[SBE] The life of a spot after DG sends it to you...

[Henry M. Seiden]

How did it get so f'd up? What's the spot. Probably national if it  
went through the same process you describe.

Henry
On May 20, 2009, at 22:49 , Ryan Salazar wrote:


> Thanks for all the comments. I just saw the spot on the air again  

> here in Fort Lauderdale. Not sure how to describe the graphics, but  

> there was a glowing white background around a logo. Right near where  

> the glowing white starts, there's blue text and it's so "washed  

> out". I just saw it on CBS. Not sure if it was a local or national  

> buy, but I think it was national, so probably ran through more passes.

>

> Ryan

>

> -----Original Message-----

> From: sbe-bounces at sbe.org [mailto:sbe-bounces at sbe.org] On Behalf Of  

> Chris Spacone

> Sent: Wednesday, May 20, 2009 8:41 PM

> To: 'sbe member discussion mail list'

> Subject: Re: [SBE] The life of a spot after DG sends it to you...

>

> CBS may have pulled the spot from the SpotBox (it is just a Windows  

> box) and

> transcoded (perhaps using something like FlipFactory) it to the file  

> format

> used on by their video server. Poorly configured FF, low bitrates  

> and a host

> of other problems could account for the artifacts. Consider that the  

> local

> station that actually played the spot OTA may well have done something

> similar to the spot.

>

> As the source material undergoes multiple ingest / encodes / transcode

> operations something called concatenation errors begin to creep in.

> Essentially the quantization step reduces the 'dynamic range' (for  

> lack of a

> better way to describe it) of the video signal which can result in  

> blocky

> artifacts. These become more and more pronounced as the material  

> undergoes

> multiple passes. Quantization problems are clearly seen with the  

> very low

> bitrate video delivered by satellite services. If you watch a black  

> field

> you can see 'rings' or contours where the black jumps from one value  

> to

> another instead of being smoothly continuous. Another error  

> introduced is

> motion artifacting. As each frame of video is analyzed by the  

> encoder a

> series of decisions are made that determine how much of the picture  

> can be

> thrown away and how much should be kept. Motion vectors from frame  

> to frame

> are calculated and a series of MPEG I, P and B frames are generated  

> as part

> of a GOP (Group Of Pictures).

>

> These artifacts can become quite obvious when the material has lots  

> of very

> small type / detail. If you can pause the playback and check  the  

> edges of

> vertical and horizontal elements you will see a sort of 'noise' (I  

> have

> heard it called mosquito noise). This noise is directly related to the

> amount of quantization being applied to the video.

>

> But all of this is speculation and partly lecture; unless you know the

> precise chain the material took along each of the steps you are stuck

> guessing. It is possible to 'objectively' measure the end result  

> against the

> source material and quantify the underlying impairments by using PQA

> testing. Again, all this helps to do is objectively determine if  

> there is a

> problem, not precisely where it was introduced (or worse yet how to  

> fix it).

>

> Chris Spacone

>

>

>

> -----Original Message-----

> From: sbe-bounces at sbe.org [mailto:sbe-bounces at sbe.org] On Behalf Of  

> Ryan

> Salazar

> Sent: Wednesday, May 20, 2009 12:12 PM

> To: sbe member discussion mail list

> Subject: [SBE] The life of a spot after DG sends it to you...

>

> Everyone,

>

> I figured this would be the best place for me to ask this question...

>

> We send spots (post production facility), to DG Fast Channel via  

> automation.

> DG always tells us the spots look great, in fact, better than most  

> spots

> they receive. They then send the spot to stations via their "Spotbox".

>

> Recently, we had an instance where they sent a spot to CBS-National.  

> CBS

> then fed the spot live via satellite to a local station. That local  

> station

> then fed it to the viewers. We received a complaint that the spot was

> pixelated and blurry. I will admit, our disclaimers were way to  

> small, but

> we had strange artifacting that we don't normally have an issue  

> with. I also

> saw a considerable amount of blocks on the screen during fast  

> movement of

> graphics. I've seen this before after files were converted over and  

> over.

>

> I assume this is because of all the levels the file went through. Us  

> to DG,

> DG to CBS. Then, CBS via Satellite to the station and the station

> broadcasts.

>

> Any ideas? I know I can't really control all the points, but want to  

> see

> what else I can come up with.

>

> Thanks!

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