125a9e5561a7f14e79b04f713a515a9464b9ea077Steven Moreland/*
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 <media/AudioResamplerPublic.h>
25#include <media/Modulo.h>
26#include <utils/threads.h>
27
28namespace android {
29
30// ----------------------------------------------------------------------------
31
32struct audio_track_cblk_t;
33class AudioTrackClientProxy;
34class StaticAudioTrackClientProxy;
35
36// ----------------------------------------------------------------------------
37
38class AudioTrack : public RefBase
39{
40public:
41
42    /* Events used by AudioTrack callback function (callback_t).
43     * Keep in sync with frameworks/base/media/java/android/media/AudioTrack.java NATIVE_EVENT_*.
44     */
45    enum event_type {
46        EVENT_MORE_DATA = 0,        // Request to write more data to buffer.
47                                    // This event only occurs for TRANSFER_CALLBACK.
48                                    // If this event is delivered but the callback handler
49                                    // does not want to write more data, the handler must
50                                    // ignore the event by setting frameCount to zero.
51                                    // This might occur, for example, if the application is
52                                    // waiting for source data or is at the end of stream.
53                                    //
54                                    // For data filling, it is preferred that the callback
55                                    // does not block and instead returns a short count on
56                                    // the amount of data actually delivered
57                                    // (or 0, if no data is currently available).
58        EVENT_UNDERRUN = 1,         // Buffer underrun occurred. This will not occur for
59                                    // static tracks.
60        EVENT_LOOP_END = 2,         // Sample loop end was reached; playback restarted from
61                                    // loop start if loop count was not 0 for a static track.
62        EVENT_MARKER = 3,           // Playback head is at the specified marker position
63                                    // (See setMarkerPosition()).
64        EVENT_NEW_POS = 4,          // Playback head is at a new position
65                                    // (See setPositionUpdatePeriod()).
66        EVENT_BUFFER_END = 5,       // Playback has completed for a static track.
67        EVENT_NEW_IAUDIOTRACK = 6,  // IAudioTrack was re-created, either due to re-routing and
68                                    // voluntary invalidation by mediaserver, or mediaserver crash.
69        EVENT_STREAM_END = 7,       // Sent after all the buffers queued in AF and HW are played
70                                    // back (after stop is called) for an offloaded track.
71#if 0   // FIXME not yet implemented
72        EVENT_NEW_TIMESTAMP = 8,    // Delivered periodically and when there's a significant change
73                                    // in the mapping from frame position to presentation time.
74                                    // See AudioTimestamp for the information included with event.
75#endif
76    };
77
78    /* Client should declare a Buffer and pass the address to obtainBuffer()
79     * and releaseBuffer().  See also callback_t for EVENT_MORE_DATA.
80     */
81
82    class Buffer
83    {
84    public:
85        // FIXME use m prefix
86        size_t      frameCount;   // number of sample frames corresponding to size;
87                                  // on input to obtainBuffer() it is the number of frames desired,
88                                  // on output from obtainBuffer() it is the number of available
89                                  //    [empty slots for] frames to be filled
90                                  // on input to releaseBuffer() it is currently ignored
91
92        size_t      size;         // input/output in bytes == frameCount * frameSize
93                                  // on input to obtainBuffer() it is ignored
94                                  // on output from obtainBuffer() it is the number of available
95                                  //    [empty slots for] bytes to be filled,
96                                  //    which is frameCount * frameSize
97                                  // on input to releaseBuffer() it is the number of bytes to
98                                  //    release
99                                  // FIXME This is redundant with respect to frameCount.  Consider
100                                  //    removing size and making frameCount the primary field.
101
102        union {
103            void*       raw;
104            short*      i16;      // signed 16-bit
105            int8_t*     i8;       // unsigned 8-bit, offset by 0x80
106        };                        // input to obtainBuffer(): unused, output: pointer to buffer
107    };
108
109    /* As a convenience, if a callback is supplied, a handler thread
110     * is automatically created with the appropriate priority. This thread
111     * invokes the callback when a new buffer becomes available or various conditions occur.
112     * Parameters:
113     *
114     * event:   type of event notified (see enum AudioTrack::event_type).
115     * user:    Pointer to context for use by the callback receiver.
116     * info:    Pointer to optional parameter according to event type:
117     *          - EVENT_MORE_DATA: pointer to AudioTrack::Buffer struct. The callback must not write
118     *            more bytes than indicated by 'size' field and update 'size' if fewer bytes are
119     *            written.
120     *          - EVENT_UNDERRUN: unused.
121     *          - EVENT_LOOP_END: pointer to an int indicating the number of loops remaining.
122     *          - EVENT_MARKER: pointer to const uint32_t containing the marker position in frames.
123     *          - EVENT_NEW_POS: pointer to const uint32_t containing the new position in frames.
124     *          - EVENT_BUFFER_END: unused.
125     *          - EVENT_NEW_IAUDIOTRACK: unused.
126     *          - EVENT_STREAM_END: unused.
127     *          - EVENT_NEW_TIMESTAMP: pointer to const AudioTimestamp.
128     */
129
130    typedef void (*callback_t)(int event, void* user, void *info);
131
132    /* Returns the minimum frame count required for the successful creation of
133     * an AudioTrack object.
134     * Returned status (from utils/Errors.h) can be:
135     *  - NO_ERROR: successful operation
136     *  - NO_INIT: audio server or audio hardware not initialized
137     *  - BAD_VALUE: unsupported configuration
138     * frameCount is guaranteed to be non-zero if status is NO_ERROR,
139     * and is undefined otherwise.
140     * FIXME This API assumes a route, and so should be deprecated.
141     */
142
143    static status_t getMinFrameCount(size_t* frameCount,
144                                     audio_stream_type_t streamType,
145                                     uint32_t sampleRate);
146
147    /* How data is transferred to AudioTrack
148     */
149    enum transfer_type {
150        TRANSFER_DEFAULT,   // not specified explicitly; determine from the other parameters
151        TRANSFER_CALLBACK,  // callback EVENT_MORE_DATA
152        TRANSFER_OBTAIN,    // call obtainBuffer() and releaseBuffer()
153        TRANSFER_SYNC,      // synchronous write()
154        TRANSFER_SHARED,    // shared memory
155    };
156
157    /* Constructs an uninitialized AudioTrack. No connection with
158     * AudioFlinger takes place.  Use set() after this.
159     */
160                        AudioTrack();
161
162    /* Creates an AudioTrack object and registers it with AudioFlinger.
163     * Once created, the track needs to be started before it can be used.
164     * Unspecified values are set to appropriate default values.
165     *
166     * Parameters:
167     *
168     * streamType:         Select the type of audio stream this track is attached to
169     *                     (e.g. AUDIO_STREAM_MUSIC).
