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rosscan
@verizon.net

rosscan

Anon

WNBC Strange Compression Artifacts

I have been noticing some weird compression issues, especially on static non moving objects, kind of like a flickering/shimmer effect with macroblocking. I watch and record the late night shows frequently and it wasn't this bad just last week.

For example, check out the artifacts on the blue wall, they're there for a few frames, then it resolves itself the next frame
»www.imagebam.com/image/7 ··· 69112896
»www.imagebam.com/image/a ··· 69112899

Fades to black can be pretty bad too.
»www.imagebam.com/image/c ··· 69113768

Got higher bitrate with the deletion of 4.2, but disappointing compression, like it's been put through an extra filter or something.

I know some people that have connections/information about 30 Rock's transmissions browse this forum, so figured I'd put this out there
UnnDunn
Premium Member
join:2005-12-21
Brooklyn, NY

UnnDunn

Premium Member

I really hope this doesn't mean Verizon has started transcoding signals.
Expand your moderator at work

fournewyork
@verizon.net

fournewyork to rosscan

Anon

to rosscan

Re: WNBC Strange Compression Artifacts

i dont see anything strange. i'm on staten island. where are you rosscan?
rosscan
join:2012-01-13

rosscan

Member

I'm from Staten Island as well. Here are some more examples
»www.imagebam.com/image/7 ··· 69287359

It's pretty bad consistently on every program, same pattern of random areas of the screen (mostly solid colors or backgrounds) getting pixely then resolving back to looking OK. Here are a few quick ones I grabbed from 30 Rock tonight, with the ending logos being the most glaring

»www.imagebam.com/image/3 ··· 69447649

Meanwhile the overall bitrate is peaking at 14mbps. Was getting great quality before the New Year when it was peaking around 12mbps. True head scratcher

icemannyr1
join:2001-04-11
Township Of Washington, NJ

icemannyr1 to rosscan

Member

to rosscan
It's not FiOS re compressing the feed. WNBC OTA has the same problem.
It's been around for about two years.
I first noticed it on any video that had the sky in it on Sunday Night Football.
It usually happens when there is a solid color at the top of the video.
It's a bunch of digital artifacts that keep changing every second.

I'll try to record and post a video sample of it.
rosscan
join:2012-01-13

rosscan

Member

Really? I've been recording consistently for over a year now and I'm just noticing it's specifically harsh in this week's programming. Maybe it has just gotten worse and more obvious despite the small increase in bitrate?

icemannyr1
join:2001-04-11
Township Of Washington, NJ

icemannyr1

Member

Here's an example of the artifacts on WNBC 4.1.
They appear at the top of the frame on the sky and logo in the first image and go away in the second image.



matcarl
Premium Member
join:2007-03-09
Franklin Square, NY

matcarl

Premium Member

Call me crazy, but I see no difference between those two pictures.
skohly
join:2009-08-19
Township Of Washington, NJ

skohly

Member

said by matcarl:

Call me crazy, but I see no difference between those two pictures.

Me either

icemannyr1
join:2001-04-11
Township Of Washington, NJ

icemannyr1 to rosscan

Member

to rosscan
The forum software remove the link to the full size files.

If you compare the two at full size the second image should be cleaner for the top half of the frame.
»imgbox.com/aawZInhD
»imgbox.com/aaq4jFia
45612019 (banned)
join:2004-02-05
New York, NY

45612019 (banned) to rosscan

Member

to rosscan
WNBC's engineers definitely fucked up the settings on their MPEG-2 encoder with the bitrate increase. It should be looking better, not worse.

Verizon isn't doing anything to the feed.
rosscan
join:2012-01-13

rosscan

Member

said by 45612019:

WNBC's engineers definitely fucked up the settings on their MPEG-2 encoder with the bitrate increase. It should be looking better, not worse.

Yes exactly, just went through my Today show recording from this morning and some panning sections and scene changes are truly horrendous. Really weird since everything was fine last week with the bitrate increase. Hope someone gets on it
45612019 (banned)
join:2004-02-05
New York, NY

45612019 (banned) to rosscan

Member

to rosscan
»www.nbcnewyork.com/contact-us/

I recommend submitting screenshots here.

What we really need to do is find an engineer @ WNBC.

icemannyr1
join:2001-04-11
Township Of Washington, NJ

icemannyr1 to rosscan

Member

to rosscan
I've noticed as of this week the change in camera shots is not clean on WNBC and that's when the extra artifacts are appearing.
It takes a half second to second for the video to be clear again.
You will notice it when they cut back to Al from the local weather update.
rosscan
join:2012-01-13

rosscan to 45612019

Member

to 45612019
Thanks for that feedback link, got a delivery failure message though so I sent one to programming as well
rosscan

rosscan

Member

More horrible shots, Golden Globes.

»www.imagebam.com/image/8 ··· 69984019
»www.imagebam.com/image/9 ··· 69984025
»www.imagebam.com/image/c ··· 69984028