AudioTrack.h revision ad3af3305f024bcbbd55c894a4995e449498e1ba
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/IAudioTrack.h>
23#include <utils/threads.h>
24
25namespace android {
26
27// ----------------------------------------------------------------------------
28
29class audio_track_cblk_t;
30class AudioTrackClientProxy;
31class StaticAudioTrackClientProxy;
32
33// ----------------------------------------------------------------------------
34
35class AudioTrack : public RefBase
36{
37public:
38    enum channel_index {
39        MONO   = 0,
40        LEFT   = 0,
41        RIGHT  = 1
42    };
43
44    /* Events used by AudioTrack callback function (callback_t).
45     * Keep in sync with frameworks/base/media/java/android/media/AudioTrack.java NATIVE_EVENT_*.
46     */
47    enum event_type {
48        EVENT_MORE_DATA = 0,        // Request to write more data to buffer.
49                                    // If this event is delivered but the callback handler
50                                    // does not want to write more data, the handler must explicitly
51                                    // ignore the event by setting frameCount to zero.
52        EVENT_UNDERRUN = 1,         // Buffer underrun occurred.
53        EVENT_LOOP_END = 2,         // Sample loop end was reached; playback restarted from
54                                    // loop start if loop count was not 0.
55        EVENT_MARKER = 3,           // Playback head is at the specified marker position
56                                    // (See setMarkerPosition()).
57        EVENT_NEW_POS = 4,          // Playback head is at a new position
58                                    // (See setPositionUpdatePeriod()).
59        EVENT_BUFFER_END = 5,       // Playback head is at the end of the buffer.
60                                    // Not currently used by android.media.AudioTrack.
61        EVENT_NEW_IAUDIOTRACK = 6,  // IAudioTrack was re-created, either due to re-routing and
62                                    // voluntary invalidation by mediaserver, or mediaserver crash.
63        EVENT_STREAM_END = 7,       // Sent after all the buffers queued in AF and HW are played
64                                    // back (after stop is called)
65    };
66
67    /* Client should declare Buffer on the stack and pass address to obtainBuffer()
68     * and releaseBuffer().  See also callback_t for EVENT_MORE_DATA.
69     */
70
71    class Buffer
72    {
73    public:
74        // FIXME use m prefix
75        size_t      frameCount;   // number of sample frames corresponding to size;
76                                  // on input it is the number of frames desired,
77                                  // on output is the number of frames actually filled
78
79        size_t      size;         // input/output in bytes == frameCount * frameSize
80                                  // FIXME this is redundant with respect to frameCount,
81                                  // and TRANSFER_OBTAIN mode is broken for 8-bit data
82                                  // since we don't define the frame format
83
84        union {
85            void*       raw;
86            short*      i16;      // signed 16-bit
87            int8_t*     i8;       // unsigned 8-bit, offset by 0x80
88        };
89    };
90
91    /* As a convenience, if a callback is supplied, a handler thread
92     * is automatically created with the appropriate priority. This thread
93     * invokes the callback when a new buffer becomes available or various conditions occur.
94     * Parameters:
95     *
96     * event:   type of event notified (see enum AudioTrack::event_type).
97     * user:    Pointer to context for use by the callback receiver.
98     * info:    Pointer to optional parameter according to event type:
99     *          - EVENT_MORE_DATA: pointer to AudioTrack::Buffer struct. The callback must not write
100     *            more bytes than indicated by 'size' field and update 'size' if fewer bytes are
101     *            written.
102     *          - EVENT_UNDERRUN: unused.
103     *          - EVENT_LOOP_END: pointer to an int indicating the number of loops remaining.
104     *          - EVENT_MARKER: pointer to const uint32_t containing the marker position in frames.
105     *          - EVENT_NEW_POS: pointer to const uint32_t containing the new position in frames.
106     *          - EVENT_BUFFER_END: unused.
107     *          - EVENT_NEW_IAUDIOTRACK: unused.
108     */
109
110    typedef void (*callback_t)(int event, void* user, void *info);
111
112    /* Returns the minimum frame count required for the successful creation of
113     * an AudioTrack object.
