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Diffstat (limited to 'include/media/AudioTrack.h')
| -rw-r--r-- | include/media/AudioTrack.h | 553 |
1 files changed, 553 insertions, 0 deletions
diff --git a/include/media/AudioTrack.h b/include/media/AudioTrack.h new file mode 100644 index 0000000..7d5d772 --- /dev/null +++ b/include/media/AudioTrack.h @@ -0,0 +1,553 @@ +/* + * 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 <binder/IInterface.h> +#include <binder/IMemory.h> +#include <utils/threads.h> + +namespace android { + +// ---------------------------------------------------------------------------- + +class audio_track_cblk_t; + +// ---------------------------------------------------------------------------- + +class AudioTrack : virtual public RefBase +{ +public: + enum channel_index { + MONO = 0, + LEFT = 0, + RIGHT = 1 + }; + + /* Events used by AudioTrack callback function (audio_track_cblk_t). + */ + enum event_type { + EVENT_MORE_DATA = 0, // Request to write more data to PCM buffer. + EVENT_UNDERRUN = 1, // PCM buffer underrun occured. + EVENT_LOOP_END = 2, // Sample loop end was reached; playback restarted from loop start if loop count was not 0. + EVENT_MARKER = 3, // Playback head is at the specified marker position (See setMarkerPosition()). + EVENT_NEW_POS = 4, // Playback head is at a new position (See setPositionUpdatePeriod()). + EVENT_BUFFER_END = 5 // Playback head is at the end of the buffer. + }; + + /* Client should declare Buffer on the stack and pass address to obtainBuffer() + * and releaseBuffer(). See also callback_t for EVENT_MORE_DATA. + */ + + class Buffer + { + public: + enum { + MUTE = 0x00000001 + }; + uint32_t flags; // 0 or MUTE + audio_format_t format; // but AUDIO_FORMAT_PCM_8_BIT -> AUDIO_FORMAT_PCM_16_BIT + // accessed directly by WebKit ANP callback + int channelCount; // will be removed in the future, do not use + + size_t frameCount; // number of sample frames corresponding to size; + // on input it is the number of frames desired, + // on output is the number of frames actually filled + + size_t size; // input/output in byte units + union { + void* raw; + short* i16; // signed 16-bit + int8_t* i8; // unsigned 8-bit, offset by 0x80 + }; + }; + + + /* 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 available or various conditions occur. + * Parameters: + * + * event: type of event notified (see enum AudioTrack::event_type). + * user: Pointer to context for use by the callback receiver. + * info: Pointer to optional parameter according to event type: + * - EVENT_MORE_DATA: pointer to AudioTrack::Buffer struct. The callback must not write + * more bytes than indicated by 'size' field and update 'size' if fewer bytes are + * written. + * - EVENT_UNDERRUN: unused. + * - EVENT_LOOP_END: pointer to an int indicating the number of loops remaining. + * - EVENT_MARKER: pointer to an uint32_t containing the marker position in frames. + * - EVENT_NEW_POS: pointer to an uint32_t containing the new position in frames. + * - EVENT_BUFFER_END: unused. + */ + + typedef void (*callback_t)(int event, void* user, void *info); + + /* Returns the minimum frame count required for the successful creation of + * an AudioTrack object. + * Returned status (from utils/Errors.h) can be: + * - NO_ERROR: successful operation + * - NO_INIT: audio server or audio hardware not initialized + */ + + static status_t getMinFrameCount(int* frameCount, + audio_stream_type_t streamType = AUDIO_STREAM_DEFAULT, + uint32_t sampleRate = 0); + + /* 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. + * + * Parameters: + * + * streamType: Select the type of audio stream this track is attached to + * (e.g. AUDIO_STREAM_MUSIC). + * sampleRate: Track sampling rate in Hz. + * format: Audio format (e.g AUDIO_FORMAT_PCM_16_BIT for signed + * 16 bits per sample). + * channelMask: Channel mask: see audio_channels_t. + * frameCount: Minimum size of track PCM buffer in frames. This defines the + * latency of the track. The actual size selected by the AudioTrack could be + * larger if the requested size is not compatible with current audio HAL + * latency. + * flags: Reserved for future use. + * cbf: Callback function. If not null, this function is called periodically + * to request new PCM data. + * user: Context for use by the callback receiver. + * notificationFrames: