AudioTrack.h revision 396fabdb6efcdac5aea3d9f559d1beedf6a4cedc
1/*
2 * Copyright (C) 2007 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#ifndef ANDROID_AUDIOTRACK_H
18#define ANDROID_AUDIOTRACK_H
19
20#include <cutils/sched_policy.h>
21#include <media/AudioSystem.h>
22#include <media/AudioTimestamp.h>
23#include <media/IAudioTrack.h>
24#include <utils/threads.h>
25
26namespace android {
27
28// ----------------------------------------------------------------------------
29
30class audio_track_cblk_t;
31class AudioTrackClientProxy;
32class StaticAudioTrackClientProxy;
33
34// ----------------------------------------------------------------------------
35
36class AudioTrack : public RefBase
37{
38public:
39    enum channel_index {
40        MONO   = 0,
41        LEFT   = 0,
42        RIGHT  = 1
43    };
44
45    /* Events used by AudioTrack callback function (callback_t).
46     * Keep in sync with frameworks/base/media/java/android/media/AudioTrack.java NATIVE_EVENT_*.
47     */
48    enum event_type {
49        EVENT_MORE_DATA = 0,        // Request to write more data to buffer.
50                                    // If this event is delivered but the callback handler
51                                    // does not want to write more data, the handler must explicitly
52                                    // ignore the event by setting frameCount to zero.
53        EVENT_UNDERRUN = 1,         // Buffer underrun occurred.
54        EVENT_LOOP_END = 2,         // Sample loop end was reached; playback restarted from
55                                    // loop start if loop count was not 0.
56        EVENT_MARKER = 3,           // Playback head is at the specified marker position
57                                    // (See setMarkerPosition()).
58        EVENT_NEW_POS = 4,          // Playback head is at a new position
59                                    // (See setPositionUpdatePeriod()).
60        EVENT_BUFFER_END = 5,       // Playback head is at the end of the buffer.
61                                    // Not currently used by android.media.AudioTrack.
62        EVENT_NEW_IAUDIOTRACK = 6,  // IAudioTrack was re-created, either due to re-routing and
63                                    // voluntary invalidation by mediaserver, or mediaserver crash.
64        EVENT_STREAM_END = 7,       // Sent after all the buffers queued in AF and HW are played
65                                    // back (after stop is called)
66        EVENT_NEW_TIMESTAMP = 8,    // Delivered periodically and when there's a significant change
67                                    // in the mapping from frame position to presentation time.
68                                    // See AudioTimestamp for the information included with event.
69    };
70
71    /* Client should declare Buffer on the stack and pass address to obtainBuffer()
72     * and releaseBuffer().  See also callback_t for EVENT_MORE_DATA.
73     */
74
75    class Buffer
76    {
77    public:
78        // FIXME use m prefix
79        size_t      frameCount;   // number of sample frames corresponding to size;
80                                  // on input it is the number of frames desired,
81                                  // on output is the number of frames actually filled
82                                  // (currently ignored, but will make the primary field in future)
83
84        size_t      size;         // input/output in bytes == frameCount * frameSize
85                                  // on output is the number of bytes actually filled
86                                  // FIXME this is redundant with respect to frameCount,
87                                  // and TRANSFER_OBTAIN mode is broken for 8-bit data
88                                  // since we don't define the frame format
89
90        union {
91            void*       raw;
92            short*      i16;      // signed 16-bit
93            int8_t*     i8;       // unsigned 8-bit, offset by 0x80
94        };
95    };
96
97    /* As a convenience, if a callback is supplied, a handler thread
98     * is automatically created with the appropriate priority. This thread
99     * invokes the callback when a new buffer becomes available or various conditions occur.
100     * Parameters:
101     *
102     * event:   type of event notified (see enum AudioTrack::event_type).
103     * user:    Pointer to context for use by the callback receiver.
104     * info:    Pointer to optional parameter according to event type:
105     *          - EVENT_MORE_DATA: pointer to AudioTrack::Buffer struct. The callback must not write
106     *            more bytes than indicated by 'size' field and update 'size' if fewer bytes are
107     *            written.
108     *          - EVENT_UNDERRUN: unused.
109     *          - EVENT_LOOP_END: pointer to an int indicating the number of loops remaining.
110     *          - EVENT_MARKER: pointer to const uint32_t containing the marker position in frames.
