Aegisub/src/audio_player_openal.cpp
Rodger Combs 16d57dac79 OpenAL: destroy context when not in use
This prevents the CoreAudio thread from spinning when paused on macOS
2018-01-27 11:34:58 -08:00

311 lines
8.8 KiB
C++

// Copyright (c) 2007, Niels Martin Hansen
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
// * Neither the name of the Aegisub Group nor the names of its contributors
// may be used to endorse or promote products derived from this software
// without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
//
// Aegisub Project http://www.aegisub.org/
/// @file audio_player_openal.cpp
/// @brief OpenAL-based audio output
/// @ingroup audio_output
///
#ifdef WITH_OPENAL
#include "include/aegisub/audio_player.h"
#include "audio_controller.h"
#include "utils.h"
#include <libaegisub/audio/provider.h>
#include <libaegisub/log.h>
#include <libaegisub/make_unique.h>
#ifdef __WINDOWS__
#include <al.h>
#include <alc.h>
#elif defined(__APPLE__)
#include <OpenAL/al.h>
#include <OpenAL/alc.h>
#else
#include <AL/al.h>
#include <AL/alc.h>
#endif
#include <vector>
#include <wx/timer.h>
// Auto-link to OpenAL lib for MSVC
#ifdef _MSC_VER
#pragma comment(lib, "openal32.lib")
#endif
namespace {
class OpenALPlayer final : public AudioPlayer, wxTimer {
/// Number of OpenAL buffers to use
static const ALsizei num_buffers = 8;
bool playing = false; ///< Is audio currently playing?
float volume = 1.f; ///< Current audio volume
ALsizei samplerate; ///< Sample rate of the audio
int bpf; ///< Bytes per frame
int64_t start_frame = 0; ///< First frame of playbacka
int64_t cur_frame = 0; ///< Next frame to write to playback buffers
int64_t end_frame = 0; ///< Last frame to play
ALCdevice *device = nullptr; ///< OpenAL device handle
ALCcontext *context = nullptr; ///< OpenAL sound context
ALuint buffers[num_buffers]; ///< OpenAL sound buffers
ALuint source = 0; ///< OpenAL playback source
/// Index into buffers, first free (unqueued) buffer to be filled
ALsizei buf_first_free = 0;
/// Index into buffers, first queued (non-free) buffer
ALsizei buf_first_queued = 0;
/// Number of free buffers
ALsizei buffers_free = 0;
/// Number of buffers which have been fully played since playback was last started
ALsizei buffers_played = 0;
wxStopWatch playback_segment_timer;
/// Buffer to decode audio into
std::vector<char> decode_buffer;
/// Fill count OpenAL buffers
void FillBuffers(ALsizei count);
/// wxTimer override to periodically fill available buffers
void Notify() override;
void InitContext();
void TeardownContext();
public:
OpenALPlayer(agi::AudioProvider *provider);
~OpenALPlayer();
void Play(int64_t start,int64_t count) override;
void Stop() override;
bool IsPlaying() override { return playing; }
int64_t GetEndPosition() override { return end_frame; }
int64_t GetCurrentPosition() override;
void SetEndPosition(int64_t pos) override;
void SetVolume(double vol) override { volume = vol; }
};
OpenALPlayer::OpenALPlayer(agi::AudioProvider *provider)
: AudioPlayer(provider)
, samplerate(provider->GetSampleRate())
, bpf(provider->GetChannels() * provider->GetBytesPerSample())
{
device = alcOpenDevice(nullptr);
if (!device) throw AudioPlayerOpenError("Failed opening default OpenAL device");
// Determine buffer length
decode_buffer.resize(samplerate * bpf / num_buffers / 2); // buffers for half a second of audio
}
OpenALPlayer::~OpenALPlayer()
{
Stop();
alcCloseDevice(device);
}
void OpenALPlayer::InitContext()
{
if (context) return;
try {
// Create context
context = alcCreateContext(device, nullptr);
if (!context) throw AudioPlayerOpenError("Failed creating OpenAL context");
if (!alcMakeContextCurrent(context)) throw AudioPlayerOpenError("Failed selecting OpenAL context");
// Clear error code
alGetError();
// Generate buffers
alGenBuffers(num_buffers, buffers);
if (alGetError() != AL_NO_ERROR) throw AudioPlayerOpenError("Error generating OpenAL buffers");
// Generate source
alGenSources(1, &source);
if (alGetError() != AL_NO_ERROR) {
alDeleteBuffers(num_buffers, buffers);
throw AudioPlayerOpenError("Error generating OpenAL source");
}
}
catch (...)
