Low delay x264 refreshing issue

[AVC_fan]

Hi, I compressed x264 at 500kbps for 720p stream(two people talking-typical conferencing case). I can see vertical refresh from frame to frame. Its annoying. I am starter in video coding so do not know why column wise refresh when motion is normally horizontal. I feel row wise refresh will be better and refreshing may not be visible. please correct me.

[LoRd_MuldeR]

Well, this is how PIR (Periodic Intra Refresh) works. Some more info is in the commit message:
http://git.videolan.org/gitweb.cgi?p=x264.git;a=commit;h=52a4fbe142926435571fbf2fb3d535e8873627d3

Probably 500 kbps is just too insanely low for 720p material, even if it's "low motion" stuff.
Pre-processing, such as denoising, may help for ultra-low bitrates, but may be difficult to do in a low-latency situation.

BTW: You didn't use "--no-psy", right? Only without that option x264 will try to hide the intra bar...

[Dark Shikari]

We tried row refresh. It's just as visible, but more importantly, it completely screws over VBV handling, so we used column instead.

In general, using intra refresh at extremely low bitrates, especially in CBR, is not a good idea.

[movmasty]

In general, using intra refresh at extremely low bitrates, especially in CBR, is not a good idea.
But what it is useful for?

Why to use at any bitrate?

I didnt find the esplication on avidemux guide, so i guess the option is not in 2.5.6?

[Shevach]

I recommend to read the following IEEE article
"Motion Adaptive Intra Refresh for the H.264 Video Coding Standard". You can understand rationale of Intra Refresh mode and find several ideas how to cope with "intra patterns".

[movmasty]

I recommend to read the following IEEE article
"Motion Adaptive Intra Refresh for the H.264 Video Coding Standard". You can understand rationale of Intra Refresh mode and find several ideas how to cope with "intra patterns".
Ya, i was searching for avidemux intra refresh and didnt get any result

the right words are x264 intra refresh

[CruNcher]

Hi, I compressed x264 at 500kbps for 720p stream(two people talking-typical conferencing case). I can see vertical refresh from frame to frame. Its annoying. I am starter in video coding so do not know why column wise refresh when motion is normally horizontal. I feel row wise refresh will be better and refreshing may not be visible. please correct me.

X264 (AVC) isn't really suited for these kind of applications you better of with something more advanced,optimized and robust for this use case (SVC) like for example http://www.vidyo.com/ http://www.youtube.com/watch?v=QN38vHZjWXw <- based on it

[nm]

X264 (AVC) isn't really suited for these kind of applications you better of with something more advanced,optimized and robust for this use case (SVC)

x264 is very suitable and optimized for low latency video conferencing if you only need one resolution at a time.

[CruNcher]

right if you have a a really calculated steady network structure bellow it, but for internet usage even with the best CDN structure you can come up with it wont be enough smooth streaming is killing to many kittens (CO2 Emissions) SVC is currently the only real efficient choice :)

[Dark Shikari]

right if you have a a really calculated steady network structure bellow it, but for internet usage even with the best CDN structure you can come up with it wont be enough smooth streaming is killing to many kittens (CO2 Emissions) SVC is currently the only real efficient choice :)"For internet usage", SVC is pointless, because there is no multicast support yet. You still have to send a full stream to every client, so SVC does nothing except waste bandwidth through its inefficiency.