111     *          - EVENT_NEW_POS: pointer to const uint32_t containing the new position in frames.
112     *          - EVENT_BUFFER_END: unused.
113     *          - EVENT_NEW_IAUDIOTRACK: unused.
114     *          - EVENT_STREAM_END: unused.
115     *          - EVENT_NEW_TIMESTAMP: pointer to const AudioTimestamp.
116     */
117
118    typedef void (*callback_t)(int event, void* user, void *info);
119
120    /* Returns the minimum frame count required for the successful creation of
121     * an AudioTrack object.
122     * Returned status (from utils/Errors.h) can be:
123     *  - NO_ERROR: successful operation
124     *  - NO_INIT: audio server or audio hardware not initialized
125     *  - BAD_VALUE: unsupported configuration
126     * frameCount is guaranteed to be non-zero if status is NO_ERROR,
127     * and is undefined otherwise.
128     */
129
130    static status_t getMinFrameCount(size_t* frameCount,
131                                     audio_stream_type_t streamType,
132                                     uint32_t sampleRate);
133
134    /* How data is transferred to AudioTrack
135     */
136    enum transfer_type {
137        TRANSFER_DEFAULT,   // not specified explicitly; determine from the other parameters
138        TRANSFER_CALLBACK,  // callback EVENT_MORE_DATA
139        TRANSFER_OBTAIN,    // FIXME deprecated: call obtainBuffer() and releaseBuffer()
140        TRANSFER_SYNC,      // synchronous write()
141        TRANSFER_SHARED,    // shared memory
142    };
143
144    /* Constructs an uninitialized AudioTrack. No connection with
145     * AudioFlinger takes place.  Use set() after this.
146     */
147                        AudioTrack();
148
149    /* Creates an AudioTrack object and registers it with AudioFlinger.
150     * Once created, the track needs to be started before it can be used.
151     * Unspecified values are set to appropriate default values.
152     * With this constructor, the track is configured for streaming mode.
153     * Data to be rendered is supplied by write() or by the callback EVENT_MORE_DATA.
154     * Intermixing a combination of write() and non-ignored EVENT_MORE_DATA is not allowed.
155     *
156     * Parameters:
157     *
158     * streamType:         Select the type of audio stream this track is attached to
159     *                     (e.g. AUDIO_STREAM_MUSIC).
160     * sampleRate:         Data source sampling rate in Hz.
161     * format:             Audio format (e.g AUDIO_FORMAT_PCM_16_BIT for signed
162     *                     16 bits per sample).
163     * channelMask:        Channel mask.
164     * frameCount:         Minimum size of track PCM buffer in frames. This defines the
165     *                     application's contribution to the
166     *                     latency of the track. The actual size selected by the AudioTrack could be
167     *                     larger if the requested size is not compatible with current audio HAL
168     *                     configuration.  Zero means to use a default value.
169     * flags:              See comments on audio_output_flags_t in <system/audio.h>.
170     * cbf:                Callback function. If not null, this function is called periodically
171     *                     to provide new data and inform of marker, position updates, etc.
172     * user:               Context for use by the callback receiver.
173     * notificationFrames: The callback function is called each time notificationFrames PCM
174     *                     frames have been consumed from track input buffer.
175     *                     This is expressed in units of frames at the initial source sample rate.
176     * sessionId:          Specific session ID, or zero to use default.
177     * transferType:       How data is transferred to AudioTrack.
178     * threadCanCallJava:  Not present in parameter list, and so is fixed at false.
179     */
180
181                        AudioTrack( audio_stream_type_t streamType,
182                                    uint32_t sampleRate,
183                                    audio_format_t format,
184                                    audio_channel_mask_t,
185                                    int frameCount       = 0,
186                                    audio_output_flags_t flags = AUDIO_OUTPUT_FLAG_NONE,
187                                    callback_t cbf       = NULL,
188                                    void* user           = NULL,
189                                    int notificationFrames = 0,
190                                    int sessionId        = 0,
191                                    transfer_type transferType = TRANSFER_DEFAULT,
192                                    const audio_offload_info_t *offloadInfo = NULL,
193                                    int uid = -1);
194
195    /* Creates an audio track and registers it with AudioFlinger.
196     * With this constructor, the track is configured for static buffer mode.
197     * The format must not be 8-bit linear PCM.
198     * Data to be rendered is passed in a shared memory buffer
199     * identified by the argument sharedBuffer, which must be non-0.
