Comcast Mpeg-4 transition 29/59 bug fix?

[soapdishbandit]

With the Comcast HD Enhanced switch-over expected to happen before the end of 2015, anyone know if switching to Mpeg-4 will fix the 29/59 1080i bug? Anyone in the Atlanta or Sacramento markets have first hand experience?

Doing some experimenting, I've finally figured out that the bug does not exist on channels broadcasting 720p. 1080i is where the bug happens. My 360 extenders seem to handle the material OK, except there is a bit of a shutter of the image. Watching the same recorded material via plex through my Sony Bdp-480 player seems to fix it (1080i/60 fps broadcast from CNN). I think I read where the Xbox 360 doesn't handle mpeg-2 1080i all that well. But I get the same shuttering on my Ceton Echo. And forget about playing anything from HBO, Starz, or Showtime HD....stuuuuddder.

[glugglug]

Since Comcast already had low bitrates with mpeg2, and the whole point of h.264 is to get them lower, you should be OK.... Although the 29/59 bug may still be there. It is not specific to mpeg2, but the fact the channel is getting re-compressed could fix it.

FiOS .TV channels are h.264 @ 8Mbps, and use a 4.2 profile (officially the 360 supports up to 4.1). It does not handle these well.

[Haba]

I don't have the bug your talking about on my Comcast WMC system htpc plus Xboxes. We do get blockiness from low bit rate 1080i close ups and panning on both the htpc and Xboxes. We are a test group for the mpeg 4 change in Champaign Illinois. I have been unable to find out the mpeg 4 details to date. I am waiting for the switch to see what happens. Channel 1995 displays a black screen with 3 white dots that take turns flashing.

[webminster]

Assume you did nothing to your WMC install to handle the new format. I wonder if extenders like the Linksys DMA2200s will handle this...

[tzr916]

Just got "the letter", says converting around middle of November here. I will be able to check for 29/59 and post results.

[soapdishbandit]

Just got "the letter", says converting around middle of November here. I will be able to check for 29/59 and post results.

Thanks! Crossing my fingers as 1080i content is the majority of my programming. 720p doesn't have the issue (and looks/runs great & smooth on my 360 extenders).

[STC]

Mpeg4 should be nicer quality even when they cram more into the pipe.

[Haba]

Since Comcast already had low bitrates with mpeg2, and the whole point of h.264 is to get them lower, you should be OK.... Although the 29/59 bug may still be there. It is not specific to mpeg2, but the fact the channel is getting re-compressed could fix it.

FiOS .TV channels are h.264 @ 8Mbps, and use a 4.2 profile (officially the 360 supports up to 4.1). It does not handle these well.

The Xbox 360 Extender is working with the h.264 Comcast has switched to for some of the hd channels in central Il. Ff rw on 720p has some issues but no lockups. Streams are under 5Mbps. Picture quality hasn't changed much.

[Haba]

Assume you did nothing to your WMC install to handle the new format. I wonder if extenders like the Linksys DMA2200s will handle this...

My understanding is that Vista era extenders will not work with the new h.264 transport stream.

[tzr916]

Just got "the letter", says converting around middle of November here. I will be able to check for 29/59 and post results.

First impressions based only on two mpeg4 recordings and brief look at live tv from IDHD, which is now mpeg4:
- able to play back on pc, ceton echo, and xbox360.
- file size is about half of mpeg2.
- general picture quality seems less sharp and motion blur is worse (in a different way). Example is vertical wallpaper, camera pans side to side, wallpaper blurs/blends/warps badly. Example bright object moves quickly off dark background leaving stray blurry pixels behind.
- 29/59 channel logo "pulsing" jaggies and on screen text "rolling" is virtually gone. But when there are certain background textures/colors or motion behind the logo or text, you can clearly see floating artifacts around the logo or text.
- 29/59 frame jumping seems to still be present, but not sure. Horizontal panning sometimes frames do jump but not nearly as bad as mpeg2. Need more testing.