170     * sampleRate:         Data source sampling rate in Hz.  Zero means to use the sink sample rate.
171     *                     A non-zero value must be specified if AUDIO_OUTPUT_FLAG_DIRECT is set.
172     *                     0 will not work with current policy implementation for direct output
173     *                     selection where an exact match is needed for sampling rate.
174     * format:             Audio format. For mixed tracks, any PCM format supported by server is OK.
175     *                     For direct and offloaded tracks, the possible format(s) depends on the
176     *                     output sink.
177     * channelMask:        Channel mask, such that audio_is_output_channel(channelMask) is true.
178     * frameCount:         Minimum size of track PCM buffer in frames. This defines the
179     *                     application's contribution to the
180     *                     latency of the track. The actual size selected by the AudioTrack could be
181     *                     larger if the requested size is not compatible with current audio HAL
182     *                     configuration.  Zero means to use a default value.
183     * flags:              See comments on audio_output_flags_t in <system/audio.h>.
184     * cbf:                Callback function. If not null, this function is called periodically
185     *                     to provide new data in TRANSFER_CALLBACK mode
186     *                     and inform of marker, position updates, etc.
187     * user:               Context for use by the callback receiver.
188     * notificationFrames: The callback function is called each time notificationFrames PCM
189     *                     frames have been consumed from track input buffer by server.
190     *                     Zero means to use a default value, which is typically:
191     *                      - fast tracks: HAL buffer size, even if track frameCount is larger
192     *                      - normal tracks: 1/2 of track frameCount
193     *                     A positive value means that many frames at initial source sample rate.
194     *                     A negative value for this parameter specifies the negative of the
195     *                     requested number of notifications (sub-buffers) in the entire buffer.
196     *                     For fast tracks, the FastMixer will process one sub-buffer at a time.
197     *                     The size of each sub-buffer is determined by the HAL.
198     *                     To get "double buffering", for example, one should pass -2.
199     *                     The minimum number of sub-buffers is 1 (expressed as -1),
200     *                     and the maximum number of sub-buffers is 8 (expressed as -8).
201     *                     Negative is only permitted for fast tracks, and if frameCount is zero.
202     *                     TODO It is ugly to overload a parameter in this way depending on
203     *                     whether it is positive, negative, or zero.  Consider splitting apart.
204     * sessionId:          Specific session ID, or zero to use default.
205     * transferType:       How data is transferred to AudioTrack.
206     * offloadInfo:        If not NULL, provides offload parameters for
207     *                     AudioSystem::getOutputForAttr().
208     * uid:                User ID of the app which initially requested this AudioTrack
209     *                     for power management tracking, or -1 for current user ID.
210     * pid:                Process ID of the app which initially requested this AudioTrack
211     *                     for power management tracking, or -1 for current process ID.
212     * pAttributes:        If not NULL, supersedes streamType for use case selection.
213     * doNotReconnect:     If set to true, AudioTrack won't automatically recreate the IAudioTrack
214                           binder to AudioFlinger.
215                           It will return an error instead.  The application will recreate
216                           the track based on offloading or different channel configuration, etc.
217     * maxRequiredSpeed:   For PCM tracks, this creates an appropriate buffer size that will allow
218     *                     maxRequiredSpeed playback. Values less than 1.0f and greater than
219     *                     AUDIO_TIMESTRETCH_SPEED_MAX will be clamped.  For non-PCM tracks
220     *                     and direct or offloaded tracks, this parameter is ignored.
221     * threadCanCallJava:  Not present in parameter list, and so is fixed at false.
222     */
223
224                        AudioTrack( audio_stream_type_t streamType,
225                                    uint32_t sampleRate,
226                                    audio_format_t format,
227                                    audio_channel_mask_t channelMask,
228                                    size_t frameCount    = 0,
229                                    audio_output_flags_t flags = AUDIO_OUTPUT_FLAG_NONE,
230                                    callback_t cbf       = NULL,
231                                    void* user           = NULL,
232                                    int32_t notificationFrames = 0,
233                                    audio_session_t sessionId  = AUDIO_SESSION_ALLOCATE,
234                                    transfer_type transferType = TRANSFER_DEFAULT,
235                                    const audio_offload_info_t *offloadInfo = NULL,
236                                    uid_t uid = AUDIO_UID_INVALID,
237                                    pid_t pid = -1,
238                                    const audio_attributes_t* pAttributes = NULL,
239                                    bool doNotReconnect = false,
240                                    float maxRequiredSpeed = 1.0f);
241
242    /* Creates an audio track and registers it with AudioFlinger.
243     * With this constructor, the track is configured for static buffer mode.
244     * Data to be rendered is passed in a shared memory buffer
245     * identified by the argument sharedBuffer, which should be non-0.
246     * If sharedBuffer is zero, this constructor is equivalent to the previous constructor
247     * but without the ability to specify a non-zero value for the frameCount parameter.
248     * The memory should be initialized to the desired data before calling start().
249     * The write() method is not supported in this case.
250     * It is recommended to pass a callback function to be notified of playback end by an
251     * EVENT_UNDERRUN event.
252     */
253
254                        AudioTrack( audio_stream_type_t streamType,
255                                    uint32_t sampleRate,
256                                    audio_format_t format,
257                                    audio_channel_mask_t channelMask,
258                                    const sp<IMemory>& sharedBuffer,
259                                    audio_output_flags_t flags = AUDIO_OUTPUT_FLAG_NONE,
260                                    callback_t cbf      = NULL,
261                                    void* user          = NULL,
262                                    int32_t notificationFrames = 0,
263                                    audio_session_t sessionId   = AUDIO_SESSION_ALLOCATE,
264                                    transfer_type transferType = TRANSFER_DEFAULT,
265                                    const audio_offload_info_t *offloadInfo = NULL,
266                                    uid_t uid = AUDIO_UID_INVALID,
267                                    pid_t pid = -1,
268                                    const audio_attributes_t* pAttributes = NULL,
269                                    bool doNotReconnect = false,
270                                    float maxRequiredSpeed = 1.0f);
271
272    /* Terminates the AudioTrack and unregisters it from AudioFlinger.
273     * Also destroys all resources associated with the AudioTrack.
274     */
275protected:
276                        virtual ~AudioTrack();
277public:
278
279    /* Initialize an AudioTrack that was created using the AudioTrack() constructor.
280     * Don't call set() more than once, or after the AudioTrack() constructors that take parameters.
281     * set() is not multi-thread safe.
282     * Returned status (from utils/Errors.h) can be:
283     *  - NO_ERROR: successful initialization
284     *  - INVALID_OPERATION: AudioTrack is already initialized
285     *  - BAD_VALUE: invalid parameter (channelMask, format, sampleRate...)