200     * The memory should be initialized to the desired data before calling start().
201     * The write() method is not supported in this case.
202     * It is recommended to pass a callback function to be notified of playback end by an
203     * EVENT_UNDERRUN event.
204     */
205
206                        AudioTrack( audio_stream_type_t streamType,
207                                    uint32_t sampleRate,
208                                    audio_format_t format,
209                                    audio_channel_mask_t channelMask,
210                                    const sp<IMemory>& sharedBuffer,
211                                    audio_output_flags_t flags = AUDIO_OUTPUT_FLAG_NONE,
212                                    callback_t cbf      = NULL,
213                                    void* user          = NULL,
214                                    int notificationFrames = 0,
215                                    int sessionId       = 0,
216                                    transfer_type transferType = TRANSFER_DEFAULT,
217                                    const audio_offload_info_t *offloadInfo = NULL,
218                                    int uid = -1);
219
220    /* Terminates the AudioTrack and unregisters it from AudioFlinger.
221     * Also destroys all resources associated with the AudioTrack.
222     */
223protected:
224                        virtual ~AudioTrack();
225public:
226
227    /* Initialize an AudioTrack that was created using the AudioTrack() constructor.
228     * Don't call set() more than once, or after the AudioTrack() constructors that take parameters.
229     * Returned status (from utils/Errors.h) can be:
230     *  - NO_ERROR: successful initialization
231     *  - INVALID_OPERATION: AudioTrack is already initialized
232     *  - BAD_VALUE: invalid parameter (channelMask, format, sampleRate...)
233     *  - NO_INIT: audio server or audio hardware not initialized
234     * If status is not equal to NO_ERROR, don't call any other APIs on this AudioTrack.
235     * If sharedBuffer is non-0, the frameCount parameter is ignored and
236     * replaced by the shared buffer's total allocated size in frame units.
237     *
238     * Parameters not listed in the AudioTrack constructors above:
239     *
240     * threadCanCallJava:  Whether callbacks are made from an attached thread and thus can call JNI.
241     */
242            status_t    set(audio_stream_type_t streamType,
243                            uint32_t sampleRate,
244                            audio_format_t format,
245                            audio_channel_mask_t channelMask,
246                            int frameCount      = 0,
247                            audio_output_flags_t flags = AUDIO_OUTPUT_FLAG_NONE,
248                            callback_t cbf      = NULL,
249                            void* user          = NULL,
250                            int notificationFrames = 0,
251                            const sp<IMemory>& sharedBuffer = 0,
252                            bool threadCanCallJava = false,
253                            int sessionId       = 0,
254                            transfer_type transferType = TRANSFER_DEFAULT,
255                            const audio_offload_info_t *offloadInfo = NULL,
256                            int uid = -1);
257
258    /* Result of constructing the AudioTrack. This must be checked for successful initialization
259     * before using any AudioTrack API (except for set()), because using
260     * an uninitialized AudioTrack produces undefined results.
261     * See set() method above for possible return codes.
262     */
263            status_t    initCheck() const   { return mStatus; }
264
265    /* Returns this track's estimated latency in milliseconds.
266     * This includes the latency due to AudioTrack buffer size, AudioMixer (if any)
267     * and audio hardware driver.
268     */
269            uint32_t    latency() const     { return mLatency; }
270
271    /* getters, see constructors and set() */
272
273            audio_stream_type_t streamType() const { return mStreamType; }
274            audio_format_t format() const   { return mFormat; }
275
276    /* Return frame size in bytes, which for linear PCM is
277     * channelCount * (bit depth per channel / 8).
278     * channelCount is determined from channelMask, and bit depth comes from format.
279     * For non-linear formats, the frame size is typically 1 byte.
280     */
281            size_t      frameSize() const   { return mFrameSize; }
282
283            uint32_t    channelCount() const { return mChannelCount; }
284            uint32_t    frameCount() const  { return mFrameCount; }
285
286    /* Return the static buffer specified in constructor or set(), or 0 for streaming mode */
287            sp<IMemory> sharedBuffer() const { return mSharedBuffer; }
288
289    /* After it's created the track is not active. Call start() to
290     * make it active. If set, the callback will start being called.
291     * If the track was previously paused, volume is ramped up over the first mix buffer.
292     */
293            status_t        start();
294
295    /* Stop a track.