114     * Returned status (from utils/Errors.h) can be:
115     *  - NO_ERROR: successful operation
116     *  - NO_INIT: audio server or audio hardware not initialized
117     */
118
119    static status_t getMinFrameCount(size_t* frameCount,
120                                     audio_stream_type_t streamType,
121                                     uint32_t sampleRate);
122
123    /* How data is transferred to AudioTrack
124     */
125    enum transfer_type {
126        TRANSFER_DEFAULT,   // not specified explicitly; determine from the other parameters
127        TRANSFER_CALLBACK,  // callback EVENT_MORE_DATA
128        TRANSFER_OBTAIN,    // FIXME deprecated: call obtainBuffer() and releaseBuffer()
129        TRANSFER_SYNC,      // synchronous write()
130        TRANSFER_SHARED,    // shared memory
131    };
132
133    /* Constructs an uninitialized AudioTrack. No connection with
134     * AudioFlinger takes place.  Use set() after this.
135     */
136                        AudioTrack();
137
138    /* Creates an AudioTrack object and registers it with AudioFlinger.
139     * Once created, the track needs to be started before it can be used.
140     * Unspecified values are set to appropriate default values.
141     * With this constructor, the track is configured for streaming mode.
142     * Data to be rendered is supplied by write() or by the callback EVENT_MORE_DATA.
143     * Intermixing a combination of write() and non-ignored EVENT_MORE_DATA is not allowed.
144     *
145     * Parameters:
146     *
147     * streamType:         Select the type of audio stream this track is attached to
148     *                     (e.g. AUDIO_STREAM_MUSIC).
149     * sampleRate:         Data source sampling rate in Hz.
150     * format:             Audio format (e.g AUDIO_FORMAT_PCM_16_BIT for signed
151     *                     16 bits per sample).
152     * channelMask:        Channel mask.
153     * frameCount:         Minimum size of track PCM buffer in frames. This defines the
154     *                     application's contribution to the
155     *                     latency of the track. The actual size selected by the AudioTrack could be
156     *                     larger if the requested size is not compatible with current audio HAL
157     *                     configuration.  Zero means to use a default value.
158     * flags:              See comments on audio_output_flags_t in <system/audio.h>.
159     * cbf:                Callback function. If not null, this function is called periodically
160     *                     to provide new data and inform of marker, position updates, etc.
161     * user:               Context for use by the callback receiver.
162     * notificationFrames: The callback function is called each time notificationFrames PCM
163     *                     frames have been consumed from track input buffer.
164     *                     This is expressed in units of frames at the initial source sample rate.
165     * sessionId:          Specific session ID, or zero to use default.
166     * transferType:       How data is transferred to AudioTrack.
167     * threadCanCallJava:  Not present in parameter list, and so is fixed at false.
168     */
169
170                        AudioTrack( audio_stream_type_t streamType,
171                                    uint32_t sampleRate  = 0,
172                                    audio_format_t format = AUDIO_FORMAT_DEFAULT,
173                                    audio_channel_mask_t channelMask = 0,
174                                    int frameCount       = 0,
175                                    audio_output_flags_t flags = AUDIO_OUTPUT_FLAG_NONE,
176                                    callback_t cbf       = NULL,
177                                    void* user           = NULL,
178                                    int notificationFrames = 0,
179                                    int sessionId        = 0,
180                                    transfer_type transferType = TRANSFER_DEFAULT,
181                                    const audio_offload_info_t *offloadInfo = NULL);
182
183    /* Creates an audio track and registers it with AudioFlinger.
184     * With this constructor, the track is configured for static buffer mode.
185     * The format must not be 8-bit linear PCM.
186     * Data to be rendered is passed in a shared memory buffer
187     * identified by the argument sharedBuffer, which must be non-0.
188     * The memory should be initialized to the desired data before calling start().
189     * The write() method is not supported in this case.
190     * It is recommended to pass a callback function to be notified of playback end by an
191     * EVENT_UNDERRUN event.
