On Tue, Jun 18, 2013 at 11:10:30AM +0100, Andy Furniss wrote:
ville.syrjala@linux.intel.com wrote:
From: Ville Syrjälä ville.syrjala@linux.intel.com
Having both modes can be beneficial for video playback cases. If you can match the video framerate exactly, and the audio and video clocks come from the same source, you should be able to avoid dropped/repeated frames without expensive operations such as resampling the audio to match video output rate.
Rather than add both variants based on the CEA extension short video descriptors in do_cea_modes(), add only one variant there. Once all the EDID has been fully probed, do a loop over the entire probed mode list, during which we add the other variants for all modes that match CEA modes. This allows us to match modes that didn't come via the CEA short video descriptors. For example one Samsung TV here doesn't have the 640x480-60 mode as a SVD, but instead it's specified via a detailed timing descriptor.
Signed-off-by: Ville Syrjälä ville.syrjala@linux.intel.com
A few people requested this. Originally I was a bit opposed to it, but when I thought about it a bit more I figured if the audio and video clocks come from the same source (or happen to be close enough w/o significant drift), this could provide a better A/V sync w/o resampling tricks.
I see this has gone in now, one thing I notice is that xorg/apps/xrandr only prints Hz to 1dp so you can't see which mode is which for the 24p and 30i cases.
Maybe someone reading has commit access for xorg?
Not sure if you noticed but I posted some relevant xrandr patches to xorg-devel. Unfortunately I got no response, and I've been too lazy to figure out who I need to pester.