[mythtv-commits] Ticket #11579: Slideshow DVDs do not play back correctly

[MythTV]

#11579: Slideshow DVDs do not play back correctly
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 Reporter:  peper03@…    |           Type:  Patch - Bug Fix
   Status:  new          |       Priority:  minor
Milestone:  unknown      |      Component:  MythTV - DVD Playback
  Version:  Master Head  |       Severity:  medium
 Keywords:               |  Ticket locked:  0
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 Slideshow DVDs (i.e. when a single video frame should be displayed for an
 arbitrary length of time) do not play back correctly (the audio track
 skips very quickly).  This makes playback of audio DVDs impossible.

 Playback of slideshows in menus works but CPU usage rises to 100% due to
 the fact that the video buffers are usually used to regulate the
 processing of new audio/video packets.  As there are always video buffers
 available, the audio buffers are filled with several seconds worth of data
 (depending on configuration this can be up to around 15 seconds) and the
 decoding loop spins rather than sleeps until space becomes available.

 The attached patches fix this problem by generating dummy video frames as
 needed.
 They also introduce a 'DVD context' class to provide a snapshot of DVD
 playback, which can be passed through the chain from the ringbuffer to the
 decoder to (in the future) the player code.  This allows the different
 stages to make decisions based on the state of the DVD data at the time
 any given frame was originally read.  The ringbuffer is sometimes around 2
 seconds ahead of the player, so if the player queries the current state of
 a value (e.g. playback time) from the ringbuffer, it may get a value that
 corresponds to the frame it will display in 2 seconds, not the frame it is
 currently displaying.

 The context class will be extended in future patches.

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Ticket URL: <http://code.mythtv.org/trac/ticket/11579>
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