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Diffstat (limited to 'include/media/AudioTrack.h')
| -rw-r--r-- | include/media/AudioTrack.h | 277 |
1 files changed, 277 insertions, 0 deletions
diff --git a/include/media/AudioTrack.h b/include/media/AudioTrack.h new file mode 100644 index 0000000..a89d7ff --- /dev/null +++ b/include/media/AudioTrack.h @@ -0,0 +1,277 @@ +/* + * 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 |