{
alcDestroyContext(context);
context = nullptr;
throw;
}
}
void OpenALPlayer::TeardownContext()
{
if (!context) return;
alcMakeContextCurrent(context);
alDeleteSources(1, &source);
alDeleteBuffers(num_buffers, buffers);
alcMakeContextCurrent(nullptr);
alcDestroyContext(context);
context = nullptr;
}
void OpenALPlayer::Play(int64_t start, int64_t count)
{
InitContext();
alcMakeContextCurrent(context);
if (playing) {
// Quick reset
playing = false;
alSourceStop(source);
alSourcei(source, AL_BUFFER, 0);
}
// Set params
start_frame = start;
cur_frame = start;
end_frame = start + count;
playing = true;
// Prepare buffers
buffers_free = num_buffers;
buffers_played = 0;
buf_first_free = 0;
buf_first_queued = 0;
FillBuffers(num_buffers);
// And go!
alSourcePlay(source);
wxTimer::Start(100);
playback_segment_timer.Start();
}
void OpenALPlayer::Stop()
{
TeardownContext();
if (!playing) return;
// Reset data
wxTimer::Stop();
playing = false;
start_frame = 0;
cur_frame = 0;
end_frame = 0;
// Then drop the playback
alcMakeContextCurrent(context);
alSourceStop(source);
alSourcei(source, AL_BUFFER, 0);
alcMakeContextCurrent(nullptr);
}
void OpenALPlayer::FillBuffers(ALsizei count)
{
InitContext();
// Do the actual filling/queueing
for (count = mid(1, count, buffers_free); count > 0; --count) {
ALsizei fill_len = mid<ALsizei>(0, decode_buffer.size() / bpf, end_frame - cur_frame);
if (fill_len > 0)
// Get fill_len frames of audio
provider->GetAudioWithVolume(&decode_buffer[0], cur_frame, fill_len, volume);
if ((size_t)fill_len * bpf < decode_buffer.size())
// And zerofill the rest
memset(&decode_buffer[fill_len * bpf], 0, decode_buffer.size() - fill_len * bpf);
cur_frame += fill_len;
alBufferData(buffers[buf_first_free], AL_FORMAT_MONO16, &decode_buffer[0], decode_buffer.size(), samplerate);
alSourceQueueBuffers(source, 1, &buffers[buf_first_free]); // FIXME: collect buffer handles and queue all at once instead of one at a time?
buf_first_free = (buf_first_free + 1) % num_buffers;
--buffers_free;
}
}
void OpenALPlayer::Notify()
{
InitContext();
alcMakeContextCurrent(context);
ALsizei newplayed;
alGetSourcei(source, AL_BUFFERS_PROCESSED, &newplayed);
LOG_D("player/audio/openal") << "buffers_played=" << buffers_played << " newplayed=" << newplayed;
if (newplayed > 0) {
// Reclaim buffers
ALuint bufs[num_buffers];
for (ALsizei i = 0; i < newplayed; ++i) {
bufs[i] = buffers[buf_first_queued];
buf_first_queued = (buf_first_queued + 1) % num_buffers;
}
alSourceUnqueueBuffers(source, newplayed, bufs);
buffers_free += newplayed;
// Update
buffers_played += newplayed;
playback_segment_timer.Start();
// Fill more buffers
FillBuffers(newplayed);
}
LOG_D("player/audio/openal") << "frames played=" << (buffers_played - num_buffers) * decode_buffer.size() / bpf << " num frames=" << end_frame - start_frame;
// Check that all of the selected audio plus one full set of buffers has been queued
if ((buffers_played - num_buffers) * (int64_t)decode_buffer.size() > (end_frame - start_frame) * bpf) {
Stop();
}
}
void OpenALPlayer::SetEndPosition(int64_t pos)
{
end_frame = pos;
}
int64_t OpenALPlayer::GetCurrentPosition()
{
// FIXME: this should be based on not duration played but actual sample being heard
// (during video playback, cur_frame might get changed to resync)
long extra = playback_segment_timer.Time();
return buffers_played * decode_buffer.size() / bpf + start_frame + extra * samplerate / 1000;
}
}
std::unique_ptr<AudioPlayer> CreateOpenALPlayer(agi::AudioProvider *provider, wxWindow *)
{
return agi::make_unique<OpenALPlayer>(provider);
}
#endif // WITH_OPENAL