192     */
193
194                        AudioTrack( audio_stream_type_t streamType,
195                                    uint32_t sampleRate = 0,
196                                    audio_format_t format = AUDIO_FORMAT_DEFAULT,
197                                    audio_channel_mask_t channelMask = 0,
198                                    const sp<IMemory>& sharedBuffer = 0,
199                                    audio_output_flags_t flags = AUDIO_OUTPUT_FLAG_NONE,
200                                    callback_t cbf      = NULL,
201                                    void* user          = NULL,
202                                    int notificationFrames = 0,
203                                    int sessionId       = 0,
204                                    transfer_type transferType = TRANSFER_DEFAULT,
205                                    const audio_offload_info_t *offloadInfo = NULL);
206
207    /* Terminates the AudioTrack and unregisters it from AudioFlinger.
208     * Also destroys all resources associated with the AudioTrack.
209     */
210protected:
211                        virtual ~AudioTrack();
212public:
213
214    /* Initialize an AudioTrack that was created using the AudioTrack() constructor.
215     * Don't call set() more than once, or after the AudioTrack() constructors that take parameters.
216     * Returned status (from utils/Errors.h) can be:
217     *  - NO_ERROR: successful initialization
218     *  - INVALID_OPERATION: AudioTrack is already initialized
219     *  - BAD_VALUE: invalid parameter (channelMask, format, sampleRate...)
220     *  - NO_INIT: audio server or audio hardware not initialized
221     * If sharedBuffer is non-0, the frameCount parameter is ignored and
222     * replaced by the shared buffer's total allocated size in frame units.
223     *
224     * Parameters not listed in the AudioTrack constructors above:
225     *
226     * threadCanCallJava:  Whether callbacks are made from an attached thread and thus can call JNI.
227     */
228            status_t    set(audio_stream_type_t streamType = AUDIO_STREAM_DEFAULT,
229                            uint32_t sampleRate = 0,
230                            audio_format_t format = AUDIO_FORMAT_DEFAULT,
231                            audio_channel_mask_t channelMask = 0,
232                            int frameCount      = 0,
233                            audio_output_flags_t flags = AUDIO_OUTPUT_FLAG_NONE,
234                            callback_t cbf      = NULL,
235                            void* user          = NULL,
236                            int notificationFrames = 0,
237                            const sp<IMemory>& sharedBuffer = 0,
238                            bool threadCanCallJava = false,
239                            int sessionId       = 0,
240                            transfer_type transferType = TRANSFER_DEFAULT,
241                            const audio_offload_info_t *offloadInfo = NULL);
242
243    /* Result of constructing the AudioTrack. This must be checked
244     * before using any AudioTrack API (except for set()), because using
245     * an uninitialized AudioTrack produces undefined results.
246     * See set() method above for possible return codes.
247     */
248            status_t    initCheck() const   { return mStatus; }
249
250    /* Returns this track's estimated latency in milliseconds.
251     * This includes the latency due to AudioTrack buffer size, AudioMixer (if any)
252     * and audio hardware driver.
253     */
254            uint32_t    latency() const     { return mLatency; }
255
256    /* getters, see constructors and set() */
257
258            audio_stream_type_t streamType() const { return mStreamType; }
259            audio_format_t format() const   { return mFormat; }
260
261    /* Return frame size in bytes, which for linear PCM is
262     * channelCount * (bit depth per channel / 8).
263     * channelCount is determined from channelMask, and bit depth comes from format.
264     * For non-linear formats, the frame size is typically 1 byte.
265     */
266            size_t      frameSize() const   { return mFrameSize; }
267
268            uint32_t    channelCount() const { return mChannelCount; }
269            uint32_t    frameCount() const  { return mFrameCount; }
270
271    /* Return the static buffer specified in constructor or set(), or 0 for streaming mode */
272            sp<IMemory> sharedBuffer() const { return mSharedBuffer; }
273
274    /* After it's created the track is not active. Call start() to
275     * make it active. If set, the callback will start being called.
276     * If the track was previously paused, volume is ramped up over the first mix buffer.
277     */
278            void        start();
279
280    /* Stop a track.
281     * In static buffer mode, the track is stopped immediately.
282     * In streaming mode, the callback will cease being called.  Note that obtainBuffer() still
283     * works and will fill up buffers until the pool is exhausted, and then will return WOULD_BLOCK.
