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

'it's me' ciaccom
Tue Aug 12 12:08:49 CEST 2008

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

 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.

More information about the ffmpeg-devel mailing list