286     *  - NO_INIT: audio server or audio hardware not initialized
287     * If status is not equal to NO_ERROR, don't call any other APIs on this AudioTrack.
288     * If sharedBuffer is non-0, the frameCount parameter is ignored and
289     * replaced by the shared buffer's total allocated size in frame units.
290     *
291     * Parameters not listed in the AudioTrack constructors above:
292     *
293     * threadCanCallJava:  Whether callbacks are made from an attached thread and thus can call JNI.
294     *
295     * Internal state post condition:
296     *      (mStreamType == AUDIO_STREAM_DEFAULT) implies this AudioTrack has valid attributes
297     */
298            status_t    set(audio_stream_type_t streamType,
299                            uint32_t sampleRate,
300                            audio_format_t format,
301                            audio_channel_mask_t channelMask,
302                            size_t frameCount   = 0,
303                            audio_output_flags_t flags = AUDIO_OUTPUT_FLAG_NONE,
304                            callback_t cbf      = NULL,
305                            void* user          = NULL,
306                            int32_t notificationFrames = 0,
307                            const sp<IMemory>& sharedBuffer = 0,
308                            bool threadCanCallJava = false,
309                            audio_session_t sessionId  = AUDIO_SESSION_ALLOCATE,
310                            transfer_type transferType = TRANSFER_DEFAULT,
311                            const audio_offload_info_t *offloadInfo = NULL,
312                            uid_t uid = AUDIO_UID_INVALID,
313                            pid_t pid = -1,
314                            const audio_attributes_t* pAttributes = NULL,
315                            bool doNotReconnect = false,
316                            float maxRequiredSpeed = 1.0f);
317
318    /* Result of constructing the AudioTrack. This must be checked for successful initialization
319     * before using any AudioTrack API (except for set()), because using
320     * an uninitialized AudioTrack produces undefined results.
321     * See set() method above for possible return codes.
322     */
323            status_t    initCheck() const   { return mStatus; }
324
325    /* Returns this track's estimated latency in milliseconds.
326     * This includes the latency due to AudioTrack buffer size, AudioMixer (if any)
327     * and audio hardware driver.
328     */
329            uint32_t    latency() const     { return mLatency; }
330
331    /* Returns the number of application-level buffer underruns
332     * since the AudioTrack was created.
333     */
334            uint32_t    getUnderrunCount() const;
335
336    /* getters, see constructors and set() */
337
338            audio_stream_type_t streamType() const;
339            audio_format_t format() const   { return mFormat; }
340
341    /* Return frame size in bytes, which for linear PCM is
342     * channelCount * (bit depth per channel / 8).
343     * channelCount is determined from channelMask, and bit depth comes from format.
344     * For non-linear formats, the frame size is typically 1 byte.
345     */
346            size_t      frameSize() const   { return mFrameSize; }
347
348            uint32_t    channelCount() const { return mChannelCount; }
349            size_t      frameCount() const  { return mFrameCount; }
350
351    /*
352     * Return the period of the notification callback in frames.
353     * This value is set when the AudioTrack is constructed.
354     * It can be modified if the AudioTrack is rerouted.
355     */
356            uint32_t    getNotificationPeriodInFrames() const { return mNotificationFramesAct; }
357
358    /* Return effective size of audio buffer that an application writes to
359     * or a negative error if the track is uninitialized.
360     */
361            ssize_t     getBufferSizeInFrames();
362
363    /* Returns the buffer duration in microseconds at current playback rate.
364     */
365            status_t    getBufferDurationInUs(int64_t *duration);
366
367    /* Set the effective size of audio buffer that an application writes to.
368     * This is used to determine the amount of available room in the buffer,
369     * which determines when a write will block.
370     * This allows an application to raise and lower the audio latency.
371     * The requested size may be adjusted so that it is
372     * greater or equal to the absolute minimum and
373     * less than or equal to the getBufferCapacityInFrames().
374     * It may also be adjusted slightly for internal reasons.
375     *
376     * Return the final size or a negative error if the track is unitialized
377     * or does not support variable sizes.
378     */
379            ssize_t     setBufferSizeInFrames(size_t size);
380
381    /* Return the static buffer specified in constructor or set(), or 0 for streaming mode */
382            sp<IMemory> sharedBuffer() const { return mSharedBuffer; }
383
384    /* After it's created the track is not active. Call start() to
385     * make it active. If set, the callback will start being called.
386     * If the track was previously paused, volume is ramped up over the first mix buffer.
387     */
388            status_t        start();
389
390    /* Stop a track.
391     * In static buffer mode, the track is stopped immediately.
392     * In streaming mode, the callback will cease being called.  Note that obtainBuffer() still
393     * works and will fill up buffers until the pool is exhausted, and then will return WOULD_BLOCK.
394     * In streaming mode the stop does not occur immediately: any data remaining in the buffer
395     * is first drained, mixed, and output, and only then is the track marked as stopped.
396     */
397            void        stop();
398            bool        stopped() const;
399
400    /* Flush a stopped or paused track. All previously buffered data is discarded immediately.
401     * This has the effect of draining the buffers without mixing or output.
402     * Flush is intended for streaming mode, for example before switching to non-contiguous content.
403     * This function is a no-op if the track is not stopped or paused, or uses a static buffer.
404     */
405            void        flush();
406
407    /* Pause a track. After pause, the callback will cease being called and
408     * obtainBuffer returns WOULD_BLOCK. Note that obtainBuffer() still works
409     * and will fill up buffers until the pool is exhausted.
410     * Volume is ramped down over the next mix buffer following the pause request,
411     * and then the track is marked as paused.  It can be resumed with ramp up by start().
412     */
413            void        pause();
414
415    /* Set volume for this track, mostly used for games' sound effects
416     * left and right volumes. Levels must be >= 0.0 and <= 1.0.
417     * This is the older API.  New applications should use setVolume(float) when possible.
418     */
419            status_t    setVolume(float left, float right);
420
421    /* Set volume for all channels.  This is the preferred API for new applications,
422     * especially for multi-channel content.
423     */
424            status_t    setVolume(float volume);
425
426    /* Set the send level for this track. An auxiliary effect should be attached
427     * to the track with attachEffect(). Level must be >= 0.0 and <= 1.0.
428     */
429            status_t    setAuxEffectSendLevel(float level);
430            void        getAuxEffectSendLevel(float* level) const;
431
432    /* Set source sample rate for this track in Hz, mostly used for games' sound effects.
433     * Zero is not permitted.
434     */
435            status_t    setSampleRate(uint32_t sampleRate);
436
437    /* Return current source sample rate in Hz.
438     * If specified as zero in constructor or set(), this will be the sink sample rate.