284     * In streaming mode the stop does not occur immediately: any data remaining in the buffer
285     * is first drained, mixed, and output, and only then is the track marked as stopped.
286     */
287            void        stop();
288            bool        stopped() const;
289
290    /* Flush a stopped or paused track. All previously buffered data is discarded immediately.
291     * This has the effect of draining the buffers without mixing or output.
292     * Flush is intended for streaming mode, for example before switching to non-contiguous content.
293     * This function is a no-op if the track is not stopped or paused, or uses a static buffer.
294     */
295            void        flush();
296
297    /* Pause a track. After pause, the callback will cease being called and
298     * obtainBuffer returns WOULD_BLOCK. Note that obtainBuffer() still works
299     * and will fill up buffers until the pool is exhausted.
300     * Volume is ramped down over the next mix buffer following the pause request,
301     * and then the track is marked as paused.  It can be resumed with ramp up by start().
302     */
303            void        pause();
304
305    /* Set volume for this track, mostly used for games' sound effects
306     * left and right volumes. Levels must be >= 0.0 and <= 1.0.
307     * This is the older API.  New applications should use setVolume(float) when possible.
308     */
309            status_t    setVolume(float left, float right);
310
311    /* Set volume for all channels.  This is the preferred API for new applications,
312     * especially for multi-channel content.
313     */
314            status_t    setVolume(float volume);
315
316    /* Set the send level for this track. An auxiliary effect should be attached
317     * to the track with attachEffect(). Level must be >= 0.0 and <= 1.0.
318     */
319            status_t    setAuxEffectSendLevel(float level);
320            void        getAuxEffectSendLevel(float* level) const;
321
322    /* Set source sample rate for this track in Hz, mostly used for games' sound effects
323     */
324            status_t    setSampleRate(uint32_t sampleRate);
325
326    /* Return current source sample rate in Hz, or 0 if unknown */
327            uint32_t    getSampleRate() const;
328
329    /* Enables looping and sets the start and end points of looping.
330     * Only supported for static buffer mode.
331     *
332     * FIXME The comments below are for the new planned interpretation which is not yet implemented.
333     * Currently the legacy behavior is still implemented, where loopStart and loopEnd
334     * are in wrapping (overflow) frame units like the return value of getPosition().
335     * The plan is to fix all callers to use the new version at same time implementation changes.
336     *
337     * Parameters:
338     *
339     * loopStart:   loop start in frames relative to start of buffer.
340     * loopEnd:     loop end in frames relative to start of buffer.
341     * loopCount:   number of loops to execute. Calling setLoop() with loopCount == 0 cancels any
342     *              pending or active loop. loopCount == -1 means infinite looping.
343     *
344     * For proper operation the following condition must be respected:
345     *      loopCount != 0 implies 0 <= loopStart < loopEnd <= frameCount().
346     *
347     * If the loop period (loopEnd - loopStart) is too small for the implementation to support,
348     * setLoop() will return BAD_VALUE.  loopCount must be >= -1.
349     *
350     */
351            status_t    setLoop(uint32_t loopStart, uint32_t loopEnd, int loopCount);
352
353    /* Sets marker position. When playback reaches the number of frames specified, a callback with
354     * event type EVENT_MARKER is called. Calling setMarkerPosition with marker == 0 cancels marker
355     * notification callback.  To set a marker at a position which would compute as 0,
356     * a workaround is to the set the marker at a nearby position such as ~0 or 1.
357     * If the AudioTrack has been opened with no callback function associated, the operation will
358     * fail.
359     *
360     * Parameters:
361     *
362     * marker:   marker position expressed in wrapping (overflow) frame units,
363     *           like the return value of getPosition().
364     *
365     * Returned status (from utils/Errors.h) can be:
366     *  - NO_ERROR: successful operation
367     *  - INVALID_OPERATION: the AudioTrack has no callback installed.
368     */
369            status_t    setMarkerPosition(uint32_t marker);
370            status_t    getMarkerPosition(uint32_t *marker) const;
371
372    /* Sets position update period. Every time the number of frames specified has been played,
373     * a callback with event type EVENT_NEW_POS is called.
374     * Calling setPositionUpdatePeriod with updatePeriod == 0 cancels new position notification
375     * callback.
