[mythtv-commits] Ticket #12827: Raspberry Pi: Digital Audio does not work

MythTV noreply at mythtv.org
Fri Aug 12 23:57:16 UTC 2016

#12827: Raspberry Pi: Digital Audio does not work
 Reporter:  pbennett              |          Owner:  pbennett
     Type:  Bug Report - General  |         Status:  accepted
 Priority:  minor                 |      Milestone:  unknown
Component:  Ports - rPi           |        Version:  Master Head
 Severity:  medium                |     Resolution:
 Keywords:                        |  Ticket locked:  0

Comment (by markspieth):

 quick review:
 * may be better to disable omx decoder instead of delete in case future
 functionality allows it again (if its not you who deals with it). perhaps
 it decodes other formats than DTS too.
 * the constraints on diverge were intended to prevent limit cycling of the
 control algo. defensive programming.
 * what is the root cause for the hdmi audio rate issue? possibilities
  * actual rate is not what is specified
  * processing latency of AC3 re-encoder (if used timestretch/nonnative
 ac3) is too large or processing latency of block is too variable or
 processing time is too large for pi.
  * other systemic manipulation of the output audio a la pulse (not sure
 about this in pi)
  * hdmi out is block outputted by the hardware in larger chunks and not
 divisible by the AC3 frame size (15ms??). this can be tested by
 determining/observing the absorption rate of the output stream.
 * should the avsync averaging number be pulled from the audio device
 instance instead of cluttering the avsync/player with audio specific
 config? common base class value for most.
 * avsyncaveraging is config now, perhaps also for the new openmax hdmi
 value (inside the openmax config value getter)?
 * why /3 when calculating avsyncinterval instead of /4? I know it works
 the same when the value is 4 with an interval of 0. curious.
 * diverge will be 0 for the passes where avsync_next indicates it is not
 set. Is this intended?

 All I can think of for now. Looks fine.

Ticket URL: <https://code.mythtv.org/trac/ticket/12827#comment:6>
MythTV <http://www.mythtv.org>
MythTV Media Center

More information about the mythtv-commits mailing list