1/*
2 * Copyright (C) 2007 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#ifndef ANDROID_AUDIOTRACK_H
18#define ANDROID_AUDIOTRACK_H
19
20#include <cutils/sched_policy.h>
21#include <media/AudioSystem.h>
22#include <media/AudioTimestamp.h>
23#include <media/IAudioTrack.h>
24#include <utils/threads.h>
25
26namespace android {
27
28// ----------------------------------------------------------------------------
29
30class audio_track_cblk_t;
31class AudioTrackClientProxy;
32class StaticAudioTrackClientProxy;
33
34// ----------------------------------------------------------------------------
35
36class AudioTrack : public RefBase
37{
38public:
39    enum channel_index {
40        MONO   = 0,
41        LEFT   = 0,
42        RIGHT  = 1
43    };
44
45    /* Events used by AudioTrack callback function (callback_t).
46     * Keep in sync with frameworks/base/media/java/android/media/AudioTrack.java NATIVE_EVENT_*.
47     */
48    enum event_type {
49        EVENT_MORE_DATA = 0,        // Request to write more data to buffer.
50                                    // If this event is delivered but the callback handler
51                                    // does not want to write more data, the handler must explicitly
52                                    // ignore the event by setting frameCount to zero.
53        EVENT_UNDERRUN = 1,         // Buffer underrun occurred.
54        EVENT_LOOP_END = 2,         // Sample loop end was reached; playback restarted from
55                                    // loop start if loop count was not 0.
56        EVENT_MARKER = 3,           // Playback head is at the specified marker position
57                                    // (See setMarkerPosition()).
58        EVENT_NEW_POS = 4,          // Playback head is at a new position
59                                    // (See setPositionUpdatePeriod()).
60        EVENT_BUFFER_END = 5,       // Playback head is at the end of the buffer.
61                                    // Not currently used by android.media.AudioTrack.
62        EVENT_NEW_IAUDIOTRACK = 6,  // IAudioTrack was re-created, either due to re-routing and
63                                    // voluntary invalidation by mediaserver, or mediaserver crash.
64        EVENT_STREAM_END = 7,       // Sent after all the buffers queued in AF and HW are played
65                                    // back (after stop is called)
66        EVENT_NEW_TIMESTAMP = 8,    // Delivered periodically and when there's a significant change
67                                    // in the mapping from frame position to presentation time.
68                                    // See AudioTimestamp for the information included with event.
69    };
70
71    /* Client should declare Buffer on the stack and pass address to obtainBuffer()
72     * and releaseBuffer().  See also callback_t for EVENT_MORE_DATA.
73     */
74
75    class Buffer
76    {
77    public:
78        // FIXME use m prefix
79        size_t      frameCount;   // number of sample frames corresponding to size;
80                                  // on input it is the number of frames desired,
81                                  // on output is the number of frames actually filled
82                                  // (currently ignored, but will make the primary field in future)
83
84        size_t      size;         // input/output in bytes == frameCount * frameSize
85                                  // on output is the number of bytes actually filled
86                                  // FIXME this is redundant with respect to frameCount,
87                                  // and TRANSFER_OBTAIN mode is broken for 8-bit data
88                                  // since we don't define the frame format
89
90        union {
91            void*       raw;
92            short*      i16;      // signed 16-bit
93            int8_t*     i8;       // unsigned 8-bit, offset by 0x80
94        };
95    };
96
97    /* As a convenience, if a callback is supplied, a handler thread
98     * is automatically created with the appropriate priority. This thread
99     * invokes the callback when a new buffer becomes available or various conditions occur.
100     * Parameters:
101     *
102     * event:   type of event notified (see enum AudioTrack::event_type).
103     * user:    Pointer to context for use by the callback receiver.
104     * info:    Pointer to optional parameter according to event type:
105     *          - EVENT_MORE_DATA: pointer to AudioTrack::Buffer struct. The callback must not write
106     *            more bytes than indicated by 'size' field and update 'size' if fewer bytes are
107     *            written.
108     *          - EVENT_UNDERRUN: unused.
109     *          - EVENT_LOOP_END: pointer to an int indicating the number of loops remaining.
110     *          - EVENT_MARKER: pointer to const uint32_t containing the marker position in frames.
111     *          - EVENT_NEW_POS: pointer to const uint32_t containing the new position in frames.
