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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      */
    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      */
    206             uint32_t    latency() const     { return mLatency; }
    207 
    208    /* getters, see constructor and set() */
    209 
    210             audio_format_t format() const   { return mFormat; }
    211             uint32_t    channelCount() const    { return mChannelCount; }
    212             size_t      frameCount() const  { return mFrameCount; }
    213             size_t      frameSize() const   { return mFrameSize; }
    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      */
    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      */
    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:
    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