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1 /*
2  * Copyright (C) 2008 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_AUDIORECORD_H
18 #define ANDROID_AUDIORECORD_H
19 
20 #include <cutils/sched_policy.h>
21 #include <media/AudioSystem.h>
22 #include <media/IAudioRecord.h>
23 #include <utils/threads.h>
24 
25 namespace android {
26 
27 // ----------------------------------------------------------------------------
28 
29 class audio_track_cblk_t;
30 class AudioRecordClientProxy;
31 
32 // ----------------------------------------------------------------------------
33 
34 class AudioRecord : public RefBase
35 {
36 public:
37 
38     /* Events used by AudioRecord callback function (callback_t).
39      * Keep in sync with frameworks/base/media/java/android/media/AudioRecord.java NATIVE_EVENT_*.
40      */
41     enum event_type {
42         EVENT_MORE_DATA = 0,        // Request to read more data from PCM buffer.
43         EVENT_OVERRUN = 1,          // PCM buffer overrun occurred.
44         EVENT_MARKER = 2,           // Record head is at the specified marker position
45                                     // (See setMarkerPosition()).
46         EVENT_NEW_POS = 3,          // Record head is at a new position
47                                     // (See setPositionUpdatePeriod()).
48         EVENT_NEW_IAUDIORECORD = 4, // IAudioRecord was re-created, either due to re-routing and
49                                     // voluntary invalidation by mediaserver, or mediaserver crash.
50     };
51 
52     /* Client should declare Buffer on the stack and pass address to obtainBuffer()
53      * and releaseBuffer().  See also callback_t for EVENT_MORE_DATA.
54      */
55 
56     class Buffer
57     {
58     public:
59         // FIXME use m prefix
60         size_t      frameCount;     // number of sample frames corresponding to size;
61                                     // on input it is the number of frames available,
62                                     // on output is the number of frames actually drained
63                                     // (currently ignored, but will make the primary field in future)
64 
65         size_t      size;           // input/output in bytes == frameCount * frameSize
66                                     // FIXME this is redundant with respect to frameCount,
67                                     // and TRANSFER_OBTAIN mode is broken for 8-bit data
68                                     // since we don't define the frame format
69 
70         union {
71             void*       raw;
72             short*      i16;        // signed 16-bit
73             int8_t*     i8;         // unsigned 8-bit, offset by 0x80
74         };
75     };
76 
77     /* As a convenience, if a callback is supplied, a handler thread
78      * is automatically created with the appropriate priority. This thread
79      * invokes the callback when a new buffer becomes ready or various conditions occur.
80      * Parameters:
81      *
82      * event:   type of event notified (see enum AudioRecord::event_type).
83      * user:    Pointer to context for use by the callback receiver.
84      * info:    Pointer to optional parameter according to event type:
85      *          - EVENT_MORE_DATA: pointer to AudioRecord::Buffer struct. The callback must not read
86      *            more bytes than indicated by 'size' field and update 'size' if fewer bytes are
87      *            consumed.
88      *          - EVENT_OVERRUN: unused.
89      *          - EVENT_MARKER: pointer to const uint32_t containing the marker position in frames.
90      *          - EVENT_NEW_POS: pointer to const uint32_t containing the new position in frames.
91      *          - EVENT_NEW_IAUDIORECORD: unused.
92      */
93 
94     typedef void (*callback_t)(int event, void* user, void *info);
95 
96     /* Returns the minimum frame count required for the successful creation of
97      * an AudioRecord object.
98      * Returned status (from utils/Errors.h) can be:
99      *  - NO_ERROR: successful operation
100      *  - NO_INIT: audio server or audio hardware not initialized
101      *  - BAD_VALUE: unsupported configuration
102      */
103 
104      static status_t getMinFrameCount(size_t* frameCount,
105                                       uint32_t sampleRate,
106                                       audio_format_t format,
107                                       audio_channel_mask_t channelMask);
108 
109     /* How data is transferred from AudioRecord
110      */
111     enum transfer_type {
112         TRANSFER_DEFAULT,   // not specified explicitly; determine from other parameters
113         TRANSFER_CALLBACK,  // callback EVENT_MORE_DATA
114         TRANSFER_OBTAIN,    // FIXME deprecated: call obtainBuffer() and releaseBuffer()
115         TRANSFER_SYNC,      // synchronous read()
116     };
117 
118     /* Constructs an uninitialized AudioRecord. No connection with
119      * AudioFlinger takes place.  Use set() after this.