376     * If the AudioTrack has been opened with no callback function associated, the operation will
377     * fail.
378     * Extremely small values may be rounded up to a value the implementation can support.
379     *
380     * Parameters:
381     *
382     * updatePeriod:  position update notification period expressed in frames.
383     *
384     * Returned status (from utils/Errors.h) can be:
385     *  - NO_ERROR: successful operation
386     *  - INVALID_OPERATION: the AudioTrack has no callback installed.
387     */
388            status_t    setPositionUpdatePeriod(uint32_t updatePeriod);
389            status_t    getPositionUpdatePeriod(uint32_t *updatePeriod) const;
390
391    /* Sets playback head position.
392     * Only supported for static buffer mode.
393     *
394     * FIXME The comments below are for the new planned interpretation which is not yet implemented.
395     * Currently the legacy behavior is still implemented, where the new position
396     * is in wrapping (overflow) frame units like the return value of getPosition().
397     * The plan is to fix all callers to use the new version at same time implementation changes.
398     *
399     * Parameters:
400     *
401     * position:  New playback head position in frames relative to start of buffer.
402     *            0 <= position <= frameCount().  Note that end of buffer is permitted,
403     *            but will result in an immediate underrun if started.
404     *
405     * Returned status (from utils/Errors.h) can be:
406     *  - NO_ERROR: successful operation
407     *  - INVALID_OPERATION: the AudioTrack is not stopped or paused, or is streaming mode.
408     *  - BAD_VALUE: The specified position is beyond the number of frames present in AudioTrack
409     *               buffer
410     */
411            status_t    setPosition(uint32_t position);
412
413    /* Return the total number of frames played since playback start.
414     * The counter will wrap (overflow) periodically, e.g. every ~27 hours at 44.1 kHz.
415     * It is reset to zero by flush(), reload(), and stop().
416     *
417     * Parameters:
418     *
419     *  position:  Address where to return play head position.
420     *
421     * Returned status (from utils/Errors.h) can be:
422     *  - NO_ERROR: successful operation
423     *  - BAD_VALUE:  position is NULL
424     */
425            status_t    getPosition(uint32_t *position) const;
426
427    /* For static buffer mode only, this returns the current playback position in frames
428     * relative to start of buffer.  It is analogous to the new API for
429     * setLoop() and setPosition().  After underrun, the position will be at end of buffer.
430     */
431            status_t    getBufferPosition(uint32_t *position);
432
433    /* Forces AudioTrack buffer full condition. When playing a static buffer, this method avoids
434     * rewriting the buffer before restarting playback after a stop.
435     * This method must be called with the AudioTrack in paused or stopped state.
436     * Not allowed in streaming mode.
437     *
438     * Returned status (from utils/Errors.h) can be:
439     *  - NO_ERROR: successful operation
440     *  - INVALID_OPERATION: the AudioTrack is not stopped or paused, or is streaming mode.
441     */
442            status_t    reload();
443
444    /* Returns a handle on the audio output used by this AudioTrack.
445     *
446     * Parameters:
447     *  none.
448     *
449     * Returned value:
450     *  handle on audio hardware output
451     */
452            audio_io_handle_t    getOutput();
453
454    /* Returns the unique session ID associated with this track.
455     *
456     * Parameters:
457     *  none.
458     *
459     * Returned value:
460     *  AudioTrack session ID.
461     */
462            int    getSessionId() const { return mSessionId; }
463
464    /* Attach track auxiliary output to specified effect. Use effectId = 0
465     * to detach track from effect.
466     *
467     * Parameters:
468     *
469     * effectId:  effectId obtained from AudioEffect::id().
470     *
471     * Returned status (from utils/Errors.h) can be:
472     *  - NO_ERROR: successful operation
473     *  - INVALID_OPERATION: the effect is not an auxiliary effect.
474     *  - BAD_VALUE: The specified effect ID is invalid
475     */
476            status_t    attachAuxEffect(int effectId);
477
478    /* Obtains a buffer of up to "audioBuffer->frameCount" empty slots for frames.
479     * After filling these slots with data, the caller should release them with releaseBuffer().