439     */
440            uint32_t    getSampleRate() const;
441
442    /* Return the original source sample rate in Hz. This corresponds to the sample rate
443     * if playback rate had normal speed and pitch.
444     */
445            uint32_t    getOriginalSampleRate() const;
446
447    /* Set source playback rate for timestretch
448     * 1.0 is normal speed: < 1.0 is slower, > 1.0 is faster
449     * 1.0 is normal pitch: < 1.0 is lower pitch, > 1.0 is higher pitch
450     *
451     * AUDIO_TIMESTRETCH_SPEED_MIN <= speed <= AUDIO_TIMESTRETCH_SPEED_MAX
452     * AUDIO_TIMESTRETCH_PITCH_MIN <= pitch <= AUDIO_TIMESTRETCH_PITCH_MAX
453     *
454     * Speed increases the playback rate of media, but does not alter pitch.
455     * Pitch increases the "tonal frequency" of media, but does not affect the playback rate.
456     */
457            status_t    setPlaybackRate(const AudioPlaybackRate &playbackRate);
458
459    /* Return current playback rate */
460            const AudioPlaybackRate& getPlaybackRate() const;
461
462    /* Enables looping and sets the start and end points of looping.
463     * Only supported for static buffer mode.
464     *
465     * Parameters:
466     *
467     * loopStart:   loop start in frames relative to start of buffer.
468     * loopEnd:     loop end in frames relative to start of buffer.
469     * loopCount:   number of loops to execute. Calling setLoop() with loopCount == 0 cancels any
470     *              pending or active loop. loopCount == -1 means infinite looping.
471     *
472     * For proper operation the following condition must be respected:
473     *      loopCount != 0 implies 0 <= loopStart < loopEnd <= frameCount().
474     *
475     * If the loop period (loopEnd - loopStart) is too small for the implementation to support,
476     * setLoop() will return BAD_VALUE.  loopCount must be >= -1.
477     *
478     */
479            status_t    setLoop(uint32_t loopStart, uint32_t loopEnd, int loopCount);
480
481    /* Sets marker position. When playback reaches the number of frames specified, a callback with
482     * event type EVENT_MARKER is called. Calling setMarkerPosition with marker == 0 cancels marker
483     * notification callback.  To set a marker at a position which would compute as 0,
484     * a workaround is to set the marker at a nearby position such as ~0 or 1.
485     * If the AudioTrack has been opened with no callback function associated, the operation will
486     * fail.
487     *
488     * Parameters:
489     *
490     * marker:   marker position expressed in wrapping (overflow) frame units,
491     *           like the return value of getPosition().
492     *
493     * Returned status (from utils/Errors.h) can be:
494     *  - NO_ERROR: successful operation
495     *  - INVALID_OPERATION: the AudioTrack has no callback installed.
496     */
497            status_t    setMarkerPosition(uint32_t marker);
498            status_t    getMarkerPosition(uint32_t *marker) const;
499
500    /* Sets position update period. Every time the number of frames specified has been played,
501     * a callback with event type EVENT_NEW_POS is called.
502     * Calling setPositionUpdatePeriod with updatePeriod == 0 cancels new position notification
503     * callback.
504     * If the AudioTrack has been opened with no callback function associated, the operation will
505     * fail.
506     * Extremely small values may be rounded up to a value the implementation can support.
507     *
508     * Parameters:
509     *
510     * updatePeriod:  position update notification period expressed in frames.
511     *
512     * Returned status (from utils/Errors.h) can be:
513     *  - NO_ERROR: successful operation
514     *  - INVALID_OPERATION: the AudioTrack has no callback installed.
515     */
516            status_t    setPositionUpdatePeriod(uint32_t updatePeriod);
517            status_t    getPositionUpdatePeriod(uint32_t *updatePeriod) const;
518
519    /* Sets playback head position.
520     * Only supported for static buffer mode.
521     *
522     * Parameters:
523     *
524     * position:  New playback head position in frames relative to start of buffer.
525     *            0 <= position <= frameCount().  Note that end of buffer is permitted,
526     *            but will result in an immediate underrun if started.
527     *
528     * Returned status (from utils/Errors.h) can be:
529     *  - NO_ERROR: successful operation
530     *  - INVALID_OPERATION: the AudioTrack is not stopped or paused, or is streaming mode.
531     *  - BAD_VALUE: The specified position is beyond the number of frames present in AudioTrack
532     *               buffer
533     */
534            status_t    setPosition(uint32_t position);
535
536    /* Return the total number of frames played since playback start.
537     * The counter will wrap (overflow) periodically, e.g. every ~27 hours at 44.1 kHz.
538     * It is reset to zero by flush(), reload(), and stop().
539     *
540     * Parameters:
541     *
542     *  position:  Address where to return play head position.
543     *
544     * Returned status (from utils/Errors.h) can be:
545     *  - NO_ERROR: successful operation
546     *  - BAD_VALUE:  position is NULL
547     */
548            status_t    getPosition(uint32_t *position);
549
550    /* For static buffer mode only, this returns the current playback position in frames
551     * relative to start of buffer.  It is analogous to the position units used by
552     * setLoop() and setPosition().  After underrun, the position will be at end of buffer.
553     */
554            status_t    getBufferPosition(uint32_t *position);
555
556    /* Forces AudioTrack buffer full condition. When playing a static buffer, this method avoids
557     * rewriting the buffer before restarting playback after a stop.
558     * This method must be called with the AudioTrack in paused or stopped state.
559     * Not allowed in streaming mode.
560     *
561     * Returned status (from utils/Errors.h) can be:
562     *  - NO_ERROR: successful operation
563     *  - INVALID_OPERATION: the AudioTrack is not stopped or paused, or is streaming mode.
564     */
565            status_t    reload();
566
567    /* Returns a handle on the audio output used by this AudioTrack.
568     *
569     * Parameters:
570     *  none.
571     *
572     * Returned value:
573     *  handle on audio hardware output, or AUDIO_IO_HANDLE_NONE if the
574     *  track needed to be re-created but that failed
575     */
576private:
577            audio_io_handle_t    getOutput() const;
578public:
579
580    /* Selects the audio device to use for output of this AudioTrack. A value of
581     * AUDIO_PORT_HANDLE_NONE indicates default (AudioPolicyManager) routing.
582     *
583     * Parameters:
584     *  The device ID of the selected device (as returned by the AudioDevicesManager API).
585     *
586     * Returned value:
587     *  - NO_ERROR: successful operation
588     *    TODO: what else can happen here?
589     */
590            status_t    setOutputDevice(audio_port_handle_t deviceId);
591
592    /* Returns the ID of the audio device selected for this AudioTrack.
593     * A value of AUDIO_PORT_HANDLE_NONE indicates default (AudioPolicyManager) routing.