296     * In static buffer mode, the track is stopped immediately.
297     * In streaming mode, the callback will cease being called.  Note that obtainBuffer() still
298     * works and will fill up buffers until the pool is exhausted, and then will return WOULD_BLOCK.
299     * In streaming mode the stop does not occur immediately: any data remaining in the buffer
300     * is first drained, mixed, and output, and only then is the track marked as stopped.
301     */
302            void        stop();
303            bool        stopped() const;
304
305    /* Flush a stopped or paused track. All previously buffered data is discarded immediately.
306     * This has the effect of draining the buffers without mixing or output.
307     * Flush is intended for streaming mode, for example before switching to non-contiguous content.
308     * This function is a no-op if the track is not stopped or paused, or uses a static buffer.
309     */
310            void        flush();
311
312    /* Pause a track. After pause, the callback will cease being called and
313     * obtainBuffer returns WOULD_BLOCK. Note that obtainBuffer() still works
314     * and will fill up buffers until the pool is exhausted.
315     * Volume is ramped down over the next mix buffer following the pause request,
316     * and then the track is marked as paused.  It can be resumed with ramp up by start().
317     */
318            void        pause();
319
320    /* Set volume for this track, mostly used for games' sound effects
321     * left and right volumes. Levels must be >= 0.0 and <= 1.0.
322     * This is the older API.  New applications should use setVolume(float) when possible.
323     */
324            status_t    setVolume(float left, float right);
325
326    /* Set volume for all channels.  This is the preferred API for new applications,
327     * especially for multi-channel content.
328     */
329            status_t    setVolume(float volume);
330
331    /* Set the send level for this track. An auxiliary effect should be attached
332     * to the track with attachEffect(). Level must be >= 0.0 and <= 1.0.
333     */
334            status_t    setAuxEffectSendLevel(float level);
335            void        getAuxEffectSendLevel(float* level) const;
336
337    /* Set source sample rate for this track in Hz, mostly used for games' sound effects
338     */
339            status_t    setSampleRate(uint32_t sampleRate);
340
341    /* Return current source sample rate in Hz, or 0 if unknown */
342            uint32_t    getSampleRate() const;
343
344    /* Enables looping and sets the start and end points of looping.
345     * Only supported for static buffer mode.
346     *
347     * Parameters:
348     *
349     * loopStart:   loop start in frames relative to start of buffer.
350     * loopEnd:     loop end in frames relative to start of buffer.
351     * loopCount:   number of loops to execute. Calling setLoop() with loopCount == 0 cancels any
352     *              pending or active loop. loopCount == -1 means infinite looping.
353     *
354     * For proper operation the following condition must be respected:
355     *      loopCount != 0 implies 0 <= loopStart < loopEnd <= frameCount().
356     *
357     * If the loop period (loopEnd - loopStart) is too small for the implementation to support,
358     * setLoop() will return BAD_VALUE.  loopCount must be >= -1.
359     *
360     */
361            status_t    setLoop(uint32_t loopStart, uint32_t loopEnd, int loopCount);
362
363    /* Sets marker position. When playback reaches the number of frames specified, a callback with
364     * event type EVENT_MARKER is called. Calling setMarkerPosition with marker == 0 cancels marker
365     * notification callback.  To set a marker at a position which would compute as 0,
366     * a workaround is to the set the marker at a nearby position such as ~0 or 1.
367     * If the AudioTrack has been opened with no callback function associated, the operation will
368     * fail.
369     *
370     * Parameters:
371     *
372     * marker:   marker position expressed in wrapping (overflow) frame units,
373     *           like the return value of getPosition().
374     *
375     * Returned status (from utils/Errors.h) can be:
376     *  - NO_ERROR: successful operation
377     *  - INVALID_OPERATION: the AudioTrack has no callback installed.
378     */
379            status_t    setMarkerPosition(uint32_t marker);
380            status_t    getMarkerPosition(uint32_t *marker) const;
381
382    /* Sets position update period. Every time the number of frames specified has been played,
383     * a callback with event type EVENT_NEW_POS is called.
384     * Calling setPositionUpdatePeriod with updatePeriod == 0 cancels new position notification
385     * callback.
386     * If the AudioTrack has been opened with no callback function associated, the operation will
387     * fail.
388     * Extremely small values may be rounded up to a value the implementation can support.