480     * If the track buffer is not full, obtainBuffer() returns as many contiguous
481     * [empty slots for] frames as are available immediately.
482     * If the track buffer is full and track is stopped, obtainBuffer() returns WOULD_BLOCK
483     * regardless of the value of waitCount.
484     * If the track buffer is full and track is not stopped, obtainBuffer() blocks with a
485     * maximum timeout based on waitCount; see chart below.
486     * Buffers will be returned until the pool
487     * is exhausted, at which point obtainBuffer() will either block
488     * or return WOULD_BLOCK depending on the value of the "waitCount"
489     * parameter.
490     * Each sample is 16-bit signed PCM.
491     *
492     * obtainBuffer() and releaseBuffer() are deprecated for direct use by applications,
493     * which should use write() or callback EVENT_MORE_DATA instead.
494     *
495     * Interpretation of waitCount:
496     *  +n  limits wait time to n * WAIT_PERIOD_MS,
497     *  -1  causes an (almost) infinite wait time,
498     *   0  non-blocking.
499     *
500     * Buffer fields
501     * On entry:
502     *  frameCount  number of frames requested
503     * After error return:
504     *  frameCount  0
505     *  size        0
506     *  raw         undefined
507     * After successful return:
508     *  frameCount  actual number of frames available, <= number requested
509     *  size        actual number of bytes available
510     *  raw         pointer to the buffer
511     */
512
513    /* FIXME Deprecated public API for TRANSFER_OBTAIN mode */
514            status_t    obtainBuffer(Buffer* audioBuffer, int32_t waitCount)
515                                __attribute__((__deprecated__));
516
517private:
518    /* New internal API
519     * If nonContig is non-NULL, it is an output parameter that will be set to the number of
520     * additional non-contiguous frames that are available immediately.
521     * FIXME We could pass an array of Buffers instead of only one Buffer to obtainBuffer(),
522     * in case the requested amount of frames is in two or more non-contiguous regions.
523     * FIXME requested and elapsed are both relative times.  Consider changing to absolute time.
524     */
525            status_t    obtainBuffer(Buffer* audioBuffer, const struct timespec *requested,
526                                     struct timespec *elapsed = NULL, size_t *nonContig = NULL);
527public:
528
529//EL_FIXME to be reconciled with new obtainBuffer() return codes and control block proxy
530//            enum {
531//            NO_MORE_BUFFERS = 0x80000001,   // same name in AudioFlinger.h, ok to be different value
532//            TEAR_DOWN       = 0x80000002,
533//            STOPPED = 1,
534//            STREAM_END_WAIT,
535//            STREAM_END
536//        };
537
538    /* Release a filled buffer of "audioBuffer->frameCount" frames for AudioFlinger to process. */
539    // FIXME make private when obtainBuffer() for TRANSFER_OBTAIN is removed
540            void        releaseBuffer(Buffer* audioBuffer);
541
542    /* As a convenience we provide a write() interface to the audio buffer.
543     * Input parameter 'size' is in byte units.
544     * This is implemented on top of obtainBuffer/releaseBuffer. For best
545     * performance use callbacks. Returns actual number of bytes written >= 0,
546     * or one of the following negative status codes:
547     *      INVALID_OPERATION   AudioTrack is configured for shared buffer mode
548     *      BAD_VALUE           size is invalid
549     *      WOULD_BLOCK         when obtainBuffer() returns same, or
550     *                          AudioTrack was stopped during the write
551     *      or any other error code returned by IAudioTrack::start() or restoreTrack_l().
552     * Not supported for static buffer mode.
553     */
554            ssize_t     write(const void* buffer, size_t size);
555
556    /*
557     * Dumps the state of an audio track.
558     */
559            status_t    dump(int fd, const Vector<String16>& args) const;
560
561    /*
562     * Return the total number of frames which AudioFlinger desired but were unavailable,
563     * and thus which resulted in an underrun.  Reset to zero by stop().
