AudioTrack obtain/release buffer comments (3f02be2c) · Commits · e / os / android_frameworks_av

include/media/AudioTrack.h

+28 −12

Original line number	Diff line number	Diff line
		@@ -63,7 +63,7 @@ public:
		// See AudioTimestamp for the information included with event.
		};

		/* Client should declare Buffer on the stack and pass address to obtainBuffer()
		/* Client should declare a Buffer and pass the address to obtainBuffer()
		* and releaseBuffer(). See also callback_t for EVENT_MORE_DATA.
		*/

		@@ -72,14 +72,20 @@ public:
		public:
		// FIXME use m prefix
		size_t frameCount; // number of sample frames corresponding to size;
		// on input it is the number of frames desired,
		// on output is the number of frames actually filled
		// (currently ignored, but will make the primary field in future)
		// on input to obtainBuffer() it is the number of frames desired,
		// on output from obtainBuffer() it is the number of available
		// [empty slots for] frames to be filled
		// on input to releaseBuffer() it is currently ignored

		size_t size; // input/output in bytes == frameCount * frameSize
		// on input it is unused
		// on output is the number of bytes actually filled
		// FIXME this is redundant with respect to frameCount.
		// on input to obtainBuffer() it is ignored
		// on output from obtainBuffer() it is the number of available
		// [empty slots for] bytes to be filled,
		// which is frameCount * frameSize
		// on input to releaseBuffer() it is the number of bytes to
		// release
		// FIXME This is redundant with respect to frameCount. Consider
		// removing size and making frameCount the primary field.

		union {
		void* raw;
		@@ -484,7 +490,8 @@ public:
		*/
		status_t attachAuxEffect(int effectId);

		/* Obtains a buffer of up to "audioBuffer->frameCount" empty slots for frames.
		/* Public API for TRANSFER_OBTAIN mode.
		* Obtains a buffer of up to "audioBuffer->frameCount" empty slots for frames.
		* After filling these slots with data, the caller should release them with releaseBuffer().
		* If the track buffer is not full, obtainBuffer() returns as many contiguous
		* [empty slots for] frames as are available immediately.
		@@ -496,7 +503,6 @@ public:
		* is exhausted, at which point obtainBuffer() will either block
		* or return WOULD_BLOCK depending on the value of the "waitCount"
		* parameter.
		* Each sample is 16-bit signed PCM.
		*
		* obtainBuffer() and releaseBuffer() are deprecated for direct use by applications,
		* which should use write() or callback EVENT_MORE_DATA instead.
		@@ -508,13 +514,15 @@ public:
		*
		* Buffer fields
		* On entry:
		* frameCount number of frames requested
		* frameCount number of [empty slots for] frames requested
		* size ignored
		* raw ignored
		* After error return:
		* frameCount 0
		* size 0
		* raw undefined
		* After successful return:
		* frameCount actual number of frames available, <= number requested
		* frameCount actual number of [empty slots for] frames available, <= number requested
		* size actual number of bytes available
		* raw pointer to the buffer
		*/
		@@ -534,7 +542,15 @@ private:
		struct timespec elapsed = NULL, size_t nonContig = NULL);
		public:

		/* Release a filled buffer of "audioBuffer->frameCount" frames for AudioFlinger to process. */
		/* Public API for TRANSFER_OBTAIN mode.
		* Release a filled buffer of frames for AudioFlinger to process.
		*
		* Buffer fields:
		* frameCount currently ignored but recommend to set to actual number of frames filled
		* size actual number of bytes filled, must be multiple of frameSize
		* raw ignored
		*
		*/
		// FIXME make private when obtainBuffer() for TRANSFER_OBTAIN is removed
		void releaseBuffer(Buffer* audioBuffer);

media/libmedia/AudioTrack.cpp

+1 −0

Original line number	Diff line number	Diff line
		@@ -1340,6 +1340,7 @@ status_t AudioTrack::obtainBuffer(Buffer* audioBuffer, const struct timespec *re

		void AudioTrack::releaseBuffer(Buffer* audioBuffer)
		{
		// FIXME add error checking on mode, by adding an internal version
		if (mTransfer == TRANSFER_SHARED) {
		return;
		}