The callback function is called each time notificationFrames PCM + * frames have been consumed from track input buffer. + * sessionId: Specific session ID, or zero to use default. + */ + + AudioTrack( audio_stream_type_t streamType, + uint32_t sampleRate = 0, + audio_format_t format = AUDIO_FORMAT_DEFAULT, + int channelMask = 0, + int frameCount = 0, + audio_policy_output_flags_t flags = AUDIO_POLICY_OUTPUT_FLAG_NONE, + callback_t cbf = NULL, + void* user = NULL, + int notificationFrames = 0, + int sessionId = 0); + + // DEPRECATED + explicit AudioTrack( int streamType, + uint32_t sampleRate = 0, + int format = AUDIO_FORMAT_DEFAULT, + int channelMask = 0, + int frameCount = 0, + uint32_t flags = (uint32_t) AUDIO_POLICY_OUTPUT_FLAG_NONE, + callback_t cbf = 0, + void* user = 0, + int notificationFrames = 0, + int sessionId = 0); + + /* Creates an audio track and registers it with AudioFlinger. With this constructor, + * the PCM data to be rendered by AudioTrack is passed in a shared memory buffer + * identified by the argument sharedBuffer. This prototype is for static buffer playback. + * PCM data must be present in memory before the AudioTrack is started. + * The write() and flush() methods are not supported in this case. + * It is recommended to pass a callback function to be notified of playback end by an + * EVENT_UNDERRUN event. + */ + + AudioTrack( audio_stream_type_t streamType, + uint32_t sampleRate = 0, + audio_format_t format = AUDIO_FORMAT_DEFAULT, + int channelMask = 0, + const sp<IMemory>& sharedBuffer = 0, + audio_policy_output_flags_t flags = AUDIO_POLICY_OUTPUT_FLAG_NONE, + callback_t cbf = NULL, + void* user = NULL, + int notificationFrames = 0, + int sessionId = 0); + + /* Terminates the AudioTrack and unregisters it from AudioFlinger. + * Also destroys all resources associated with the AudioTrack. + */ + ~AudioTrack(); + + + /* Initialize an uninitialized AudioTrack. + * Returned status (from utils/Errors.h) can be: + * - NO_ERROR: successful initialization + * - INVALID_OPERATION: AudioTrack is already initialized + * - BAD_VALUE: invalid parameter (channels, format, sampleRate...) + * - NO_INIT: audio server or audio hardware not initialized + * */ + status_t set(audio_stream_type_t streamType = AUDIO_STREAM_DEFAULT, + uint32_t sampleRate = 0, + audio_format_t format = AUDIO_FORMAT_DEFAULT, + int channelMask = 0, + int frameCount = 0, + audio_policy_output_flags_t flags = AUDIO_POLICY_OUTPUT_FLAG_NONE, + callback_t cbf = NULL, + void* user = NULL, + int notificationFrames = 0, + const sp<IMemory>& sharedBuffer = 0, + bool threadCanCallJava = false, + int sessionId = 0); + + + /* Result of constructing the AudioTrack. This must be checked + * before using any AudioTrack API (except for set()), because using + * an uninitialized AudioTrack produces undefined results. + * See set() method above for possible return codes. + */ + status_t initCheck() const; + + /* Returns this track's estimated latency in milliseconds. + * This includes the latency due to AudioTrack buffer size, AudioMixer (if any) + * and audio hardware driver. + */ + uint32_t latency() const; + + /* getters, see constructors and set() */ + + audio_stream_type_t streamType() const; + audio_format_t format() const; + int channelCount() const; + uint32_t frameCount() const; + + /* Return channelCount * (bit depth per channel / 8). + * channelCount is determined from channelMask, and bit depth comes from format. + */ + size_t frameSize() const; + + sp<IMemory>& sharedBuffer(); + + + /* 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 stopped. + */ + 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 unmute this track. + * While muted, the callback, if set, is still called. + */ + void mute(bool); + bool muted() const; + + /* Set volume for this track, mostly used for games' sound effects + * left and right volumes. Levels must be >= 0.0 and <= 1.0. + */ + status_t setVolume(float left, float right); + void getVolume(float* left, float* right) const; + + /* Set the send level for this track. An auxiliary effect should be attached + * to the track with attachEffect(). Level must be >= 0.0 and <= 1.0. + */ + status_t setAuxEffectSendLevel(float level); + void getAuxEffectSendLevel(float* level) const; + + /* Set sample rate for this track, mostly used for games' sound effects + */ + status_t