564     */
565            uint32_t    getUnderrunFrames() const;
566
567    /* Get the flags */
568            audio_output_flags_t getFlags() const { return mFlags; }
569
570    /* Set parameters - only possible when using direct output */
571            status_t    setParameters(const String8& keyValuePairs);
572
573    /* Get parameters */
574            String8     getParameters(const String8& keys);
575
576protected:
577    /* copying audio tracks is not allowed */
578                        AudioTrack(const AudioTrack& other);
579            AudioTrack& operator = (const AudioTrack& other);
580
581    /* a small internal class to handle the callback */
582    class AudioTrackThread : public Thread
583    {
584    public:
585        AudioTrackThread(AudioTrack& receiver, bool bCanCallJava = false);
586
587        // Do not call Thread::requestExitAndWait() without first calling requestExit().
588        // Thread::requestExitAndWait() is not virtual, and the implementation doesn't do enough.
589        virtual void        requestExit();
590
591                void        pause();    // suspend thread from execution at next loop boundary
592                void        resume();   // allow thread to execute, if not requested to exit
593                void        pauseConditional();
594                                        // like pause(), but only if prior resume() wasn't latched
595
596    private:
597        friend class AudioTrack;
598        virtual bool        threadLoop();
599        AudioTrack&         mReceiver;
600        virtual ~AudioTrackThread();
601        Mutex               mMyLock;    // Thread::mLock is private
602        Condition           mMyCond;    // Thread::mThreadExitedCondition is private
603        bool                mPaused;    // whether thread is currently paused
604        bool                mResumeLatch;   // whether next pauseConditional() will be a nop
605    };
606
607            // body of AudioTrackThread::threadLoop()
608            // returns the maximum amount of time before we would like to run again, where:
609            //      0           immediately
610            //      > 0         no later than this many nanoseconds from now
611            //      NS_WHENEVER still active but no particular deadline
612            //      NS_INACTIVE inactive so don't run again until re-started
613            //      NS_NEVER    never again
614            static const nsecs_t NS_WHENEVER = -1, NS_INACTIVE = -2, NS_NEVER = -3;
615            nsecs_t processAudioBuffer(const sp<AudioTrackThread>& thread);
616            status_t processStreamEnd(int32_t waitCount);
617
618
619            // caller must hold lock on mLock for all _l methods
620
621            status_t createTrack_l(audio_stream_type_t streamType,
622                                 uint32_t sampleRate,
623                                 audio_format_t format,
624                                 size_t frameCount,
625                                 audio_output_flags_t flags,
626                                 const sp<IMemory>& sharedBuffer,
627                                 audio_io_handle_t output,
628                                 size_t epoch);
629
630            // can only be called when mState != STATE_ACTIVE
631            void flush_l();
632
633            void setLoop_l(uint32_t loopStart, uint32_t loopEnd, int loopCount);
634            audio_io_handle_t getOutput_l();
635
636            status_t getPosition_l(uint32_t *position);
637
638            // FIXME enum is faster than strcmp() for parameter 'from'
639            status_t restoreTrack_l(const char *from);
640
641    // may be changed if IAudioTrack is re-created
642    sp<IAudioTrack>         mAudioTrack;
643    sp<IMemory>             mCblkMemory;
644    audio_track_cblk_t*     mCblk;                  // re-load after mLock.unlock()
645
646    sp<AudioTrackThread>    mAudioTrackThread;
647    float                   mVolume[2];
648    float                   mSendLevel;
649    uint32_t                mSampleRate;
650    size_t                  mFrameCount;            // corresponds to current IAudioTrack
651    size_t                  mReqFrameCount;         // frame count to request the next time a new
652                                                    // IAudioTrack is needed
653
654
655    // constant after constructor or set()
656    audio_format_t          mFormat;                // as requested by client, not forced to 16-bit
657    audio_stream_type_t     mStreamType;
658    uint32_t                mChannelCount;
659    audio_channel_mask_t    mChannelMask;
660    transfer_type           mTransfer;
661
662    // mFrameSize is equal to mFrameSizeAF for non-PCM or 16-bit PCM data.  For 8-bit PCM data, it's
663    // twice as large as mFrameSize because data is expanded to 16-bit before it's stored in buffer.
664    size_t                  mFrameSize;             // app-level frame size
665    size_t                  mFrameSizeAF;           // AudioFlinger frame size
666
667    status_t                mStatus;
668
669    // can change dynamically when IAudioTrack invalidated
670    uint32_t                mLatency;               // in ms
671
672    // Indicates the current track state.  Protected by mLock.