389     *
390     * Parameters:
391     *
392     * updatePeriod:  position update notification period expressed in frames.
393     *
394     * Returned status (from utils/Errors.h) can be:
395     *  - NO_ERROR: successful operation
396     *  - INVALID_OPERATION: the AudioTrack has no callback installed.
397     */
398            status_t    setPositionUpdatePeriod(uint32_t updatePeriod);
399            status_t    getPositionUpdatePeriod(uint32_t *updatePeriod) const;
400
401    /* Sets playback head position.
402     * Only supported for static buffer mode.
403     *
404     * Parameters:
405     *
406     * position:  New playback head position in frames relative to start of buffer.
407     *            0 <= position <= frameCount().  Note that end of buffer is permitted,
408     *            but will result in an immediate underrun if started.
409     *
410     * Returned status (from utils/Errors.h) can be:
411     *  - NO_ERROR: successful operation
412     *  - INVALID_OPERATION: the AudioTrack is not stopped or paused, or is streaming mode.
413     *  - BAD_VALUE: The specified position is beyond the number of frames present in AudioTrack
414     *               buffer
415     */
416            status_t    setPosition(uint32_t position);
417
418    /* Return the total number of frames played since playback start.
419     * The counter will wrap (overflow) periodically, e.g. every ~27 hours at 44.1 kHz.
420     * It is reset to zero by flush(), reload(), and stop().
421     *
422     * Parameters:
423     *
424     *  position:  Address where to return play head position.
425     *
426     * Returned status (from utils/Errors.h) can be:
427     *  - NO_ERROR: successful operation
428     *  - BAD_VALUE:  position is NULL
429     */
430            status_t    getPosition(uint32_t *position) const;
431
432    /* For static buffer mode only, this returns the current playback position in frames
433     * relative to start of buffer.  It is analogous to the position units used by
434     * setLoop() and setPosition().  After underrun, the position will be at end of buffer.
435     */
436            status_t    getBufferPosition(uint32_t *position);
437
438    /* Forces AudioTrack buffer full condition. When playing a static buffer, this method avoids
439     * rewriting the buffer before restarting playback after a stop.
440     * This method must be called with the AudioTrack in paused or stopped state.
441     * Not allowed in streaming mode.
442     *
443     * Returned status (from utils/Errors.h) can be:
444     *  - NO_ERROR: successful operation
445     *  - INVALID_OPERATION: the AudioTrack is not stopped or paused, or is streaming mode.
446     */
447            status_t    reload();
448
449    /* Returns a handle on the audio output used by this AudioTrack.
450     *
451     * Parameters:
452     *  none.
453     *
454     * Returned value:
455     *  handle on audio hardware output
456     */
457            audio_io_handle_t    getOutput();
458
459    /* Returns the unique session ID associated with this track.
460     *
461     * Parameters:
462     *  none.
463     *
464     * Returned value:
465     *  AudioTrack session ID.
466     */
467            int    getSessionId() const { return mSessionId; }
468
469    /* Attach track auxiliary output to specified effect. Use effectId = 0
470     * to detach track from effect.
471     *
472     * Parameters:
473     *
474     * effectId:  effectId obtained from AudioEffect::id().
475     *
476     * Returned status (from utils/Errors.h) can be:
477     *  - NO_ERROR: successful operation
478     *  - INVALID_OPERATION: the effect is not an auxiliary effect.
479     *  - BAD_VALUE: The specified effect ID is invalid
480     */
481            status_t    attachAuxEffect(int effectId);
482
483    /* Obtains a buffer of up to "audioBuffer->frameCount" empty slots for frames.
484     * After filling these slots with data, the caller should release them with releaseBuffer().
485     * If the track buffer is not full, obtainBuffer() returns as many contiguous
486     * [empty slots for] frames as are available immediately.
487     * If the track buffer is full and track is stopped, obtainBuffer() returns WOULD_BLOCK
488     * regardless of the value of waitCount.
489     * If the track buffer is full and track is not stopped, obtainBuffer() blocks with a
490     * maximum timeout based on waitCount; see chart below.
491     * Buffers will be returned until the pool
492     * is exhausted, at which point obtainBuffer() will either block
493     * or return WOULD_BLOCK depending on the value of the "waitCount"
494     * parameter.
495     * Each sample is 16-bit signed PCM.
