Force refresh of xf86VidMode current modeline

[Cédric Schieli <cschieli@…>]

After changing the mode with XRRSetScreenConfigAndRate, the modeline returned by XF86VidModeGetModeLine is wrong until XRRGetScreenInfo is called (at least for X.Org 1.14.5 and 1.15.0 with Intel video driver).

DisplayResX::SwitchToVideo first calls XRRGetScreenInfo, then calls XRRSetScreenConfigAndRate. This leads to XF86VidModeGetModeLine always returning the previous modeline instead of the current one.

This was causing juddering in some cases, because the refreshrate used in MythPlayer for initializing avsync_predictor is obtained from XF86VidModeGetModeLine.

For example the following scenario was causing me consistent juddering every second:

The display has modelines for 24 Hz, 50 Hz and 60 Hz modes, and the desktop mode is 60 Hz. I first play a 23.976 fps video. The display switches to 24 Hz mode, but the refreshrate used by avsync_predictor is set to 60. This does not cause noticeable judderng. Then, I play a 25 fps video. The display switches to 50 Hz mode, and the refreshrate is set to 24 (the previous one). Every second the avsync_predictor kicks in and drops some frames.

This patch fixes this issue by calling XRRGetScreenInfo after the mode is changed by XRRSetScreenConfigAndRate.

[JYA]

Thank you for this.

Sounds just like a work around a X bug really.

Anyhow, please read http://www.mythtv.org/wiki/Coding_Standards Do not use tabs, use spaces (4 spaces indentation)

[Cédric Schieli <cschieli@…>]

In b8d5f110581bee170807e32e4c919f6f17e6a9e1/mythtv:

Error: Processor CommitTicketReference failed

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[Cédric Schieli <cschieli@…>]

In d1aa80d3f96a5215090efa94bed2d3dabee5381b/mythtv:

Error: Processor CommitTicketReference failed

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