112     *          - EVENT_BUFFER_END: unused.
113     *          - EVENT_NEW_IAUDIOTRACK: unused.
114     *          - EVENT_STREAM_END: unused.
115     *          - EVENT_NEW_TIMESTAMP: pointer to const AudioTimestamp.
116     */
117
118    typedef void (*callback_t)(int event, void* user, void *info);
119
120    /* Returns the minimum frame count required for the successful creation of
121     * an AudioTrack object.
122     * Returned status (from utils/Errors.h) can be:
123     *  - NO_ERROR: successful operation
124     *  - NO_INIT: audio server or audio hardware not initialized
125     *  - BAD_VALUE: unsupported configuration
126     */
127
128    static status_t getMinFrameCount(size_t* frameCount,
129                                     audio_stream_type_t streamType,
130                                     uint32_t sampleRate);
131
132    /* How data is transferred to AudioTrack
133     */
134    enum transfer_type {
135        TRANSFER_DEFAULT,   // not specified explicitly; determine from the other parameters
136        TRANSFER_CALLBACK,  // callback EVENT_MORE_DATA
137        TRANSFER_OBTAIN,    // FIXME deprecated: call obtainBuffer() and releaseBuffer()
138        TRANSFER_SYNC,      // synchronous write()
139        TRANSFER_SHARED,    // shared memory
140    };
141
142    /* Constructs an uninitialized AudioTrack. No connection with
143     * AudioFlinger takes place.  Use set() after this.
144     */
145                        AudioTrack();
146
147    /* Creates an AudioTrack object and registers it with AudioFlinger.
148     * Once created, the track needs to be started before it can be used.
149     * Unspecified values are set to appropriate default values.
150     * With this constructor, the track is configured for streaming mode.
151     * Data to be rendered is supplied by write() or by the callback EVENT_MORE_DATA.
152     * Intermixing a combination of write() and non-ignored EVENT_MORE_DATA is not allowed.
153     *
154     * Parameters:
155     *
156     * streamType:         Select the type of audio stream this track is attached to
157     *                     (e.g. AUDIO_STREAM_MUSIC).
158     * sampleRate:         Data source sampling rate in Hz.
159     * format:             Audio format (e.g AUDIO_FORMAT_PCM_16_BIT for signed
160     *                     16 bits per sample).
161     * channelMask:        Channel mask.
162     * frameCount:         Minimum size of track PCM buffer in frames. This defines the
163     *                     application's contribution to the
164     *                     latency of the track. The actual size selected by the AudioTrack could be
165     *                     larger if the requested size is not compatible with current audio HAL
166     *                     configuration.  Zero means to use a default value.
167     * flags:              See comments on audio_output_flags_t in <system/audio.h>.
168     * cbf:                Callback function. If not null, this function is called periodically
169     *                     to provide new data and inform of marker, position updates, etc.
170     * user:               Context for use by the callback receiver.
171     * notificationFrames: The callback function is called each time notificationFrames PCM
172     *                     frames have been consumed from track input buffer.
173     *                     This is expressed in units of frames at the initial source sample rate.
174     * sessionId:          Specific session ID, or zero to use default.
175     * transferType:       How data is transferred to AudioTrack.
176     * threadCanCallJava:  Not present in parameter list, and so is fixed at false.
177     */
178
179                        AudioTrack( audio_stream_type_t streamType,
180                                    uint32_t sampleRate,
181                                    audio_format_t format,
182                                    audio_channel_mask_t,
183                                    int frameCount       = 0,
184                                    audio_output_flags_t flags = AUDIO_OUTPUT_FLAG_NONE,
185                                    callback_t cbf       = NULL,
186                                    void* user           = NULL,
187                                    int notificationFrames = 0,
188                                    int sessionId        = 0,
189                                    transfer_type transferType = TRANSFER_DEFAULT,
190                                    const audio_offload_info_t *offloadInfo = NULL);
191
192    /* Creates an audio track and registers it with AudioFlinger.
193     * With this constructor, the track is configured for static buffer mode.
194     * The format must not be 8-bit linear PCM.
195     * Data to be rendered is passed in a shared memory buffer
196     * identified by the argument sharedBuffer, which must be non-0.
197     * The memory should be initialized to the desired data before calling start().