496     *
497     * obtainBuffer() and releaseBuffer() are deprecated for direct use by applications,
498     * which should use write() or callback EVENT_MORE_DATA instead.
499     *
500     * Interpretation of waitCount:
501     *  +n  limits wait time to n * WAIT_PERIOD_MS,
502     *  -1  causes an (almost) infinite wait time,
503     *   0  non-blocking.
504     *
505     * Buffer fields
506     * On entry:
507     *  frameCount  number of frames requested
508     * After error return:
509     *  frameCount  0
510     *  size        0
511     *  raw         undefined
512     * After successful return:
513     *  frameCount  actual number of frames available, <= number requested
514     *  size        actual number of bytes available
515     *  raw         pointer to the buffer
516     */
517
518    /* FIXME Deprecated public API for TRANSFER_OBTAIN mode */
519            status_t    obtainBuffer(Buffer* audioBuffer, int32_t waitCount)
520                                __attribute__((__deprecated__));
521
522private:
523    /* If nonContig is non-NULL, it is an output parameter that will be set to the number of
524     * additional non-contiguous frames that are available immediately.
525     * FIXME We could pass an array of Buffers instead of only one Buffer to obtainBuffer(),
526     * in case the requested amount of frames is in two or more non-contiguous regions.
527     * FIXME requested and elapsed are both relative times.  Consider changing to absolute time.
528     */
529            status_t    obtainBuffer(Buffer* audioBuffer, const struct timespec *requested,
530                                     struct timespec *elapsed = NULL, size_t *nonContig = NULL);
531public:
532
533//EL_FIXME to be reconciled with new obtainBuffer() return codes and control block proxy
534//            enum {
535//            NO_MORE_BUFFERS = 0x80000001,   // same name in AudioFlinger.h, ok to be different value
536//            TEAR_DOWN       = 0x80000002,
537//            STOPPED = 1,
538//            STREAM_END_WAIT,
539//            STREAM_END
540//        };
541
542    /* Release a filled buffer of "audioBuffer->frameCount" frames for AudioFlinger to process. */
543    // FIXME make private when obtainBuffer() for TRANSFER_OBTAIN is removed
544            void        releaseBuffer(Buffer* audioBuffer);
545
546    /* As a convenience we provide a write() interface to the audio buffer.
547     * Input parameter 'size' is in byte units.
548     * This is implemented on top of obtainBuffer/releaseBuffer. For best
549     * performance use callbacks. Returns actual number of bytes written >= 0,
550     * or one of the following negative status codes:
551     *      INVALID_OPERATION   AudioTrack is configured for static buffer or streaming mode
552     *      BAD_VALUE           size is invalid
553     *      WOULD_BLOCK         when obtainBuffer() returns same, or
554     *                          AudioTrack was stopped during the write
555     *      or any other error code returned by IAudioTrack::start() or restoreTrack_l().
556     */
557            ssize_t     write(const void* buffer, size_t size);
558
559    /*
560     * Dumps the state of an audio track.
561     */
562            status_t    dump(int fd, const Vector<String16>& args) const;
563
564    /*
565     * Return the total number of frames which AudioFlinger desired but were unavailable,
566     * and thus which resulted in an underrun.  Reset to zero by stop().
567     */
568            uint32_t    getUnderrunFrames() const;
569
570    /* Get the flags */
571            audio_output_flags_t getFlags() const { return mFlags; }
572
573    /* Set parameters - only possible when using direct output */
574            status_t    setParameters(const String8& keyValuePairs);
575
576    /* Get parameters */
577            String8     getParameters(const String8& keys);
578
579    /* Poll for a timestamp on demand.
580     * Use if EVENT_NEW_TIMESTAMP is not delivered often enough for your needs,
581     * or if you need to get the most recent timestamp outside of the event callback handler.
582     * Caution: calling this method too often may be inefficient;
583     * if you need a high resolution mapping between frame position and presentation time,
584     * consider implementing that at application level, based on the low resolution timestamps.
585     * Returns NO_ERROR if timestamp is valid.
586     */
587            status_t    getTimestamp(AudioTimestamp& timestamp);
588
589protected:
590    /* copying audio tracks is not allowed */
591                        AudioTrack(const AudioTrack& other);
592            AudioTrack& operator = (const AudioTrack& other);
593
594    /* a small internal class to handle the callback */
595    class AudioTrackThread : public Thread
596    {
597    public:
598        AudioTrackThread(AudioTrack& receiver, bool bCanCallJava = false);
599
600        // Do not call Thread::requestExitAndWait() without first calling requestExit().
