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      1 /*
      2  * Copyright (C) 2007 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #ifndef ANDROID_AUDIOTRACK_H
     18 #define ANDROID_AUDIOTRACK_H
     19 
     20 #include <cutils/sched_policy.h>
     21 #include <media/AudioSystem.h>
     22 #include <media/AudioTimestamp.h>
     23 #include <media/IAudioTrack.h>
     24 #include <media/AudioResamplerPublic.h>
     25 #include <media/MediaAnalyticsItem.h>
     26 #include <media/Modulo.h>
     27 #include <utils/threads.h>
     28 
     29 namespace android {
     30 
     31 // ----------------------------------------------------------------------------
     32 
     33 struct audio_track_cblk_t;
     34 class AudioTrackClientProxy;
     35 class StaticAudioTrackClientProxy;
     36 
     37 // ----------------------------------------------------------------------------
     38 
     39 class AudioTrack : public AudioSystem::AudioDeviceCallback
     40 {
     41 public:
     42 
     43     /* Events used by AudioTrack callback function (callback_t).
     44      * Keep in sync with frameworks/base/media/java/android/media/AudioTrack.java NATIVE_EVENT_*.
     45      */
     46     enum event_type {
     47         EVENT_MORE_DATA = 0,        // Request to write more data to buffer.
     48                                     // This event only occurs for TRANSFER_CALLBACK.
     49                                     // If this event is delivered but the callback handler
     50                                     // does not want to write more data, the handler must
     51                                     // ignore the event by setting frameCount to zero.
     52                                     // This might occur, for example, if the application is
     53                                     // waiting for source data or is at the end of stream.
     54                                     //
     55                                     // For data filling, it is preferred that the callback
     56                                     // does not block and instead returns a short count on
     57                                     // the amount of data actually delivered
     58                                     // (or 0, if no data is currently available).
     59         EVENT_UNDERRUN = 1,         // Buffer underrun occurred. This will not occur for
     60                                     // static tracks.
     61         EVENT_LOOP_END = 2,         // Sample loop end was reached; playback restarted from
     62                                     // loop start if loop count was not 0 for a static track.
     63         EVENT_MARKER = 3,           // Playback head is at the specified marker position
     64                                     // (See setMarkerPosition()).
     65         EVENT_NEW_POS = 4,          // Playback head is at a new position
     66                                     // (See setPositionUpdatePeriod()).
     67         EVENT_BUFFER_END = 5,       // Playback has completed for a static track.
     68         EVENT_NEW_IAUDIOTRACK = 6,  // IAudioTrack was re-created, either due to re-routing and
     69                                     // voluntary invalidation by mediaserver, or mediaserver crash.
     70         EVENT_STREAM_END = 7,       // Sent after all the buffers queued in AF and HW are played
     71                                     // back (after stop is called) for an offloaded track.
     72 #if 0   // FIXME not yet implemented
     73         EVENT_NEW_TIMESTAMP = 8,    // Delivered periodically and when there's a significant change
     74                                     // in the mapping from frame position to presentation time.
     75                                     // See AudioTimestamp for the information included with event.
     76 #endif
     77     };
     78 
     79     /* Client should declare a Buffer and pass the address to obtainBuffer()
     80      * and releaseBuffer().  See also callback_t for EVENT_MORE_DATA.
     81      */
     82 
     83     class Buffer
     84     {
     85     public:
     86         // FIXME use m prefix
     87         size_t      frameCount;   // number of sample frames corresponding to size;
     88                                   // on input to obtainBuffer() it is the number of frames desired,
     89                                   // on output from obtainBuffer() it is the number of available
     90                                   //    [empty slots for] frames to be filled
     91                                   // on input to releaseBuffer() it is currently ignored
     92 
     93         size_t      size;         // input/output in bytes == frameCount * frameSize
     94                                   // on input to obtainBuffer() it is ignored
     95                                   // on output from obtainBuffer() it is the number of available
     96                                   //    [empty slots for] bytes to be filled,
     97                                   //    which is frameCount * frameSize
     98                                   // on input to releaseBuffer() it is the number of bytes to
     99                                   //    release
    100                                   // FIXME This is redundant with respect to frameCount.  Consider
    101                                   //    removing size and making frameCount the primary field.
    102 
    103         union {
    104             void*       raw;
    105             short*      i16;      // signed 16-bit
    106             int8_t*     i8;       // unsigned 8-bit, offset by 0x80
    107         };                        // input to obtainBuffer(): unused, output: pointer to buffer
    108     };
    109 
    110     /* As a convenience, if a callback is supplied, a handler thread
    111      * is automatically created with the appropriate priority. This thread
    112      * invokes the callback when a new buffer becomes available or various conditions occur.
    113      * Parameters:
    114      *
    115      * event:   type of event notified (see enum AudioTrack::event_type).
    116      * user:    Pointer to context for use by the callback receiver.
    117      * info:    Pointer to optional parameter according to event type:
    118      *          - EVENT_MORE_DATA: pointer to AudioTrack::Buffer struct. The callback must not write
    119      *            more bytes than indicated by 'size' field and update 'size' if fewer bytes are
    120      *            written.
    121      *          - EVENT_UNDERRUN: unused.
    122      *          - EVENT_LOOP_END: pointer to an int indicating the number of loops remaining.
    123      *          - EVENT_MARKER: pointer to const uint32_t containing the marker position in frames.
    124      *          - EVENT_NEW_POS: pointer to const uint32_t containing the new position in frames.
    125      *          - EVENT_BUFFER_END: unused.
    126      *          - EVENT_NEW_IAUDIOTRACK: unused.
    127      *          - EVENT_STREAM_END: unused.
    128      *          - EVENT_NEW_TIMESTAMP: pointer to const AudioTimestamp.
    129      */
    130 
    131     typedef void (*callback_t)(int event, void* user, void *info);
    132 
    133     /* Returns the minimum frame count required for the successful creation of
    134      * an AudioTrack object.
    135      * Returned status (from utils/Errors.h) can be:
    136      *  - NO_ERROR: successful operation
    137      *  - NO_INIT: audio server or audio hardware not initialized
    138      *  - BAD_VALUE: unsupported configuration
    139      * frameCount is guaranteed to be non-zero if status is NO_ERROR,
    140      * and is undefined otherwise.
    141      * FIXME This API assumes a route, and so should be deprecated.
    142      */
    143 
    144     static status_t getMinFrameCount(size_t* frameCount,
    145                                      audio_stream_type_t streamType,
    146                                      uint32_t sampleRate);
    147 
    148     /* How data is transferred to AudioTrack
    149      */
    150     enum transfer_type {
    151         TRANSFER_DEFAULT,   // not specified explicitly; determine from the other parameters
    152         TRANSFER_CALLBACK,  // callback EVENT_MORE_DATA
    153         TRANSFER_OBTAIN,    // call obtainBuffer() and releaseBuffer()
    154         TRANSFER_SYNC,      // synchronous write()
    155         TRANSFER_SHARED,    // shared memory
    156     };
    157 
    158     /* Constructs an uninitialized AudioTrack. No connection with
    159      * AudioFlinger takes place.  Use set() after this.
    160      */
    161                         AudioTrack();
    162 
    163     /* Creates an AudioTrack object and registers it with AudioFlinger.
    164      * Once created, the track needs to be started before it can be used.
    165      * Unspecified values are set to appropriate default values.
    166      *
    167      * Parameters:
    168      *
    169      * streamType:         Select the type of audio stream this track is attached to
    170      *                     (e.g. AUDIO_STREAM_MUSIC).