198     * The write() method is not supported in this case.
199     * It is recommended to pass a callback function to be notified of playback end by an
200     * EVENT_UNDERRUN event.
201     */
202
203                        AudioTrack( audio_stream_type_t streamType,
204                                    uint32_t sampleRate,
205                                    audio_format_t format,
206                                    audio_channel_mask_t channelMask,
207                                    const sp<IMemory>& sharedBuffer,
208                                    audio_output_flags_t flags = AUDIO_OUTPUT_FLAG_NONE,
209                                    callback_t cbf      = NULL,
210                                    void* user          = NULL,
211                                    int notificationFrames = 0,
212                                    int sessionId       = 0,
213                                    transfer_type transferType = TRANSFER_DEFAULT,
214                                    const audio_offload_info_t *offloadInfo = NULL);
215
216    /* Terminates the AudioTrack and unregisters it from AudioFlinger.
217     * Also destroys all resources associated with the AudioTrack.
218     */
219protected:
220                        virtual ~AudioTrack();
221public:
222
223    /* Initialize an AudioTrack that was created using the AudioTrack() constructor.
224     * Don't call set() more than once, or after the AudioTrack() constructors that take parameters.
225     * Returned status (from utils/Errors.h) can be:
226     *  - NO_ERROR: successful initialization
227     *  - INVALID_OPERATION: AudioTrack is already initialized
228     *  - BAD_VALUE: invalid parameter (channelMask, format, sampleRate...)
229     *  - NO_INIT: audio server or audio hardware not initialized
230     * If status is not equal to NO_ERROR, don't call any other APIs on this AudioTrack.
231     * If sharedBuffer is non-0, the frameCount parameter is ignored and
232     * replaced by the shared buffer's total allocated size in frame units.
233     *
234     * Parameters not listed in the AudioTrack constructors above:
235     *
236     * threadCanCallJava:  Whether callbacks are made from an attached thread and thus can call JNI.
237     */
238            status_t    set(audio_stream_type_t streamType,
239                            uint32_t sampleRate,
240                            audio_format_t format,
241                            audio_channel_mask_t channelMask,
242                            int frameCount      = 0,
243                            audio_output_flags_t flags = AUDIO_OUTPUT_FLAG_NONE,
244                            callback_t cbf      = NULL,
245                            void* user          = NULL,
246                            int notificationFrames = 0,
247                            const sp<IMemory>& sharedBuffer = 0,
248                            bool threadCanCallJava = false,
249                            int sessionId       = 0,
250                            transfer_type transferType = TRANSFER_DEFAULT,
251                            const audio_offload_info_t *offloadInfo = NULL);
252
253    /* Result of constructing the AudioTrack. This must be checked for successful initialization
254     * before using any AudioTrack API (except for set()), because using
255     * an uninitialized AudioTrack produces undefined results.
256     * See set() method above for possible return codes.
257     */
258            status_t    initCheck() const   { return mStatus; }
259
260    /* Returns this track's estimated latency in milliseconds.
261     * This includes the latency due to AudioTrack buffer size, AudioMixer (if any)
262     * and audio hardware driver.
263     */
264            uint32_t    latency() const     { return mLatency; }
265
266    /* getters, see constructors and set() */
267
268            audio_stream_type_t streamType() const { return mStreamType; }
269            audio_format_t format() const   { return mFormat; }
270
271    /* Return frame size in bytes, which for linear PCM is
272     * channelCount * (bit depth per channel / 8).
273     * channelCount is determined from channelMask, and bit depth comes from format.
274     * For non-linear formats, the frame size is typically 1 byte.
275     */
276            size_t      frameSize() const   { return mFrameSize; }
277
278            uint32_t    channelCount() const { return mChannelCount; }
279            uint32_t    frameCount() const  { return mFrameCount; }
280
281    /* Return the static buffer specified in constructor or set(), or 0 for streaming mode */
282            sp<IMemory> sharedBuffer() const { return mSharedBuffer; }
283
284    /* After it's created the track is not active. Call start() to
285     * make it active. If set, the callback will start being called.
286     * If the track was previously paused, volume is ramped up over the first mix buffer.
287     */
288            status_t        start();
289
290    /* Stop a track.
291     * In static buffer mode, the track is stopped immediately.