120      */
121                         AudioRecord();
122 
123     /* Creates an AudioRecord object and registers it with AudioFlinger.
124      * Once created, the track needs to be started before it can be used.
125      * Unspecified values are set to appropriate default values.
126      *
127      * Parameters:
128      *
129      * inputSource:        Select the audio input to record from (e.g. AUDIO_SOURCE_DEFAULT).
130      * sampleRate:         Data sink sampling rate in Hz.
131      * format:             Audio format (e.g AUDIO_FORMAT_PCM_16_BIT for signed
132      *                     16 bits per sample).
133      * channelMask:        Channel mask, such that audio_is_input_channel(channelMask) is true.
134      * frameCount:         Minimum size of track PCM buffer in frames. This defines the
135      *                     application's contribution to the
136      *                     latency of the track.  The actual size selected by the AudioRecord could
137      *                     be larger if the requested size is not compatible with current audio HAL
138      *                     latency.  Zero means to use a default value.
139      * cbf:                Callback function. If not null, this function is called periodically
140      *                     to consume new PCM data and inform of marker, position updates, etc.
141      * user:               Context for use by the callback receiver.
142      * notificationFrames: The callback function is called each time notificationFrames PCM
143      *                     frames are ready in record track output buffer.
144      * sessionId:          Not yet supported.
145      * transferType:       How data is transferred from AudioRecord.
146      * flags:              See comments on audio_input_flags_t in <system/audio.h>
147      * threadCanCallJava:  Not present in parameter list, and so is fixed at false.
148      */
149 
150                         AudioRecord(audio_source_t inputSource,
151                                     uint32_t sampleRate,
152                                     audio_format_t format,
153                                     audio_channel_mask_t channelMask,
154                                     int frameCount      = 0,
155                                     callback_t cbf = NULL,
156                                     void* user = NULL,
157                                     int notificationFrames = 0,
158                                     int sessionId = 0,
159                                     transfer_type transferType = TRANSFER_DEFAULT,
160                                     audio_input_flags_t flags = AUDIO_INPUT_FLAG_NONE);
161 
162     /* Terminates the AudioRecord and unregisters it from AudioFlinger.
163      * Also destroys all resources associated with the AudioRecord.
164      */
165 protected:
166                         virtual ~AudioRecord();
167 public:
168 
169     /* Initialize an AudioRecord that was created using the AudioRecord() constructor.
170      * Don't call set() more than once, or after an AudioRecord() constructor that takes parameters.
171      * Returned status (from utils/Errors.h) can be:
172      *  - NO_ERROR: successful intialization
173      *  - INVALID_OPERATION: AudioRecord is already initialized or record device is already in use
174      *  - BAD_VALUE: invalid parameter (channels, format, sampleRate...)
175      *  - NO_INIT: audio server or audio hardware not initialized
176      *  - PERMISSION_DENIED: recording is not allowed for the requesting process
177      *
178      * Parameters not listed in the AudioRecord constructors above:
179      *
180      * threadCanCallJava:  Whether callbacks are made from an attached thread and thus can call JNI.
181      */
182             status_t    set(audio_source_t inputSource,
183                             uint32_t sampleRate,
184                             audio_format_t format,
185                             audio_channel_mask_t channelMask,
186                             int frameCount      = 0,
187                             callback_t cbf = NULL,
188                             void* user = NULL,
189                             int notificationFrames = 0,
190                             bool threadCanCallJava = false,
191                             int sessionId = 0,
192                             transfer_type transferType = TRANSFER_DEFAULT,
193                             audio_input_flags_t flags = AUDIO_INPUT_FLAG_NONE);
194 
195     /* Result of constructing the AudioRecord. This must be checked
196      * before using any AudioRecord API (except for set()), because using
197      * an uninitialized AudioRecord produces undefined results.
198      * See set() method above for possible return codes.
199      */
initCheck()200             status_t    initCheck() const   { return mStatus; }
201 
202     /* Returns this track's estimated latency in milliseconds.
203      * This includes the latency due to AudioRecord buffer size,
204      * and audio hardware driver.
205      */
latency()206             uint32_t    latency() const     { return mLatency; }
207 
208    /* getters, see constructor and set() */
209 
format()210             audio_format_t format() const   { return mFormat; }
channelCount()211             uint32_t    channelCount() const    { return mChannelCount; }
frameCount()212             size_t      frameCount() const  { return mFrameCount; }
frameSize()213             size_t      frameSize() const   { return mFrameSize; }
inputSource()214             audio_source_t inputSource() const  { return mInputSource; }
215 
216     /* After it's created the track is not active. Call start() to
217      * make it active. If set, the callback will start being called.