    171      * sampleRate:         Data source sampling rate in Hz.  Zero means to use the sink sample rate.
    172      *                     A non-zero value must be specified if AUDIO_OUTPUT_FLAG_DIRECT is set.
    173      *                     0 will not work with current policy implementation for direct output
    174      *                     selection where an exact match is needed for sampling rate.
    175      * format:             Audio format. For mixed tracks, any PCM format supported by server is OK.
    176      *                     For direct and offloaded tracks, the possible format(s) depends on the
    177      *                     output sink.
    178      * channelMask:        Channel mask, such that audio_is_output_channel(channelMask) is true.
    179      * frameCount:         Minimum size of track PCM buffer in frames. This defines the
    180      *                     application's contribution to the
    181      *                     latency of the track. The actual size selected by the AudioTrack could be
    182      *                     larger if the requested size is not compatible with current audio HAL
    183      *                     configuration.  Zero means to use a default value.
    184      * flags:              See comments on audio_output_flags_t in <system/audio.h>.
    185      * cbf:                Callback function. If not null, this function is called periodically
    186      *                     to provide new data in TRANSFER_CALLBACK mode
    187      *                     and inform of marker, position updates, etc.
    188      * user:               Context for use by the callback receiver.
    189      * notificationFrames: The callback function is called each time notificationFrames PCM
    190      *                     frames have been consumed from track input buffer by server.
    191      *                     Zero means to use a default value, which is typically:
    192      *                      - fast tracks: HAL buffer size, even if track frameCount is larger
    193      *                      - normal tracks: 1/2 of track frameCount
    194      *                     A positive value means that many frames at initial source sample rate.
    195      *                     A negative value for this parameter specifies the negative of the
    196      *                     requested number of notifications (sub-buffers) in the entire buffer.
    197      *                     For fast tracks, the FastMixer will process one sub-buffer at a time.
    198      *                     The size of each sub-buffer is determined by the HAL.
    199      *                     To get "double buffering", for example, one should pass -2.
    200      *                     The minimum number of sub-buffers is 1 (expressed as -1),
    201      *                     and the maximum number of sub-buffers is 8 (expressed as -8).
    202      *                     Negative is only permitted for fast tracks, and if frameCount is zero.
    203      *                     TODO It is ugly to overload a parameter in this way depending on
    204      *                     whether it is positive, negative, or zero.  Consider splitting apart.
    205      * sessionId:          Specific session ID, or zero to use default.
    206      * transferType:       How data is transferred to AudioTrack.
    207      * offloadInfo:        If not NULL, provides offload parameters for
    208      *                     AudioSystem::getOutputForAttr().
    209      * uid:                User ID of the app which initially requested this AudioTrack
    210      *                     for power management tracking, or -1 for current user ID.
    211      * pid:                Process ID of the app which initially requested this AudioTrack
    212      *                     for power management tracking, or -1 for current process ID.
    213      * pAttributes:        If not NULL, supersedes streamType for use case selection.
    214      * doNotReconnect:     If set to true, AudioTrack won't automatically recreate the IAudioTrack
    215                            binder to AudioFlinger.
    216                            It will return an error instead.  The application will recreate
    217                            the track based on offloading or different channel configuration, etc.
    218      * maxRequiredSpeed:   For PCM tracks, this creates an appropriate buffer size that will allow
    219      *                     maxRequiredSpeed playback. Values less than 1.0f and greater than
    220      *                     AUDIO_TIMESTRETCH_SPEED_MAX will be clamped.  For non-PCM tracks
    221      *                     and direct or offloaded tracks, this parameter is ignored.
    222      * selectedDeviceId:   Selected device id of the app which initially requested the AudioTrack
    223      *                     to open with a specific device.
    224      * threadCanCallJava:  Not present in parameter list, and so is fixed at false.
    225      */
    226 
    227                         AudioTrack( audio_stream_type_t streamType,
    228                                     uint32_t sampleRate,
    229                                     audio_format_t format,
    230                                     audio_channel_mask_t channelMask,
    231                                     size_t frameCount    = 0,
    232                                     audio_output_flags_t flags = AUDIO_OUTPUT_FLAG_NONE,
    233                                     callback_t cbf       = NULL,
    234                                     void* user           = NULL,
    235                                     int32_t notificationFrames = 0,
    236                                     audio_session_t sessionId  = AUDIO_SESSION_ALLOCATE,
    237                                     transfer_type transferType = TRANSFER_DEFAULT,
    238                                     const audio_offload_info_t *offloadInfo = NULL,
    239                                     uid_t uid = AUDIO_UID_INVALID,
    240                                     pid_t pid = -1,
    241                                     const audio_attributes_t* pAttributes = NULL,
    242                                     bool doNotReconnect = false,
    243                                     float maxRequiredSpeed = 1.0f,
    244                                     audio_port_handle_t selectedDeviceId = AUDIO_PORT_HANDLE_NONE);
    245 
    246     /* Creates an audio track and registers it with AudioFlinger.
    247      * With this constructor, the track is configured for static buffer mode.
    248      * Data to be rendered is passed in a shared memory buffer
    249      * identified by the argument sharedBuffer, which should be non-0.
    250      * If sharedBuffer is zero, this constructor is equivalent to the previous constructor
    251      * but without the ability to specify a non-zero value for the frameCount parameter.
    252      * The memory should be initialized to the desired data before calling start().
    253      * The write() method is not supported in this case.
    254      * It is recommended to pass a callback function to be notified of playback end by an
    255      * EVENT_UNDERRUN event.
    256      */
    257 
    258                         AudioTrack( audio_stream_type_t streamType,
    259                                     uint32_t sampleRate,
    260                                     audio_format_t format,
    261                                     audio_channel_mask_t channelMask,
    262                                     const sp<IMemory>& sharedBuffer,
    263                                     audio_output_flags_t flags = AUDIO_OUTPUT_FLAG_NONE,
    264                                     callback_t cbf      = NULL,
    265                                     void* user          = NULL,
    266                                     int32_t notificationFrames = 0,
    267                                     audio_session_t sessionId   = AUDIO_SESSION_ALLOCATE,
    268                                     transfer_type transferType = TRANSFER_DEFAULT,
    269                                     const audio_offload_info_t *offloadInfo = NULL,
    270                                     uid_t uid = AUDIO_UID_INVALID,
    271                                     pid_t pid = -1,
    272                                     const audio_attributes_t* pAttributes = NULL,
    273                                     bool doNotReconnect = false,
    274                                     float maxRequiredSpeed = 1.0f);
    275 
    276     /* Terminates the AudioTrack and unregisters it from AudioFlinger.
    277      * Also destroys all resources associated with the AudioTrack.
    278      */
    279 protected:
    280                         virtual ~AudioTrack();
    281 public:
    282 
    283     /* Initialize an AudioTrack that was created using the AudioTrack() constructor.
    284      * Don't call set() more than once, or after the AudioTrack() constructors that take parameters.
    285      * set() is not multi-thread safe.
    286      * Returned status (from utils/Errors.h) can be:
    287      *  - NO_ERROR: successful initialization
    288      *  - INVALID_OPERATION: AudioTrack is already initialized
    289      *  - BAD_VALUE: invalid parameter (channelMask, format, sampleRate...)
    290      *  - NO_INIT: audio server or audio hardware not initialized
    291      * If status is not equal to NO_ERROR, don't call any other APIs on this AudioTrack.