292     * In streaming mode, the callback will cease being called.  Note that obtainBuffer() still
293     * works and will fill up buffers until the pool is exhausted, and then will return WOULD_BLOCK.
294     * In streaming mode the stop does not occur immediately: any data remaining in the buffer
295     * is first drained, mixed, and output, and only then is the track marked as stopped.
296     */
297            void        stop();
298            bool        stopped() const;
299
300    /* Flush a stopped or paused track. All previously buffered data is discarded immediately.
301     * This has the effect of draining the buffers without mixing or output.
302     * Flush is intended for streaming mode, for example before switching to non-contiguous content.
303     * This function is a no-op if the track is not stopped or paused, or uses a static buffer.
304     */
305            void        flush();
306
307    /* Pause a track. After pause, the callback will cease being called and
308     * obtainBuffer returns WOULD_BLOCK. Note that obtainBuffer() still works
309     * and will fill up buffers until the pool is exhausted.
310     * Volume is ramped down over the next mix buffer following the pause request,
311     * and then the track is marked as paused.  It can be resumed with ramp up by start().
312     */
313            void        pause();
314
315    /* Set volume for this track, mostly used for games' sound effects
316     * left and right volumes. Levels must be >= 0.0 and <= 1.0.
317     * This is the older API.  New applications should use setVolume(float) when possible.
318     */
319            status_t    setVolume(float left, float right);
320
321    /* Set volume for all channels.  This is the preferred API for new applications,
322     * especially for multi-channel content.
323     */
324            status_t    setVolume(float volume);
325
326    /* Set the send level for this track. An auxiliary effect should be attached
327     * to the track with attachEffect(). Level must be >= 0.0 and <= 1.0.
328     */
329            status_t    setAuxEffectSendLevel(float level);
330            void        getAuxEffectSendLevel(float* level) const;
331
332    /* Set source sample rate for this track in Hz, mostly used for games' sound effects
333     */
334            status_t    setSampleRate(uint32_t sampleRate);
335
336    /* Return current source sample rate in Hz, or 0 if unknown */
337            uint32_t    getSampleRate() const;
338
339    /* Enables looping and sets the start and end points of looping.
340     * Only supported for static buffer mode.
341     *
342     * Parameters:
343     *
344     * loopStart:   loop start in frames relative to start of buffer.
345     * loopEnd:     loop end in frames relative to start of buffer.
346     * loopCount:   number of loops to execute. Calling setLoop() with loopCount == 0 cancels any
347     *              pending or active loop. loopCount == -1 means infinite looping.
348     *
349     * For proper operation the following condition must be respected:
350     *      loopCount != 0 implies 0 <= loopStart < loopEnd <= frameCount().
351     *
352     * If the loop period (loopEnd - loopStart) is too small for the implementation to support,
353     * setLoop() will return BAD_VALUE.  loopCount must be >= -1.
354     *
355     */
356            status_t    setLoop(uint32_t loopStart, uint32_t loopEnd, int loopCount);
357
358    /* Sets marker position. When playback reaches the number of frames specified, a callback with
359     * event type EVENT_MARKER is called. Calling setMarkerPosition with marker == 0 cancels marker
360     * notification callback.  To set a marker at a position which would compute as 0,
361     * a workaround is to the set the marker at a nearby position such as ~0 or 1.
362     * If the AudioTrack has been opened with no callback function associated, the operation will
363     * fail.
364     *
365     * Parameters:
366     *
367     * marker:   marker position expressed in wrapping (overflow) frame units,
368     *           like the return value of getPosition().
369     *
370     * Returned status (from utils/Errors.h) can be:
371     *  - NO_ERROR: successful operation
372     *  - INVALID_OPERATION: the AudioTrack has no callback installed.
373     */
374            status_t    setMarkerPosition(uint32_t marker);
375            status_t    getMarkerPosition(uint32_t *marker) const;
376
377    /* Sets position update period. Every time the number of frames specified has been played,
378     * a callback with event type EVENT_NEW_POS is called.
379     * Calling setPositionUpdatePeriod with updatePeriod == 0 cancels new position notification
380     * callback.
381     * If the AudioTrack has been opened with no callback function associated, the operation will
382     * fail.
383     * Extremely small values may be rounded up to a value the implementation can support.
384     *
385     * Parameters:
386     *
387     * updatePeriod:  position update notification period expressed in frames.
