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      1 /*
      2  * Copyright 2018 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_JAUDIOTRACK_H
     18 #define ANDROID_JAUDIOTRACK_H
     19 
     20 #include <jni.h>
     21 #include <media/AudioResamplerPublic.h>
     22 #include <media/AudioSystem.h>
     23 #include <media/VolumeShaper.h>
     24 #include <system/audio.h>
     25 #include <utils/Errors.h>
     26 
     27 #include <media/AudioTimestamp.h>   // It has dependency on audio.h/Errors.h, but doesn't
     28                                     // include them in it. Therefore it is included here at last.
     29 
     30 namespace android {
     31 
     32 class JAudioTrack {
     33 public:
     34 
     35     /* Events used by AudioTrack callback function (callback_t).
     36      * Keep in sync with frameworks/base/media/java/android/media/AudioTrack.java NATIVE_EVENT_*.
     37      */
     38     enum event_type {
     39         EVENT_MORE_DATA = 0,        // Request to write more data to buffer.
     40         EVENT_NEW_IAUDIOTRACK = 6,  // IAudioTrack was re-created, either due to re-routing and
     41                                     // voluntary invalidation by mediaserver, or mediaserver crash.
     42         EVENT_STREAM_END = 7,       // Sent after all the buffers queued in AF and HW are played
     43                                     // back (after stop is called) for an offloaded track.
     44     };
     45 
     46     class Buffer
     47     {
     48     public:
     49         size_t      mSize;        // input/output in bytes.
     50         void*       mData;        // pointer to the audio data.
     51     };
     52 
     53     /* As a convenience, if a callback is supplied, a handler thread
     54      * is automatically created with the appropriate priority. This thread
     55      * invokes the callback when a new buffer becomes available or various conditions occur.
     56      *
     57      * Parameters:
     58      *
     59      * event:   type of event notified (see enum AudioTrack::event_type).
     60      * user:    Pointer to context for use by the callback receiver.
     61      * info:    Pointer to optional parameter according to event type:
     62      *          - EVENT_MORE_DATA: pointer to JAudioTrack::Buffer struct. The callback must not
     63      *            write more bytes than indicated by 'size' field and update 'size' if fewer bytes
     64      *            are written.
     65      *          - EVENT_NEW_IAUDIOTRACK: unused.
     66      *          - EVENT_STREAM_END: unused.
     67      */
     68 
     69     typedef void (*callback_t)(int event, void* user, void *info);
     70 
     71     /* Creates an JAudioTrack object for non-offload mode.
     72      * Once created, the track needs to be started before it can be used.
     73      * Unspecified values are set to appropriate default values.
     74      *
     75      * Parameters:
     76      *
     77      * streamType:         Select the type of audio stream this track is attached to
     78      *                     (e.g. AUDIO_STREAM_MUSIC).
     79      * sampleRate:         Data source sampling rate in Hz.  Zero means to use the sink sample rate.
     80      *                     A non-zero value must be specified if AUDIO_OUTPUT_FLAG_DIRECT is set.
     81      *                     0 will not work with current policy implementation for direct output
     82      *                     selection where an exact match is needed for sampling rate.
     83      *                     (TODO: Check direct output after flags can be used in Java AudioTrack.)
     84      * format:             Audio format. For mixed tracks, any PCM format supported by server is OK.
     85      *                     For direct and offloaded tracks, the possible format(s) depends on the
     86      *                     output sink.
     87      *                     (TODO: How can we check whether a format is supported?)
     88      * channelMask:        Channel mask, such that audio_is_output_channel(channelMask) is true.
     89      * cbf:                Callback function. If not null, this function is called periodically
     90      *                     to provide new data and inform of marker, position updates, etc.
     91      * user:               Context for use by the callback receiver.
     92      * frameCount:         Minimum size of track PCM buffer in frames. This defines the
     93      *                     application's contribution to the latency of the track.
     94      *                     The actual size selected by the JAudioTrack could be larger if the
     95      *                     requested size is not compatible with current audio HAL configuration.
