2012 State of the Union TECHNICAL comments

I'm watching on CBS on Comcast in Savannah, and I do hear the odd noise, but it has the best picture, so I'm sticking here.

One thing I have notice from the side shots is the light rays coming off of the TV lights appearing to look like spotlights.

Does anyone know which news organization was responsible for the pool feed this year?

I noticed that ABC had a twitter hashtag #SOTU the entire time.

Just completely embarrassing and unprofessional. I thought the hashtags were supposed to be for pimping the networks' own shows? Now they're pimping presidential speeches? Err?

Surfed around the HD channels with it on:

ABC
CBS
FOX
NBC
PBS
CNN
FOX News
FOX Business News
MSNBC

For whatever reason, NBC looked the best tonight.

CBS looked DARK. Also heard the chirping and saw the spotlight effect on the wide shot from the President's right.

Here are screencaps. Audio on CBS was fine here and had the least delay. CNN seemed to look the best on my TV this year. Without question, Fox News was the absolute worst - it looked like a 480i upconvert.

CBS:


NBC:


ABC:


Fox:


My local PBS station:


Fox News Channel:


CNN:


MSNBC:


CNBC:

CNN always looks the best here. They finally got their HD house in order IMO.

The FOX News feed does look to be a 480i upconvert as evidenced by the stepping on the diagonals from the scaler:




The FOX network feed looks like a 1080i to 720p crossconvert as the diagonals are smooth:

The bug for this station has no animation, and what is shown is the normal transparency. The word "prime" is actually displayed between the big L and the PBS logo, but, against dark backgrounds, it's often impossible to see.

Unfortunately, as nice as the bug is, the overall picture quality of the station is typically just so-so, due to having five subchannels in addition to the main HD stream.

IMO, PBS went from first to worst. 19 Mbs would be adequate on most material with MPEG 4, particularly with 720p, but MPEG 2 is not enough.

As most viewers get their locals via cable and sat providers, it's time that stations start sending them dedicated MPEG 4 feeds. This could permit better than OTA quality. Cable stations already have this option. The downside could be that stations could add more streams to their OTA and then expect the provider to carry them all from direct feeds.

Yep, five subchannels, including one that is just an SD simulcast of the main HD channel. That said, even though quantity over quality is the motto here, the station's general manager, who is also the chief engineer, seems to be willing to listen to any concerns and, to my eyes, has done something in the last year or so to slightly improve the HD picture. I think average bitrates were shifted around a bit (HD averages 9 Mbps) and perhaps there were some encoder changes. Of course, the HD picture still isn't very comparable to the HD on the CBS O&O down the dial.

If I watched national PBS programs more often, I would probably get myself a FTA satellite system and take advantage of the 1080i stream that's available on the Ku band.

Converting from 1080i to 720p may actually decrease noise for re-encoding as quantizing errors increase at higher frequencies due to larger coefficients in the quantizing matrix. The higher horizontal frequencies in the 1080i are filtered out for scaling from 1920 to 1280 pixels. Vertical conversion involves de-interlacing so motion compensation can be compromised from the lower frame to frame correlation. DCT blocks are larger onscreen in 720p which could make the block boundries more apparent. However, from empirical observation and from theoretical advantages of encoding efficiencies for progressive formats with twice the frame rate, conversion to 720p does appear to allow better results at lower bitrates. It's still the lesser of two evils and still not pretty.

ABC and NBC are using MPEG 4 for network distribution using Ericsson (Tandberg) encoders with phase-align audio for 5.1, CBS continues to use MPEG 2 at 40 Mbs with Dolby E for 5.1 using Harris encoders and FOX is now using Motorola encoders for the splicer system. Using a ratio of around 2:1 for cascaded encoding minimizes loss of downstream encoding efficiency from added noise, so as stated sending a network at ATSC bitrates of 19 Mbs is insufficient unless the stream itself is turned around directly for broadcast. While the splicer system does allow for efficient MPEG 2 network distribution at lower bitrates, it's not as efficient as using MPEG 4.

There seems to be a growing movement towards 1080/50p and perhaps 1080/60p. With the increased encoding efficiency of progressive formats, the extra bandwidth to carry twice the pixels requires far less than twice the bitrate, in fact some have stated it is nearly the same. On a live event such as the SOTU, it would be ideal as there would be minimal loss with conversion to 1080i and 720p. The downside to using 1080p (and 720p on some cameras) as compared to 1080i on live cameras would be the 50% loss of light sensitivity (1 stop) from not using the sensor row pixel grouping in interlace mode. Maybe by then 4k live production will be on the horizon and 1080p would be a moot point. Dual link 3G or single 6G, that should be interesting.