388     *
389     * Returned status (from utils/Errors.h) can be:
390     *  - NO_ERROR: successful operation
391     *  - INVALID_OPERATION: the AudioTrack has no callback installed.
392     */
393            status_t    setPositionUpdatePeriod(uint32_t updatePeriod);
394            status_t    getPositionUpdatePeriod(uint32_t *updatePeriod) const;
395
396    /* Sets playback head position.
397     * Only supported for static buffer mode.
398     *
399     * Parameters:
400     *
401     * position:  New playback head position in frames relative to start of buffer.
402     *            0 <= position <= frameCount().  Note that end of buffer is permitted,
403     *            but will result in an immediate underrun if started.
404     *
405     * Returned status (from utils/Errors.h) can be:
406     *  - NO_ERROR: successful operation
407     *  - INVALID_OPERATION: the AudioTrack is not stopped or paused, or is streaming mode.
408     *  - BAD_VALUE: The specified position is beyond the number of frames present in AudioTrack
409     *               buffer
410     */
411            status_t    setPosition(uint32_t position);
412
413    /* Return the total number of frames played since playback start.
414     * The counter will wrap (overflow) periodically, e.g. every ~27 hours at 44.1 kHz.
415     * It is reset to zero by flush(), reload(), and stop().
416     *
417     * Parameters:
418     *
419     *  position:  Address where to return play head position.
420     *
421     * Returned status (from utils/Errors.h) can be:
422     *  - NO_ERROR: successful operation
423     *  - BAD_VALUE:  position is NULL
424     */
425            status_t    getPosition(uint32_t *position) const;
426
427    /* For static buffer mode only, this returns the current playback position in frames
428     * relative to start of buffer.  It is analogous to the position units used by
429     * setLoop() and setPosition().  After underrun, the position will be at end of buffer.
430     */
431            status_t    getBufferPosition(uint32_t *position);
432
433    /* Forces AudioTrack buffer full condition. When playing a static buffer, this method avoids
434     * rewriting the buffer before restarting playback after a stop.
435     * This method must be called with the AudioTrack in paused or stopped state.
436     * Not allowed in streaming mode.
437     *
438     * Returned status (from utils/Errors.h) can be:
439     *  - NO_ERROR: successful operation
440     *  - INVALID_OPERATION: the AudioTrack is not stopped or paused, or is streaming mode.
441     */
442            status_t    reload();
443
444    /* Returns a handle on the audio output used by this AudioTrack.
445     *
446     * Parameters:
447     *  none.
448     *
449     * Returned value:
450     *  handle on audio hardware output
451     */
452            audio_io_handle_t    getOutput();
453
454    /* Returns the unique session ID associated with this track.
455     *
456     * Parameters:
457     *  none.
458     *
459     * Returned value:
460     *  AudioTrack session ID.
461     */
462            int    getSessionId() const { return mSessionId; }
463
464    /* Attach track auxiliary output to specified effect. Use effectId = 0
465     * to detach track from effect.
466     *
467     * Parameters:
468     *
469     * effectId:  effectId obtained from AudioEffect::id().
470     *
471     * Returned status (from utils/Errors.h) can be:
472     *  - NO_ERROR: successful operation
473     *  - INVALID_OPERATION: the effect is not an auxiliary effect.
474     *  - BAD_VALUE: The specified effect ID is invalid
475     */
476            status_t    attachAuxEffect(int effectId);
477
478    /* Obtains a buffer of up to "audioBuffer->frameCount" empty slots for frames.
479     * After filling these slots with data, the caller should release them with releaseBuffer().
480     * If the track buffer is not full, obtainBuffer() returns as many contiguous
481     * [empty slots for] frames as are available immediately.
482     * If the track buffer is full and track is stopped, obtainBuffer() returns WOULD_BLOCK
483     * regardless of the value of waitCount.
484     * If the track buffer is full and track is not stopped, obtainBuffer() blocks with a
485     * maximum timeout based on waitCount; see chart below.
486     * Buffers will be returned until the pool
487     * is exhausted, at which point obtainBuffer() will either block
488     * or return WOULD_BLOCK depending on the value of the "waitCount"
489     * parameter.
490     * Each sample is 16-bit signed PCM.