    292      * If sharedBuffer is non-0, the frameCount parameter is ignored and
    293      * replaced by the shared buffer's total allocated size in frame units.
    294      *
    295      * Parameters not listed in the AudioTrack constructors above:
    296      *
    297      * threadCanCallJava:  Whether callbacks are made from an attached thread and thus can call JNI.
    298      *
    299      * Internal state post condition:
    300      *      (mStreamType == AUDIO_STREAM_DEFAULT) implies this AudioTrack has valid attributes
    301      */
    302             status_t    set(audio_stream_type_t streamType,
    303                             uint32_t sampleRate,
    304                             audio_format_t format,
    305                             audio_channel_mask_t channelMask,
    306                             size_t frameCount   = 0,
    307                             audio_output_flags_t flags = AUDIO_OUTPUT_FLAG_NONE,
    308                             callback_t cbf      = NULL,
    309                             void* user          = NULL,
    310                             int32_t notificationFrames = 0,
    311                             const sp<IMemory>& sharedBuffer = 0,
    312                             bool threadCanCallJava = false,
    313                             audio_session_t sessionId  = AUDIO_SESSION_ALLOCATE,
    314                             transfer_type transferType = TRANSFER_DEFAULT,
    315                             const audio_offload_info_t *offloadInfo = NULL,
    316                             uid_t uid = AUDIO_UID_INVALID,
    317                             pid_t pid = -1,
    318                             const audio_attributes_t* pAttributes = NULL,
    319                             bool doNotReconnect = false,
    320                             float maxRequiredSpeed = 1.0f,
    321                             audio_port_handle_t selectedDeviceId = AUDIO_PORT_HANDLE_NONE);
    322 
    323     /* Result of constructing the AudioTrack. This must be checked for successful initialization
    324      * before using any AudioTrack API (except for set()), because using
    325      * an uninitialized AudioTrack produces undefined results.
    326      * See set() method above for possible return codes.
    327      */
    328             status_t    initCheck() const   { return mStatus; }
    329 
    330     /* Returns this track's estimated latency in milliseconds.
    331      * This includes the latency due to AudioTrack buffer size, AudioMixer (if any)
    332      * and audio hardware driver.
    333      */
    334             uint32_t    latency();
    335 
    336     /* Returns the number of application-level buffer underruns
    337      * since the AudioTrack was created.
    338      */
    339             uint32_t    getUnderrunCount() const;
    340 
    341     /* getters, see constructors and set() */
    342 
    343             audio_stream_type_t streamType() const;
    344             audio_format_t format() const   { return mFormat; }
    345 
    346     /* Return frame size in bytes, which for linear PCM is
    347      * channelCount * (bit depth per channel / 8).
    348      * channelCount is determined from channelMask, and bit depth comes from format.
    349      * For non-linear formats, the frame size is typically 1 byte.
    350      */
    351             size_t      frameSize() const   { return mFrameSize; }
    352 
    353             uint32_t    channelCount() const { return mChannelCount; }
    354             size_t      frameCount() const  { return mFrameCount; }
    355 
    356     /*
    357      * Return the period of the notification callback in frames.
    358      * This value is set when the AudioTrack is constructed.
    359      * It can be modified if the AudioTrack is rerouted.
    360      */
    361             uint32_t    getNotificationPeriodInFrames() const { return mNotificationFramesAct; }
    362 
    363     /* Return effective size of audio buffer that an application writes to
    364      * or a negative error if the track is uninitialized.
    365      */
    366             ssize_t     getBufferSizeInFrames();
    367 
    368     /* Returns the buffer duration in microseconds at current playback rate.
    369      */
    370             status_t    getBufferDurationInUs(int64_t *duration);
    371 
    372     /* Set the effective size of audio buffer that an application writes to.
    373      * This is used to determine the amount of available room in the buffer,
    374      * which determines when a write will block.
    375      * This allows an application to raise and lower the audio latency.
    376      * The requested size may be adjusted so that it is
    377      * greater or equal to the absolute minimum and
    378      * less than or equal to the getBufferCapacityInFrames().
    379      * It may also be adjusted slightly for internal reasons.
    380      *
    381      * Return the final size or a negative error if the track is unitialized
    382      * or does not support variable sizes.
    383      */
    384             ssize_t     setBufferSizeInFrames(size_t size);
    385 
    386     /* Return the static buffer specified in constructor or set(), or 0 for streaming mode */
    387             sp<IMemory> sharedBuffer() const { return mSharedBuffer; }
    388 
    389     /*
    390      * return metrics information for the current track.
    391      */
    392             status_t getMetrics(MediaAnalyticsItem * &item);
    393 
    394     /* After it's created the track is not active. Call start() to
    395      * make it active. If set, the callback will start being called.
    396      * If the track was previously paused, volume is ramped up over the first mix buffer.
    397      */
    398             status_t        start();
    399 
    400     /* Stop a track.
    401      * In static buffer mode, the track is stopped immediately.
    402      * In streaming mode, the callback will cease being called.  Note that obtainBuffer() still
    403      * works and will fill up buffers until the pool is exhausted, and then will return WOULD_BLOCK.
    404      * In streaming mode the stop does not occur immediately: any data remaining in the buffer
    405      * is first drained, mixed, and output, and only then is the track marked as stopped.
    406      */
    407             void        stop();
    408             bool        stopped() const;
    409 
    410     /* Flush a stopped or paused track. All previously buffered data is discarded immediately.
    411      * This has the effect of draining the buffers without mixing or output.
    412      * Flush is intended for streaming mode, for example before switching to non-contiguous content.
    413      * This function is a no-op if the track is not stopped or paused, or uses a static buffer.
    414      */
    415             void        flush();
    416 
    417     /* Pause a track. After pause, the callback will cease being called and
    418      * obtainBuffer returns WOULD_BLOCK. Note that obtainBuffer() still works
    419      * and will fill up buffers until the pool is exhausted.
    420      * Volume is ramped down over the next mix buffer following the pause request,
    421      * and then the track is marked as paused.  It can be resumed with ramp up by start().
    422      */
    423             void        pause();
    424 
    425     /* Set volume for this track, mostly used for games' sound effects
    426      * left and right volumes. Levels must be >= 0.0 and <= 1.0.
    427      * This is the older API.  New applications should use setVolume(float) when possible.
    428      */
    429             status_t    setVolume(float left, float right);
    430 
    431     /* Set volume for all channels.  This is the preferred API for new applications,
    432      * especially for multi-channel content.
    433      */
    434             status_t    setVolume(float volume);
    435 
    436     /* Set the send level for this track. An auxiliary effect should be attached
    437      * to the track with attachEffect(). Level must be >= 0.0 and <= 1.0.
    438      */
    439             status_t    setAuxEffectSendLevel(float level);
    440             void        getAuxEffectSendLevel(float* level) const;
    441 
    442     /* Set source sample rate for this track in Hz, mostly used for games' sound effects.
    443      * Zero is not permitted.
    444      */
    445             status_t    setSampleRate(uint32_t sampleRate);
    446 
    447     /* Return current source sample rate in Hz.
    448      * If specified as zero in constructor or set(), this will be the sink sample rate.
    449      */
    450             uint32_t    getSampleRate() const;
    451 
    452     /* Return the original source sample rate in Hz. This corresponds to the sample rate
    453      * if playback rate had normal speed and pitch.
