AudioTrack.h revision ed30470cf0a20c0c1edb2b82075985ccaa6c75c1
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 <media/AudioResamplerPublic.h>
25#include <media/MediaAnalyticsItem.h>
26#include <media/Modulo.h>
27#include <utils/threads.h>
28
29namespace android {
30
31// ----------------------------------------------------------------------------
32
33struct audio_track_cblk_t;
34class AudioTrackClientProxy;
35class StaticAudioTrackClientProxy;
36
37// ----------------------------------------------------------------------------
38
39class AudioTrack : public AudioSystem::AudioDeviceCallback
40{
41public:
42
43    /* Events used by AudioTrack callback function (callback_t).
44     * Keep in sync with frameworks/base/media/java/android/media/AudioTrack.java NATIVE_EVENT_*.
45     */
46    enum event_type {
47        EVENT_MORE_DATA = 0,        // Request to write more data to buffer.
48                                    // This event only occurs for TRANSFER_CALLBACK.
49                                    // If this event is delivered but the callback handler
50                                    // does not want to write more data, the handler must
51                                    // ignore the event by setting frameCount to zero.
52                                    // This might occur, for example, if the application is
53                                    // waiting for source data or is at the end of stream.
54                                    //
55                                    // For data filling, it is preferred that the callback
56                                    // does not block and instead returns a short count on
57                                    // the amount of data actually delivered
58                                    // (or 0, if no data is currently available).
59        EVENT_UNDERRUN = 1,         // Buffer underrun occurred. This will not occur for
60                                    // static tracks.
61        EVENT_LOOP_END = 2,         // Sample loop end was reached; playback restarted from
62                                    // loop start if loop count was not 0 for a static track.
63        EVENT_MARKER = 3,           // Playback head is at the specified marker position
64                                    // (See setMarkerPosition()).
65        EVENT_NEW_POS = 4,          // Playback head is at a new position
66                                    // (See setPositionUpdatePeriod()).
67        EVENT_BUFFER_END = 5,       // Playback has completed for a static track.
68        EVENT_NEW_IAUDIOTRACK = 6,  // IAudioTrack was re-created, either due to re-routing and
69                                    // voluntary invalidation by mediaserver, or mediaserver crash.
70        EVENT_STREAM_END = 7,       // Sent after all the buffers queued in AF and HW are played
71                                    // back (after stop is called) for an offloaded track.
72#if 0   // FIXME not yet implemented
73        EVENT_NEW_TIMESTAMP = 8,    // Delivered periodically and when there's a significant change
74                                    // in the mapping from frame position to presentation time.
75                                    // See AudioTimestamp for the information included with event.
76#endif
77    };
78
79    /* Client should declare a Buffer and pass the address to obtainBuffer()
80     * and releaseBuffer().  See also callback_t for EVENT_MORE_DATA.
81     */
82
83    class Buffer
84    {
85    public:
86        // FIXME use m prefix
87        size_t      frameCount;   // number of sample frames corresponding to size;
88                                  // on input to obtainBuffer() it is the number of frames desired,
89                                  // on output from obtainBuffer() it is the number of available
90                                  //    [empty slots for] frames to be filled
91                                  // on input to releaseBuffer() it is currently ignored
92
93        size_t      size;         // input/output in bytes == frameCount * frameSize
94                                  // on input to obtainBuffer() it is ignored
95                                  // on output from obtainBuffer() it is the number of available
96                                  //    [empty slots for] bytes to be filled,
97                                  //    which is frameCount * frameSize
98                                  // on input to releaseBuffer() it is the number of bytes to
99                                  //    release
100                                  // FIXME This is redundant with respect to frameCount.  Consider
101                                  //    removing size and making frameCount the primary field.
102
103        union {
104            void*       raw;
105            short*      i16;      // signed 16-bit
106            int8_t*     i8;       // unsigned 8-bit, offset by 0x80
107        };                        // input to obtainBuffer(): unused, output: pointer to buffer
108    };
109
110    /* As a convenience, if a callback is supplied, a handler thread
111     * is automatically created with the appropriate priority. This thread
112     * invokes the callback when a new buffer becomes available or various conditions occur.
113     * Parameters:
114     *
115     * event:   type of event notified (see enum AudioTrack::event_type).
116     * user:    Pointer to context for use by the callback receiver.
117     * info:    Pointer to optional parameter according to event type:
118     *          - EVENT_MORE_DATA: pointer to AudioTrack::Buffer struct. The callback must not write
119     *            more bytes than indicated by 'size' field and update 'size' if fewer bytes are
120     *            written.
121     *          - EVENT_UNDERRUN: unused.
122     *          - EVENT_LOOP_END: pointer to an int indicating the number of loops remaining.
123     *          - EVENT_MARKER: pointer to const uint32_t containing the marker position in frames.
124     *          - EVENT_NEW_POS: pointer to const uint32_t containing the new position in frames.
125     *          - EVENT_BUFFER_END: unused.
126     *          - EVENT_NEW_IAUDIOTRACK: unused.
127     *          - EVENT_STREAM_END: unused.
128     *          - EVENT_NEW_TIMESTAMP: pointer to const AudioTimestamp.
129     */
130
131    typedef void (*callback_t)(int event, void* user, void *info);
132
133    /* Returns the minimum frame count required for the successful creation of
134     * an AudioTrack object.
135     * Returned status (from utils/Errors.h) can be:
136     *  - NO_ERROR: successful operation
137     *  - NO_INIT: audio server or audio hardware not initialized
138     *  - BAD_VALUE: unsupported configuration
139     * frameCount is guaranteed to be non-zero if status is NO_ERROR,
140     * and is undefined otherwise.
141     * FIXME This API assumes a route, and so should be deprecated.
142     */
143
144    static status_t getMinFrameCount(size_t* frameCount,
145                                     audio_stream_type_t streamType,
146                                     uint32_t sampleRate);
147
148    /* How data is transferred to AudioTrack
149     */
150    enum transfer_type {
151        TRANSFER_DEFAULT,   // not specified explicitly; determine from the other parameters
152        TRANSFER_CALLBACK,  // callback EVENT_MORE_DATA
153        TRANSFER_OBTAIN,    // call obtainBuffer() and releaseBuffer()
154        TRANSFER_SYNC,      // synchronous write()
155        TRANSFER_SHARED,    // shared memory
156    };
157
158    /* Constructs an uninitialized AudioTrack. No connection with
159     * AudioFlinger takes place.  Use set() after this.
160     */
161                        AudioTrack();
162
163    /* Creates an AudioTrack object and registers it with AudioFlinger.
164     * Once created, the track needs to be started before it can be used.
165     * Unspecified values are set to appropriate default values.
166     *
167     * Parameters:
168     *
169     * streamType:         Select the type of audio stream this track is attached to
170     *                     (e.g. AUDIO_STREAM_MUSIC).
171     * sampleRate:         Data source sampling rate in Hz.  Zero means to use the sink sample rate.
172     *                     A non-zero value must be specified if AUDIO_OUTPUT_FLAG_DIRECT is set.