     96      *                     Zero means to use a default value.
     97      * sessionId:          Specific session ID, or zero to use default.
     98      * pAttributes:        If not NULL, supersedes streamType for use case selection.
     99      * maxRequiredSpeed:   For PCM tracks, this creates an appropriate buffer size that will allow
    100      *                     maxRequiredSpeed playback. Values less than 1.0f and greater than
    101      *                     AUDIO_TIMESTRETCH_SPEED_MAX will be clamped.  For non-PCM tracks
    102      *                     and direct or offloaded tracks, this parameter is ignored.
    103      *                     (TODO: Handle this after offload / direct track is supported.)
    104      *
    105      * TODO: Revive removed arguments after offload mode is supported.
    106      */
    107     JAudioTrack(audio_stream_type_t streamType,
    108                 uint32_t sampleRate,
    109                 audio_format_t format,
    110                 audio_channel_mask_t channelMask,
    111                 callback_t cbf,
    112                 void* user,
    113                 size_t frameCount = 0,
    114                 audio_session_t sessionId  = AUDIO_SESSION_ALLOCATE,
    115                 const audio_attributes_t* pAttributes = NULL,
    116                 float maxRequiredSpeed = 1.0f);
    117 
    118     /*
    119        // Q. May be used in AudioTrack.setPreferredDevice(AudioDeviceInfo)?
    120        audio_port_handle_t selectedDeviceId,
    121 
    122        // TODO: No place to use these values.
    123        int32_t notificationFrames,
    124        const audio_offload_info_t *offloadInfo,
    125     */
    126 
    127     virtual ~JAudioTrack();
    128 
    129     size_t frameCount();
    130     size_t channelCount();
    131 
    132     /* Returns this track's estimated latency in milliseconds.
    133      * This includes the latency due to AudioTrack buffer size, AudioMixer (if any)
    134      * and audio hardware driver.
    135      */
    136     uint32_t latency();
    137 
    138     /* Return the total number of frames played since playback start.
    139      * The counter will wrap (overflow) periodically, e.g. every ~27 hours at 44.1 kHz.
    140      * It is reset to zero by flush(), reload(), and stop().
    141      *
    142      * Parameters:
    143      *
    144      * position: Address where to return play head position.
    145      *
    146      * Returned status (from utils/Errors.h) can be:
    147      *  - NO_ERROR: successful operation
    148      *  - BAD_VALUE: position is NULL
    149      */
    150     status_t getPosition(uint32_t *position);
    151 
    152     // TODO: Does this comment apply same to Java AudioTrack::getTimestamp?
    153     // Changed the return type from status_t to bool, since Java AudioTrack::getTimestamp returns
    154     // boolean. Will Java getTimestampWithStatus() be public?
    155     /* Poll for a timestamp on demand.
    156      * Use if EVENT_NEW_TIMESTAMP is not delivered often enough for your needs,
    157      * or if you need to get the most recent timestamp outside of the event callback handler.
    158      * Caution: calling this method too often may be inefficient;
    159      * if you need a high resolution mapping between frame position and presentation time,
    160      * consider implementing that at application level, based on the low resolution timestamps.
    161      * Returns true if timestamp is valid.
    162      * The timestamp parameter is undefined on return, if false is returned.
    163      */
    164     bool getTimestamp(AudioTimestamp& timestamp);
    165 
    166     // TODO: This doc is just copied from AudioTrack.h. Revise it after implemenation.
    167     /* Return the extended timestamp, with additional timebase info and improved drain behavior.
    168      *
    169      * This is similar to the AudioTrack.java API:
    170      * getTimestamp(@NonNull AudioTimestamp timestamp, @AudioTimestamp.Timebase int timebase)
    171      *
    172      * Some differences between this method and the getTimestamp(AudioTimestamp& timestamp) method
    173      *
    174      *   1. stop() by itself does not reset the frame position.
    175      *      A following start() resets the frame position to 0.