601        // Thread::requestExitAndWait() is not virtual, and the implementation doesn't do enough.
602        virtual void        requestExit();
603
604                void        pause();    // suspend thread from execution at next loop boundary
605                void        resume();   // allow thread to execute, if not requested to exit
606
607    private:
608                void        pauseInternal(nsecs_t ns = 0LL);
609                                        // like pause(), but only used internally within thread
610
611        friend class AudioTrack;
612        virtual bool        threadLoop();
613        AudioTrack&         mReceiver;
614        virtual ~AudioTrackThread();
615        Mutex               mMyLock;    // Thread::mLock is private
616        Condition           mMyCond;    // Thread::mThreadExitedCondition is private
617        bool                mPaused;    // whether thread is requested to pause at next loop entry
618        bool                mPausedInt; // whether thread internally requests pause
619        nsecs_t             mPausedNs;  // if mPausedInt then associated timeout, otherwise ignored
620        bool                mIgnoreNextPausedInt;   // whether to ignore next mPausedInt request
621    };
622
623            // body of AudioTrackThread::threadLoop()
624            // returns the maximum amount of time before we would like to run again, where:
625            //      0           immediately
626            //      > 0         no later than this many nanoseconds from now
627            //      NS_WHENEVER still active but no particular deadline
628            //      NS_INACTIVE inactive so don't run again until re-started
629            //      NS_NEVER    never again
630            static const nsecs_t NS_WHENEVER = -1, NS_INACTIVE = -2, NS_NEVER = -3;
631            nsecs_t processAudioBuffer();
632            status_t processStreamEnd(int32_t waitCount);
633
634
635            // caller must hold lock on mLock for all _l methods
636
637            status_t createTrack_l(audio_stream_type_t streamType,
638                                 uint32_t sampleRate,
639                                 audio_format_t format,
640                                 size_t frameCount,
641                                 audio_output_flags_t flags,
642                                 const sp<IMemory>& sharedBuffer,
643                                 audio_io_handle_t output,
644                                 size_t epoch);
645
646            // can only be called when mState != STATE_ACTIVE
647            void flush_l();
648
649            void setLoop_l(uint32_t loopStart, uint32_t loopEnd, int loopCount);
650            audio_io_handle_t getOutput_l();
651
652            // FIXME enum is faster than strcmp() for parameter 'from'
653            status_t restoreTrack_l(const char *from);
654
655            bool     isOffloaded() const
656                { return (mFlags & AUDIO_OUTPUT_FLAG_COMPRESS_OFFLOAD) != 0; }
657
658    // Next 3 fields may be changed if IAudioTrack is re-created, but always != 0
659    sp<IAudioTrack>         mAudioTrack;
660    sp<IMemory>             mCblkMemory;
661    audio_track_cblk_t*     mCblk;                  // re-load after mLock.unlock()
662
663    sp<AudioTrackThread>    mAudioTrackThread;
664    float                   mVolume[2];
665    float                   mSendLevel;
666    mutable uint32_t        mSampleRate;            // mutable because getSampleRate() can update it.
667    size_t                  mFrameCount;            // corresponds to current IAudioTrack, value is
668                                                    // reported back by AudioFlinger to the client
669    size_t                  mReqFrameCount;         // frame count to request the first or next time
670                                                    // a new IAudioTrack is needed, non-decreasing
671
672    // constant after constructor or set()
673    audio_format_t          mFormat;                // as requested by client, not forced to 16-bit
674    audio_stream_type_t     mStreamType;
675    uint32_t                mChannelCount;
676    audio_channel_mask_t    mChannelMask;
677    transfer_type           mTransfer;
678
679    // mFrameSize is equal to mFrameSizeAF for non-PCM or 16-bit PCM data.  For 8-bit PCM data, it's
680    // twice as large as mFrameSize because data is expanded to 16-bit before it's stored in buffer.
681    size_t                  mFrameSize;             // app-level frame size
682    size_t                  mFrameSizeAF;           // AudioFlinger frame size
683
684    status_t                mStatus;
685
686    // can change dynamically when IAudioTrack invalidated
687    uint32_t                mLatency;               // in ms
688
689    // Indicates the current track state.  Protected by mLock.