    454      */
    455             uint32_t    getOriginalSampleRate() const;
    456 
    457     /* Set source playback rate for timestretch
    458      * 1.0 is normal speed: < 1.0 is slower, > 1.0 is faster
    459      * 1.0 is normal pitch: < 1.0 is lower pitch, > 1.0 is higher pitch
    460      *
    461      * AUDIO_TIMESTRETCH_SPEED_MIN <= speed <= AUDIO_TIMESTRETCH_SPEED_MAX
    462      * AUDIO_TIMESTRETCH_PITCH_MIN <= pitch <= AUDIO_TIMESTRETCH_PITCH_MAX
    463      *
    464      * Speed increases the playback rate of media, but does not alter pitch.
    465      * Pitch increases the "tonal frequency" of media, but does not affect the playback rate.
    466      */
    467             status_t    setPlaybackRate(const AudioPlaybackRate &playbackRate);
    468 
    469     /* Return current playback rate */
    470             const AudioPlaybackRate& getPlaybackRate() const;
    471 
    472     /* Enables looping and sets the start and end points of looping.
    473      * Only supported for static buffer mode.
    474      *
    475      * Parameters:
    476      *
    477      * loopStart:   loop start in frames relative to start of buffer.
    478      * loopEnd:     loop end in frames relative to start of buffer.
    479      * loopCount:   number of loops to execute. Calling setLoop() with loopCount == 0 cancels any
    480      *              pending or active loop. loopCount == -1 means infinite looping.
    481      *
    482      * For proper operation the following condition must be respected:
    483      *      loopCount != 0 implies 0 <= loopStart < loopEnd <= frameCount().
    484      *
    485      * If the loop period (loopEnd - loopStart) is too small for the implementation to support,
    486      * setLoop() will return BAD_VALUE.  loopCount must be >= -1.
    487      *
    488      */
    489             status_t    setLoop(uint32_t loopStart, uint32_t loopEnd, int loopCount);
    490 
    491     /* Sets marker position. When playback reaches the number of frames specified, a callback with
    492      * event type EVENT_MARKER is called. Calling setMarkerPosition with marker == 0 cancels marker
    493      * notification callback.  To set a marker at a position which would compute as 0,
    494      * a workaround is to set the marker at a nearby position such as ~0 or 1.
    495      * If the AudioTrack has been opened with no callback function associated, the operation will
    496      * fail.
    497      *
    498      * Parameters:
    499      *
    500      * marker:   marker position expressed in wrapping (overflow) frame units,
    501      *           like the return value of getPosition().
    502      *
    503      * Returned status (from utils/Errors.h) can be:
    504      *  - NO_ERROR: successful operation
    505      *  - INVALID_OPERATION: the AudioTrack has no callback installed.
    506      */
    507             status_t    setMarkerPosition(uint32_t marker);
    508             status_t    getMarkerPosition(uint32_t *marker) const;
    509 
    510     /* Sets position update period. Every time the number of frames specified has been played,
    511      * a callback with event type EVENT_NEW_POS is called.
    512      * Calling setPositionUpdatePeriod with updatePeriod == 0 cancels new position notification
    513      * callback.
    514      * If the AudioTrack has been opened with no callback function associated, the operation will
    515      * fail.
    516      * Extremely small values may be rounded up to a value the implementation can support.
    517      *
    518      * Parameters:
    519      *
    520      * updatePeriod:  position update notification period expressed in frames.
    521      *
    522      * Returned status (from utils/Errors.h) can be:
    523      *  - NO_ERROR: successful operation
    524      *  - INVALID_OPERATION: the AudioTrack has no callback installed.
    525      */
    526             status_t    setPositionUpdatePeriod(uint32_t updatePeriod);
    527             status_t    getPositionUpdatePeriod(uint32_t *updatePeriod) const;
    528 
    529     /* Sets playback head position.
    530      * Only supported for static buffer mode.
    531      *
    532      * Parameters:
    533      *
    534      * position:  New playback head position in frames relative to start of buffer.
    535      *            0 <= position <= frameCount().  Note that end of buffer is permitted,
    536      *            but will result in an immediate underrun if started.
    537      *
    538      * Returned status (from utils/Errors.h) can be:
    539      *  - NO_ERROR: successful operation
    540      *  - INVALID_OPERATION: the AudioTrack is not stopped or paused, or is streaming mode.
    541      *  - BAD_VALUE: The specified position is beyond the number of frames present in AudioTrack
    542      *               buffer
    543      */
    544             status_t    setPosition(uint32_t position);
    545 
    546     /* Return the total number of frames played since playback start.
    547      * The counter will wrap (overflow) periodically, e.g. every ~27 hours at 44.1 kHz.
    548      * It is reset to zero by flush(), reload(), and stop().
    549      *
    550      * Parameters:
    551      *
    552      *  position:  Address where to return play head position.
    553      *
    554      * Returned status (from utils/Errors.h) can be:
    555      *  - NO_ERROR: successful operation
    556      *  - BAD_VALUE:  position is NULL
    557      */
    558             status_t    getPosition(uint32_t *position);
    559 
    560     /* For static buffer mode only, this returns the current playback position in frames
    561      * relative to start of buffer.  It is analogous to the position units used by
    562      * setLoop() and setPosition().  After underrun, the position will be at end of buffer.
    563      */
    564             status_t    getBufferPosition(uint32_t *position);
    565 
    566     /* Forces AudioTrack buffer full condition. When playing a static buffer, this method avoids
    567      * rewriting the buffer before restarting playback after a stop.
    568      * This method must be called with the AudioTrack in paused or stopped state.
    569      * Not allowed in streaming mode.
    570      *
    571      * Returned status (from utils/Errors.h) can be:
    572      *  - NO_ERROR: successful operation
    573      *  - INVALID_OPERATION: the AudioTrack is not stopped or paused, or is streaming mode.
    574      */
    575             status_t    reload();
    576 
    577     /**
    578      * @param transferType
    579      * @return text string that matches the enum name
    580      */
    581             static const char * convertTransferToText(transfer_type transferType);
    582 
    583     /* Returns a handle on the audio output used by this AudioTrack.
    584      *
    585      * Parameters:
    586      *  none.
    587      *
    588      * Returned value:
    589      *  handle on audio hardware output, or AUDIO_IO_HANDLE_NONE if the
    590      *  track needed to be re-created but that failed
    591      */
    592 private:
    593             audio_io_handle_t    getOutput() const;
    594 public:
    595 
    596     /* Selects the audio device to use for output of this AudioTrack. A value of
    597      * AUDIO_PORT_HANDLE_NONE indicates default (AudioPolicyManager) routing.
    598      *
    599      * Parameters:
    600      *  The device ID of the selected device (as returned by the AudioDevicesManager API).
    601      *
    602      * Returned value:
    603      *  - NO_ERROR: successful operation
    604      *    TODO: what else can happen here?
    605      */
    606             status_t    setOutputDevice(audio_port_handle_t deviceId);
    607 
    608     /* Returns the ID of the audio device selected for this AudioTrack.
    609      * A value of AUDIO_PORT_HANDLE_NONE indicates default (AudioPolicyManager) routing.
    610      *
    611      * Parameters:
    612      *  none.
    613      */
    614      audio_port_handle_t getOutputDevice();
    615 
    616      /* Returns the ID of the audio device actually used by the output to which this AudioTrack is
    617       * attached.
    618       * When the AudioTrack is inactive, the device ID returned can be either:
    619       * - AUDIO_PORT_HANDLE_NONE if the AudioTrack is not attached to any output.
    620       * - The device ID used before paused or stopped.