173     *                     0 will not work with current policy implementation for direct output
174     *                     selection where an exact match is needed for sampling rate.
175     * format:             Audio format. For mixed tracks, any PCM format supported by server is OK.
176     *                     For direct and offloaded tracks, the possible format(s) depends on the
177     *                     output sink.
178     * channelMask:        Channel mask, such that audio_is_output_channel(channelMask) is true.
179     * frameCount:         Minimum size of track PCM buffer in frames. This defines the
180     *                     application's contribution to the
181     *                     latency of the track. The actual size selected by the AudioTrack could be
182     *                     larger if the requested size is not compatible with current audio HAL
183     *                     configuration.  Zero means to use a default value.
184     * flags:              See comments on audio_output_flags_t in <system/audio.h>.
185     * cbf:                Callback function. If not null, this function is called periodically
186     *                     to provide new data in TRANSFER_CALLBACK mode
187     *                     and inform of marker, position updates, etc.
188     * user:               Context for use by the callback receiver.
189     * notificationFrames: The callback function is called each time notificationFrames PCM
190     *                     frames have been consumed from track input buffer by server.
191     *                     Zero means to use a default value, which is typically:
192     *                      - fast tracks: HAL buffer size, even if track frameCount is larger
193     *                      - normal tracks: 1/2 of track frameCount
194     *                     A positive value means that many frames at initial source sample rate.
195     *                     A negative value for this parameter specifies the negative of the
196     *                     requested number of notifications (sub-buffers) in the entire buffer.
197     *                     For fast tracks, the FastMixer will process one sub-buffer at a time.
198     *                     The size of each sub-buffer is determined by the HAL.
199     *                     To get "double buffering", for example, one should pass -2.
200     *                     The minimum number of sub-buffers is 1 (expressed as -1),
201     *                     and the maximum number of sub-buffers is 8 (expressed as -8).
202     *                     Negative is only permitted for fast tracks, and if frameCount is zero.
203     *                     TODO It is ugly to overload a parameter in this way depending on
204     *                     whether it is positive, negative, or zero.  Consider splitting apart.
205     * sessionId:          Specific session ID, or zero to use default.
206     * transferType:       How data is transferred to AudioTrack.
207     * offloadInfo:        If not NULL, provides offload parameters for
208     *                     AudioSystem::getOutputForAttr().
209     * uid:                User ID of the app which initially requested this AudioTrack
210     *                     for power management tracking, or -1 for current user ID.
211     * pid:                Process ID of the app which initially requested this AudioTrack
212     *                     for power management tracking, or -1 for current process ID.
213     * pAttributes:        If not NULL, supersedes streamType for use case selection.
214     * doNotReconnect:     If set to true, AudioTrack won't automatically recreate the IAudioTrack
215                           binder to AudioFlinger.
216                           It will return an error instead.  The application will recreate
217                           the track based on offloading or different channel configuration, etc.
218     * maxRequiredSpeed:   For PCM tracks, this creates an appropriate buffer size that will allow
219     *                     maxRequiredSpeed playback. Values less than 1.0f and greater than
220     *                     AUDIO_TIMESTRETCH_SPEED_MAX will be clamped.  For non-PCM tracks
221     *                     and direct or offloaded tracks, this parameter is ignored.
222     * selectedDeviceId:   Selected device id of the app which initially requested the AudioTrack
223     *                     to open with a specific device.
224     * threadCanCallJava:  Not present in parameter list, and so is fixed at false.
225     */
226
227                        AudioTrack( audio_stream_type_t streamType,
228                                    uint32_t sampleRate,
229                                    audio_format_t format,
230                                    audio_channel_mask_t channelMask,
231                                    size_t frameCount    = 0,
232                                    audio_output_flags_t flags = AUDIO_OUTPUT_FLAG_NONE,
233                                    callback_t cbf       = NULL,
234                                    void* user           = NULL,
235                                    int32_t notificationFrames = 0,
236                                    audio_session_t sessionId  = AUDIO_SESSION_ALLOCATE,
237                                    transfer_type transferType = TRANSFER_DEFAULT,
238                                    const audio_offload_info_t *offloadInfo = NULL,
239                                    uid_t uid = AUDIO_UID_INVALID,
240                                    pid_t pid = -1,
241                                    const audio_attributes_t* pAttributes = NULL,
242                                    bool doNotReconnect = false,
243                                    float maxRequiredSpeed = 1.0f,
244                                    audio_port_handle_t selectedDeviceId = AUDIO_PORT_HANDLE_NONE);
245
246    /* Creates an audio track and registers it with AudioFlinger.
247     * With this constructor, the track is configured for static buffer mode.
248     * Data to be rendered is passed in a shared memory buffer
249     * identified by the argument sharedBuffer, which should be non-0.
250     * If sharedBuffer is zero, this constructor is equivalent to the previous constructor
251     * but without the ability to specify a non-zero value for the frameCount parameter.
252     * The memory should be initialized to the desired data before calling start().
253     * The write() method is not supported in this case.
254     * It is recommended to pass a callback function to be notified of playback end by an
255     * EVENT_UNDERRUN event.
256     */
257
258                        AudioTrack( audio_stream_type_t streamType,
259                                    uint32_t sampleRate,
260                                    audio_format_t format,
261                                    audio_channel_mask_t channelMask,
262                                    const sp<IMemory>& sharedBuffer,
263                                    audio_output_flags_t flags = AUDIO_OUTPUT_FLAG_NONE,
264                                    callback_t cbf      = NULL,
265                                    void* user          = NULL,
266                                    int32_t notificationFrames = 0,
267                                    audio_session_t sessionId   = AUDIO_SESSION_ALLOCATE,
268                                    transfer_type transferType = TRANSFER_DEFAULT,
269                                    const audio_offload_info_t *offloadInfo = NULL,
270                                    uid_t uid = AUDIO_UID_INVALID,
271                                    pid_t pid = -1,
272                                    const audio_attributes_t* pAttributes = NULL,
273                                    bool doNotReconnect = false,
274                                    float maxRequiredSpeed = 1.0f);
275
276    /* Terminates the AudioTrack and unregisters it from AudioFlinger.
277     * Also destroys all resources associated with the AudioTrack.
278     */
279protected:
280                        virtual ~AudioTrack();
281public:
282
283    /* Initialize an AudioTrack that was created using the AudioTrack() constructor.
284     * Don't call set() more than once, or after the AudioTrack() constructors that take parameters.
285     * set() is not multi-thread safe.
286     * Returned status (from utils/Errors.h) can be:
287     *  - NO_ERROR: successful initialization
288     *  - INVALID_OPERATION: AudioTrack is already initialized
289     *  - BAD_VALUE: invalid parameter (channelMask, format, sampleRate...)
290     *  - NO_INIT: audio server or audio hardware not initialized
291     * If status is not equal to NO_ERROR, don't call any other APIs on this AudioTrack.
