Opened 12 years ago

Closed 12 years ago

#5962 closed enhancement (invalid)

Global audio offset/delay config to delay audio on playback for displays which add video lag

Reported by: grokky Owned by: Isaac Richards
Priority: minor Milestone: unknown
Component: mythtv Version: unknown
Severity: low Keywords: audio offset delay
Cc: Ticket locked: no


With the increasing number of TV's performing significant image processing (ie, motionflow, de-blurring, etc), and such processing taking a finite time, this can result in audio being ahead of video. In some cases turning off extra processing in the TV can reduce this lag, but sometimes some of this processing is beneficial, even with mythtv.

This most commonly occurs if audio is not being processed via the TV, ie, it is passthrough, or routed directly to a receiver/amplifier from the frontend, whilst video goes direct to the TV.

As myth can do some of the processing work (such as upscaling) to provide a similar video stream to the TV, regardless of source, I suspect the processing delay added by any TV would be quite constant, regardless of source/quality/bitrate etc. Without myth (ie using the internal tuner of a digital 1080p TV), processing time could vary if it was tuned to a 1080p station, vs say a 720p or SD channel.

As a result, it might be possible (and extremely useful to those people affected by this), to add a config item either globally, or by channel, to code in an audio offset to start all recordings,livetv or mythvideo playback with, which could then be further altered during playback if required (unlikely) by the usual mechanism.

This would alleviate the need to dial in an offset each and every time playback is started.

I would be happy to test any work done in this area, and we could start with just a DB config item, rather than GUI.

Change History (2)

comment:1 Changed 12 years ago by grokky

OK. My bad. I didn't read the feature wish list on the wiki or the ticket creation guidelines properly. This feature request is already on the wiki, so this ticket can be closed if it is not appropriate.

comment:2 Changed 12 years ago by Dibblah

Resolution: invalid
Status: newclosed
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