    176      *   2. flush() by itself does not reset the frame position.
    177      *      The frame position advances by the number of frames flushed,
    178      *      when the first frame after flush reaches the audio sink.
    179      *   3. BOOTTIME clock offsets are provided to help synchronize with
    180      *      non-audio streams, e.g. sensor data.
    181      *   4. Position is returned with 64 bits of resolution.
    182      *
    183      * Parameters:
    184      *  timestamp: A pointer to the caller allocated ExtendedTimestamp.
    185      *
    186      * Returns NO_ERROR    on success; timestamp is filled with valid data.
    187      *         BAD_VALUE   if timestamp is NULL.
    188      *         WOULD_BLOCK if called immediately after start() when the number
    189      *                     of frames consumed is less than the
    190      *                     overall hardware latency to physical output. In WOULD_BLOCK cases,
    191      *                     one might poll again, or use getPosition(), or use 0 position and
    192      *                     current time for the timestamp.
    193      *                     If WOULD_BLOCK is returned, the timestamp is still
    194      *                     modified with the LOCATION_CLIENT portion filled.
    195      *         DEAD_OBJECT if AudioFlinger dies or the output device changes and
    196      *                     the track cannot be automatically restored.
    197      *                     The application needs to recreate the AudioTrack
    198      *                     because the audio device changed or AudioFlinger died.
    199      *                     This typically occurs for direct or offloaded tracks
    200      *                     or if mDoNotReconnect is true.
    201      *         INVALID_OPERATION  if called on a offloaded or direct track.
    202      *                     Use getTimestamp(AudioTimestamp& timestamp) instead.
    203      */
    204     status_t getTimestamp(ExtendedTimestamp *timestamp);
    205 
    206     /* Set source playback rate for timestretch
    207      * 1.0 is normal speed: < 1.0 is slower, > 1.0 is faster
    208      * 1.0 is normal pitch: < 1.0 is lower pitch, > 1.0 is higher pitch
    209      *
    210      * AUDIO_TIMESTRETCH_SPEED_MIN <= speed <= AUDIO_TIMESTRETCH_SPEED_MAX
    211      * AUDIO_TIMESTRETCH_PITCH_MIN <= pitch <= AUDIO_TIMESTRETCH_PITCH_MAX
    212      *
    213      * Speed increases the playback rate of media, but does not alter pitch.
    214      * Pitch increases the "tonal frequency" of media, but does not affect the playback rate.
    215      */
    216     status_t setPlaybackRate(const AudioPlaybackRate &playbackRate);
    217 
    218     /* Return current playback rate */
    219     const AudioPlaybackRate getPlaybackRate();
    220 
    221     /* Sets the volume shaper object */
    222     media::VolumeShaper::Status applyVolumeShaper(
    223             const sp<media::VolumeShaper::Configuration>& configuration,
    224             const sp<media::VolumeShaper::Operation>& operation);
    225 
    226     /* Set the send level for this track. An auxiliary effect should be attached
    227      * to the track with attachEffect(). Level must be >= 0.0 and <= 1.0.
    228      */
    229     status_t setAuxEffectSendLevel(float level);
    230 
    231     /* Attach track auxiliary output to specified effect. Use effectId = 0
    232      * to detach track from effect.
    233      *
    234      * Parameters:
    235      *
    236      * effectId: effectId obtained from AudioEffect::id().
    237      *
    238      * Returned status (from utils/Errors.h) can be:
    239      *  - NO_ERROR: successful operation
    240      *  - INVALID_OPERATION: The effect is not an auxiliary effect.
    241      *  - BAD_VALUE: The specified effect ID is invalid.
    242      */
    243     status_t attachAuxEffect(int effectId);
    244 
    245     /* Set volume for this track, mostly used for games' sound effects
    246      * left and right volumes. Levels must be >= 0.0 and <= 1.0.
    247      * This is the older API.  New applications should use setVolume(float) when possible.