292     * If sharedBuffer is non-0, the frameCount parameter is ignored and
293     * replaced by the shared buffer's total allocated size in frame units.
294     *
295     * Parameters not listed in the AudioTrack constructors above:
296     *
297     * threadCanCallJava:  Whether callbacks are made from an attached thread and thus can call JNI.
298     *
299     * Internal state post condition:
300     *      (mStreamType == AUDIO_STREAM_DEFAULT) implies this AudioTrack has valid attributes
301     */
302            status_t    set(audio_stream_type_t streamType,
303                            uint32_t sampleRate,
304                            audio_format_t format,
305                            audio_channel_mask_t channelMask,
306                            size_t frameCount   = 0,
307                            audio_output_flags_t flags = AUDIO_OUTPUT_FLAG_NONE,
308                            callback_t cbf      = NULL,
309                            void* user          = NULL,
310                            int32_t notificationFrames = 0,
311                            const sp<IMemory>& sharedBuffer = 0,
312                            bool threadCanCallJava = false,
313                            audio_session_t sessionId  = AUDIO_SESSION_ALLOCATE,
314                            transfer_type transferType = TRANSFER_DEFAULT,
315                            const audio_offload_info_t *offloadInfo = NULL,
316                            uid_t uid = AUDIO_UID_INVALID,
317                            pid_t pid = -1,
318                            const audio_attributes_t* pAttributes = NULL,
319                            bool doNotReconnect = false,
320                            float maxRequiredSpeed = 1.0f,
321                            audio_port_handle_t selectedDeviceId = AUDIO_PORT_HANDLE_NONE);
322
323    /* Result of constructing the AudioTrack. This must be checked for successful initialization
324     * before using any AudioTrack API (except for set()), because using
325     * an uninitialized AudioTrack produces undefined results.
326     * See set() method above for possible return codes.
327     */
328            status_t    initCheck() const   { return mStatus; }
329
330    /* Returns this track's estimated latency in milliseconds.
331     * This includes the latency due to AudioTrack buffer size, AudioMixer (if any)
332     * and audio hardware driver.
333     */
334            uint32_t    latency();
335
336    /* Returns the number of application-level buffer underruns
337     * since the AudioTrack was created.
338     */
339            uint32_t    getUnderrunCount() const;
340
341    /* getters, see constructors and set() */
342
343            audio_stream_type_t streamType() const;
344            audio_format_t format() const   { return mFormat; }
345
346    /* Return frame size in bytes, which for linear PCM is
347     * channelCount * (bit depth per channel / 8).
348     * channelCount is determined from channelMask, and bit depth comes from format.
349     * For non-linear formats, the frame size is typically 1 byte.
350     */
351            size_t      frameSize() const   { return mFrameSize; }
352
353            uint32_t    channelCount() const { return mChannelCount; }
354            size_t      frameCount() const  { return mFrameCount; }
355
356    /*
357     * Return the period of the notification callback in frames.
358     * This value is set when the AudioTrack is constructed.
359     * It can be modified if the AudioTrack is rerouted.
360     */
361            uint32_t    getNotificationPeriodInFrames() const { return mNotificationFramesAct; }
362
363    /* Return effective size of audio buffer that an application writes to
364     * or a negative error if the track is uninitialized.
365     */
366            ssize_t     getBufferSizeInFrames();
367
368    /* Returns the buffer duration in microseconds at current playback rate.
369     */
370            status_t    getBufferDurationInUs(int64_t *duration);
371
372    /* Set the effective size of audio buffer that an application writes to.
373     * This is used to determine the amount of available room in the buffer,
374     * which determines when a write will block.
375     * This allows an application to raise and lower the audio latency.
376     * The requested size may be adjusted so that it is
377     * greater or equal to the absolute minimum and
378     * less than or equal to the getBufferCapacityInFrames().
379     * It may also be adjusted slightly for internal reasons.
380     *
381     * Return the final size or a negative error if the track is unitialized
382     * or does not support variable sizes.
383     */
384            ssize_t     setBufferSizeInFrames(size_t size);
385
386    /* Return the static buffer specified in constructor or set(), or 0 for streaming mode */
387            sp<IMemory> sharedBuffer() const { return mSharedBuffer; }
388
389    /* After it's created the track is not active. Call start() to
390     * make it active. If set, the callback will start being called.
391     * If the track was previously paused, volume is ramped up over the first mix buffer.
392     */
393            status_t        start();
394
395    /* Stop a track.
396     * In static buffer mode, the track is stopped immediately.
397     * In streaming mode, the callback will cease being called.  Note that obtainBuffer() still
398     * works and will fill up buffers until the pool is exhausted, and then will return WOULD_BLOCK.
399     * In streaming mode the stop does not occur immediately: any data remaining in the buffer
400     * is first drained, mixed, and output, and only then is the track marked as stopped.
401     */
402            void        stop();
403            bool        stopped() const;
404
405    /* Flush a stopped or paused track. All previously buffered data is discarded immediately.
406     * This has the effect of draining the buffers without mixing or output.
407     * Flush is intended for streaming mode, for example before switching to non-contiguous content.
408     * This function is a no-op if the track is not stopped or paused, or uses a static buffer.
409     */
410            void        flush();
411
412    /* Pause a track. After pause, the callback will cease being called and
413     * obtainBuffer returns WOULD_BLOCK. Note that obtainBuffer() still works
414     * and will fill up buffers until the pool is exhausted.
415     * Volume is ramped down over the next mix buffer following the pause request,
416     * and then the track is marked as paused.  It can be resumed with ramp up by start().
417     */
418            void        pause();
419
420    /* Set volume for this track, mostly used for games' sound effects
421     * left and right volumes. Levels must be >= 0.0 and <= 1.0.
422     * This is the older API.  New applications should use setVolume(float) when possible.
423     */
424            status_t    setVolume(float left, float right);
425
426    /* Set volume for all channels.  This is the preferred API for new applications,
427     * especially for multi-channel content.
428     */
429            status_t    setVolume(float volume);
430
431    /* Set the send level for this track. An auxiliary effect should be attached
432     * to the track with attachEffect(). Level must be >= 0.0 and <= 1.0.
433     */
434            status_t    setAuxEffectSendLevel(float level);
435            void        getAuxEffectSendLevel(float* level) const;
436
437    /* Set source sample rate for this track in Hz, mostly used for games' sound effects.
438     * Zero is not permitted.
439     */
440            status_t    setSampleRate(uint32_t sampleRate);
441
442    /* Return current source sample rate in Hz.
443     * If specified as zero in constructor or set(), this will be the sink sample rate.
444     */
445            uint32_t    getSampleRate() const;
446
447    /* Return the original source sample rate in Hz. This corresponds to the sample rate
448     * if playback rate had normal speed and pitch.