594     *
595     * Parameters:
596     *  none.
597     */
598     audio_port_handle_t getOutputDevice();
599
600     /* Returns the ID of the audio device actually used by the output to which this AudioTrack is
601      * attached.
602      * A value of AUDIO_PORT_HANDLE_NONE indicates the audio track is not attached to any output.
603      *
604      * Parameters:
605      *  none.
606      */
607     audio_port_handle_t getRoutedDeviceId();
608
609    /* Returns the unique session ID associated with this track.
610     *
611     * Parameters:
612     *  none.
613     *
614     * Returned value:
615     *  AudioTrack session ID.
616     */
617            audio_session_t getSessionId() const { return mSessionId; }
618
619    /* Attach track auxiliary output to specified effect. Use effectId = 0
620     * to detach track from effect.
621     *
622     * Parameters:
623     *
624     * effectId:  effectId obtained from AudioEffect::id().
625     *
626     * Returned status (from utils/Errors.h) can be:
627     *  - NO_ERROR: successful operation
628     *  - INVALID_OPERATION: the effect is not an auxiliary effect.
629     *  - BAD_VALUE: The specified effect ID is invalid
630     */
631            status_t    attachAuxEffect(int effectId);
632
633    /* Public API for TRANSFER_OBTAIN mode.
634     * Obtains a buffer of up to "audioBuffer->frameCount" empty slots for frames.
635     * After filling these slots with data, the caller should release them with releaseBuffer().
636     * If the track buffer is not full, obtainBuffer() returns as many contiguous
637     * [empty slots for] frames as are available immediately.
638     *
639     * If nonContig is non-NULL, it is an output parameter that will be set to the number of
640     * additional non-contiguous frames that are predicted to be available immediately,
641     * if the client were to release the first frames and then call obtainBuffer() again.
642     * This value is only a prediction, and needs to be confirmed.
643     * It will be set to zero for an error return.
644     *
645     * If the track buffer is full and track is stopped, obtainBuffer() returns WOULD_BLOCK
646     * regardless of the value of waitCount.
647     * If the track buffer is full and track is not stopped, obtainBuffer() blocks with a
648     * maximum timeout based on waitCount; see chart below.
649     * Buffers will be returned until the pool
650     * is exhausted, at which point obtainBuffer() will either block
651     * or return WOULD_BLOCK depending on the value of the "waitCount"
652     * parameter.
653     *
654     * Interpretation of waitCount:
655     *  +n  limits wait time to n * WAIT_PERIOD_MS,
656     *  -1  causes an (almost) infinite wait time,
657     *   0  non-blocking.
658     *
659     * Buffer fields
660     * On entry:
661     *  frameCount  number of [empty slots for] frames requested
662     *  size        ignored
663     *  raw         ignored
664     * After error return:
665     *  frameCount  0
666     *  size        0
667     *  raw         undefined
668     * After successful return:
669     *  frameCount  actual number of [empty slots for] frames available, <= number requested
670     *  size        actual number of bytes available
671     *  raw         pointer to the buffer
672     */
673            status_t    obtainBuffer(Buffer* audioBuffer, int32_t waitCount,
674                                size_t *nonContig = NULL);
675
676private:
677    /* If nonContig is non-NULL, it is an output parameter that will be set to the number of
678     * additional non-contiguous frames that are predicted to be available immediately,
679     * if the client were to release the first frames and then call obtainBuffer() again.
680     * This value is only a prediction, and needs to be confirmed.
681     * It will be set to zero for an error return.
682     * FIXME We could pass an array of Buffers instead of only one Buffer to obtainBuffer(),
683     * in case the requested amount of frames is in two or more non-contiguous regions.
684     * FIXME requested and elapsed are both relative times.  Consider changing to absolute time.
685     */
686            status_t    obtainBuffer(Buffer* audioBuffer, const struct timespec *requested,
687                                     struct timespec *elapsed = NULL, size_t *nonContig = NULL);
688public:
689
690    /* Public API for TRANSFER_OBTAIN mode.
691     * Release a filled buffer of frames for AudioFlinger to process.
692     *
693     * Buffer fields:
694     *  frameCount  currently ignored but recommend to set to actual number of frames filled
695     *  size        actual number of bytes filled, must be multiple of frameSize
696     *  raw         ignored
697     */
698            void        releaseBuffer(const Buffer* audioBuffer);
699
700    /* As a convenience we provide a write() interface to the audio buffer.
701     * Input parameter 'size' is in byte units.
702     * This is implemented on top of obtainBuffer/releaseBuffer. For best
703     * performance use callbacks. Returns actual number of bytes written >= 0,
704     * or one of the following negative status codes:
705     *      INVALID_OPERATION   AudioTrack is configured for static buffer or streaming mode
706     *      BAD_VALUE           size is invalid
707     *      WOULD_BLOCK         when obtainBuffer() returns same, or
708     *                          AudioTrack was stopped during the write
709     *      DEAD_OBJECT         when AudioFlinger dies or the output device changes and
710     *                          the track cannot be automatically restored.
711     *                          The application needs to recreate the AudioTrack
712     *                          because the audio device changed or AudioFlinger died.
713     *                          This typically occurs for direct or offload tracks
714     *                          or if mDoNotReconnect is true.
715     *      or any other error code returned by IAudioTrack::start() or restoreTrack_l().
716     * Default behavior is to only return when all data has been transferred. Set 'blocking' to
717     * false for the method to return immediately without waiting to try multiple times to write
718     * the full content of the buffer.
719     */
720            ssize_t     write(const void* buffer, size_t size, bool blocking = true);
721
722    /*
723     * Dumps the state of an audio track.
724     * Not a general-purpose API; intended only for use by media player service to dump its tracks.
725     */
726            status_t    dump(int fd, const Vector<String16>& args) const;
727
728    /*
729     * Return the total number of frames which AudioFlinger desired but were unavailable,
730     * and thus which resulted in an underrun.  Reset to zero by stop().
731     */
732            uint32_t    getUnderrunFrames() const;
733
734    /* Get the flags */
735            audio_output_flags_t getFlags() const { AutoMutex _l(mLock); return mFlags; }
736
737    /* Set parameters - only possible when using direct output */
738            status_t    setParameters(const String8& keyValuePairs);
739
740    /* Sets the volume shaper object */
741            VolumeShaper::Status applyVolumeShaper(
742                    const sp<VolumeShaper::Configuration>& configuration,
743                    const sp<VolumeShaper::Operation>& operation);
744
745    /* Gets the volume shaper state */
746            sp<VolumeShaper::State> getVolumeShaperState(int id);
747
748    /* Get parameters */
749            String8     getParameters(const String8& keys);
750
751    /* Poll for a timestamp on demand.