    248      */
    249     status_t setVolume(float left, float right);
    250 
    251     /* Set volume for all channels. This is the preferred API for new applications,
    252      * especially for multi-channel content.
    253      */
    254     status_t setVolume(float volume);
    255 
    256     // TODO: Does this comment equally apply to the Java AudioTrack::play()?
    257     /* After it's created the track is not active. Call start() to
    258      * make it active. If set, the callback will start being called.
    259      * If the track was previously paused, volume is ramped up over the first mix buffer.
    260      */
    261     status_t start();
    262 
    263     // TODO: Does this comment still applies? It seems not. (obtainBuffer, AudioFlinger, ...)
    264     /* As a convenience we provide a write() interface to the audio buffer.
    265      * Input parameter 'size' is in byte units.
    266      * This is implemented on top of obtainBuffer/releaseBuffer. For best
    267      * performance use callbacks. Returns actual number of bytes written >= 0,
    268      * or one of the following negative status codes:
    269      *      INVALID_OPERATION   AudioTrack is configured for static buffer or streaming mode
    270      *      BAD_VALUE           size is invalid
    271      *      WOULD_BLOCK         when obtainBuffer() returns same, or
    272      *                          AudioTrack was stopped during the write
    273      *      DEAD_OBJECT         when AudioFlinger dies or the output device changes and
    274      *                          the track cannot be automatically restored.
    275      *                          The application needs to recreate the AudioTrack
    276      *                          because the audio device changed or AudioFlinger died.
    277      *                          This typically occurs for direct or offload tracks
    278      *                          or if mDoNotReconnect is true.
    279      *      or any other error code returned by IAudioTrack::start() or restoreTrack_l().
    280      * Default behavior is to only return when all data has been transferred. Set 'blocking' to
    281      * false for the method to return immediately without waiting to try multiple times to write
    282      * the full content of the buffer.
    283      */
    284     ssize_t write(const void* buffer, size_t size, bool blocking = true);
    285 
    286     // TODO: Does this comment equally apply to the Java AudioTrack::stop()?
    287     /* Stop a track.
    288      * In static buffer mode, the track is stopped immediately.
    289      * In streaming mode, the callback will cease being called.  Note that obtainBuffer() still
    290      * works and will fill up buffers until the pool is exhausted, and then will return WOULD_BLOCK.
    291      * In streaming mode the stop does not occur immediately: any data remaining in the buffer
    292      * is first drained, mixed, and output, and only then is the track marked as stopped.
    293      */
    294     void stop();
    295     bool stopped() const;
    296 
    297     // TODO: Does this comment equally apply to the Java AudioTrack::flush()?
    298     /* Flush a stopped or paused track. All previously buffered data is discarded immediately.
    299      * This has the effect of draining the buffers without mixing or output.
    300      * Flush is intended for streaming mode, for example before switching to non-contiguous content.
    301      * This function is a no-op if the track is not stopped or paused, or uses a static buffer.
    302      */
    303     void flush();
    304 
    305     // TODO: Does this comment equally apply to the Java AudioTrack::pause()?
    306     // At least we are not using obtainBuffer.
    307     /* Pause a track. After pause, the callback will cease being called and
    308      * obtainBuffer returns WOULD_BLOCK. Note that obtainBuffer() still works
    309      * and will fill up buffers until the pool is exhausted.
    310      * Volume is ramped down over the next mix buffer following the pause request,
    311      * and then the track is marked as paused. It can be resumed with ramp up by start().
    312      */
    313     void pause();
    314 
    315     bool isPlaying() const;
    316 
    317     /* Return current source sample rate in Hz.
    318      * If specified as zero in constructor, this will be the sink sample rate.
    319      */
    320     uint32_t getSampleRate();
    321 
    322     /* Returns the buffer duration in microseconds at current playback rate. */
    323     status_t getBufferDurationInUs(int64_t *duration);
    324 
    325     audio_format_t format();
    326 
    327     /*
    328      * Dumps the state of an audio track.
    329      * Not a general-purpose API; intended only for use by media player service to dump its tracks.