491     *
492     * obtainBuffer() and releaseBuffer() are deprecated for direct use by applications,
493     * which should use write() or callback EVENT_MORE_DATA instead.
494     *
495     * Interpretation of waitCount:
496     *  +n  limits wait time to n * WAIT_PERIOD_MS,
497     *  -1  causes an (almost) infinite wait time,
498     *   0  non-blocking.
499     *
500     * Buffer fields
501     * On entry:
502     *  frameCount  number of frames requested
503     * After error return:
504     *  frameCount  0
505     *  size        0
506     *  raw         undefined
507     * After successful return:
508     *  frameCount  actual number of frames available, <= number requested
509     *  size        actual number of bytes available
510     *  raw         pointer to the buffer
511     */
512
513    /* FIXME Deprecated public API for TRANSFER_OBTAIN mode */
514            status_t    obtainBuffer(Buffer* audioBuffer, int32_t waitCount)
515                                __attribute__((__deprecated__));
516
517private:
518    /* If nonContig is non-NULL, it is an output parameter that will be set to the number of
519     * additional non-contiguous frames that are available immediately.
520     * FIXME We could pass an array of Buffers instead of only one Buffer to obtainBuffer(),
521     * in case the requested amount of frames is in two or more non-contiguous regions.
522     * FIXME requested and elapsed are both relative times.  Consider changing to absolute time.
523     */
524            status_t    obtainBuffer(Buffer* audioBuffer, const struct timespec *requested,
525                                     struct timespec *elapsed = NULL, size_t *nonContig = NULL);
526public:
527
528//EL_FIXME to be reconciled with new obtainBuffer() return codes and control block proxy
529//            enum {
530//            NO_MORE_BUFFERS = 0x80000001,   // same name in AudioFlinger.h, ok to be different value
531//            TEAR_DOWN       = 0x80000002,
532//            STOPPED = 1,
533//            STREAM_END_WAIT,
534//            STREAM_END
535//        };
536
537    /* Release a filled buffer of "audioBuffer->frameCount" frames for AudioFlinger to process. */
538    // FIXME make private when obtainBuffer() for TRANSFER_OBTAIN is removed
539            void        releaseBuffer(Buffer* audioBuffer);
540
541    /* As a convenience we provide a write() interface to the audio buffer.
542     * Input parameter 'size' is in byte units.
543     * This is implemented on top of obtainBuffer/releaseBuffer. For best
544     * performance use callbacks. Returns actual number of bytes written >= 0,
545     * or one of the following negative status codes:
546     *      INVALID_OPERATION   AudioTrack is configured for static buffer or streaming mode
547     *      BAD_VALUE           size is invalid
548     *      WOULD_BLOCK         when obtainBuffer() returns same, or
549     *                          AudioTrack was stopped during the write
550     *      or any other error code returned by IAudioTrack::start() or restoreTrack_l().
551     */
552            ssize_t     write(const void* buffer, size_t size);
553
554    /*
555     * Dumps the state of an audio track.
556     */
557            status_t    dump(int fd, const Vector<String16>& args) const;
558
559    /*
560     * Return the total number of frames which AudioFlinger desired but were unavailable,
561     * and thus which resulted in an underrun.  Reset to zero by stop().
562     */
563            uint32_t    getUnderrunFrames() const;
564
565    /* Get the flags */
566            audio_output_flags_t getFlags() const { return mFlags; }
567
568    /* Set parameters - only possible when using direct output */
569            status_t    setParameters(const String8& keyValuePairs);
570
571    /* Get parameters */
572            String8     getParameters(const String8& keys);
573
574    /* Poll for a timestamp on demand.
575     * Use if EVENT_NEW_TIMESTAMP is not delivered often enough for your needs,
576     * or if you need to get the most recent timestamp outside of the event callback handler.
577     * Caution: calling this method too often may be inefficient;
578     * if you need a high resolution mapping between frame position and presentation time,
579     * consider implementing that at application level, based on the low resolution timestamps.
580     * Returns NO_ERROR if timestamp is valid.
581     */
582            status_t    getTimestamp(AudioTimestamp& timestamp);
583
584protected:
585    /* copying audio tracks is not allowed */
586                        AudioTrack(const AudioTrack& other);
587            AudioTrack& operator = (const AudioTrack& other);
588
589    /* a small internal class to handle the callback */
590    class AudioTrackThread : public Thread
591    {
592    public:
593        AudioTrackThread(AudioTrack& receiver, bool bCanCallJava = false);
594
595        // Do not call Thread::requestExitAndWait() without first calling requestExit().