    621       * - The device ID selected by audio policy manager of setOutputDevice() if the AudioTrack
    622       * has not been started yet.
    623       *
    624       * Parameters:
    625       *  none.
    626       */
    627      audio_port_handle_t getRoutedDeviceId();
    628 
    629     /* Returns the unique session ID associated with this track.
    630      *
    631      * Parameters:
    632      *  none.
    633      *
    634      * Returned value:
    635      *  AudioTrack session ID.
    636      */
    637             audio_session_t getSessionId() const { return mSessionId; }
    638 
    639     /* Attach track auxiliary output to specified effect. Use effectId = 0
    640      * to detach track from effect.
    641      *
    642      * Parameters:
    643      *
    644      * effectId:  effectId obtained from AudioEffect::id().
    645      *
    646      * Returned status (from utils/Errors.h) can be:
    647      *  - NO_ERROR: successful operation
    648      *  - INVALID_OPERATION: the effect is not an auxiliary effect.
    649      *  - BAD_VALUE: The specified effect ID is invalid
    650      */
    651             status_t    attachAuxEffect(int effectId);
    652 
    653     /* Public API for TRANSFER_OBTAIN mode.
    654      * Obtains a buffer of up to "audioBuffer->frameCount" empty slots for frames.
    655      * After filling these slots with data, the caller should release them with releaseBuffer().
    656      * If the track buffer is not full, obtainBuffer() returns as many contiguous
    657      * [empty slots for] frames as are available immediately.
    658      *
    659      * If nonContig is non-NULL, it is an output parameter that will be set to the number of
    660      * additional non-contiguous frames that are predicted to be available immediately,
    661      * if the client were to release the first frames and then call obtainBuffer() again.
    662      * This value is only a prediction, and needs to be confirmed.
    663      * It will be set to zero for an error return.
    664      *
    665      * If the track buffer is full and track is stopped, obtainBuffer() returns WOULD_BLOCK
    666      * regardless of the value of waitCount.
    667      * If the track buffer is full and track is not stopped, obtainBuffer() blocks with a
    668      * maximum timeout based on waitCount; see chart below.
    669      * Buffers will be returned until the pool
    670      * is exhausted, at which point obtainBuffer() will either block
    671      * or return WOULD_BLOCK depending on the value of the "waitCount"
    672      * parameter.
    673      *
    674      * Interpretation of waitCount:
    675      *  +n  limits wait time to n * WAIT_PERIOD_MS,
    676      *  -1  causes an (almost) infinite wait time,
    677      *   0  non-blocking.
    678      *
    679      * Buffer fields
    680      * On entry:
    681      *  frameCount  number of [empty slots for] frames requested
    682      *  size        ignored
    683      *  raw         ignored
    684      * After error return:
    685      *  frameCount  0
    686      *  size        0
    687      *  raw         undefined
    688      * After successful return:
    689      *  frameCount  actual number of [empty slots for] frames available, <= number requested
    690      *  size        actual number of bytes available
    691      *  raw         pointer to the buffer
    692      */
    693             status_t    obtainBuffer(Buffer* audioBuffer, int32_t waitCount,
    694                                 size_t *nonContig = NULL);
    695 
    696 private:
    697     /* If nonContig is non-NULL, it is an output parameter that will be set to the number of
    698      * additional non-contiguous frames that are predicted to be available immediately,
    699      * if the client were to release the first frames and then call obtainBuffer() again.
    700      * This value is only a prediction, and needs to be confirmed.
    701      * It will be set to zero for an error return.
    702      * FIXME We could pass an array of Buffers instead of only one Buffer to obtainBuffer(),
    703      * in case the requested amount of frames is in two or more non-contiguous regions.
    704      * FIXME requested and elapsed are both relative times.  Consider changing to absolute time.
    705      */
    706             status_t    obtainBuffer(Buffer* audioBuffer, const struct timespec *requested,
    707                                      struct timespec *elapsed = NULL, size_t *nonContig = NULL);
    708 public:
    709 
    710     /* Public API for TRANSFER_OBTAIN mode.
    711      * Release a filled buffer of frames for AudioFlinger to process.
    712      *
    713      * Buffer fields:
    714      *  frameCount  currently ignored but recommend to set to actual number of frames filled
    715      *  size        actual number of bytes filled, must be multiple of frameSize
    716      *  raw         ignored
    717      */
    718             void        releaseBuffer(const Buffer* audioBuffer);
    719 
    720     /* As a convenience we provide a write() interface to the audio buffer.
    721      * Input parameter 'size' is in byte units.
    722      * This is implemented on top of obtainBuffer/releaseBuffer. For best
    723      * performance use callbacks. Returns actual number of bytes written >= 0,
    724      * or one of the following negative status codes:
    725      *      INVALID_OPERATION   AudioTrack is configured for static buffer or streaming mode
    726      *      BAD_VALUE           size is invalid
    727      *      WOULD_BLOCK         when obtainBuffer() returns same, or
    728      *                          AudioTrack was stopped during the write
    729      *      DEAD_OBJECT         when AudioFlinger dies or the output device changes and
    730      *                          the track cannot be automatically restored.
    731      *                          The application needs to recreate the AudioTrack
    732      *                          because the audio device changed or AudioFlinger died.
    733      *                          This typically occurs for direct or offload tracks
    734      *                          or if mDoNotReconnect is true.
    735      *      or any other error code returned by IAudioTrack::start() or restoreTrack_l().
    736      * Default behavior is to only return when all data has been transferred. Set 'blocking' to
    737      * false for the method to return immediately without waiting to try multiple times to write
    738      * the full content of the buffer.
    739      */
    740             ssize_t     write(const void* buffer, size_t size, bool blocking = true);
    741 
    742     /*
    743      * Dumps the state of an audio track.
    744      * Not a general-purpose API; intended only for use by media player service to dump its tracks.
    745      */
    746             status_t    dump(int fd, const Vector<String16>& args) const;
    747 
    748     /*
    749      * Return the total number of frames which AudioFlinger desired but were unavailable,
    750      * and thus which resulted in an underrun.  Reset to zero by stop().
    751      */
    752             uint32_t    getUnderrunFrames() const;
    753 
    754     /* Get the flags */
    755             audio_output_flags_t getFlags() const { AutoMutex _l(mLock); return mFlags; }
    756 
    757     /* Set parameters - only possible when using direct output */
    758             status_t    setParameters(const String8& keyValuePairs);
    759 
    760     /* Sets the volume shaper object */
    761             media::VolumeShaper::Status applyVolumeShaper(
    762                     const sp<media::VolumeShaper::Configuration>& configuration,
    763                     const sp<media::VolumeShaper::Operation>& operation);
    764 
    765     /* Gets the volume shaper state */
    766             sp<media::VolumeShaper::State> getVolumeShaperState(int id);
    767 
    768     /* Selects the presentation (if available) */
    769             status_t    selectPresentation(int presentationId, int programId);
    770 
    771     /* Get parameters */
    772             String8     getParameters(const String8& keys);
    773 
    774     /* Poll for a timestamp on demand.
    775      * Use if EVENT_NEW_TIMESTAMP is not delivered often enough for your needs,
    776      * or if you need to get the most recent timestamp outside of the event callback handler.
    777      * Caution: calling this method too often may be inefficient;
    778      * if you need a high resolution mapping between frame position and presentation time,
    779      * consider implementing that at application level, based on the low resolution timestamps.
    780      * Returns NO_ERROR    if timestamp is valid.