218      * If event is not AudioSystem::SYNC_EVENT_NONE, the capture start will be delayed until
219      * the specified event occurs on the specified trigger session.
220      */
221             status_t    start(AudioSystem::sync_event_t event = AudioSystem::SYNC_EVENT_NONE,
222                               int triggerSession = 0);
223 
224     /* Stop a track. If set, the callback will cease being called.  Note that obtainBuffer() still
225      * works and will drain buffers until the pool is exhausted, and then will return WOULD_BLOCK.
226      */
227             void        stop();
228             bool        stopped() const;
229 
230     /* Return the sink sample rate for this record track in Hz.
231      * Unlike AudioTrack, the sample rate is const after initialization, so doesn't need a lock.
232      */
getSampleRate()233             uint32_t    getSampleRate() const   { return mSampleRate; }
234 
235     /* Sets marker position. When record reaches the number of frames specified,
236      * a callback with event type EVENT_MARKER is called. Calling setMarkerPosition
237      * with marker == 0 cancels marker notification callback.
238      * To set a marker at a position which would compute as 0,
239      * a workaround is to the set the marker at a nearby position such as ~0 or 1.
240      * If the AudioRecord has been opened with no callback function associated,
241      * the operation will fail.
242      *
243      * Parameters:
244      *
245      * marker:   marker position expressed in wrapping (overflow) frame units,
246      *           like the return value of getPosition().
247      *
248      * Returned status (from utils/Errors.h) can be:
249      *  - NO_ERROR: successful operation
250      *  - INVALID_OPERATION: the AudioRecord has no callback installed.
251      */
252             status_t    setMarkerPosition(uint32_t marker);
253             status_t    getMarkerPosition(uint32_t *marker) const;
254 
255     /* Sets position update period. Every time the number of frames specified has been recorded,
256      * a callback with event type EVENT_NEW_POS is called.
257      * Calling setPositionUpdatePeriod with updatePeriod == 0 cancels new position notification
258      * callback.
259      * If the AudioRecord has been opened with no callback function associated,
260      * the operation will fail.
261      * Extremely small values may be rounded up to a value the implementation can support.
262      *
263      * Parameters:
264      *
265      * updatePeriod:  position update notification period expressed in frames.
266      *
267      * Returned status (from utils/Errors.h) can be:
268      *  - NO_ERROR: successful operation
269      *  - INVALID_OPERATION: the AudioRecord has no callback installed.
270      */
271             status_t    setPositionUpdatePeriod(uint32_t updatePeriod);
272             status_t    getPositionUpdatePeriod(uint32_t *updatePeriod) const;
273 
274     /* Return the total number of frames recorded since recording started.
275      * The counter will wrap (overflow) periodically, e.g. every ~27 hours at 44.1 kHz.
276      * It is reset to zero by stop().
277      *
278      * Parameters:
279      *
280      *  position:  Address where to return record head position.
281      *
282      * Returned status (from utils/Errors.h) can be:
283      *  - NO_ERROR: successful operation
284      *  - BAD_VALUE:  position is NULL
285      */
286             status_t    getPosition(uint32_t *position) const;
287 
288     /* Returns a handle on the audio input used by this AudioRecord.
289      *
290      * Parameters:
291      *  none.
292      *
293      * Returned value:
294      *  handle on audio hardware input
295      */
296             audio_io_handle_t    getInput() const;
297 
298     /* Returns the audio session ID associated with this AudioRecord.
299      *
300      * Parameters:
301      *  none.
302      *
303      * Returned value:
304      *  AudioRecord session ID.
305      *
306      * No lock needed because session ID doesn't change after first set().
307      */
getSessionId()308             int    getSessionId() const { return mSessionId; }
309 
310     /* Obtains a buffer of up to "audioBuffer->frameCount" full frames.
311      * After draining these frames of data, the caller should release them with releaseBuffer().
312      * If the track buffer is not empty, obtainBuffer() returns as many contiguous
313      * full frames as are available immediately.
314      * If the track buffer is empty and track is stopped, obtainBuffer() returns WOULD_BLOCK
315      * regardless of the value of waitCount.
316      * If the track buffer is empty and track is not stopped, obtainBuffer() blocks with a
317      * maximum timeout based on waitCount; see chart below.