596        // Thread::requestExitAndWait() is not virtual, and the implementation doesn't do enough.
597        virtual void        requestExit();
598
599                void        pause();    // suspend thread from execution at next loop boundary
600                void        resume();   // allow thread to execute, if not requested to exit
601
602    private:
603                void        pauseInternal(nsecs_t ns = 0LL);
604                                        // like pause(), but only used internally within thread
605
606        friend class AudioTrack;
607        virtual bool        threadLoop();
608        AudioTrack&         mReceiver;
609        virtual ~AudioTrackThread();
610        Mutex               mMyLock;    // Thread::mLock is private
611        Condition           mMyCond;    // Thread::mThreadExitedCondition is private
612        bool                mPaused;    // whether thread is requested to pause at next loop entry
613        bool                mPausedInt; // whether thread internally requests pause
614        nsecs_t             mPausedNs;  // if mPausedInt then associated timeout, otherwise ignored
615        bool                mIgnoreNextPausedInt;   // whether to ignore next mPausedInt request
616    };
617
618            // body of AudioTrackThread::threadLoop()
619            // returns the maximum amount of time before we would like to run again, where:
620            //      0           immediately
621            //      > 0         no later than this many nanoseconds from now
622            //      NS_WHENEVER still active but no particular deadline
623            //      NS_INACTIVE inactive so don't run again until re-started
624            //      NS_NEVER    never again
625            static const nsecs_t NS_WHENEVER = -1, NS_INACTIVE = -2, NS_NEVER = -3;
626            nsecs_t processAudioBuffer(const sp<AudioTrackThread>& thread);
627            status_t processStreamEnd(int32_t waitCount);
628
629
630            // caller must hold lock on mLock for all _l methods
631
632            status_t createTrack_l(audio_stream_type_t streamType,
633                                 uint32_t sampleRate,
634                                 audio_format_t format,
635                                 size_t frameCount,
636                                 audio_output_flags_t flags,
637                                 const sp<IMemory>& sharedBuffer,
638                                 audio_io_handle_t output,
639                                 size_t epoch);
640
641            // can only be called when mState != STATE_ACTIVE
642            void flush_l();
643
644            void setLoop_l(uint32_t loopStart, uint32_t loopEnd, int loopCount);
645            audio_io_handle_t getOutput_l();
646
647            // FIXME enum is faster than strcmp() for parameter 'from'
648            status_t restoreTrack_l(const char *from);
649
650            bool     isOffloaded() const
651                { return (mFlags & AUDIO_OUTPUT_FLAG_COMPRESS_OFFLOAD) != 0; }
652
653    // Next 3 fields may be changed if IAudioTrack is re-created, but always != 0
654    sp<IAudioTrack>         mAudioTrack;
655    sp<IMemory>             mCblkMemory;
656    audio_track_cblk_t*     mCblk;                  // re-load after mLock.unlock()
657
658    sp<AudioTrackThread>    mAudioTrackThread;
659    float                   mVolume[2];
660    float                   mSendLevel;
661    uint32_t                mSampleRate;
662    size_t                  mFrameCount;            // corresponds to current IAudioTrack
663    size_t                  mReqFrameCount;         // frame count to request the next time a new
664                                                    // IAudioTrack is needed
665
666
667    // constant after constructor or set()
668    audio_format_t          mFormat;                // as requested by client, not forced to 16-bit
669    audio_stream_type_t     mStreamType;
670    uint32_t                mChannelCount;
671    audio_channel_mask_t    mChannelMask;
672    transfer_type           mTransfer;
673
674    // mFrameSize is equal to mFrameSizeAF for non-PCM or 16-bit PCM data.  For 8-bit PCM data, it's
675    // twice as large as mFrameSize because data is expanded to 16-bit before it's stored in buffer.
676    size_t                  mFrameSize;             // app-level frame size
677    size_t                  mFrameSizeAF;           // AudioFlinger frame size
678
679    status_t                mStatus;
680
681    // can change dynamically when IAudioTrack invalidated
682    uint32_t                mLatency;               // in ms
683
684    // Indicates the current track state.  Protected by mLock.