    781      *         WOULD_BLOCK if called in STOPPED or FLUSHED state, or if called immediately after
    782      *                     start/ACTIVE, when the number of frames consumed is less than the
    783      *                     overall hardware latency to physical output. In WOULD_BLOCK cases,
    784      *                     one might poll again, or use getPosition(), or use 0 position and
    785      *                     current time for the timestamp.
    786      *         DEAD_OBJECT if AudioFlinger dies or the output device changes and
    787      *                     the track cannot be automatically restored.
    788      *                     The application needs to recreate the AudioTrack
    789      *                     because the audio device changed or AudioFlinger died.
    790      *                     This typically occurs for direct or offload tracks
    791      *                     or if mDoNotReconnect is true.
    792      *         INVALID_OPERATION  wrong state, or some other error.
    793      *
    794      * The timestamp parameter is undefined on return, if status is not NO_ERROR.
    795      */
    796             status_t    getTimestamp(AudioTimestamp& timestamp);
    797 private:
    798             status_t    getTimestamp_l(AudioTimestamp& timestamp);
    799 public:
    800 
    801     /* Return the extended timestamp, with additional timebase info and improved drain behavior.
    802      *
    803      * This is similar to the AudioTrack.java API:
    804      * getTimestamp(@NonNull AudioTimestamp timestamp, @AudioTimestamp.Timebase int timebase)
    805      *
    806      * Some differences between this method and the getTimestamp(AudioTimestamp& timestamp) method
    807      *
    808      *   1. stop() by itself does not reset the frame position.
    809      *      A following start() resets the frame position to 0.
    810      *   2. flush() by itself does not reset the frame position.
    811      *      The frame position advances by the number of frames flushed,
    812      *      when the first frame after flush reaches the audio sink.
    813      *   3. BOOTTIME clock offsets are provided to help synchronize with
    814      *      non-audio streams, e.g. sensor data.
    815      *   4. Position is returned with 64 bits of resolution.
    816      *
    817      * Parameters:
    818      *  timestamp: A pointer to the caller allocated ExtendedTimestamp.
    819      *
    820      * Returns NO_ERROR    on success; timestamp is filled with valid data.
    821      *         BAD_VALUE   if timestamp is NULL.
    822      *         WOULD_BLOCK if called immediately after start() when the number
    823      *                     of frames consumed is less than the
    824      *                     overall hardware latency to physical output. In WOULD_BLOCK cases,
    825      *                     one might poll again, or use getPosition(), or use 0 position and
    826      *                     current time for the timestamp.
    827      *                     If WOULD_BLOCK is returned, the timestamp is still
    828      *                     modified with the LOCATION_CLIENT portion filled.
    829      *         DEAD_OBJECT if AudioFlinger dies or the output device changes and
    830      *                     the track cannot be automatically restored.
    831      *                     The application needs to recreate the AudioTrack
    832      *                     because the audio device changed or AudioFlinger died.
    833      *                     This typically occurs for direct or offloaded tracks
    834      *                     or if mDoNotReconnect is true.
    835      *         INVALID_OPERATION  if called on a offloaded or direct track.
    836      *                     Use getTimestamp(AudioTimestamp& timestamp) instead.
    837      */
    838             status_t getTimestamp(ExtendedTimestamp *timestamp);
    839 private:
    840             status_t getTimestamp_l(ExtendedTimestamp *timestamp);
    841 public:
    842 
    843     /* Add an AudioDeviceCallback. The caller will be notified when the audio device to which this
    844      * AudioTrack is routed is updated.
    845      * Replaces any previously installed callback.
    846      * Parameters:
    847      *  callback:  The callback interface
    848      * Returns NO_ERROR if successful.
    849      *         INVALID_OPERATION if the same callback is already installed.
    850      *         NO_INIT or PREMISSION_DENIED if AudioFlinger service is not reachable
    851      *         BAD_VALUE if the callback is NULL
    852      */
    853             status_t addAudioDeviceCallback(const sp<AudioSystem::AudioDeviceCallback>& callback);
    854 
    855     /* remove an AudioDeviceCallback.
    856      * Parameters:
    857      *  callback:  The callback interface
    858      * Returns NO_ERROR if successful.
    859      *         INVALID_OPERATION if the callback is not installed
    860      *         BAD_VALUE if the callback is NULL
    861      */
    862             status_t removeAudioDeviceCallback(
    863                     const sp<AudioSystem::AudioDeviceCallback>& callback);
    864 
    865             // AudioSystem::AudioDeviceCallback> virtuals
    866             virtual void onAudioDeviceUpdate(audio_io_handle_t audioIo,
    867                                              audio_port_handle_t deviceId);
    868 
    869 
    870 
    871     /* Obtain the pending duration in milliseconds for playback of pure PCM
    872      * (mixable without embedded timing) data remaining in AudioTrack.
    873      *
    874      * This is used to estimate the drain time for the client-server buffer
    875      * so the choice of ExtendedTimestamp::LOCATION_SERVER is default.
    876      * One may optionally request to find the duration to play through the HAL
    877      * by specifying a location ExtendedTimestamp::LOCATION_KERNEL; however,
    878      * INVALID_OPERATION may be returned if the kernel location is unavailable.
    879      *
    880      * Returns NO_ERROR  if successful.
    881      *         INVALID_OPERATION if ExtendedTimestamp::LOCATION_KERNEL cannot be obtained
    882      *                   or the AudioTrack does not contain pure PCM data.
    883      *         BAD_VALUE if msec is nullptr or location is invalid.
    884      */
    885             status_t pendingDuration(int32_t *msec,
    886                     ExtendedTimestamp::Location location = ExtendedTimestamp::LOCATION_SERVER);
    887 
    888     /* hasStarted() is used to determine if audio is now audible at the device after
    889      * a start() command. The underlying implementation checks a nonzero timestamp position
    890      * or increment for the audible assumption.
    891      *
    892      * hasStarted() returns true if the track has been started() and audio is audible
    893      * and no subsequent pause() or flush() has been called.  Immediately after pause() or
    894      * flush() hasStarted() will return false.
    895      *
    896      * If stop() has been called, hasStarted() will return true if audio is still being
    897      * delivered or has finished delivery (even if no audio was written) for both offloaded
    898      * and normal tracks. This property removes a race condition in checking hasStarted()
    899      * for very short clips, where stop() must be called to finish drain.
    900      *
    901      * In all cases, hasStarted() may turn false briefly after a subsequent start() is called
    902      * until audio becomes audible again.
    903      */
    904             bool hasStarted(); // not const
    905 
    906             bool isPlaying() {
    907                 AutoMutex lock(mLock);
    908                 return mState == STATE_ACTIVE || mState == STATE_STOPPING;
    909             }
    910 protected:
    911     /* copying audio tracks is not allowed */
    912                         AudioTrack(const AudioTrack& other);
    913             AudioTrack& operator = (const AudioTrack& other);
    914 
    915     /* a small internal class to handle the callback */
    916     class AudioTrackThread : public Thread
    917     {
    918     public:
    919         AudioTrackThread(AudioTrack& receiver, bool bCanCallJava = false);
    920 
    921         // Do not call Thread::requestExitAndWait() without first calling requestExit().
    922         // Thread::requestExitAndWait() is not virtual, and the implementation doesn't do enough.
    923         virtual void        requestExit();
    924 
    925                 void        pause();    // suspend thread from execution at next loop boundary
    926                 void        resume();   // allow thread to execute, if not requested to exit
    927                 void        wake();     // wake to handle changed notification conditions.