449     */
450            uint32_t    getOriginalSampleRate() const;
451
452    /* Set source playback rate for timestretch
453     * 1.0 is normal speed: < 1.0 is slower, > 1.0 is faster
454     * 1.0 is normal pitch: < 1.0 is lower pitch, > 1.0 is higher pitch
455     *
456     * AUDIO_TIMESTRETCH_SPEED_MIN <= speed <= AUDIO_TIMESTRETCH_SPEED_MAX
457     * AUDIO_TIMESTRETCH_PITCH_MIN <= pitch <= AUDIO_TIMESTRETCH_PITCH_MAX
458     *
459     * Speed increases the playback rate of media, but does not alter pitch.
460     * Pitch increases the "tonal frequency" of media, but does not affect the playback rate.
461     */
462            status_t    setPlaybackRate(const AudioPlaybackRate &playbackRate);
463
464    /* Return current playback rate */
465            const AudioPlaybackRate& getPlaybackRate() const;
466
467    /* Enables looping and sets the start and end points of looping.
468     * Only supported for static buffer mode.
469     *
470     * Parameters:
471     *
472     * loopStart:   loop start in frames relative to start of buffer.
473     * loopEnd:     loop end in frames relative to start of buffer.
474     * loopCount:   number of loops to execute. Calling setLoop() with loopCount == 0 cancels any
475     *              pending or active loop. loopCount == -1 means infinite looping.
476     *
477     * For proper operation the following condition must be respected:
478     *      loopCount != 0 implies 0 <= loopStart < loopEnd <= frameCount().
479     *
480     * If the loop period (loopEnd - loopStart) is too small for the implementation to support,
481     * setLoop() will return BAD_VALUE.  loopCount must be >= -1.
482     *
483     */
484            status_t    setLoop(uint32_t loopStart, uint32_t loopEnd, int loopCount);
485
486    /* Sets marker position. When playback reaches the number of frames specified, a callback with
487     * event type EVENT_MARKER is called. Calling setMarkerPosition with marker == 0 cancels marker
488     * notification callback.  To set a marker at a position which would compute as 0,
489     * a workaround is to set the marker at a nearby position such as ~0 or 1.
490     * If the AudioTrack has been opened with no callback function associated, the operation will
491     * fail.
492     *
493     * Parameters:
494     *
495     * marker:   marker position expressed in wrapping (overflow) frame units,
496     *           like the return value of getPosition().
497     *
498     * Returned status (from utils/Errors.h) can be:
499     *  - NO_ERROR: successful operation
500     *  - INVALID_OPERATION: the AudioTrack has no callback installed.
501     */
502            status_t    setMarkerPosition(uint32_t marker);
503            status_t    getMarkerPosition(uint32_t *marker) const;
504
505    /* Sets position update period. Every time the number of frames specified has been played,
506     * a callback with event type EVENT_NEW_POS is called.
507     * Calling setPositionUpdatePeriod with updatePeriod == 0 cancels new position notification
508     * callback.
509     * If the AudioTrack has been opened with no callback function associated, the operation will
510     * fail.
511     * Extremely small values may be rounded up to a value the implementation can support.
512     *
513     * Parameters:
514     *
515     * updatePeriod:  position update notification period expressed in frames.
516     *
517     * Returned status (from utils/Errors.h) can be:
518     *  - NO_ERROR: successful operation
519     *  - INVALID_OPERATION: the AudioTrack has no callback installed.
520     */
521            status_t    setPositionUpdatePeriod(uint32_t updatePeriod);
522            status_t    getPositionUpdatePeriod(uint32_t *updatePeriod) const;
523
524    /* Sets playback head position.
525     * Only supported for static buffer mode.
526     *
527     * Parameters:
528     *
529     * position:  New playback head position in frames relative to start of buffer.
530     *            0 <= position <= frameCount().  Note that end of buffer is permitted,
531     *            but will result in an immediate underrun if started.
532     *
533     * Returned status (from utils/Errors.h) can be:
534     *  - NO_ERROR: successful operation
535     *  - INVALID_OPERATION: the AudioTrack is not stopped or paused, or is streaming mode.
536     *  - BAD_VALUE: The specified position is beyond the number of frames present in AudioTrack
537     *               buffer
538     */
539            status_t    setPosition(uint32_t position);
540
541    /* Return the total number of frames played since playback start.
542     * The counter will wrap (overflow) periodically, e.g. every ~27 hours at 44.1 kHz.
543     * It is reset to zero by flush(), reload(), and stop().
544     *
545     * Parameters:
546     *
547     *  position:  Address where to return play head position.
548     *
549     * Returned status (from utils/Errors.h) can be:
550     *  - NO_ERROR: successful operation
551     *  - BAD_VALUE:  position is NULL
552     */
553            status_t    getPosition(uint32_t *position);
554
555    /* For static buffer mode only, this returns the current playback position in frames
556     * relative to start of buffer.  It is analogous to the position units used by
557     * setLoop() and setPosition().  After underrun, the position will be at end of buffer.
558     */
559            status_t    getBufferPosition(uint32_t *position);
560
561    /* Forces AudioTrack buffer full condition. When playing a static buffer, this method avoids
562     * rewriting the buffer before restarting playback after a stop.
563     * This method must be called with the AudioTrack in paused or stopped state.
564     * Not allowed in streaming mode.
565     *
566     * Returned status (from utils/Errors.h) can be:
567     *  - NO_ERROR: successful operation
568     *  - INVALID_OPERATION: the AudioTrack is not stopped or paused, or is streaming mode.
569     */
570            status_t    reload();
571
572    /**
573     * @param transferType
574     * @return text string that matches the enum name
575     */
576            static const char * convertTransferToText(transfer_type transferType);
577
578    /* Returns a handle on the audio output used by this AudioTrack.
579     *
580     * Parameters:
581     *  none.
582     *
583     * Returned value:
584     *  handle on audio hardware output, or AUDIO_IO_HANDLE_NONE if the
585     *  track needed to be re-created but that failed
586     */
587private:
588            audio_io_handle_t    getOutput() const;
589public:
590
591    /* Selects the audio device to use for output of this AudioTrack. A value of
592     * AUDIO_PORT_HANDLE_NONE indicates default (AudioPolicyManager) routing.
593     *
594     * Parameters:
595     *  The device ID of the selected device (as returned by the AudioDevicesManager API).
596     *
597     * Returned value:
598     *  - NO_ERROR: successful operation
599     *    TODO: what else can happen here?
600     */
601            status_t    setOutputDevice(audio_port_handle_t deviceId);
602
603    /* Returns the ID of the audio device selected for this AudioTrack.
604     * A value of AUDIO_PORT_HANDLE_NONE indicates default (AudioPolicyManager) routing.
605     *
606     * Parameters:
607     *  none.
608     */
609     audio_port_handle_t getOutputDevice();
610
611     /* Returns the ID of the audio device actually used by the output to which this AudioTrack is
612      * attached.
613      * When the AudioTrack is inactive, the device ID returned can be either:
614      * - AUDIO_PORT_HANDLE_NONE if the AudioTrack is not attached to any output.
615      * - The device ID used before paused or stopped.
616      * - The device ID selected by audio policy manager of setOutputDevice() if the AudioTrack
617      * has not been started yet.
618      *
619      * Parameters:
620      *  none.