690    enum State {
691        STATE_ACTIVE,
692        STATE_STOPPED,
693        STATE_PAUSED,
694        STATE_PAUSED_STOPPING,
695        STATE_FLUSHED,
696        STATE_STOPPING,
697    }                       mState;
698
699    // for client callback handler
700    callback_t              mCbf;                   // callback handler for events, or NULL
701    void*                   mUserData;
702
703    // for notification APIs
704    uint32_t                mNotificationFramesReq; // requested number of frames between each
705                                                    // notification callback,
706                                                    // at initial source sample rate
707    uint32_t                mNotificationFramesAct; // actual number of frames between each
708                                                    // notification callback,
709                                                    // at initial source sample rate
710    bool                    mRefreshRemaining;      // processAudioBuffer() should refresh
711                                                    // mRemainingFrames and mRetryOnPartialBuffer
712
713    // These are private to processAudioBuffer(), and are not protected by a lock
714    uint32_t                mRemainingFrames;       // number of frames to request in obtainBuffer()
715    bool                    mRetryOnPartialBuffer;  // sleep and retry after partial obtainBuffer()
716    uint32_t                mObservedSequence;      // last observed value of mSequence
717
718    sp<IMemory>             mSharedBuffer;
719    uint32_t                mLoopPeriod;            // in frames, zero means looping is disabled
720    uint32_t                mMarkerPosition;        // in wrapping (overflow) frame units
721    bool                    mMarkerReached;
722    uint32_t                mNewPosition;           // in frames
723    uint32_t                mUpdatePeriod;          // in frames, zero means no EVENT_NEW_POS
724
725    audio_output_flags_t    mFlags;
726    int                     mSessionId;
727    int                     mAuxEffectId;
728
729    mutable Mutex           mLock;
730
731    bool                    mIsTimed;
732    int                     mPreviousPriority;          // before start()
733    SchedPolicy             mPreviousSchedulingGroup;
734    bool                    mAwaitBoost;    // thread should wait for priority boost before running
735
736    // The proxy should only be referenced while a lock is held because the proxy isn't
737    // multi-thread safe, especially the SingleStateQueue part of the proxy.
738    // An exception is that a blocking ClientProxy::obtainBuffer() may be called without a lock,
739    // provided that the caller also holds an extra reference to the proxy and shared memory to keep
740    // them around in case they are replaced during the obtainBuffer().
741    sp<StaticAudioTrackClientProxy> mStaticProxy;   // for type safety only
742    sp<AudioTrackClientProxy>       mProxy;         // primary owner of the memory
743
744    bool                    mInUnderrun;            // whether track is currently in underrun state
745    String8                 mName;                  // server's name for this IAudioTrack
746
747private:
748    class DeathNotifier : public IBinder::DeathRecipient {
749    public:
750        DeathNotifier(AudioTrack* audioTrack) : mAudioTrack(audioTrack) { }
751    protected:
752        virtual void        binderDied(const wp<IBinder>& who);
753    private:
754        const wp<AudioTrack> mAudioTrack;
755    };
756
757    sp<DeathNotifier>       mDeathNotifier;
758    uint32_t                mSequence;              // incremented for each new IAudioTrack attempt
759    audio_io_handle_t       mOutput;                // cached output io handle
760    int                     mClientUid;
761};
762
763class TimedAudioTrack : public AudioTrack
764{
765public:
766    TimedAudioTrack();
767
768    /* allocate a shared memory buffer that can be passed to queueTimedBuffer */
769    status_t allocateTimedBuffer(size_t size, sp<IMemory>* buffer);
770
771    /* queue a buffer obtained via allocateTimedBuffer for playback at the
772       given timestamp.  PTS units are microseconds on the media time timeline.
773       The media time transform (set with setMediaTimeTransform) set by the
774       audio producer will handle converting from media time to local time
775       (perhaps going through the common time timeline in the case of
776       synchronized multiroom audio case) */
777    status_t queueTimedBuffer(const sp<IMemory>& buffer, int64_t pts);
778
779    /* define a transform between media time and either common time or
780       local time */
781    enum TargetTimeline {LOCAL_TIME, COMMON_TIME};
782    status_t setMediaTimeTransform(const LinearTransform& xform,
783                                   TargetTimeline target);
784};
785
786}; // namespace android
787
788#endif // ANDROID_AUDIOTRACK_H
789