    928 
    929     private:
    930                 void        pauseInternal(nsecs_t ns = 0LL);
    931                                         // like pause(), but only used internally within thread
    932 
    933         friend class AudioTrack;
    934         virtual bool        threadLoop();
    935         AudioTrack&         mReceiver;
    936         virtual ~AudioTrackThread();
    937         Mutex               mMyLock;    // Thread::mLock is private
    938         Condition           mMyCond;    // Thread::mThreadExitedCondition is private
    939         bool                mPaused;    // whether thread is requested to pause at next loop entry
    940         bool                mPausedInt; // whether thread internally requests pause
    941         nsecs_t             mPausedNs;  // if mPausedInt then associated timeout, otherwise ignored
    942         bool                mIgnoreNextPausedInt;   // skip any internal pause and go immediately
    943                                         // to processAudioBuffer() as state may have changed
    944                                         // since pause time calculated.
    945     };
    946 
    947             // body of AudioTrackThread::threadLoop()
    948             // returns the maximum amount of time before we would like to run again, where:
    949             //      0           immediately
    950             //      > 0         no later than this many nanoseconds from now
    951             //      NS_WHENEVER still active but no particular deadline
    952             //      NS_INACTIVE inactive so don't run again until re-started
    953             //      NS_NEVER    never again
    954             static const nsecs_t NS_WHENEVER = -1, NS_INACTIVE = -2, NS_NEVER = -3;
    955             nsecs_t processAudioBuffer();
    956 
    957             // caller must hold lock on mLock for all _l methods
    958 
    959             void updateLatency_l(); // updates mAfLatency and mLatency from AudioSystem cache
    960 
    961             status_t createTrack_l();
    962 
    963             // can only be called when mState != STATE_ACTIVE
    964             void flush_l();
    965 
    966             void setLoop_l(uint32_t loopStart, uint32_t loopEnd, int loopCount);
    967 
    968             // FIXME enum is faster than strcmp() for parameter 'from'
    969             status_t restoreTrack_l(const char *from);
    970 
    971             uint32_t    getUnderrunCount_l() const;
    972 
    973             bool     isOffloaded() const;
    974             bool     isDirect() const;
    975             bool     isOffloadedOrDirect() const;
    976 
    977             bool     isOffloaded_l() const
    978                 { return (mFlags & AUDIO_OUTPUT_FLAG_COMPRESS_OFFLOAD) != 0; }
    979 
    980             bool     isOffloadedOrDirect_l() const
    981                 { return (mFlags & (AUDIO_OUTPUT_FLAG_COMPRESS_OFFLOAD|
    982                                                 AUDIO_OUTPUT_FLAG_DIRECT)) != 0; }
    983 
    984             bool     isDirect_l() const
    985                 { return (mFlags & AUDIO_OUTPUT_FLAG_DIRECT) != 0; }
    986 
    987             // pure pcm data is mixable (which excludes HW_AV_SYNC, with embedded timing)
    988             bool     isPurePcmData_l() const
    989                 { return audio_is_linear_pcm(mFormat)
    990                         && (mAttributes.flags & AUDIO_FLAG_HW_AV_SYNC) == 0; }
    991 
    992             // increment mPosition by the delta of mServer, and return new value of mPosition
    993             Modulo<uint32_t> updateAndGetPosition_l();
    994 
    995             // check sample rate and speed is compatible with AudioTrack
    996             bool     isSampleRateSpeedAllowed_l(uint32_t sampleRate, float speed);
    997 
    998             void     restartIfDisabled();
    999 
   1000             void     updateRoutedDeviceId_l();
   1001 
   1002     // Next 4 fields may be changed if IAudioTrack is re-created, but always != 0
   1003     sp<IAudioTrack>         mAudioTrack;
   1004     sp<IMemory>             mCblkMemory;
   1005     audio_track_cblk_t*     mCblk;                  // re-load after mLock.unlock()
   1006     audio_io_handle_t       mOutput;                // returned by AudioSystem::getOutputForAttr()
   1007 
   1008     sp<AudioTrackThread>    mAudioTrackThread;
   1009     bool                    mThreadCanCallJava;
   1010 
   1011     float                   mVolume[2];
   1012     float                   mSendLevel;
   1013     mutable uint32_t        mSampleRate;            // mutable because getSampleRate() can update it
   1014     uint32_t                mOriginalSampleRate;
   1015     AudioPlaybackRate       mPlaybackRate;
   1016     float                   mMaxRequiredSpeed;      // use PCM buffer size to allow this speed
   1017 
   1018     // Corresponds to current IAudioTrack, value is reported back by AudioFlinger to the client.
   1019     // This allocated buffer size is maintained by the proxy.
   1020     size_t                  mFrameCount;            // maximum size of buffer
   1021 
   1022     size_t                  mReqFrameCount;         // frame count to request the first or next time
   1023                                                     // a new IAudioTrack is needed, non-decreasing
   1024 
   1025     // The following AudioFlinger server-side values are cached in createAudioTrack_l().
   1026     // These values can be used for informational purposes until the track is invalidated,
   1027     // whereupon restoreTrack_l() calls createTrack_l() to update the values.
   1028     uint32_t                mAfLatency;             // AudioFlinger latency in ms
   1029     size_t                  mAfFrameCount;          // AudioFlinger frame count
   1030     uint32_t                mAfSampleRate;          // AudioFlinger sample rate
   1031 
   1032     // constant after constructor or set()
   1033     audio_format_t          mFormat;                // as requested by client, not forced to 16-bit
   1034     audio_stream_type_t     mStreamType;            // mStreamType == AUDIO_STREAM_DEFAULT implies
   1035                                                     // this AudioTrack has valid attributes
   1036     uint32_t                mChannelCount;
   1037     audio_channel_mask_t    mChannelMask;
   1038     sp<IMemory>             mSharedBuffer;
   1039     transfer_type           mTransfer;
   1040     audio_offload_info_t    mOffloadInfoCopy;
   1041     const audio_offload_info_t* mOffloadInfo;
   1042     audio_attributes_t      mAttributes;
   1043 
   1044     size_t                  mFrameSize;             // frame size in bytes
   1045 
   1046     status_t                mStatus;
   1047 
   1048     // can change dynamically when IAudioTrack invalidated
   1049     uint32_t                mLatency;               // in ms
   1050 
   1051     // Indicates the current track state.  Protected by mLock.
   1052     enum State {
   1053         STATE_ACTIVE,
   1054         STATE_STOPPED,
   1055         STATE_PAUSED,
   1056         STATE_PAUSED_STOPPING,
   1057         STATE_FLUSHED,
   1058         STATE_STOPPING,
   1059     }                       mState;
   1060 
   1061     // for client callback handler
   1062     callback_t              mCbf;                   // callback handler for events, or NULL
   1063     void*                   mUserData;
   1064 
   1065     // for notification APIs
   1066 
   1067     // next 2 fields are const after constructor or set()
   1068     uint32_t                mNotificationFramesReq; // requested number of frames between each
   1069                                                     // notification callback,
   1070                                                     // at initial source sample rate
   1071     uint32_t                mNotificationsPerBufferReq;
   1072                                                     // requested number of notifications per buffer,
   1073                                                     // currently only used for fast tracks with
   1074                                                     // default track buffer size
   1075 
   1076     uint32_t                mNotificationFramesAct; // actual number of frames between each
   1077                                                     // notification callback,
   1078                                                     // at initial source sample rate
   1079     bool                    mRefreshRemaining;      // processAudioBuffer() should refresh
   1080                                                     // mRemainingFrames and mRetryOnPartialBuffer
   1081 
   1082                                                     // used for static track cbf and restoration
   1083     int32_t                 mLoopCount;             // last setLoop loopCount; zero means disabled
   1084     uint32_t                mLoopStart;             // last setLoop loopStart
   1085     uint32_t                mLoopEnd;               // last setLoop loopEnd
   1086     int32_t                 mLoopCountNotified;     // the last loopCount notified by callback.