621      */
622     audio_port_handle_t getRoutedDeviceId();
623
624    /* Returns the unique session ID associated with this track.
625     *
626     * Parameters:
627     *  none.
628     *
629     * Returned value:
630     *  AudioTrack session ID.
631     */
632            audio_session_t getSessionId() const { return mSessionId; }
633
634    /* Attach track auxiliary output to specified effect. Use effectId = 0
635     * to detach track from effect.
636     *
637     * Parameters:
638     *
639     * effectId:  effectId obtained from AudioEffect::id().
640     *
641     * Returned status (from utils/Errors.h) can be:
642     *  - NO_ERROR: successful operation
643     *  - INVALID_OPERATION: the effect is not an auxiliary effect.
644     *  - BAD_VALUE: The specified effect ID is invalid
645     */
646            status_t    attachAuxEffect(int effectId);
647
648    /* Public API for TRANSFER_OBTAIN mode.
649     * Obtains a buffer of up to "audioBuffer->frameCount" empty slots for frames.
650     * After filling these slots with data, the caller should release them with releaseBuffer().
651     * If the track buffer is not full, obtainBuffer() returns as many contiguous
652     * [empty slots for] frames as are available immediately.
653     *
654     * If nonContig is non-NULL, it is an output parameter that will be set to the number of
655     * additional non-contiguous frames that are predicted to be available immediately,
656     * if the client were to release the first frames and then call obtainBuffer() again.
657     * This value is only a prediction, and needs to be confirmed.
658     * It will be set to zero for an error return.
659     *
660     * If the track buffer is full and track is stopped, obtainBuffer() returns WOULD_BLOCK
661     * regardless of the value of waitCount.
662     * If the track buffer is full and track is not stopped, obtainBuffer() blocks with a
663     * maximum timeout based on waitCount; see chart below.
664     * Buffers will be returned until the pool
665     * is exhausted, at which point obtainBuffer() will either block
666     * or return WOULD_BLOCK depending on the value of the "waitCount"
667     * parameter.
668     *
669     * Interpretation of waitCount:
670     *  +n  limits wait time to n * WAIT_PERIOD_MS,
671     *  -1  causes an (almost) infinite wait time,
672     *   0  non-blocking.
673     *
674     * Buffer fields
675     * On entry:
676     *  frameCount  number of [empty slots for] frames requested
677     *  size        ignored
678     *  raw         ignored
679     * After error return:
680     *  frameCount  0
681     *  size        0
682     *  raw         undefined
683     * After successful return:
684     *  frameCount  actual number of [empty slots for] frames available, <= number requested
685     *  size        actual number of bytes available
686     *  raw         pointer to the buffer
687     */
688            status_t    obtainBuffer(Buffer* audioBuffer, int32_t waitCount,
689                                size_t *nonContig = NULL);
690
691private:
692    /* If nonContig is non-NULL, it is an output parameter that will be set to the number of
693     * additional non-contiguous frames that are predicted to be available immediately,
694     * if the client were to release the first frames and then call obtainBuffer() again.
695     * This value is only a prediction, and needs to be confirmed.
696     * It will be set to zero for an error return.
697     * FIXME We could pass an array of Buffers instead of only one Buffer to obtainBuffer(),
698     * in case the requested amount of frames is in two or more non-contiguous regions.
699     * FIXME requested and elapsed are both relative times.  Consider changing to absolute time.
700     */
701            status_t    obtainBuffer(Buffer* audioBuffer, const struct timespec *requested,
702                                     struct timespec *elapsed = NULL, size_t *nonContig = NULL);
703public:
704
705    /* Public API for TRANSFER_OBTAIN mode.
706     * Release a filled buffer of frames for AudioFlinger to process.
707     *
708     * Buffer fields:
709     *  frameCount  currently ignored but recommend to set to actual number of frames filled
710     *  size        actual number of bytes filled, must be multiple of frameSize
711     *  raw         ignored
712     */
713            void        releaseBuffer(const Buffer* audioBuffer);
714
715    /* As a convenience we provide a write() interface to the audio buffer.
716     * Input parameter 'size' is in byte units.
717     * This is implemented on top of obtainBuffer/releaseBuffer. For best
718     * performance use callbacks. Returns actual number of bytes written >= 0,
719     * or one of the following negative status codes:
720     *      INVALID_OPERATION   AudioTrack is configured for static buffer or streaming mode
721     *      BAD_VALUE           size is invalid
722     *      WOULD_BLOCK         when obtainBuffer() returns same, or
723     *                          AudioTrack was stopped during the write
724     *      DEAD_OBJECT         when AudioFlinger dies or the output device changes and
725     *                          the track cannot be automatically restored.
726     *                          The application needs to recreate the AudioTrack
727     *                          because the audio device changed or AudioFlinger died.
728     *                          This typically occurs for direct or offload tracks
729     *                          or if mDoNotReconnect is true.
730     *      or any other error code returned by IAudioTrack::start() or restoreTrack_l().
731     * Default behavior is to only return when all data has been transferred. Set 'blocking' to
732     * false for the method to return immediately without waiting to try multiple times to write
733     * the full content of the buffer.
734     */
735            ssize_t     write(const void* buffer, size_t size, bool blocking = true);
736
737    /*
738     * Dumps the state of an audio track.
739     * Not a general-purpose API; intended only for use by media player service to dump its tracks.
740     */
741            status_t    dump(int fd, const Vector<String16>& args) const;
742
743    /*
744     * Return the total number of frames which AudioFlinger desired but were unavailable,
745     * and thus which resulted in an underrun.  Reset to zero by stop().
746     */
747            uint32_t    getUnderrunFrames() const;
748
749    /* Get the flags */
750            audio_output_flags_t getFlags() const { AutoMutex _l(mLock); return mFlags; }
751
752    /* Set parameters - only possible when using direct output */
753            status_t    setParameters(const String8& keyValuePairs);
754
755    /* Sets the volume shaper object */
756            media::VolumeShaper::Status applyVolumeShaper(
757                    const sp<media::VolumeShaper::Configuration>& configuration,
758                    const sp<media::VolumeShaper::Operation>& operation);
759
760    /* Gets the volume shaper state */
761            sp<media::VolumeShaper::State> getVolumeShaperState(int id);
762
763    /* Get parameters */
764            String8     getParameters(const String8& keys);
765
766    /* Poll for a timestamp on demand.
767     * Use if EVENT_NEW_TIMESTAMP is not delivered often enough for your needs,
768     * or if you need to get the most recent timestamp outside of the event callback handler.
769     * Caution: calling this method too often may be inefficient;
770     * if you need a high resolution mapping between frame position and presentation time,
771     * consider implementing that at application level, based on the low resolution timestamps.
772     * Returns NO_ERROR    if timestamp is valid.
773     *         WOULD_BLOCK if called in STOPPED or FLUSHED state, or if called immediately after
774     *                     start/ACTIVE, when the number of frames consumed is less than the
775     *                     overall hardware latency to physical output. In WOULD_BLOCK cases,
776     *                     one might poll again, or use getPosition(), or use 0 position and
777     *                     current time for the timestamp.