    330      */
    331     status_t dump(int fd, const Vector<String16>& args) const;
    332 
    333     /* Returns the ID of the audio device actually used by the output to which this AudioTrack is
    334      * attached. When the AudioTrack is inactive, it will return AUDIO_PORT_HANDLE_NONE.
    335      */
    336     audio_port_handle_t getRoutedDeviceId();
    337 
    338     /* Returns the ID of the audio session this AudioTrack belongs to. */
    339     audio_session_t getAudioSessionId();
    340 
    341     /* Selects the audio device to use for output of this AudioTrack. A value of
    342      * AUDIO_PORT_HANDLE_NONE indicates default routing.
    343      *
    344      * Parameters:
    345      *  The device ID of the selected device (as returned by the AudioDevicesManager API).
    346      *
    347      * Returned value:
    348      *  - NO_ERROR: successful operation
    349      *  - BAD_VALUE: failed to find the valid output device with given device Id.
    350      */
    351     status_t setOutputDevice(audio_port_handle_t deviceId);
    352 
    353     // TODO: Add AUDIO_OUTPUT_FLAG_DIRECT when it is possible to check.
    354     // TODO: Add AUDIO_FLAG_HW_AV_SYNC when it is possible to check.
    355     /* Returns the flags */
    356     audio_output_flags_t getFlags() const { return mFlags; }
    357 
    358     /* Obtain the pending duration in milliseconds for playback of pure PCM data remaining in
    359      * AudioTrack.
    360      *
    361      * Returns NO_ERROR if successful.
    362      *         INVALID_OPERATION if the AudioTrack does not contain pure PCM data.
    363      *         BAD_VALUE if msec is nullptr.
    364      */
    365     status_t pendingDuration(int32_t *msec);
    366 
    367     /* Adds an AudioDeviceCallback. The caller will be notified when the audio device to which this
    368      * AudioTrack is routed is updated.
    369      * Replaces any previously installed callback.
    370      *
    371      * Parameters:
    372      *
    373      * callback: The callback interface
    374      *
    375      * Returns NO_ERROR if successful.
    376      *         INVALID_OPERATION if the same callback is already installed.
    377      *         NO_INIT or PREMISSION_DENIED if AudioFlinger service is not reachable
    378      *         BAD_VALUE if the callback is NULL
    379      */
    380     status_t addAudioDeviceCallback(const sp<AudioSystem::AudioDeviceCallback>& callback);
    381 
    382     /* Removes an AudioDeviceCallback.
    383      *
    384      * Parameters:
    385      *
    386      * callback: The callback interface
    387      *
    388      * Returns NO_ERROR if successful.
    389      *         INVALID_OPERATION if the callback is not installed
    390      *         BAD_VALUE if the callback is NULL
    391      */
    392     status_t removeAudioDeviceCallback(const sp<AudioSystem::AudioDeviceCallback>& callback);
    393 
    394 private:
    395     audio_output_flags_t mFlags;
    396 
    397     jclass mAudioTrackCls;
    398     jobject mAudioTrackObj;
    399 
    400     /* Creates a Java VolumeShaper.Configuration object from VolumeShaper::Configuration */
    401     jobject createVolumeShaperConfigurationObj(
    402             const sp<media::VolumeShaper::Configuration>& config);
    403 
    404     /* Creates a Java VolumeShaper.Operation object from VolumeShaper::Operation */
    405     jobject createVolumeShaperOperationObj(
    406             const sp<media::VolumeShaper::Operation>& operation);
    407 
    408     /* Creates a Java StreamEventCallback object */
    409     jobject createStreamEventCallback(callback_t cbf, void* user);
    410 
    411     /* Creates a Java Executor object for running a callback */
    412     jobject createCallbackExecutor();
    413 
    414     status_t javaToNativeStatus(int javaStatus);
    415 };
    416 
    417 }; // namespace android
    418 
    419 #endif // ANDROID_JAUDIOTRACK_H
    420