318      * Buffers will be returned until the pool
319      * is exhausted, at which point obtainBuffer() will either block
320      * or return WOULD_BLOCK depending on the value of the "waitCount"
321      * parameter.
322      *
323      * obtainBuffer() and releaseBuffer() are deprecated for direct use by applications,
324      * which should use read() or callback EVENT_MORE_DATA instead.
325      *
326      * Interpretation of waitCount:
327      *  +n  limits wait time to n * WAIT_PERIOD_MS,
328      *  -1  causes an (almost) infinite wait time,
329      *   0  non-blocking.
330      *
331      * Buffer fields
332      * On entry:
333      *  frameCount  number of frames requested
334      * After error return:
335      *  frameCount  0
336      *  size        0
337      *  raw         undefined
338      * After successful return:
339      *  frameCount  actual number of frames available, <= number requested
340      *  size        actual number of bytes available
341      *  raw         pointer to the buffer
342      */
343 
344     /* FIXME Deprecated public API for TRANSFER_OBTAIN mode */
345             status_t    obtainBuffer(Buffer* audioBuffer, int32_t waitCount)
346                                 __attribute__((__deprecated__));
347 
348 private:
349     /* If nonContig is non-NULL, it is an output parameter that will be set to the number of
350      * additional non-contiguous frames that are available immediately.
351      * FIXME We could pass an array of Buffers instead of only one Buffer to obtainBuffer(),
352      * in case the requested amount of frames is in two or more non-contiguous regions.
353      * FIXME requested and elapsed are both relative times.  Consider changing to absolute time.
354      */
355             status_t    obtainBuffer(Buffer* audioBuffer, const struct timespec *requested,
356                                      struct timespec *elapsed = NULL, size_t *nonContig = NULL);
357 public:
358 
359     /* Release an emptied buffer of "audioBuffer->frameCount" frames for AudioFlinger to re-fill. */
360     // FIXME make private when obtainBuffer() for TRANSFER_OBTAIN is removed
361             void        releaseBuffer(Buffer* audioBuffer);
362 
363     /* As a convenience we provide a read() interface to the audio buffer.
364      * Input parameter 'size' is in byte units.
365      * This is implemented on top of obtainBuffer/releaseBuffer. For best
366      * performance use callbacks. Returns actual number of bytes read >= 0,
367      * or one of the following negative status codes:
368      *      INVALID_OPERATION   AudioRecord is configured for streaming mode
369      *      BAD_VALUE           size is invalid
370      *      WOULD_BLOCK         when obtainBuffer() returns same, or
371      *                          AudioRecord was stopped during the read
372      *      or any other error code returned by IAudioRecord::start() or restoreRecord_l().
373      */
374             ssize_t     read(void* buffer, size_t size);
375 
376     /* Return the number of input frames lost in the audio driver since the last call of this
377      * function.  Audio driver is expected to reset the value to 0 and restart counting upon
378      * returning the current value by this function call.  Such loss typically occurs when the
379      * user space process is blocked longer than the capacity of audio driver buffers.
380      * Units: the number of input audio frames.
381      */
382             unsigned int  getInputFramesLost() const;
383 
384 private:
385     /* copying audio record objects is not allowed */
386                         AudioRecord(const AudioRecord& other);
387             AudioRecord& operator = (const AudioRecord& other);
388 
389     /* a small internal class to handle the callback */
390     class AudioRecordThread : public Thread
391     {
392     public:
393         AudioRecordThread(AudioRecord& receiver, bool bCanCallJava = false);
394 
395         // Do not call Thread::requestExitAndWait() without first calling requestExit().
396         // Thread::requestExitAndWait() is not virtual, and the implementation doesn't do enough.