752     * Use if EVENT_NEW_TIMESTAMP is not delivered often enough for your needs,
753     * or if you need to get the most recent timestamp outside of the event callback handler.
754     * Caution: calling this method too often may be inefficient;
755     * if you need a high resolution mapping between frame position and presentation time,
756     * consider implementing that at application level, based on the low resolution timestamps.
757     * Returns NO_ERROR    if timestamp is valid.
758     *         WOULD_BLOCK if called in STOPPED or FLUSHED state, or if called immediately after
759     *                     start/ACTIVE, when the number of frames consumed is less than the
760     *                     overall hardware latency to physical output. In WOULD_BLOCK cases,
761     *                     one might poll again, or use getPosition(), or use 0 position and
762     *                     current time for the timestamp.
763     *         DEAD_OBJECT if AudioFlinger dies or the output device changes and
764     *                     the track cannot be automatically restored.
765     *                     The application needs to recreate the AudioTrack
766     *                     because the audio device changed or AudioFlinger died.
767     *                     This typically occurs for direct or offload tracks
768     *                     or if mDoNotReconnect is true.
769     *         INVALID_OPERATION  wrong state, or some other error.
770     *
771     * The timestamp parameter is undefined on return, if status is not NO_ERROR.
772     */
773            status_t    getTimestamp(AudioTimestamp& timestamp);
774private:
775            status_t    getTimestamp_l(AudioTimestamp& timestamp);
776public:
777
778    /* Return the extended timestamp, with additional timebase info and improved drain behavior.
779     *
780     * This is similar to the AudioTrack.java API:
781     * getTimestamp(@NonNull AudioTimestamp timestamp, @AudioTimestamp.Timebase int timebase)
782     *
783     * Some differences between this method and the getTimestamp(AudioTimestamp& timestamp) method
784     *
785     *   1. stop() by itself does not reset the frame position.
786     *      A following start() resets the frame position to 0.
787     *   2. flush() by itself does not reset the frame position.
788     *      The frame position advances by the number of frames flushed,
789     *      when the first frame after flush reaches the audio sink.
790     *   3. BOOTTIME clock offsets are provided to help synchronize with
791     *      non-audio streams, e.g. sensor data.
792     *   4. Position is returned with 64 bits of resolution.
793     *
794     * Parameters:
795     *  timestamp: A pointer to the caller allocated ExtendedTimestamp.
796     *
797     * Returns NO_ERROR    on success; timestamp is filled with valid data.
798     *         BAD_VALUE   if timestamp is NULL.
799     *         WOULD_BLOCK if called immediately after start() when the number
800     *                     of frames consumed is less than the
801     *                     overall hardware latency to physical output. In WOULD_BLOCK cases,
802     *                     one might poll again, or use getPosition(), or use 0 position and
803     *                     current time for the timestamp.
804     *                     If WOULD_BLOCK is returned, the timestamp is still
805     *                     modified with the LOCATION_CLIENT portion filled.
806     *         DEAD_OBJECT if AudioFlinger dies or the output device changes and
807     *                     the track cannot be automatically restored.
808     *                     The application needs to recreate the AudioTrack
809     *                     because the audio device changed or AudioFlinger died.
810     *                     This typically occurs for direct or offloaded tracks
811     *                     or if mDoNotReconnect is true.
812     *         INVALID_OPERATION  if called on a offloaded or direct track.
813     *                     Use getTimestamp(AudioTimestamp& timestamp) instead.
814     */
815            status_t getTimestamp(ExtendedTimestamp *timestamp);
816private:
817            status_t getTimestamp_l(ExtendedTimestamp *timestamp);
818public:
819
820    /* Add an AudioDeviceCallback. The caller will be notified when the audio device to which this
821     * AudioTrack is routed is updated.
822     * Replaces any previously installed callback.
823     * Parameters:
824     *  callback:  The callback interface
825     * Returns NO_ERROR if successful.
826     *         INVALID_OPERATION if the same callback is already installed.
827     *         NO_INIT or PREMISSION_DENIED if AudioFlinger service is not reachable
828     *         BAD_VALUE if the callback is NULL
829     */
830            status_t addAudioDeviceCallback(const sp<AudioSystem::AudioDeviceCallback>& callback);
831
832    /* remove an AudioDeviceCallback.
833     * Parameters:
834     *  callback:  The callback interface
835     * Returns NO_ERROR if successful.
836     *         INVALID_OPERATION if the callback is not installed
837     *         BAD_VALUE if the callback is NULL
838     */
839            status_t removeAudioDeviceCallback(
840                    const sp<AudioSystem::AudioDeviceCallback>& callback);
841
842    /* Obtain the pending duration in milliseconds for playback of pure PCM
843     * (mixable without embedded timing) data remaining in AudioTrack.
844     *
845     * This is used to estimate the drain time for the client-server buffer
846     * so the choice of ExtendedTimestamp::LOCATION_SERVER is default.
847     * One may optionally request to find the duration to play through the HAL
848     * by specifying a location ExtendedTimestamp::LOCATION_KERNEL; however,
849     * INVALID_OPERATION may be returned if the kernel location is unavailable.
850     *
851     * Returns NO_ERROR  if successful.
852     *         INVALID_OPERATION if ExtendedTimestamp::LOCATION_KERNEL cannot be obtained
853     *                   or the AudioTrack does not contain pure PCM data.
854     *         BAD_VALUE if msec is nullptr or location is invalid.
855     */
856            status_t pendingDuration(int32_t *msec,
857                    ExtendedTimestamp::Location location = ExtendedTimestamp::LOCATION_SERVER);
858
859    /* hasStarted() is used to determine if audio is now audible at the device after
860     * a start() command. The underlying implementation checks a nonzero timestamp position
861     * or increment for the audible assumption.
862     *
863     * hasStarted() returns true if the track has been started() and audio is audible
864     * and no subsequent pause() or flush() has been called.  Immediately after pause() or
865     * flush() hasStarted() will return false.
866     *
867     * If stop() has been called, hasStarted() will return true if audio is still being
868     * delivered or has finished delivery (even if no audio was written) for both offloaded
869     * and normal tracks. This property removes a race condition in checking hasStarted()
870     * for very short clips, where stop() must be called to finish drain.
871     *
872     * In all cases, hasStarted() may turn false briefly after a subsequent start() is called
873     * until audio becomes audible again.
874     */
875            bool hasStarted(); // not const
876
877            bool isPlaying() {
878                AutoMutex lock(mLock);
879                return mState == STATE_ACTIVE || mState == STATE_STOPPING;
880            }
881protected:
882    /* copying audio tracks is not allowed */
883                        AudioTrack(const AudioTrack& other);
884            AudioTrack& operator = (const AudioTrack& other);
885
886    /* a small internal class to handle the callback */
887    class AudioTrackThread : public Thread
888    {
889    public:
890        AudioTrackThread(AudioTrack& receiver, bool bCanCallJava = false);
891
892        // Do not call Thread::requestExitAndWait() without first calling requestExit().
