[mythtv-users] 0.19, XvMC, and Prebuffer pause

Steve Malenfant smalenfant at gmail.com
Sat Feb 25 15:43:00 UTC 2006


So, I've tried recompiling with static buffers of 65384KB.  That
didn't work.  There is something about the 1080i stream of terminator
which makes it work just great.

If I play the video with no audio (audio device=none), every single
channel works without any prebuffering.  I was expecting that because
the problem seems to be related to a sync with audio and video.  Not
sure why video is always a few frames in advance on the audio, but
that's what causing the prebuffering pause it seems.

Something isn't right in 0.19.

Steve M.

On 2/24/06, Steve Malenfant <smalenfant at gmail.com> wrote:
> So I've compared a few programs, Terminator 3, Olympic and American Idol.
> There is huge difference in the number of buffer allocated.  I'll include
> what I think is relevant here, but I'll save the log for later.  The only
> one that play fine is Terminator 3 which uses 65384 KB buffers.  That's
> actually the only stream that works on my box right now.  So is it possible
> that this buffer management isn't working properly or the buffer aren't
> suited right?  Who can bring the attention of this to one of the developper
> (if not reading, and if my info is relevant)?
>
>  Terminator 3(1080i, WGCL, perfect playback, 0.18 recording) :
>  stream: start_time: 38308.760 duration: 8335.827 bitrate=18421 kb/s
>  2006-02-24 20:31:52.445 detectInterlace(Detect Scan, Detect Scan, 29.97,
> 1088) ->Interlaced Scan
>  2006-02-24 20:31:52.445 Interlaced: Interlaced Scan  video_height: 1088
> fps: 29.97
>  2006-02-24 20:31:52.447
> RingBuf(myth://192.168.11.24:6543/1046_20060219210000.mpg):
> CalcReadAheadThresh(65384 KB)
>                           -> threshhold(2650 KB) min read(32 KB) blk
> size(512 KB)
>
>  Olympic (1080i, NBC, stutters, 0.19 recording) :
>  stream: start_time: 64275.281 duration: 14176.624 bitrate=15627 kb/s
>  2006-02-24 20:44:36.735 detectInterlace(Detect Scan, Detect Scan, 29.97,
> 1088) ->Interlaced Scan
>  2006-02-24 20:44:36.735 Interlaced: Interlaced Scan  video_height: 1088
> fps: 29.97
>  2006-02-24 20:44:36.736
> RingBuf(myth://192.168.11.24:6543/1111_20060223200400.mpg):
> CalcReadAheadThresh(16384 KB)
>                           -> threshhold(856 KB) min read(32 KB) blk size(256
> KB)
>
>
>  American Idol (720p, FOX, stutters, 0.19 recording) :
>
>  stream: start_time: 65694.620 duration: 3605.606 bitrate=12973 kb/s
> 2006-02-24 20:33:23.624 detectInterlace(Detect Scan, Detect Scan, 59.9401,
> 720) ->Progressive Scan
>  2006-02-24 20:33:23.625 Interlaced: Progressive Scan  video_height: 720
> fps: 59.9401
>  2006-02-24 20:33:23.632
> RingBuf(myth://192.168.11.24:6543/1051_20060223200000.mpg):
> CalcReadAheadThresh(15384 KB)
>                           -> threshhold(819 KB) min read(32 KB) blk size(256
> KB)
>
>  Steve M.
>
> On 2/24/06, Ray Lischner <linux at tempest-sw.com> wrote:
> > On Friday 24 February 2006 11:13 am, Joe Silver wrote:
> >
> > > The pauses aren't so much pauses as they are momentary (like 1/10th of
> > > a second) blip in the audio.  Maybe the video skips too, but it's much
> > > easier to notice the audio.
> >
> > Another reason why I may not have noticed anything so far. A minor blip
> > in the sound of skis slicing through snow would not draw my attention.
> > Once I can clear the Olympics off my disk drive, I'll try to pay
> > attention and see whether I can detect the prebuffering pauses.
> > --
> > Ray Lischner
> > _______________________________________________
> > mythtv-users mailing list
> > mythtv-users at mythtv.org
> > http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
> >
>
>


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