blob: baa19ad5a85088ab9d6831781f2dcf39631fa6e0 [file] [log] [blame]
// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "media/audio/pulse/pulse_output.h"
#include <pulse/pulseaudio.h>
#include <stdint.h>
#include "base/single_thread_task_runner.h"
#include "base/time/time.h"
#include "media/audio/audio_device_description.h"
#include "media/audio/audio_manager_base.h"
#include "media/audio/pulse/pulse_util.h"
#include "media/base/audio_sample_types.h"
namespace media {
using pulse::AutoPulseLock;
using pulse::WaitForOperationCompletion;
// static, pa_stream_notify_cb
void PulseAudioOutputStream::StreamNotifyCallback(pa_stream* s, void* p_this) {
PulseAudioOutputStream* stream = static_cast<PulseAudioOutputStream*>(p_this);
// Forward unexpected failures to the AudioSourceCallback if available. All
// these variables are only modified under pa_threaded_mainloop_lock() so this
// should be thread safe.
if (s && stream->source_callback_ &&
pa_stream_get_state(s) == PA_STREAM_FAILED) {
stream->source_callback_->OnError();
}
pa_threaded_mainloop_signal(stream->pa_mainloop_, 0);
}
// static, pa_stream_request_cb_t
void PulseAudioOutputStream::StreamRequestCallback(pa_stream* s, size_t len,
void* p_this) {
// Fulfill write request; must always result in a pa_stream_write() call.
static_cast<PulseAudioOutputStream*>(p_this)->FulfillWriteRequest(len);
}
PulseAudioOutputStream::PulseAudioOutputStream(const AudioParameters& params,
const std::string& device_id,
AudioManagerBase* manager)
: params_(AudioParameters(params.format(),
params.channel_layout(),
params.sample_rate(),
// Ignore the given bits per sample. We
// want 32 because we're outputting
// floats.
32,
params.frames_per_buffer())),
device_id_(device_id),
manager_(manager),
pa_context_(NULL),
pa_mainloop_(NULL),
pa_stream_(NULL),
volume_(1.0f),
source_callback_(NULL) {
CHECK(params_.IsValid());
audio_bus_ = AudioBus::Create(params_);
}
PulseAudioOutputStream::~PulseAudioOutputStream() {
// All internal structures should already have been freed in Close(), which
// calls AudioManagerBase::ReleaseOutputStream() which deletes this object.
DCHECK(!pa_stream_);
DCHECK(!pa_context_);
DCHECK(!pa_mainloop_);
}
bool PulseAudioOutputStream::Open() {
DCHECK(thread_checker_.CalledOnValidThread());
return pulse::CreateOutputStream(
&pa_mainloop_, &pa_context_, &pa_stream_, params_, device_id_,
AudioManager::GetGlobalAppName(), &StreamNotifyCallback,
&StreamRequestCallback, this);
}
void PulseAudioOutputStream::Reset() {
if (!pa_mainloop_) {
DCHECK(!pa_stream_);
DCHECK(!pa_context_);
return;
}
{
AutoPulseLock auto_lock(pa_mainloop_);
// Close the stream.
if (pa_stream_) {
// Ensure all samples are played out before shutdown.
pa_operation* operation = pa_stream_flush(
pa_stream_, &pulse::StreamSuccessCallback, pa_mainloop_);
WaitForOperationCompletion(pa_mainloop_, operation);
// Release PulseAudio structures.
pa_stream_disconnect(pa_stream_);
pa_stream_set_write_callback(pa_stream_, NULL, NULL);
pa_stream_set_state_callback(pa_stream_, NULL, NULL);
pa_stream_unref(pa_stream_);
pa_stream_ = NULL;
}
if (pa_context_) {
pa_context_disconnect(pa_context_);
pa_context_set_state_callback(pa_context_, NULL, NULL);
pa_context_unref(pa_context_);
pa_context_ = NULL;
}
}
pa_threaded_mainloop_stop(pa_mainloop_);
pa_threaded_mainloop_free(pa_mainloop_);
pa_mainloop_ = NULL;
}
void PulseAudioOutputStream::Close() {
DCHECK(thread_checker_.CalledOnValidThread());
Reset();
// Signal to the manager that we're closed and can be removed.
