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Pixelating 720p input

Posted: 26 Nov 2012 11:55
by pk21x
i am using blackmagic intensity pro with windows

trying to stream a 720p input and transcode it to

2000kbs 25fps h264 ts

it works great and then it starts to pixelate or whatever its called

processor is around 40- and goes up to 70

can someone plz help ive been working on this for a week and im not getting anywhere :(

Image

Re: Pixelating 720p input

Posted: 27 Nov 2012 16:15
by pk21x
anyone please? before i start ripping my hair off :(

Re: Pixelating 720p input

Posted: 28 Nov 2012 09:59
by pk21x
i did a stream with Xsplit for 2hours.. not a single pixelation it ran smooth and no problems..

so the problem lies in vlc

it will run for 15-20min then it starts if i unplug the video input and plug it back in it all goes back to normal :l

Re: Pixelating 720p input

Posted: 28 Nov 2012 12:15
by pk21x
update!! if i stream the video only.. it works perfect.. as soon as i add audio the problem starts..

so.. im using black magic intenstiy pro for video input the decilink audi is not working so im using rca to jack for audio through the microphone input

what could be causing this?

Re: Pixelating 720p input

Posted: 28 Nov 2012 13:01
by Rémi Denis-Courmont
Drift between audio and video timing.

Re: Pixelating 720p input

Posted: 28 Nov 2012 15:25
by pk21x
why does that happen..?

does the audio go suddenly out of sync and vlc is trying to fix this?

is there anyway to disable or change some settings in vlc?

i got it to run 1hour without problem

Re: Pixelating 720p input

Posted: 28 Nov 2012 16:18
by Rémi Denis-Courmont
I don't know, but it seems quite probable that the analog audio clock and the SDI clock are not in perfect sync since they are completley separate hardware...

Re: Pixelating 720p input

Posted: 28 Nov 2012 16:49
by pk21x
why does it work for some time and then it all goes to hell

and what is package with too strange dts?

dont you know of something i can try maybe?

Re: Pixelating 720p input

Posted: 28 Nov 2012 17:00
by Rémi Denis-Courmont
That's the nature of drift. It accumulates until it is too big.

Re: Pixelating 720p input

Posted: 28 Nov 2012 17:27
by pk21x
it must be a setting in vlc that can fix this because it works in flash media encoder with audio and video from seperate device?

Re: Pixelating 720p input

Posted: 28 Nov 2012 21:31
by pk21x
did another test.. 4 hours running now without sound not a single problem..

Re: Pixelating 720p input

Posted: 29 Nov 2012 09:07
by Rémi Denis-Courmont
The solution to drift is probably to use SDI for both video and audio... Not that it would help you.

Re: Pixelating 720p input

Posted: 29 Nov 2012 09:52
by pk21x
im not getting sound with blackmagic audio in vlc thats why im doing it the other way :)

but i dont care if the audio goes out of sync if it just doesnt affect the video is there no way to disable resampling or something like that?

or to get the blackmagic audio to work???

Re: Pixelating 720p input

Posted: 29 Nov 2012 13:56
by Rémi Denis-Courmont
You cannot mux unsynched tracks. Either there is audio and it needs to be synched, or there is no audio at all.

Re: Pixelating 720p input

Posted: 29 Nov 2012 14:54
by pk21x
you think that if i can sync the audio the problem will be solved??

do you have anything i can try to do? if you can help me solve this i will put a picture of you on my desk :)

Re: Pixelating 720p input

Posted: 29 Nov 2012 15:19
by Rémi Denis-Courmont
It's plausible. I can't promise anything.

Re: Pixelating 720p input

Posted: 29 Nov 2012 16:04
by pk21x
if i leave buffer on 300ms and skip mux caching i get thousand of

main warning: late buffer for mux input (27038)
main warning: late buffer for mux input (1794954)

errors but the audio and video is very good.. and also when this drift happens the audio is still in sync i really cant see anything wrong..!

if i leave this late buffer for mux input will this cause crashing ?

Re: Pixelating 720p input

Posted: 29 Nov 2012 17:57
by pk21x
ok.. it ran for almost 2 hours then it started.. i disabled the audio on the streaming it continues pixelating for some time.. i enable the audio again and it works perfectly cpu went from 100 to 38-45