893        // Thread::requestExitAndWait() is not virtual, and the implementation doesn't do enough.
894        virtual void        requestExit();
895
896                void        pause();    // suspend thread from execution at next loop boundary
897                void        resume();   // allow thread to execute, if not requested to exit
898                void        wake();     // wake to handle changed notification conditions.
899
900    private:
901                void        pauseInternal(nsecs_t ns = 0LL);
902                                        // like pause(), but only used internally within thread
903
904        friend class AudioTrack;
905        virtual bool        threadLoop();
906        AudioTrack&         mReceiver;
907        virtual ~AudioTrackThread();
908        Mutex               mMyLock;    // Thread::mLock is private
909        Condition           mMyCond;    // Thread::mThreadExitedCondition is private
910        bool                mPaused;    // whether thread is requested to pause at next loop entry
911        bool                mPausedInt; // whether thread internally requests pause
912        nsecs_t             mPausedNs;  // if mPausedInt then associated timeout, otherwise ignored
913        bool                mIgnoreNextPausedInt;   // skip any internal pause and go immediately
914                                        // to processAudioBuffer() as state may have changed
915                                        // since pause time calculated.
916    };
917
918            // body of AudioTrackThread::threadLoop()
919            // returns the maximum amount of time before we would like to run again, where:
920            //      0           immediately
921            //      > 0         no later than this many nanoseconds from now
922            //      NS_WHENEVER still active but no particular deadline
923            //      NS_INACTIVE inactive so don't run again until re-started
924            //      NS_NEVER    never again
925            static const nsecs_t NS_WHENEVER = -1, NS_INACTIVE = -2, NS_NEVER = -3;
926            nsecs_t processAudioBuffer();
927
928            // caller must hold lock on mLock for all _l methods
929
930            status_t createTrack_l();
931
932            // can only be called when mState != STATE_ACTIVE
933            void flush_l();
934
935            void setLoop_l(uint32_t loopStart, uint32_t loopEnd, int loopCount);
936
937            // FIXME enum is faster than strcmp() for parameter 'from'
938            status_t restoreTrack_l(const char *from);
939
940            uint32_t    getUnderrunCount_l() const;
941
942            bool     isOffloaded() const;
943            bool     isDirect() const;
944            bool     isOffloadedOrDirect() const;
945
946            bool     isOffloaded_l() const
947                { return (mFlags & AUDIO_OUTPUT_FLAG_COMPRESS_OFFLOAD) != 0; }
948
949            bool     isOffloadedOrDirect_l() const
950                { return (mFlags & (AUDIO_OUTPUT_FLAG_COMPRESS_OFFLOAD|
951                                                AUDIO_OUTPUT_FLAG_DIRECT)) != 0; }
952
953            bool     isDirect_l() const
954                { return (mFlags & AUDIO_OUTPUT_FLAG_DIRECT) != 0; }
955
956            // pure pcm data is mixable (which excludes HW_AV_SYNC, with embedded timing)
957            bool     isPurePcmData_l() const
958                { return audio_is_linear_pcm(mFormat)
959                        && (mAttributes.flags & AUDIO_FLAG_HW_AV_SYNC) == 0; }
960
961            // increment mPosition by the delta of mServer, and return new value of mPosition
962            Modulo<uint32_t> updateAndGetPosition_l();
963
964            // check sample rate and speed is compatible with AudioTrack
965            bool     isSampleRateSpeedAllowed_l(uint32_t sampleRate, float speed) const;
966
967            void     restartIfDisabled();
968
969    // Next 4 fields may be changed if IAudioTrack is re-created, but always != 0
970    sp<IAudioTrack>         mAudioTrack;
971    sp<IMemory>             mCblkMemory;
972    audio_track_cblk_t*     mCblk;                  // re-load after mLock.unlock()
973    audio_io_handle_t       mOutput;                // returned by AudioSystem::getOutput()
974
975    sp<AudioTrackThread>    mAudioTrackThread;
976    bool                    mThreadCanCallJava;
977
978    float                   mVolume[2];
979    float                   mSendLevel;
980    mutable uint32_t        mSampleRate;            // mutable because getSampleRate() can update it
981    uint32_t                mOriginalSampleRate;
982    AudioPlaybackRate       mPlaybackRate;
983    float                   mMaxRequiredSpeed;      // use PCM buffer size to allow this speed
984
985    // Corresponds to current IAudioTrack, value is reported back by AudioFlinger to the client.
986    // This allocated buffer size is maintained by the proxy.
987    size_t                  mFrameCount;            // maximum size of buffer
988
989    size_t                  mReqFrameCount;         // frame count to request the first or next time
990                                                    // a new IAudioTrack is needed, non-decreasing
991
992    // The following AudioFlinger server-side values are cached in createAudioTrack_l().
993    // These values can be used for informational purposes until the track is invalidated,
994    // whereupon restoreTrack_l() calls createTrack_l() to update the values.
995    uint32_t                mAfLatency;             // AudioFlinger latency in ms
996    size_t                  mAfFrameCount;          // AudioFlinger frame count
997    uint32_t                mAfSampleRate;          // AudioFlinger sample rate
998
999    // constant after constructor or set()
1000    audio_format_t          mFormat;                // as requested by client, not forced to 16-bit
1001    audio_stream_type_t     mStreamType;            // mStreamType == AUDIO_STREAM_DEFAULT implies
1002                                                    // this AudioTrack has valid attributes
1003    uint32_t                mChannelCount;
1004    audio_channel_mask_t    mChannelMask;
1005    sp<IMemory>             mSharedBuffer;
1006    transfer_type           mTransfer;
1007    audio_offload_info_t    mOffloadInfoCopy;
1008    const audio_offload_info_t* mOffloadInfo;
1009    audio_attributes_t      mAttributes;
1010
1011    size_t                  mFrameSize;             // frame size in bytes
1012
1013    status_t                mStatus;
1014
1015    // can change dynamically when IAudioTrack invalidated
1016    uint32_t                mLatency;               // in ms
1017
1018    // Indicates the current track state.  Protected by mLock.