685    enum State {
686        STATE_ACTIVE,
687        STATE_STOPPED,
688        STATE_PAUSED,
689        STATE_PAUSED_STOPPING,
690        STATE_FLUSHED,
691        STATE_STOPPING,
692    }                       mState;
693
694    // for client callback handler
695    callback_t              mCbf;                   // callback handler for events, or NULL
696    void*                   mUserData;
697
698    // for notification APIs
699    uint32_t                mNotificationFramesReq; // requested number of frames between each
700                                                    // notification callback,
701                                                    // at initial source sample rate
702    uint32_t                mNotificationFramesAct; // actual number of frames between each
703                                                    // notification callback,
704                                                    // at initial source sample rate
705    bool                    mRefreshRemaining;      // processAudioBuffer() should refresh next 2
706
707    // These are private to processAudioBuffer(), and are not protected by a lock
708    uint32_t                mRemainingFrames;       // number of frames to request in obtainBuffer()
709    bool                    mRetryOnPartialBuffer;  // sleep and retry after partial obtainBuffer()
710    uint32_t                mObservedSequence;      // last observed value of mSequence
711
712    sp<IMemory>             mSharedBuffer;
713    uint32_t                mLoopPeriod;            // in frames, zero means looping is disabled
714    uint32_t                mMarkerPosition;        // in wrapping (overflow) frame units
715    bool                    mMarkerReached;
716    uint32_t                mNewPosition;           // in frames
717    uint32_t                mUpdatePeriod;          // in frames, zero means no EVENT_NEW_POS
718
719    audio_output_flags_t    mFlags;
720    int                     mSessionId;
721    int                     mAuxEffectId;
722
723    mutable Mutex           mLock;
724
725    bool                    mIsTimed;
726    int                     mPreviousPriority;          // before start()
727    SchedPolicy             mPreviousSchedulingGroup;
728    bool                    mAwaitBoost;    // thread should wait for priority boost before running
729
730    // The proxy should only be referenced while a lock is held because the proxy isn't
731    // multi-thread safe, especially the SingleStateQueue part of the proxy.
732    // An exception is that a blocking ClientProxy::obtainBuffer() may be called without a lock,
733    // provided that the caller also holds an extra reference to the proxy and shared memory to keep
734    // them around in case they are replaced during the obtainBuffer().
735    sp<StaticAudioTrackClientProxy> mStaticProxy;   // for type safety only
736    sp<AudioTrackClientProxy>       mProxy;         // primary owner of the memory
737
738    bool                    mInUnderrun;            // whether track is currently in underrun state
739    String8                 mName;                  // server's name for this IAudioTrack
740
741private:
742    class DeathNotifier : public IBinder::DeathRecipient {
743    public:
744        DeathNotifier(AudioTrack* audioTrack) : mAudioTrack(audioTrack) { }
745    protected:
746        virtual void        binderDied(const wp<IBinder>& who);
747    private:
748        const wp<AudioTrack> mAudioTrack;
749    };
750
751    sp<DeathNotifier>       mDeathNotifier;
752    uint32_t                mSequence;              // incremented for each new IAudioTrack attempt
753    audio_io_handle_t       mOutput;                // cached output io handle
754};
755
756class TimedAudioTrack : public AudioTrack
757{
758public:
759    TimedAudioTrack();
760
761    /* allocate a shared memory buffer that can be passed to queueTimedBuffer */
762    status_t allocateTimedBuffer(size_t size, sp<IMemory>* buffer);
763
764    /* queue a buffer obtained via allocateTimedBuffer for playback at the
765       given timestamp.  PTS units are microseconds on the media time timeline.
766       The media time transform (set with setMediaTimeTransform) set by the
767       audio producer will handle converting from media time to local time
768       (perhaps going through the common time timeline in the case of
769       synchronized multiroom audio case) */
770    status_t queueTimedBuffer(const sp<IMemory>& buffer, int64_t pts);
771
772    /* define a transform between media time and either common time or
773       local time */
774    enum TargetTimeline {LOCAL_TIME, COMMON_TIME};
775    status_t setMediaTimeTransform(const LinearTransform& xform,
776                                   TargetTimeline target);
777};
778
779}; // namespace android
780
781#endif // ANDROID_AUDIOTRACK_H
782