778     *         DEAD_OBJECT if AudioFlinger dies or the output device changes and
779     *                     the track cannot be automatically restored.
780     *                     The application needs to recreate the AudioTrack
781     *                     because the audio device changed or AudioFlinger died.
782     *                     This typically occurs for direct or offload tracks
783     *                     or if mDoNotReconnect is true.
784     *         INVALID_OPERATION  wrong state, or some other error.
785     *
786     * The timestamp parameter is undefined on return, if status is not NO_ERROR.
787     */
788            status_t    getTimestamp(AudioTimestamp& timestamp);
789private:
790            status_t    getTimestamp_l(AudioTimestamp& timestamp);
791public:
792
793    /* Return the extended timestamp, with additional timebase info and improved drain behavior.
794     *
795     * This is similar to the AudioTrack.java API:
796     * getTimestamp(@NonNull AudioTimestamp timestamp, @AudioTimestamp.Timebase int timebase)
797     *
798     * Some differences between this method and the getTimestamp(AudioTimestamp& timestamp) method
799     *
800     *   1. stop() by itself does not reset the frame position.
801     *      A following start() resets the frame position to 0.
802     *   2. flush() by itself does not reset the frame position.
803     *      The frame position advances by the number of frames flushed,
804     *      when the first frame after flush reaches the audio sink.
805     *   3. BOOTTIME clock offsets are provided to help synchronize with
806     *      non-audio streams, e.g. sensor data.
807     *   4. Position is returned with 64 bits of resolution.
808     *
809     * Parameters:
810     *  timestamp: A pointer to the caller allocated ExtendedTimestamp.
811     *
812     * Returns NO_ERROR    on success; timestamp is filled with valid data.
813     *         BAD_VALUE   if timestamp is NULL.
814     *         WOULD_BLOCK if called immediately after start() when the number
815     *                     of frames consumed is less than the
816     *                     overall hardware latency to physical output. In WOULD_BLOCK cases,
817     *                     one might poll again, or use getPosition(), or use 0 position and
818     *                     current time for the timestamp.
819     *                     If WOULD_BLOCK is returned, the timestamp is still
820     *                     modified with the LOCATION_CLIENT portion filled.
821     *         DEAD_OBJECT if AudioFlinger dies or the output device changes and
822     *                     the track cannot be automatically restored.
823     *                     The application needs to recreate the AudioTrack
824     *                     because the audio device changed or AudioFlinger died.
825     *                     This typically occurs for direct or offloaded tracks
826     *                     or if mDoNotReconnect is true.
827     *         INVALID_OPERATION  if called on a offloaded or direct track.
828     *                     Use getTimestamp(AudioTimestamp& timestamp) instead.
829     */
830            status_t getTimestamp(ExtendedTimestamp *timestamp);
831private:
832            status_t getTimestamp_l(ExtendedTimestamp *timestamp);
833public:
834
835    /* Add an AudioDeviceCallback. The caller will be notified when the audio device to which this
836     * AudioTrack is routed is updated.
837     * Replaces any previously installed callback.
838     * Parameters:
839     *  callback:  The callback interface
840     * Returns NO_ERROR if successful.
841     *         INVALID_OPERATION if the same callback is already installed.
842     *         NO_INIT or PREMISSION_DENIED if AudioFlinger service is not reachable
843     *         BAD_VALUE if the callback is NULL
844     */
845            status_t addAudioDeviceCallback(const sp<AudioSystem::AudioDeviceCallback>& callback);
846
847    /* remove an AudioDeviceCallback.
848     * Parameters:
849     *  callback:  The callback interface
850     * Returns NO_ERROR if successful.
851     *         INVALID_OPERATION if the callback is not installed
852     *         BAD_VALUE if the callback is NULL
853     */
854            status_t removeAudioDeviceCallback(
855                    const sp<AudioSystem::AudioDeviceCallback>& callback);
856
857            // AudioSystem::AudioDeviceCallback> virtuals
858            virtual void onAudioDeviceUpdate(audio_io_handle_t audioIo,
859                                             audio_port_handle_t deviceId);
860
861
862
863    /* Obtain the pending duration in milliseconds for playback of pure PCM
864     * (mixable without embedded timing) data remaining in AudioTrack.
865     *
866     * This is used to estimate the drain time for the client-server buffer
867     * so the choice of ExtendedTimestamp::LOCATION_SERVER is default.
868     * One may optionally request to find the duration to play through the HAL
869     * by specifying a location ExtendedTimestamp::LOCATION_KERNEL; however,
870     * INVALID_OPERATION may be returned if the kernel location is unavailable.
871     *
872     * Returns NO_ERROR  if successful.
873     *         INVALID_OPERATION if ExtendedTimestamp::LOCATION_KERNEL cannot be obtained
874     *                   or the AudioTrack does not contain pure PCM data.
875     *         BAD_VALUE if msec is nullptr or location is invalid.
876     */
877            status_t pendingDuration(int32_t *msec,
878                    ExtendedTimestamp::Location location = ExtendedTimestamp::LOCATION_SERVER);
879
880    /* hasStarted() is used to determine if audio is now audible at the device after
881     * a start() command. The underlying implementation checks a nonzero timestamp position
882     * or increment for the audible assumption.
883     *
884     * hasStarted() returns true if the track has been started() and audio is audible
885     * and no subsequent pause() or flush() has been called.  Immediately after pause() or
886     * flush() hasStarted() will return false.
887     *
888     * If stop() has been called, hasStarted() will return true if audio is still being
889     * delivered or has finished delivery (even if no audio was written) for both offloaded
890     * and normal tracks. This property removes a race condition in checking hasStarted()
891     * for very short clips, where stop() must be called to finish drain.
892     *
893     * In all cases, hasStarted() may turn false briefly after a subsequent start() is called
894     * until audio becomes audible again.
895     */
896            bool hasStarted(); // not const
897
898            bool isPlaying() {
899                AutoMutex lock(mLock);
900                return mState == STATE_ACTIVE || mState == STATE_STOPPING;
901            }
902protected:
903    /* copying audio tracks is not allowed */
904                        AudioTrack(const AudioTrack& other);
905            AudioTrack& operator = (const AudioTrack& other);
906
907    /* a small internal class to handle the callback */
908    class AudioTrackThread : public Thread
909    {
910    public:
911        AudioTrackThread(AudioTrack& receiver, bool bCanCallJava = false);
912
913        // Do not call Thread::requestExitAndWait() without first calling requestExit().
914        // Thread::requestExitAndWait() is not virtual, and the implementation doesn't do enough.
915        virtual void        requestExit();
916
917                void        pause();    // suspend thread from execution at next loop boundary
918                void        resume();   // allow thread to execute, if not requested to exit
919                void        wake();     // wake to handle changed notification conditions.