1019    enum State {
1020        STATE_ACTIVE,
1021        STATE_STOPPED,
1022        STATE_PAUSED,
1023        STATE_PAUSED_STOPPING,
1024        STATE_FLUSHED,
1025        STATE_STOPPING,
1026    }                       mState;
1027
1028    // for client callback handler
1029    callback_t              mCbf;                   // callback handler for events, or NULL
1030    void*                   mUserData;
1031
1032    // for notification APIs
1033
1034    // next 2 fields are const after constructor or set()
1035    uint32_t                mNotificationFramesReq; // requested number of frames between each
1036                                                    // notification callback,
1037                                                    // at initial source sample rate
1038    uint32_t                mNotificationsPerBufferReq;
1039                                                    // requested number of notifications per buffer,
1040                                                    // currently only used for fast tracks with
1041                                                    // default track buffer size
1042
1043    uint32_t                mNotificationFramesAct; // actual number of frames between each
1044                                                    // notification callback,
1045                                                    // at initial source sample rate
1046    bool                    mRefreshRemaining;      // processAudioBuffer() should refresh
1047                                                    // mRemainingFrames and mRetryOnPartialBuffer
1048
1049                                                    // used for static track cbf and restoration
1050    int32_t                 mLoopCount;             // last setLoop loopCount; zero means disabled
1051    uint32_t                mLoopStart;             // last setLoop loopStart
1052    uint32_t                mLoopEnd;               // last setLoop loopEnd
1053    int32_t                 mLoopCountNotified;     // the last loopCount notified by callback.
1054                                                    // mLoopCountNotified counts down, matching
1055                                                    // the remaining loop count for static track
1056                                                    // playback.
1057
1058    // These are private to processAudioBuffer(), and are not protected by a lock
1059    uint32_t                mRemainingFrames;       // number of frames to request in obtainBuffer()
1060    bool                    mRetryOnPartialBuffer;  // sleep and retry after partial obtainBuffer()
1061    uint32_t                mObservedSequence;      // last observed value of mSequence
1062
1063    Modulo<uint32_t>        mMarkerPosition;        // in wrapping (overflow) frame units
1064    bool                    mMarkerReached;
1065    Modulo<uint32_t>        mNewPosition;           // in frames
1066    uint32_t                mUpdatePeriod;          // in frames, zero means no EVENT_NEW_POS
1067
1068    Modulo<uint32_t>        mServer;                // in frames, last known mProxy->getPosition()
1069                                                    // which is count of frames consumed by server,
1070                                                    // reset by new IAudioTrack,
1071                                                    // whether it is reset by stop() is TBD
1072    Modulo<uint32_t>        mPosition;              // in frames, like mServer except continues
1073                                                    // monotonically after new IAudioTrack,
1074                                                    // and could be easily widened to uint64_t
1075    Modulo<uint32_t>        mReleased;              // count of frames released to server
1076                                                    // but not necessarily consumed by server,
1077                                                    // reset by stop() but continues monotonically
1078                                                    // after new IAudioTrack to restore mPosition,
1079                                                    // and could be easily widened to uint64_t
1080    int64_t                 mStartUs;               // the start time after flush or stop.
1081                                                    // only used for offloaded and direct tracks.
1082    ExtendedTimestamp       mStartEts;              // Extended timestamp at start for normal
1083                                                    // AudioTracks.
1084    AudioTimestamp          mStartTs;               // Timestamp at start for offloaded or direct
1085                                                    // AudioTracks.
1086
1087    bool                    mPreviousTimestampValid;// true if mPreviousTimestamp is valid
1088    bool                    mTimestampStartupGlitchReported; // reduce log spam
1089    bool                    mRetrogradeMotionReported; // reduce log spam
1090    AudioTimestamp          mPreviousTimestamp;     // used to detect retrograde motion
1091    ExtendedTimestamp::Location mPreviousLocation;  // location used for previous timestamp
1092
1093    uint32_t                mUnderrunCountOffset;   // updated when restoring tracks
1094
1095    int64_t                 mFramesWritten;         // total frames written. reset to zero after
1096                                                    // the start() following stop(). It is not
1097                                                    // changed after restoring the track or
1098                                                    // after flush.
1099    int64_t                 mFramesWrittenServerOffset; // An offset to server frames due to
1100                                                    // restoring AudioTrack, or stop/start.
1101                                                    // This offset is also used for static tracks.
1102    int64_t                 mFramesWrittenAtRestore; // Frames written at restore point (or frames
1103                                                    // delivered for static tracks).
1104                                                    // -1 indicates no previous restore point.
1105
1106    audio_output_flags_t    mFlags;                 // same as mOrigFlags, except for bits that may
1107                                                    // be denied by client or server, such as
1108                                                    // AUDIO_OUTPUT_FLAG_FAST.  mLock must be
1109                                                    // held to read or write those bits reliably.
1110    audio_output_flags_t    mOrigFlags;             // as specified in constructor or set(), const
1111
1112    bool                    mDoNotReconnect;
1113
1114    audio_session_t         mSessionId;
1115    int                     mAuxEffectId;
1116
1117    mutable Mutex           mLock;
1118
1119    int                     mPreviousPriority;          // before start()
1120    SchedPolicy             mPreviousSchedulingGroup;
1121    bool                    mAwaitBoost;    // thread should wait for priority boost before running
1122
1123    // The proxy should only be referenced while a lock is held because the proxy isn't
1124    // multi-thread safe, especially the SingleStateQueue part of the proxy.
1125    // An exception is that a blocking ClientProxy::obtainBuffer() may be called without a lock,
1126    // provided that the caller also holds an extra reference to the proxy and shared memory to keep
1127    // them around in case they are replaced during the obtainBuffer().
1128    sp<StaticAudioTrackClientProxy> mStaticProxy;   // for type safety only
1129    sp<AudioTrackClientProxy>       mProxy;         // primary owner of the memory
1130
1131    bool                    mInUnderrun;            // whether track is currently in underrun state
1132    uint32_t                mPausedPosition;
1133
1134    // For Device Selection API
1135    //  a value of AUDIO_PORT_HANDLE_NONE indicated default (AudioPolicyManager) routing.
1136    audio_port_handle_t     mSelectedDeviceId;
1137
1138    sp<VolumeHandler>       mVolumeHandler;
1139
1140private:
1141    class DeathNotifier : public IBinder::DeathRecipient {
1142    public:
1143        DeathNotifier(AudioTrack* audioTrack) : mAudioTrack(audioTrack) { }
1144    protected:
1145        virtual void        binderDied(const wp<IBinder>& who);
1146    private:
1147        const wp<AudioTrack> mAudioTrack;
1148    };
1149
1150    sp<DeathNotifier>       mDeathNotifier;
1151    uint32_t                mSequence;              // incremented for each new IAudioTrack attempt
1152    uid_t                   mClientUid;
1153    pid_t                   mClientPid;
1154
1155    sp<AudioSystem::AudioDeviceCallback> mDeviceCallback;
1156    audio_port_handle_t     mPortId;  // unique ID allocated by audio policy
1157};
1158
1159}; // namespace android
1160
1161#endif // ANDROID_AUDIOTRACK_H
1162