Save audio sync adjustment per channel

[Mark Buechler <Mark.Buechler@…>]

This patch allows the user to save the current audio sync adjustment for the watched channel. This presents a submenu to "Adjust Audio Sync" to "Save Adjustment". However, clicking "Adjust Audio Sync" has the same behavior as before.

[Mark Buechler <Mark.Buechler@…>]

The patch. This requires an additional column to mythconverg.channel, patch for dbcheck included.

[Mark Buechler <Mark.Buechler@…>]

Looks like the audio sync adjustment isn't getting properly set in all cases. I'll submit a second patch fixing this.

[Robin Gilks <g8ecj@…>]

I get several channels from 2 sources - DVB-S and an STB via IVTV s-video input. The DVB-S channels are OK but the IVTV channels require a 260mS adjustment on all of them so I'm not sure if per channel is correct, maybe the patch should look at per video source (or whatever its called this week) instead.

I also see a difference per frontend as well so maybe it needs to be indexed per host.

Good idea to save it though :-)

[Mark Buechler <Mark.Buechler@…>]

Better patch

[Mark Buechler <Mark.Buechler@…>]

Created second patch. This one properly sets audio sync when changing channels by direction, by channum and by switching inputs. Also, modified the Audio Sync dialog to show the saved value.

[Mark Buechler <Mark.Buechler@…>]

Forgot to initialize audiosyncSaved and set it on SaveAudiosyncToDb?().

[Mark Buechler <Mark.Buechler@…>]

Forgot case for watch recording and saving audio sync

[Dibblah]

Mark, is there a possibility of you enhancing this with a 'global' per front end default in the settings table? Changing the "Save sync" so it can also save this global value would be good.

[robertm]

See #6581, #4262 for alternate approaches.

[robertm]

See also #7772.

[Andreas Fey]

A general control over all playback media would be great (as in #6581), because when using a Flat TV as a display I have an exact delay of 200ms everytime; setting this delay thousand times for all channels might get boring...

[natuk]

Identical problem here between two frontends, one syncing by default, the other one always about 500ms off. So a per frontend setting would make sense.

[markk]

The offset is now persistent for each frontend following r27148. There are no plans to add a per-channel offset.

[Tianon Gravi <admwiggin@…>]

What about per-input source? All my videos in MythVideo? play perfectly, but the ones I have recorded play best with a 370ms offset (the weirdest part is that the exact same recording file plays perfectly synced in VLC outside of MythTV, but that's a different topic).

[sphery]

Per-input source, like per-channel and per-CODEC, offsets would be applied across all frontends--regardless of how they were connected to audio output (digital connection to receiver, digital connection to TV, analog connection to speakers, ...), so it would likely make things better on one frontend and worse on another. We are not going to make per-input, per-channel, per-CODEC offset settings for each host.

The current approach provides a good compromise that allows each system to be adjusted for equipment delays (such as differences in delay within a TV and an audio receiver each receiving direct input from the MythTV box). If the issue is caused by differences in audio delay within processing equipment based on the CODEC used, you'll need to either adjust for that delay in the equipment (i.e. pass audio and video through an A/V receiver and set it to account for the various delays) or use TOGGLEAUDIOSYNC (or the MENU) to bring up the "Adjust Audio Sync" control and make adjustments when necessary. If the issue is caused by broken encoding by the broadcaster/re-broadcaster (that truly affects all shows on a given channel or input), you should contact your broadcaster/re-broadcaster to get them to fix the problem rather than attempt to work around it.