_size;
out->conversion_buffer = realloc(out->conversion_buffer,
out->conversion_buffer_size);
}
/* convert data */
const audio_format_t audio_format = out_get_format(&(out->stream.common));
const unsigned sample_size_in_bytes = audio_bytes_per_sample(audio_format);
num_write_buff_bytes =
adjust_channels(write_buff, num_req_channels,
out->conversion_buffer, num_device_channels,
sample_size_in_bytes, num_write_buff_bytes);
write_buff = out->conversion_buffer;
}
if (write_buff != NULL && num_write_buff_bytes != 0) {
proxy_write(&out->proxy, write_buff, num_write_buff_bytes);
}
pthread_mutex_unlock(&out->lock);
return bytes;
err:
pthread_mutex_unlock(&out->lock);
if (ret != 0) {
usleep(bytes * 1000000 / audio_stream_out_frame_size(stream) /
out_get_sample_rate(&stream->common));
}
return bytes;
}
