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/*
* Copyright (C) 2007 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef ANDROID_AUDIOTRACK_H
#define ANDROID_AUDIOTRACK_H
#include <stdint.h>
#include <sys/types.h>
#include <media/IAudioFlinger.h>
#include <media/IAudioTrack.h>
#include <media/AudioSystem.h>
#include <utils/RefBase.h>
#include <utils/Errors.h>
#include <utils/IInterface.h>
#include <utils/IMemory.h>
#include <utils/threads.h>
namespace android {
// ----------------------------------------------------------------------------
class audio_track_cblk_t;
// ----------------------------------------------------------------------------
class AudioTrack
{
public:
enum stream_type {
DEFAULT =-1,
VOICE_CALL = 0,
SYSTEM = 1,
RING = 2,
MUSIC = 3,
ALARM = 4,
NUM_STREAM_TYPES
};
enum channel_index {
MONO = 0,
LEFT = 0,
RIGHT = 1
};
/* Create Buffer on the stack and pass it to obtainBuffer()
* and releaseBuffer().
*/
class Buffer
{
public:
enum {
MUTE = 0x00000001
};
uint32_t flags;
int channelCount;
int format;
size_t frameCount;
size_t size;
union {
void* raw;
short* i16;
int8_t* i8;
};
};
/* Returns AudioFlinger's frame count. AudioTrack's buffers will
* be created with this size.
*/
static size_t frameCount();
/* As a convenience, if a callback is supplied, a handler thread
* is automatically created with the appropriate priority. This thread
* invokes the callback when a new buffer becomes availlable.
*/
typedef void (*callback_t)(void* user, const Buffer& info);
/* Constructs an uninitialized AudioTrack. No connection with
* AudioFlinger takes place.
*/
AudioTrack();
/* Creates an audio track and registers it with AudioFlinger.
* Once created, the track needs to be started before it can be used.
* Unspecified values are set to the audio hardware's current
* values.
*/
AudioTrack( int streamType,
uint32_t sampleRate = 0,
int format = 0,
int channelCount = 0,
int bufferCount = 0,
uint32_t flags = 0,
callback_t cbf = 0, void* user = 0);
/* Terminates the AudioTrack and unregisters it from AudioFlinger.
* Also destroys all resources assotiated with the AudioTrack.
*/
~AudioTrack();
/* Initialize an uninitialized AudioTrack. */
status_t set(int streamType =-1,
uint32_t sampleRate = 0,
int format = 0,
int channelCount = 0,
int bufferCount = 0,
uint32_t flags = 0,
callback_t cbf = 0, void* user = 0);
/* Result of constructing the AudioTrack. This must be checked
* before using any AudioTrack API (except for set()), using
* an uninitialized AudoiTrack prduces undefined results.
*/
status_t initCheck() const;
/* Returns this track's latency in nanoseconds or framecount.
* This only includes the latency due to the fill buffer size.
* In particular, the hardware or driver latencies are not accounted.
*/
nsecs_t latency() const;
/* getters, see constructor */
int streamType() const;
uint32_t sampleRate() const;
int format() const;
int channelCount() const;
int bufferCount() const;
/* After it's created the track is not active. Call start() to
* make it active. If set, the callback will start being called.
*/
void start();
/* Stop a track. If set, the callback will cease being called and
* obtainBuffer returns STOPPED. Note that obtainBuffer() still works
* and will fill up buffers until the pool is exhausted.
*/
void stop();
bool stopped() const;
/* flush a stopped track. All pending buffers are discarded.
* This function has no effect if the track is not stoped.
*/
void flush();
/* Pause a track. If set, the callback will cease being called and
* obtainBuffer returns STOPPED. Note that obtainBuffer() still works
* and will fill up buffers until the pool is exhausted.
*/
void pause();
/* mute or unmutes this track.
* While mutted, the callback, if set, is still called.
*/
void mute(bool);
bool muted() const;
/* set volume for this track, mostly used for games' sound effects
*/
void setVolume(float left, float right);
void getVolume(float* left, float* right);
/* set sample rate for this track, mostly used for games' sound effects
*/
void setSampleRate(int sampleRate);
uint32_t getSampleRate();
/* obtains a buffer of "frameCount" frames. The buffer must be
* filled entirely. If the track is stopped, obtainBuffer() returns
* STOPPED instead of NO_ERROR as long as there are buffers availlable,
* at which point NO_MORE_BUFFERS is returned.
* Buffers will be returned until the pool (buffercount())
* is exhausted, at which point obtainBuffer() will either block
* or return WOULD_BLOCK depending on the value of the "blocking"
* parameter.
*/
enum {
NO_MORE_BUFFERS = 0x80000001,
STOPPED = 1
};
status_t obtainBuffer(Buffer* audioBuffer, bool blocking);
void releaseBuffer(Buffer* audioBuffer);
/* As a convenience we provide a write() interface to the audio buffer.
* This is implemented on top of lockBuffer/unlockBuffer. For best
* performance
*
*/
ssize_t write(const void* buffer, size_t size);
/*
* Dumps the state of an audio track.
*/
status_t dump(int fd, const Vector<String16>& args) const;
private:
/* copying audio tracks is not allowed */
AudioTrack(const AudioTrack& other);
AudioTrack& operator = (const AudioTrack& other);
/* a small internal class to handle the callback */
class AudioTrackThread : public Thread
{
public:
AudioTrackThread(AudioTrack& receiver);
private:
friend class AudioTrack;
virtual bool threadLoop();
virtual status_t readyToRun();
virtual void onFirstRef();
AudioTrack& mReceiver;
Mutex mLock;
};
bool processAudioBuffer(const sp<AudioTrackThread>& thread);
sp<IAudioFlinger> mAudioFlinger;
sp<IAudioTrack> mAudioTrack;
sp<IMemory> mCblkMemory;
sp<AudioTrackThread> mAudioTrackThread;
float mVolume[2];
uint32_t mSampleRate;
size_t mFrameCount;
audio_track_cblk_t* mCblk;
uint8_t mStreamType;
uint8_t mFormat;
uint8_t mBufferCount;
uint8_t mChannelCount : 4;
uint8_t mMuted : 1;
uint8_t mReserved : 2;
status_t mStatus;
nsecs_t mLatency;
volatile int32_t mActive;
callback_t mCbf;
void* mUserData;
AudioTrack::Buffer mAudioBuffer;
size_t mPosition;
uint32_t mReservedFBC[4];
};
}; // namespace android
#endif // ANDROID_AUDIOTRACK_H
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