diff options
Diffstat (limited to 'include/private/media/AudioTrackShared.h')
| -rw-r--r-- | include/private/media/AudioTrackShared.h | 47 |
1 files changed, 39 insertions, 8 deletions
diff --git a/include/private/media/AudioTrackShared.h b/include/private/media/AudioTrackShared.h index 20abd51..dd97ce4 100644 --- a/include/private/media/AudioTrackShared.h +++ b/include/private/media/AudioTrackShared.h @@ -59,8 +59,8 @@ struct audio_track_cblk_t // The data members are grouped so that members accessed frequently and in the same context // are in the same line of data cache. - Mutex lock; - Condition cv; + Mutex lock; // sizeof(int) + Condition cv; // sizeof(int) volatile uint32_t user; volatile uint32_t server; uint32_t userBase; @@ -71,21 +71,28 @@ struct audio_track_cblk_t uint32_t loopStart; uint32_t loopEnd; int loopCount; - volatile union { - uint16_t volume[2]; - uint32_t volumeLR; - }; + + // Channel volumes are fixed point U4.12, so 0x1000 means 1.0. + // Left channel is in [0:15], right channel is in [16:31]. + // Always read and write the combined pair atomically. + // For AudioTrack only, not used by AudioRecord. +private: + uint32_t mVolumeLR; +public: + uint32_t sampleRate; // NOTE: audio_track_cblk_t::frameSize is not equal to AudioTrack::frameSize() for // 8 bit PCM data: in this case, mCblk->frameSize is based on a sample size of // 16 bit because data is converted to 16 bit before being stored in buffer - uint8_t frameSize; + uint8_t frameSize; // would normally be size_t, but 8 bits is plenty uint8_t pad1; uint16_t bufferTimeoutMs; // Maximum cumulated timeout before restarting audioflinger uint16_t waitTimeMs; // Cumulated wait time - uint16_t sendLevel; +private: + uint16_t mSendLevel; // Fixed point U4.12 so 0x1000 means 1.0 +public: volatile int32_t flags; // Cache line boundary (32 bytes) @@ -98,6 +105,30 @@ struct audio_track_cblk_t uint32_t framesAvailable_l(); uint32_t framesReady(); bool tryLock(); + + // No barriers on the following operations, so the ordering of loads/stores + // with respect to other parameters is UNPREDICTABLE. That's considered safe. + + // for AudioTrack client only, caller must limit to 0.0 <= sendLevel <= 1.0 + void setSendLevel(float sendLevel) { + mSendLevel = uint16_t(sendLevel * 0x1000); + } + + // for AudioFlinger only; the return value must be validated by the caller + uint16_t getSendLevel_U4_12() const { + return mSendLevel; + } + + // for AudioTrack client only, caller must limit to 0 <= volumeLR <= 0x10001000 + void setVolumeLR(uint32_t volumeLR) { + mVolumeLR = volumeLR; + } + + // for AudioFlinger only; the return value must be validated by the caller + uint32_t getVolumeLR() const { + return mVolumeLR; + } + }; |