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author | Glenn Kasten <gkasten@google.com> | 2013-09-10 09:23:07 -0700 |
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committer | Glenn Kasten <gkasten@google.com> | 2013-09-10 09:23:48 -0700 |
commit | 22a06b752f7c350f8d8eaec029c9df69d708126f (patch) | |
tree | 88cc944948018b2b5b048db1f0a6c1bd88c3bc39 | |
parent | eb485256e99e97653773024951568aadcc60f6a4 (diff) | |
download | libhardware-22a06b752f7c350f8d8eaec029c9df69d708126f.tar.gz |
Clarify return values of get_presentation_position
Change-Id: I495d7abd7e366849308c66bcaee99554dcd244aa
-rw-r--r-- | include/hardware/audio.h | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/include/hardware/audio.h b/include/hardware/audio.h index f8419807..6ba2544e 100644 --- a/include/hardware/audio.h +++ b/include/hardware/audio.h @@ -358,10 +358,18 @@ struct audio_stream_out { int (*flush)(struct audio_stream_out* stream); /** - * Return the number of audio frames presented to an external observer. + * Return a recent count of the number of audio frames presented to an external observer. * This excludes frames which have been written but are still in the pipeline. * The count is not reset to zero when output enters standby. * Also returns the value of CLOCK_MONOTONIC as of this presentation count. + * The returned count is expected to be 'recent', + * but does not need to be the most recent possible value. + * However, the associated time should correspond to whatever count is returned. + * Example: assume that N+M frames have been presented, where M is a 'small' number. + * Then it is permissible to return N instead of N+M, + * and the timestamp should correspond to N rather than N+M. + * The terms 'recent' and 'small' are not defined. + * They reflect the quality of the implementation. * * 3.0 and higher only. */ |