397         virtual void        requestExit();
398 
399                 void        pause();    // suspend thread from execution at next loop boundary
400                 void        resume();   // allow thread to execute, if not requested to exit
401 
402     private:
403                 void        pauseInternal(nsecs_t ns = 0LL);
404                                         // like pause(), but only used internally within thread
405 
406         friend class AudioRecord;
407         virtual bool        threadLoop();
408         AudioRecord&        mReceiver;
409         virtual ~AudioRecordThread();
410         Mutex               mMyLock;    // Thread::mLock is private
411         Condition           mMyCond;    // Thread::mThreadExitedCondition is private
412         bool                mPaused;    // whether thread is requested to pause at next loop entry
413         bool                mPausedInt; // whether thread internally requests pause
414         nsecs_t             mPausedNs;  // if mPausedInt then associated timeout, otherwise ignored
415     };
416 
417             // body of AudioRecordThread::threadLoop()
418             // returns the maximum amount of time before we would like to run again, where:
419             //      0           immediately
420             //      > 0         no later than this many nanoseconds from now
421             //      NS_WHENEVER still active but no particular deadline
422             //      NS_INACTIVE inactive so don't run again until re-started
423             //      NS_NEVER    never again
424             static const nsecs_t NS_WHENEVER = -1, NS_INACTIVE = -2, NS_NEVER = -3;
425             nsecs_t processAudioBuffer(const sp<AudioRecordThread>& thread);
426 
427             // caller must hold lock on mLock for all _l methods
428             status_t openRecord_l(size_t epoch);
429 
430             // FIXME enum is faster than strcmp() for parameter 'from'
431             status_t restoreRecord_l(const char *from);
432 
433     sp<AudioRecordThread>   mAudioRecordThread;
434     mutable Mutex           mLock;
435 
436     // Current client state:  false = stopped, true = active.  Protected by mLock.  If more states
437     // are added, consider changing this to enum State { ... } mState as in AudioTrack.
438     bool                    mActive;
439 
440     // for client callback handler
441     callback_t              mCbf;               // callback handler for events, or NULL
442     void*                   mUserData;
443 
444     // for notification APIs
445     uint32_t                mNotificationFramesReq; // requested number of frames between each
446                                                     // notification callback
447     uint32_t                mNotificationFramesAct; // actual number of frames between each
448                                                     // notification callback
449     bool                    mRefreshRemaining;  // processAudioBuffer() should refresh next 2
450 
451     // These are private to processAudioBuffer(), and are not protected by a lock
452     uint32_t                mRemainingFrames;       // number of frames to request in obtainBuffer()
453     bool                    mRetryOnPartialBuffer;  // sleep and retry after partial obtainBuffer()
454     int                     mObservedSequence;      // last observed value of mSequence
455 
456     uint32_t                mMarkerPosition;    // in wrapping (overflow) frame units
457     bool                    mMarkerReached;
458     uint32_t                mNewPosition;       // in frames
459     uint32_t                mUpdatePeriod;      // in frames, zero means no EVENT_NEW_POS
460 
461     status_t                mStatus;
462 
463     // constant after constructor or set()
464     uint32_t                mSampleRate;
465     size_t                  mFrameCount;
466     audio_format_t          mFormat;
467     uint32_t                mChannelCount;
468     size_t                  mFrameSize;         // app-level frame size == AudioFlinger frame size
469     audio_source_t          mInputSource;
470     uint32_t                mLatency;           // in ms
471     audio_channel_mask_t    mChannelMask;
472     audio_input_flags_t     mFlags;
473     int                     mSessionId;
474     transfer_type           mTransfer;
475 
476     audio_io_handle_t       mInput;             // returned by AudioSystem::getInput()
477 
478     // may be changed if IAudioRecord object is re-created
479     sp<IAudioRecord>        mAudioRecord;
480     sp<IMemory>             mCblkMemory;
481     audio_track_cblk_t*     mCblk;              // re-load after mLock.unlock()
482 
483     int                     mPreviousPriority;  // before start()
484     SchedPolicy             mPreviousSchedulingGroup;
485     bool                    mAwaitBoost;    // thread should wait for priority boost before running
486 
487     // The proxy should only be referenced while a lock is held because the proxy isn't
488     // multi-thread safe.
489     // An exception is that a blocking ClientProxy::obtainBuffer() may be called without a lock,
490     // provided that the caller also holds an extra reference to the proxy and shared memory to keep
491     // them around in case they are replaced during the obtainBuffer().
492     sp<AudioRecordClientProxy> mProxy;
493 
494     bool                    mInOverrun;         // whether recorder is currently in overrun state
495 
496 private:
497     class DeathNotifier : public IBinder::DeathRecipient {
498     public:
DeathNotifier(AudioRecord * audioRecord)499         DeathNotifier(AudioRecord* audioRecord) : mAudioRecord(audioRecord) { }
500     protected:
501         virtual void        binderDied(const wp<IBinder>& who);
502     private:
503         const wp<AudioRecord> mAudioRecord;
504     };
505 
506     sp<DeathNotifier>       mDeathNotifier;
507     uint32_t                mSequence;              // incremented for each new IAudioRecord attempt
508 };
509 
510 }; // namespace android
511 
512 #endif // ANDROID_AUDIORECORD_H
513