920
921    private:
922                void        pauseInternal(nsecs_t ns = 0LL);
923                                        // like pause(), but only used internally within thread
924
925        friend class AudioTrack;
926        virtual bool        threadLoop();
927        AudioTrack&         mReceiver;
928        virtual ~AudioTrackThread();
929        Mutex               mMyLock;    // Thread::mLock is private
930        Condition           mMyCond;    // Thread::mThreadExitedCondition is private
931        bool                mPaused;    // whether thread is requested to pause at next loop entry
932        bool                mPausedInt; // whether thread internally requests pause
933        nsecs_t             mPausedNs;  // if mPausedInt then associated timeout, otherwise ignored
934        bool                mIgnoreNextPausedInt;   // skip any internal pause and go immediately
935                                        // to processAudioBuffer() as state may have changed
936                                        // since pause time calculated.
937    };
938
939            // body of AudioTrackThread::threadLoop()
940            // returns the maximum amount of time before we would like to run again, where:
941            //      0           immediately
942            //      > 0         no later than this many nanoseconds from now
943            //      NS_WHENEVER still active but no particular deadline
944            //      NS_INACTIVE inactive so don't run again until re-started
945            //      NS_NEVER    never again
946            static const nsecs_t NS_WHENEVER = -1, NS_INACTIVE = -2, NS_NEVER = -3;
947            nsecs_t processAudioBuffer();
948
949            // caller must hold lock on mLock for all _l methods
950
951            void updateLatency_l(); // updates mAfLatency and mLatency from AudioSystem cache
952
953            status_t createTrack_l();
954
955            // can only be called when mState != STATE_ACTIVE
956            void flush_l();
957
958            void setLoop_l(uint32_t loopStart, uint32_t loopEnd, int loopCount);
959
960            // FIXME enum is faster than strcmp() for parameter 'from'
961            status_t restoreTrack_l(const char *from);
962
963            uint32_t    getUnderrunCount_l() const;
964
965            bool     isOffloaded() const;
966            bool     isDirect() const;
967            bool     isOffloadedOrDirect() const;
968
969            bool     isOffloaded_l() const
970                { return (mFlags & AUDIO_OUTPUT_FLAG_COMPRESS_OFFLOAD) != 0; }
971
972            bool     isOffloadedOrDirect_l() const
973                { return (mFlags & (AUDIO_OUTPUT_FLAG_COMPRESS_OFFLOAD|
974                                                AUDIO_OUTPUT_FLAG_DIRECT)) != 0; }
975
976            bool     isDirect_l() const
977                { return (mFlags & AUDIO_OUTPUT_FLAG_DIRECT) != 0; }
978
979            // pure pcm data is mixable (which excludes HW_AV_SYNC, with embedded timing)
980            bool     isPurePcmData_l() const
981                { return audio_is_linear_pcm(mFormat)
982                        && (mAttributes.flags & AUDIO_FLAG_HW_AV_SYNC) == 0; }
983
984            // increment mPosition by the delta of mServer, and return new value of mPosition
985            Modulo<uint32_t> updateAndGetPosition_l();
986
987            // check sample rate and speed is compatible with AudioTrack
988            bool     isSampleRateSpeedAllowed_l(uint32_t sampleRate, float speed);
989
990            void     restartIfDisabled();
991
992            void     updateRoutedDeviceId_l();
993
994    // Next 4 fields may be changed if IAudioTrack is re-created, but always != 0
995    sp<IAudioTrack>         mAudioTrack;
996    sp<IMemory>             mCblkMemory;
997    audio_track_cblk_t*     mCblk;                  // re-load after mLock.unlock()
998    audio_io_handle_t       mOutput;                // returned by AudioSystem::getOutputForAttr()
999
1000    sp<AudioTrackThread>    mAudioTrackThread;
1001    bool                    mThreadCanCallJava;
1002
1003    float                   mVolume[2];
1004    float                   mSendLevel;
1005    mutable uint32_t        mSampleRate;            // mutable because getSampleRate() can update it
1006    uint32_t                mOriginalSampleRate;
1007    AudioPlaybackRate       mPlaybackRate;
1008    float                   mMaxRequiredSpeed;      // use PCM buffer size to allow this speed
1009
1010    // Corresponds to current IAudioTrack, value is reported back by AudioFlinger to the client.
1011    // This allocated buffer size is maintained by the proxy.
1012    size_t                  mFrameCount;            // maximum size of buffer
1013
1014    size_t                  mReqFrameCount;         // frame count to request the first or next time
1015                                                    // a new IAudioTrack is needed, non-decreasing
1016
1017    // The following AudioFlinger server-side values are cached in createAudioTrack_l().
1018    // These values can be used for informational purposes until the track is invalidated,
1019    // whereupon restoreTrack_l() calls createTrack_l() to update the values.
1020    uint32_t                mAfLatency;             // AudioFlinger latency in ms
1021    size_t                  mAfFrameCount;          // AudioFlinger frame count
1022    uint32_t                mAfSampleRate;          // AudioFlinger sample rate
1023
1024    // constant after constructor or set()
1025    audio_format_t          mFormat;                // as requested by client, not forced to 16-bit
1026    audio_stream_type_t     mStreamType;            // mStreamType == AUDIO_STREAM_DEFAULT implies
1027                                                    // this AudioTrack has valid attributes
1028    uint32_t                mChannelCount;
1029    audio_channel_mask_t    mChannelMask;
1030    sp<IMemory>             mSharedBuffer;
1031    transfer_type           mTransfer;
1032    audio_offload_info_t    mOffloadInfoCopy;
1033    const audio_offload_info_t* mOffloadInfo;
1034    audio_attributes_t      mAttributes;
1035
1036    size_t                  mFrameSize;             // frame size in bytes
1037
1038    status_t                mStatus;
1039
1040    // can change dynamically when IAudioTrack invalidated
1041    uint32_t                mLatency;               // in ms
1042
1043    // Indicates the current track state.  Protected by mLock.
1044    enum State {
1045        STATE_ACTIVE,
1046        STATE_STOPPED,
1047        STATE_PAUSED,
1048        STATE_PAUSED_STOPPING,
1049        STATE_FLUSHED,
1050        STATE_STOPPING,
1051    }                       mState;
1052
1053    // for client callback handler
1054    callback_t              mCbf;                   // callback handler for events, or NULL
1055    void*                   mUserData;
1056
1057    // for notification APIs
1058
1059    // next 2 fields are const after constructor or set()
1060    uint32_t                mNotificationFramesReq; // requested number of frames between each
1061                                                    // notification callback,
1062                                                    // at initial source sample rate
1063    uint32_t                mNotificationsPerBufferReq;
1064                                                    // requested number of notifications per buffer,
1065                                                    // currently only used for fast tracks with
1066                                                    // default track buffer size
1067
1068    uint32_t                mNotificationFramesAct; // actual number of frames between each
1069                                                    // notification callback,
1070                                                    // at initial source sample rate
1071    bool                    mRefreshRemaining;      // processAudioBuffer() should refresh
1072                                                    // mRemainingFrames and mRetryOnPartialBuffer
1073
1074                                                    // used for static track cbf and restoration
1075    int32_t                 mLoopCount;             // last setLoop loopCount; zero means disabled
1076    uint32_t                mLoopStart;             // last setLoop loopStart
1077    uint32_t                mLoopEnd;               // last setLoop loopEnd
1078    int32_t                 mLoopCountNotified;     // the last loopCount notified by callback.