// This should be the last call in the function as it deletes "this".
manager_->ReleaseOutputStream(this);
}
void PulseAudioOutputStream::FulfillWriteRequest(size_t requested_bytes) {
int bytes_remaining = requested_bytes;
while (bytes_remaining > 0) {
void* buffer = NULL;
size_t bytes_to_fill = params_.GetBytesPerBuffer();
CHECK_GE(pa_stream_begin_write(pa_stream_, &buffer, &bytes_to_fill), 0);
CHECK_EQ(bytes_to_fill, static_cast<size_t>(params_.GetBytesPerBuffer()));
// NOTE: |bytes_to_fill| may be larger than |requested_bytes| now, this is
// okay since pa_stream_begin_write() is the authoritative source on how
// much can be written.
int frames_filled = 0;
if (source_callback_) {
const base::TimeDelta delay = pulse::GetHardwareLatency(pa_stream_);
frames_filled = source_callback_->OnMoreData(
delay, base::TimeTicks::Now(), 0, audio_bus_.get());
// Zero any unfilled data so it plays back as silence.
if (frames_filled < audio_bus_->frames()) {
audio_bus_->ZeroFramesPartial(
frames_filled, audio_bus_->frames() - frames_filled);
}
audio_bus_->Scale(volume_);
audio_bus_->ToInterleaved<Float32SampleTypeTraits>(
audio_bus_->frames(), reinterpret_cast<float*>(buffer));
} else {
memset(buffer, 0, bytes_to_fill);
}
if (pa_stream_write(pa_stream_, buffer, bytes_to_fill, NULL, 0LL,
PA_SEEK_RELATIVE) < 0) {
if (source_callback_) {
source_callback_->OnError();
}
}
// NOTE: As mentioned above, |bytes_remaining| may be negative after this.
bytes_remaining -= bytes_to_fill;
// Despite telling Pulse to only request certain buffer sizes, it will not
// always obey. In these cases we need to avoid back to back reads from
// the renderer as it won't have time to complete the request.
//
// We can't defer the callback as Pulse will never call us again until we've
// satisfied writing the requested number of bytes.
//
// TODO(dalecurtis): It might be worth choosing the sleep duration based on
// the hardware latency return above. Watch http://crbug.com/366433 to see
// if a more complicated wait process is necessary. We may also need to see
// if a PostDelayedTask should be used here to avoid blocking the PulseAudio
// command thread.
if (source_callback_ && bytes_remaining > 0)
base::PlatformThread::Sleep(params_.GetBufferDuration() / 4);
}
}
void PulseAudioOutputStream::Start(AudioSourceCallback* callback) {
DCHECK(thread_checker_.CalledOnValidThread());
CHECK(callback);
CHECK(pa_stream_);
AutoPulseLock auto_lock(pa_mainloop_);
// Ensure the context and stream are ready.
if (pa_context_get_state(pa_context_) != PA_CONTEXT_READY &&
pa_stream_get_state(pa_stream_) != PA_STREAM_READY) {
callback->OnError();
return;
}
source_callback_ = callback;
// Uncork (resume) the stream.
pa_operation* operation = pa_stream_cork(
pa_stream_, 0, &pulse::StreamSuccessCallback, pa_mainloop_);
WaitForOperationCompletion(pa_mainloop_, operation);
}
void PulseAudioOutputStream::Stop() {
DCHECK(thread_checker_.CalledOnValidThread());
// Cork (pause) the stream. Waiting for the main loop lock will ensure
// outstanding callbacks have completed.
AutoPulseLock auto_lock(pa_mainloop_);
// Set |source_callback_| to NULL so all FulfillWriteRequest() calls which may
// occur while waiting on the flush and cork exit immediately.
source_callback_ = NULL;
// Flush the stream prior to cork, doing so after will cause hangs. Write
// callbacks are suspended while inside pa_threaded_mainloop_lock() so this
// is all thread safe.
pa_operation* operation = pa_stream_flush(
pa_stream_, &pulse::StreamSuccessCallback, pa_mainloop_);
WaitForOperationCompletion(pa_mainloop_, operation);
operation = pa_stream_cork(pa_stream_, 1, &pulse::StreamSuccessCallback,
pa_mainloop_);
WaitForOperationCompletion(pa_mainloop_, operation);
}
void PulseAudioOutputStream::SetVolume(double volume) {
DCHECK(thread_checker_.CalledOnValidThread());
// Waiting for the main loop lock will ensure outstanding callbacks have
// completed and |volume_| is not accessed from them.
AutoPulseLock auto_lock(pa_mainloop_);
volume_ = static_cast<float>(volume);
}
void PulseAudioOutputStream::GetVolume(double* volume) {
DCHECK(thread_checker_.CalledOnValidThread());
*volume = volume_;
}
} // namespace media