[mythtv] [mythtv-commits] mythtv branch master updated by cpinkham. v0.26-pre-894-gf66816d

Chris Pinkham cpinkham at bc2va.org
Wed Jul 18 04:00:27 UTC 2012


* On Mon Jul 16, 2012 at 11:59:10PM -0400, George Nassas wrote:
> For fun I ran ffmpeg against all of my .ts files. It turns out there are 30,330 of them belonging to the 52 streams I have queued up to watch. Here are occurrence counts for the most common segment durations:
> 
>    7429  00:00:11.52
>    4560  00:00:12.00
>    2309  00:00:02.97
>    2291  00:00:11.97
>    2290  00:00:11.99

Dod you script this?  I'd like to run some tests here to test
this.  I'm not sure what could be causing this right now.  I've
noticed segments that vary in size by 50% or so, but didn't
think that the lengths were different, I figured it was the
encoding efficiency in some frames or sequences.

> In light of what JYA said about the m3u8 target duration being a
> max I guess the .ts writer should buffer until it knows the next
> keyframe will fit inside that max duration. I say that without
> having the slightest clue of how much effort it would be to code
> so don't take it as a feature request or anything.

It's not the next keyframe that needs to fit, it's everything
after the next keyframe since the segments should start on a
keyframe so you can 'seek' to any given segment and immediately
start playing frames without having to decode X amount of frames
before being able to display video.  Currently the code splits
off another segment when it detects we've been more than 10 seconds
and the next frame is a keyframe.  That's why I'm not sure you're
seeing what you're seeing, but then I haven't looked at the code
yet because I'm trying to figure out the audio issue first.

--
Chris


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