[FFmpeg-devel] H.264 - interlacing artifacts fix: No balanced CPU-core usage

'it's me' ciaccom
Tue Aug 12 18:06:32 CEST 2008


hello Michael again,

a user out of vdr-portal was so nice and attached two files - one corresponding to a stream before 
the provider changed their encoding and one after the changes:

* 1 minute Discovery 1080i as mkv ~ 105 MByte (before encoder changes): http://uploaded.to/?id=fxfwcx
* 1 minute Discovery 1080i as mkv ~ 90 MByte (after encoder changes): http://uploaded.to/?id=0gqbo8

The application vdr uses xine/xine-lib (which was compiled with external ffmpeg (svn) support to encode 
the h.264 live stream). vdr-sxfe is the "frontend" to xine - so it makes no difference, when streamed via 
xine directly or via vdr-sxfe (which is a plugin for vdr).

Also another user there at that forum reported, that when a HD-channel out of the named transponder is 
streamed via mplayer directly the cpu-usage is balanced over 2 cores even perfectly. So it seems that 
xine/xine-lib has a problem and not ffmpeg itself (?).

Maybe you can give a short answer/assumption, that helps a bit to pinpoint the source of the symptoms.

Thanks a lot!
ciax
   

> From: ciaccom at hotmail.com
> To: ffmpeg-devel at mplayerhq.hu
> Date: Tue, 12 Aug 2008 12:08:49 +0200
> Subject: Re: [FFmpeg-devel] H.264 - interlacing artifacts fix:	No	balanced	CPU-core usage
> 
> 
> hello Michael,
> 
> thank you very much for your answer. i know, my description is not really knwoledgeable - so it's maybe not
> suitable to post in the devel-list. furthermore i'm not able to reproduce the old status, cause of following fact: 
> 
> the problem occured with the change in encoding the HD-live stream by tv-providers (especially: transponder 
> 11914 on sat astra 19.2E - eg: anixe-hd, astra-hd+). they do not use IDR- nor I-Frames anymore, but only 
> intra encodete macroblocks (info was investigated in appropriate portals). so it's not possible to illustrate the 
> old status, where these frames existed in the stream.
> 
> ffmpeg team then published it's fix described in http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/2008-July/050391.html 
> (H.264 & interlacing artifacts). this was the solution for artifacts also described here: "Possible PAFF interlaced stream 
> bug(s) fixed in FFMPEG" - http://linuxtv.org/pipermail/vdr/2008-August/017457.html.
> 
> i'm using vdr (a linux PVR) here in conjunction with xine (HG revision) compiled with --with-external-ffmpeg (the 
> ffmpeg sources, where the bug-fix was included (i don't know the exact revision of ffmpeg with the fix - should be a 
> bit before rev. 14405).
> 
> "top" shows this: (vdr-sxfe is the process responsible for viewing the HD-stream, it's a kind of xine-frontend/interface)
> 
> top - 12:02:35 up 7 min,  2 users,  load average: 1.10, 0.80, 0.38
> Tasks:  92 total,   1 running,  91 sleeping,   0 stopped,   0 zombie
> Cpu0  :100.0%us,  0.0%sy,  0.0%ni,  0.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
> Cpu1  :  7.3%us,  0.7%sy,  0.7%ni, 90.3%id,  0.0%wa,  0.0%hi,  1.0%si,  0.0%st
> Mem:   2062360k total,   527136k used,  1535224k free,    69088k buffers
> Swap:   979956k total,        0k used,   979956k free,   242396k cached
> 
>   PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
>  5708 ciax      20   0  391m 102m  49m S  101  5.1   3:58.69 vdr-sxfe
>  5704 root      19  -1  135m  67m  57m S    4  3.3   0:18.88 Xorg
>  5677 root      20   0  555m  70m  11m S    3  3.5   0:15.53 vdr
> .
> .
> 
> as you can see, there are two cores - one is at 100% and the vdr-sxfe also - it does not scale balanced over both 
> cores. before the provider encoder change the two cores were used at the same level.
> 
> sorry - i'm complete wrong in this mailling list and maybe the problem is not ffmpeg, but xine/vdr-sxfe itself! But i'm 
> not alone with these symptoms.
> 
> thank you for your time and i apologize inconvenience!
> best wishes, ciax
>     
> 
> > Date: Mon, 11 Aug 2008 21:20:54 +0200
> > From: michaelni at gmx.at
> > To: ffmpeg-devel at mplayerhq.hu
> > Subject: Re: [FFmpeg-devel] H.264 - interlacing artifacts fix: No	balanced	CPU-core usage
> > 
> > On Mon, Aug 11, 2008 at 01:07:21PM +0200, 'it's me' wrote:
> > > 
> > > Hi there,
> > > 
> > > sorry for this double post - i was not sure if "ffmpeg-user" list is appropriate for this question. 
> > > referencing to the changes coming with this fix out of ffmpeg-devel list (H.264 & interlacing artifacts:
> > > http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/2008-July/050391.html) i must recognize a significant 
> > > increase in CPU usage. 
> > > 
> > > Especially using ffmpeg (since SVN-r14496 where the fix is included) for decoding HD-live material via 
> > > xine (ex. xineliboutput/vdr) the according processes (xine, vdr-sxfe) do not scale balanced between 
> > > the 2 cpu-cores (2 threads). one core is at 100% now, which was not the case before the provider encoder
> > > changes (no IDR-/I-frames anymore). So live HD-channels are jerked now :(
> > 
> > We need a complere bugreport you are missing approximately 99%
> > which exact revissiom broke it
> > which file? url of where its available
> > how to reproduce? exact command lines, exact output from whatever tool you use
> > to identify cpu useage with old and new revissions
> > 
> > also this belongs to our issue tracker
> > i normally do not mind complete, short and clean bugreports on ffmpeg-dev 
> > but this one doesnt look like one.
> > 
> > [...]
> > -- 
> > Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
> > 
> > Dictatorship naturally arises out of democracy, and the most aggravated
> > form of tyranny and slavery out of the most extreme liberty. -- Plato
> 
> _________________________________________________________________
> Windows Live Spaces - Ihr Leben, Ihr Space. Hier klicken und informieren.
> http://get.live.com/spaces/overview
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel at mplayerhq.hu
> https://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel

_________________________________________________________________
Windows Live Spaces - Ihr Leben, Ihr Space. Hier klicken und informieren.
http://get.live.com/spaces/overview



More information about the ffmpeg-devel mailing list