673    enum State {
674        STATE_ACTIVE,
675        STATE_STOPPED,
676        STATE_PAUSED,
677        STATE_FLUSHED,
678    }                       mState;
679
680    callback_t              mCbf;                   // callback handler for events, or NULL
681    void*                   mUserData;              // for client callback handler
682
683    // for notification APIs
684    uint32_t                mNotificationFramesReq; // requested number of frames between each
685                                                    // notification callback,
686                                                    // at initial source sample rate
687    uint32_t                mNotificationFramesAct; // actual number of frames between each
688                                                    // notification callback,
689                                                    // at initial source sample rate
690    bool                    mRefreshRemaining;      // processAudioBuffer() should refresh next 2
691
692    // These are private to processAudioBuffer(), and are not protected by a lock
693    uint32_t                mRemainingFrames;       // number of frames to request in obtainBuffer()
694    bool                    mRetryOnPartialBuffer;  // sleep and retry after partial obtainBuffer()
695    int                     mObservedSequence;      // last observed value of mSequence
696
697    sp<IMemory>             mSharedBuffer;
698    uint32_t                mLoopPeriod;            // in frames, zero means looping is disabled
699    uint32_t                mMarkerPosition;        // in wrapping (overflow) frame units
700    bool                    mMarkerReached;
701    uint32_t                mNewPosition;           // in frames
702    uint32_t                mUpdatePeriod;          // in frames, zero means no EVENT_NEW_POS
703
704    audio_output_flags_t    mFlags;
705    int                     mSessionId;
706    int                     mAuxEffectId;
707
708    mutable Mutex           mLock;
709
710    bool                    mIsTimed;
711    int                     mPreviousPriority;          // before start()
712    SchedPolicy             mPreviousSchedulingGroup;
713    bool                    mAwaitBoost;    // thread should wait for priority boost before running
714
715    // The proxy should only be referenced while a lock is held because the proxy isn't
716    // multi-thread safe, especially the SingleStateQueue part of the proxy.
717    // An exception is that a blocking ClientProxy::obtainBuffer() may be called without a lock,
718    // provided that the caller also holds an extra reference to the proxy and shared memory to keep
719    // them around in case they are replaced during the obtainBuffer().
720    sp<StaticAudioTrackClientProxy> mStaticProxy;   // for type safety only
721    sp<AudioTrackClientProxy>       mProxy;         // primary owner of the memory
722
723    bool                    mInUnderrun;            // whether track is currently in underrun state
724
725private:
726    class DeathNotifier : public IBinder::DeathRecipient {
727    public:
728        DeathNotifier(AudioTrack* audioTrack) : mAudioTrack(audioTrack) { }
729    protected:
730        virtual void        binderDied(const wp<IBinder>& who);
731    private:
732        const wp<AudioTrack> mAudioTrack;
733    };
734
735    sp<DeathNotifier>       mDeathNotifier;
736    uint32_t                mSequence;              // incremented for each new IAudioTrack attempt
737};
738
739class TimedAudioTrack : public AudioTrack
740{
741public:
742    TimedAudioTrack();
743
744    /* allocate a shared memory buffer that can be passed to queueTimedBuffer */
745    status_t allocateTimedBuffer(size_t size, sp<IMemory>* buffer);
746
747    /* queue a buffer obtained via allocateTimedBuffer for playback at the
748       given timestamp.  PTS units are microseconds on the media time timeline.
749       The media time transform (set with setMediaTimeTransform) set by the
750       audio producer will handle converting from media time to local time
751       (perhaps going through the common time timeline in the case of
752       synchronized multiroom audio case) */
753    status_t queueTimedBuffer(const sp<IMemory>& buffer, int64_t pts);
754
755    /* define a transform between media time and either common time or
756       local time */
757    enum TargetTimeline {LOCAL_TIME, COMMON_TIME};
758    status_t setMediaTimeTransform(const LinearTransform& xform,
759                                   TargetTimeline target);
760};
761
762}; // namespace android
763
764#endif // ANDROID_AUDIOTRACK_H
765