   1087                                                     // mLoopCountNotified counts down, matching
   1088                                                     // the remaining loop count for static track
   1089                                                     // playback.
   1090 
   1091     // These are private to processAudioBuffer(), and are not protected by a lock
   1092     uint32_t                mRemainingFrames;       // number of frames to request in obtainBuffer()
   1093     bool                    mRetryOnPartialBuffer;  // sleep and retry after partial obtainBuffer()
   1094     uint32_t                mObservedSequence;      // last observed value of mSequence
   1095 
   1096     Modulo<uint32_t>        mMarkerPosition;        // in wrapping (overflow) frame units
   1097     bool                    mMarkerReached;
   1098     Modulo<uint32_t>        mNewPosition;           // in frames
   1099     uint32_t                mUpdatePeriod;          // in frames, zero means no EVENT_NEW_POS
   1100 
   1101     Modulo<uint32_t>        mServer;                // in frames, last known mProxy->getPosition()
   1102                                                     // which is count of frames consumed by server,
   1103                                                     // reset by new IAudioTrack,
   1104                                                     // whether it is reset by stop() is TBD
   1105     Modulo<uint32_t>        mPosition;              // in frames, like mServer except continues
   1106                                                     // monotonically after new IAudioTrack,
   1107                                                     // and could be easily widened to uint64_t
   1108     Modulo<uint32_t>        mReleased;              // count of frames released to server
   1109                                                     // but not necessarily consumed by server,
   1110                                                     // reset by stop() but continues monotonically
   1111                                                     // after new IAudioTrack to restore mPosition,
   1112                                                     // and could be easily widened to uint64_t
   1113     int64_t                 mStartFromZeroUs;       // the start time after flush or stop,
   1114                                                     // when position should be 0.
   1115                                                     // only used for offloaded and direct tracks.
   1116     int64_t                 mStartNs;               // the time when start() is called.
   1117     ExtendedTimestamp       mStartEts;              // Extended timestamp at start for normal
   1118                                                     // AudioTracks.
   1119     AudioTimestamp          mStartTs;               // Timestamp at start for offloaded or direct
   1120                                                     // AudioTracks.
   1121 
   1122     bool                    mPreviousTimestampValid;// true if mPreviousTimestamp is valid
   1123     bool                    mTimestampStartupGlitchReported; // reduce log spam
   1124     bool                    mRetrogradeMotionReported; // reduce log spam
   1125     AudioTimestamp          mPreviousTimestamp;     // used to detect retrograde motion
   1126     ExtendedTimestamp::Location mPreviousLocation;  // location used for previous timestamp
   1127 
   1128     uint32_t                mUnderrunCountOffset;   // updated when restoring tracks
   1129 
   1130     int64_t                 mFramesWritten;         // total frames written. reset to zero after
   1131                                                     // the start() following stop(). It is not
   1132                                                     // changed after restoring the track or
   1133                                                     // after flush.
   1134     int64_t                 mFramesWrittenServerOffset; // An offset to server frames due to
   1135                                                     // restoring AudioTrack, or stop/start.
   1136                                                     // This offset is also used for static tracks.
   1137     int64_t                 mFramesWrittenAtRestore; // Frames written at restore point (or frames
   1138                                                     // delivered for static tracks).
   1139                                                     // -1 indicates no previous restore point.
   1140 
   1141     audio_output_flags_t    mFlags;                 // same as mOrigFlags, except for bits that may
   1142                                                     // be denied by client or server, such as
   1143                                                     // AUDIO_OUTPUT_FLAG_FAST.  mLock must be
   1144                                                     // held to read or write those bits reliably.
   1145     audio_output_flags_t    mOrigFlags;             // as specified in constructor or set(), const
   1146 
   1147     bool                    mDoNotReconnect;
   1148 
   1149     audio_session_t         mSessionId;
   1150     int                     mAuxEffectId;
   1151 
   1152     mutable Mutex           mLock;
   1153 
   1154     int                     mPreviousPriority;          // before start()
   1155     SchedPolicy             mPreviousSchedulingGroup;
   1156     bool                    mAwaitBoost;    // thread should wait for priority boost before running
   1157 
   1158     // The proxy should only be referenced while a lock is held because the proxy isn't
   1159     // multi-thread safe, especially the SingleStateQueue part of the proxy.
   1160     // An exception is that a blocking ClientProxy::obtainBuffer() may be called without a lock,
   1161     // provided that the caller also holds an extra reference to the proxy and shared memory to keep
   1162     // them around in case they are replaced during the obtainBuffer().
   1163     sp<StaticAudioTrackClientProxy> mStaticProxy;   // for type safety only
   1164     sp<AudioTrackClientProxy>       mProxy;         // primary owner of the memory
   1165 
   1166     bool                    mInUnderrun;            // whether track is currently in underrun state
   1167     uint32_t                mPausedPosition;
   1168 
   1169     // For Device Selection API
   1170     //  a value of AUDIO_PORT_HANDLE_NONE indicated default (AudioPolicyManager) routing.
   1171     audio_port_handle_t    mSelectedDeviceId; // Device requested by the application.
   1172     audio_port_handle_t    mRoutedDeviceId;   // Device actually selected by audio policy manager:
   1173                                               // May not match the app selection depending on other
   1174                                               // activity and connected devices.
   1175 
   1176     sp<media::VolumeHandler>       mVolumeHandler;
   1177 
   1178 private:
   1179     class DeathNotifier : public IBinder::DeathRecipient {
   1180     public:
   1181         DeathNotifier(AudioTrack* audioTrack) : mAudioTrack(audioTrack) { }
   1182     protected:
   1183         virtual void        binderDied(const wp<IBinder>& who);
   1184     private:
   1185         const wp<AudioTrack> mAudioTrack;
   1186     };
   1187 
   1188     sp<DeathNotifier>       mDeathNotifier;
   1189     uint32_t                mSequence;              // incremented for each new IAudioTrack attempt
   1190     uid_t                   mClientUid;
   1191     pid_t                   mClientPid;
   1192 
   1193     wp<AudioSystem::AudioDeviceCallback> mDeviceCallback;
   1194 
   1195 private:
   1196     class MediaMetrics {
   1197       public:
   1198         MediaMetrics() : mAnalyticsItem(new MediaAnalyticsItem("audiotrack")) {
   1199         }
   1200         ~MediaMetrics() {
   1201             // mAnalyticsItem alloc failure will be flagged in the constructor
   1202             // don't log empty records
   1203             if (mAnalyticsItem->count() > 0) {
   1204                 mAnalyticsItem->selfrecord();
   1205             }
   1206         }
   1207         void gather(const AudioTrack *track);
   1208         MediaAnalyticsItem *dup() { return mAnalyticsItem->dup(); }
   1209       private:
   1210         std::unique_ptr<MediaAnalyticsItem> mAnalyticsItem;
   1211     };
   1212     MediaMetrics mMediaMetrics;
   1213 };
   1214 
   1215 }; // namespace android
   1216 
   1217 #endif // ANDROID_AUDIOTRACK_H
   1218