setSampleRate(int sampleRate); + uint32_t getSampleRate() const; + + /* Enables looping and sets the start and end points of looping. + * + * Parameters: + * + * loopStart: loop start expressed as the number of PCM frames played since AudioTrack start. + * loopEnd: loop end expressed as the number of PCM frames played since AudioTrack start. + * loopCount: number of loops to execute. Calling setLoop() with loopCount == 0 cancels any + * pending or active loop. loopCount = -1 means infinite looping. + * + * For proper operation the following condition must be respected: + * (loopEnd-loopStart) <= framecount() + */ + status_t setLoop(uint32_t loopStart, uint32_t loopEnd, int loopCount); + + /* Sets marker position. When playback reaches the number of frames specified, a callback with + * event type EVENT_MARKER is called. Calling setMarkerPosition with marker == 0 cancels marker + * notification callback. + * If the AudioTrack has been opened with no callback function associated, the operation will fail. + * + * Parameters: + * + * marker: marker position expressed in frames. + * + * Returned status (from utils/Errors.h) can be: + * - NO_ERROR: successful operation + * - INVALID_OPERATION: the AudioTrack has no callback installed. + */ + status_t setMarkerPosition(uint32_t marker); + status_t getMarkerPosition(uint32_t *marker) const; + + + /* Sets position update period. Every time the number of frames specified has been played, + * a callback with event type EVENT_NEW_POS is called. + * Calling setPositionUpdatePeriod with updatePeriod == 0 cancels new position notification + * callback. + * If the AudioTrack has been opened with no callback function associated, the operation will fail. + * + * Parameters: + * + * updatePeriod: position update notification period expressed in frames. + * + * Returned status (from utils/Errors.h) can be: + * - NO_ERROR: successful operation + * - INVALID_OPERATION: the AudioTrack has no callback installed. + */ + status_t setPositionUpdatePeriod(uint32_t updatePeriod); + status_t getPositionUpdatePeriod(uint32_t *updatePeriod) const; + + /* Sets playback head position within AudioTrack buffer. The new position is specified + * in number of frames. + * This method must be called with the AudioTrack in paused or stopped state. + * Note that the actual position set is <position> modulo the AudioTrack buffer size in frames. + * Therefore using this method makes sense only when playing a "static" audio buffer + * as opposed to streaming. + * The getPosition() method on the other hand returns the total number of frames played since + * playback start. + * + * Parameters: + * + * position: New playback head position within AudioTrack buffer. + * + * Returned status (from utils/Errors.h) can be: + * - NO_ERROR: successful operation + * - INVALID_OPERATION: the AudioTrack is not stopped. + * - BAD_VALUE: The specified position is beyond the number of frames present in AudioTrack buffer + */ + status_t setPosition(uint32_t position); + status_t getPosition(uint32_t *position); + + /* Forces AudioTrack buffer full condition. When playing a static buffer, this method avoids + * rewriting the buffer before restarting playback after a stop. + * This method must be called with the AudioTrack in paused or stopped state. + * + * Returned status (from utils/Errors.h) can be: + * - NO_ERROR: successful operation + * - INVALID_OPERATION: the AudioTrack is not stopped. + */ + status_t reload(); + + /* Returns a handle on the audio output used by this AudioTrack. + * + * Parameters: + * none. + * + * Returned value: + * handle on audio hardware output + */ + audio_io_handle_t getOutput(); + + /* Returns the unique session ID associated with this track. + * + * Parameters: + * none. + * + * Returned value: + * AudioTrack session ID. + */ + int getSessionId() const; + + /* Attach track auxiliary output to specified effect. Use effectId = 0 + * to detach track from effect. + * + * Parameters: + * + * effectId: effectId obtained from AudioEffect::id(). + * + * Returned status (from utils/Errors.h) can be: + * - NO_ERROR: successful operation + * - INVALID_OPERATION: the effect is not an auxiliary effect. + * - BAD_VALUE: The specified effect ID is invalid + */ + status_t attachAuxEffect(int effectId); + + /* Obtains a buffer of "frameCount" frames. The buffer must be + * filled entirely, and then released with releaseBuffer(). + * If the track is stopped, obtainBuffer() returns + * STOPPED instead of NO_ERROR as long as there are buffers available, + * 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. + * + * Interpretation of waitCount: + * +n limits wait time to n * WAIT_PERIOD_MS, + * -1 causes an (almost) infinite wait time, + * 0 non-blocking. + */ + + enum { + NO_MORE_BUFFERS = 0x80000001, // same name in AudioFlinger.h, ok to be different value + STOPPED = 1 + }; + + status_t obtainBuffer(Buffer* audioBuffer, int32_t waitCount); + + /* Release a filled buffer of "frameCount" frames for AudioFlinger to process. */ + void releaseBuffer(Buffer* audioBuffer); + + /* As a convenience we provide a write() interface to the audio buffer. + * This is implemented on top of obtainBuffer/releaseBuffer. For best + * performance use callbacks. Returns actual number of bytes written >= 0, + * or one of the following negative status codes: + * INVALID_OPERATION AudioTrack is configured for shared buffer mode + * BAD_VALUE size is invalid + * STOPPED AudioTrack was stopped during the write + * NO_MORE_BUFFERS when obtainBuffer() returns same + * or any other error code returned by IAudioTrack::start() or restoreTrack_l(). + */ + 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; + +protected: + /* 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, bool bCanCallJava = false); + private: + friend class AudioTrack; + virtual bool threadLoop(); + virtual status_t readyToRun(); + virtual void onFirstRef(); + AudioTrack& mReceiver; + }; + + // body of AudioTrackThread::threadLoop() + bool processAudioBuffer(const sp<AudioTrackThread>& thread); + + status_t createTrack_l(audio_stream_type_t streamType, + uint32_t sampleRate, + audio_format_t format, + uint32_t channelMask, + int frameCount, + audio_policy_output_flags_t flags, + const sp<IMemory>& sharedBuffer, + audio_io_handle_t output); + void flush_l(); + status_t setLoop_l(uint32_t loopStart, uint32_t loopEnd, int loopCount); + audio_io_handle_t getOutput_l(); + status_t restoreTrack_l(audio_track_cblk_t*& cblk, bool fromStart); + bool stopped_l() const { return !mActive; } + + sp<IAudioTrack> mAudioTrack; + sp<IMemory> mCblkMemory; + sp<AudioTrackThread> mAudioTrackThread; + + float mVolume[2]; + float mSendLevel; + uint32_t mFrameCount; + + audio_track_cblk_t* mCblk; + audio_format_t mFormat; + audio_stream_type_t mStreamType; + uint8_t mChannelCount; + uint8_t mMuted; + uint8_t mReserved; + uint32_t mChannelMask; + status_t mStatus; + uint32_t mLatency; + + bool mActive; // protected by mLock + + callback_t mCbf; // callback handler for events, or NULL + void* mUserData; + uint32_t mNotificationFramesReq; // requested number of frames between each notification callback + uint32_t mNotificationFramesAct; // actual number of frames between each notification callback + sp<IMemory> mSharedBuffer; + int mLoopCount; + uint32_t mRemainingFrames; + uint32_t mMarkerPosition; + bool mMarkerReached; + uint32_t mNewPosition; + uint32_t mUpdatePeriod; + bool mFlushed; // FIXME will be made obsolete by making flush() synchronous + audio_policy_output_flags_t mFlags; + int mSessionId; + int mAuxEffectId; + mutable Mutex mLock; + status_t mRestoreStatus; + bool mIsTimed; + int mPreviousPriority; // before start() + int mPreviousSchedulingGroup; +}; + +class TimedAudioTrack : public AudioTrack +{ +public: + TimedAudioTrack(); + + /* allocate a shared memory buffer that can be passed to queueTimedBuffer */ + status_t allocateTimedBuffer(size_t size, sp<IMemory>* buffer); + + /* queue a buffer obtained via allocateTimedBuffer for playback at the + given timestamp. PTS units a microseconds on the media time timeline. + The media time transform (set with setMediaTimeTransform) set by the + audio producer will handle converting from media time to local time + (perhaps going through the common time timeline in the case of + synchronized multiroom audio case) */ + status_t queueTimedBuffer(const sp<IMemory>& buffer, int64_t pts); + + /* define a transform between media time and either common time or + local time */ + enum TargetTimeline {LOCAL_TIME, COMMON_TIME}; + status_t setMediaTimeTransform(const LinearTransform& xform, + TargetTimeline target); +}; + +}; // namespace android + +#endif // ANDROID_AUDIOTRACK_H |