1079                                                    // mLoopCountNotified counts down, matching
1080                                                    // the remaining loop count for static track
1081                                                    // playback.
1082
1083    // These are private to processAudioBuffer(), and are not protected by a lock
1084    uint32_t                mRemainingFrames;       // number of frames to request in obtainBuffer()
1085    bool                    mRetryOnPartialBuffer;  // sleep and retry after partial obtainBuffer()
1086    uint32_t                mObservedSequence;      // last observed value of mSequence
1087
1088    Modulo<uint32_t>        mMarkerPosition;        // in wrapping (overflow) frame units
1089    bool                    mMarkerReached;
1090    Modulo<uint32_t>        mNewPosition;           // in frames
1091    uint32_t                mUpdatePeriod;          // in frames, zero means no EVENT_NEW_POS
1092
1093    Modulo<uint32_t>        mServer;                // in frames, last known mProxy->getPosition()
1094                                                    // which is count of frames consumed by server,
1095                                                    // reset by new IAudioTrack,
1096                                                    // whether it is reset by stop() is TBD
1097    Modulo<uint32_t>        mPosition;              // in frames, like mServer except continues
1098                                                    // monotonically after new IAudioTrack,
1099                                                    // and could be easily widened to uint64_t
1100    Modulo<uint32_t>        mReleased;              // count of frames released to server
1101                                                    // but not necessarily consumed by server,
1102                                                    // reset by stop() but continues monotonically
1103                                                    // after new IAudioTrack to restore mPosition,
1104                                                    // and could be easily widened to uint64_t
1105    int64_t                 mStartFromZeroUs;       // the start time after flush or stop,
1106                                                    // when position should be 0.
1107                                                    // only used for offloaded and direct tracks.
1108    int64_t                 mStartNs;               // the time when start() is called.
1109    ExtendedTimestamp       mStartEts;              // Extended timestamp at start for normal
1110                                                    // AudioTracks.
1111    AudioTimestamp          mStartTs;               // Timestamp at start for offloaded or direct
1112                                                    // AudioTracks.
1113
1114    bool                    mPreviousTimestampValid;// true if mPreviousTimestamp is valid
1115    bool                    mTimestampStartupGlitchReported; // reduce log spam
1116    bool                    mRetrogradeMotionReported; // reduce log spam
1117    AudioTimestamp          mPreviousTimestamp;     // used to detect retrograde motion
1118    ExtendedTimestamp::Location mPreviousLocation;  // location used for previous timestamp
1119
1120    uint32_t                mUnderrunCountOffset;   // updated when restoring tracks
1121
1122    int64_t                 mFramesWritten;         // total frames written. reset to zero after
1123                                                    // the start() following stop(). It is not
1124                                                    // changed after restoring the track or
1125                                                    // after flush.
1126    int64_t                 mFramesWrittenServerOffset; // An offset to server frames due to
1127                                                    // restoring AudioTrack, or stop/start.
1128                                                    // This offset is also used for static tracks.
1129    int64_t                 mFramesWrittenAtRestore; // Frames written at restore point (or frames
1130                                                    // delivered for static tracks).
1131                                                    // -1 indicates no previous restore point.
1132
1133    audio_output_flags_t    mFlags;                 // same as mOrigFlags, except for bits that may
1134                                                    // be denied by client or server, such as
1135                                                    // AUDIO_OUTPUT_FLAG_FAST.  mLock must be
1136                                                    // held to read or write those bits reliably.
1137    audio_output_flags_t    mOrigFlags;             // as specified in constructor or set(), const
1138
1139    bool                    mDoNotReconnect;
1140
1141    audio_session_t         mSessionId;
1142    int                     mAuxEffectId;
1143
1144    mutable Mutex           mLock;
1145
1146    int                     mPreviousPriority;          // before start()
1147    SchedPolicy             mPreviousSchedulingGroup;
1148    bool                    mAwaitBoost;    // thread should wait for priority boost before running
1149
1150    // The proxy should only be referenced while a lock is held because the proxy isn't
1151    // multi-thread safe, especially the SingleStateQueue part of the proxy.
1152    // An exception is that a blocking ClientProxy::obtainBuffer() may be called without a lock,
1153    // provided that the caller also holds an extra reference to the proxy and shared memory to keep
1154    // them around in case they are replaced during the obtainBuffer().
1155    sp<StaticAudioTrackClientProxy> mStaticProxy;   // for type safety only
1156    sp<AudioTrackClientProxy>       mProxy;         // primary owner of the memory
1157
1158    bool                    mInUnderrun;            // whether track is currently in underrun state
1159    uint32_t                mPausedPosition;
1160
1161    // For Device Selection API
1162    //  a value of AUDIO_PORT_HANDLE_NONE indicated default (AudioPolicyManager) routing.
1163    audio_port_handle_t    mSelectedDeviceId; // Device requested by the application.
1164    audio_port_handle_t    mRoutedDeviceId;   // Device actually selected by audio policy manager:
1165                                              // May not match the app selection depending on other
1166                                              // activity and connected devices.
1167
1168    sp<media::VolumeHandler>       mVolumeHandler;
1169
1170private:
1171    class DeathNotifier : public IBinder::DeathRecipient {
1172    public:
1173        DeathNotifier(AudioTrack* audioTrack) : mAudioTrack(audioTrack) { }
1174    protected:
1175        virtual void        binderDied(const wp<IBinder>& who);
1176    private:
1177        const wp<AudioTrack> mAudioTrack;
1178    };
1179
1180    sp<DeathNotifier>       mDeathNotifier;
1181    uint32_t                mSequence;              // incremented for each new IAudioTrack attempt
1182    uid_t                   mClientUid;
1183    pid_t                   mClientPid;
1184
1185    wp<AudioSystem::AudioDeviceCallback> mDeviceCallback;
1186
1187private:
1188    class MediaMetrics {
1189      public:
1190        MediaMetrics() : mAnalyticsItem(new MediaAnalyticsItem("audiotrack")) {
1191        }
1192        ~MediaMetrics() {
1193            // mAnalyticsItem alloc failure will be flagged in the constructor
1194            // don't log empty records
1195            if (mAnalyticsItem->count() > 0) {
1196                mAnalyticsItem->setFinalized(true);
1197                mAnalyticsItem->selfrecord();
1198            }
1199        }
1200        void gather(const AudioTrack *track);
1201      private:
1202        std::unique_ptr<MediaAnalyticsItem> mAnalyticsItem;
1203    };
1204    MediaMetrics mMediaMetrics;
1205};
1206
1207}; // namespace android
1208
1209#endif // ANDROID_AUDIOTRACK_H
1210