: CBC-HD Official Thread (No Hockey)
2007-02-13, 02:17 PM
Does the CBC ever use separate sources of the same program for the 4:3 and 16:9 broadcasts if they are available? An example of this would be to use the widescreen recording of a movie on the digital channels and the full screen recording on the analog channels. The alternate is to use the same source for both broadcasts and either letterbox it or crop it to fit the screen.
The program deliveries vary from show to show. Often we will get an HD version along with an anamorphic SD copy. The SD can be letterboxed or center cut.
2007-02-13, 04:59 PM
Thanks for the reply. I understand that it varies from show to show and if you have a WS source you can either letterbox it or centre cut it, but I was wondering if you ever get a WS/HD version for the digital channel and 4:3 pan and scan version for SD?
One situation where I could see wanting different 4:3 and 16:9 versions of a program is when doing interviews. Typically in 4:3 you will only show the person who is talking. In 16:9 you could potentially show both people at the same time in side-by-side windows while still only showing one person at a time in the 4:3 version. This could solve the problem of what to do with all that extra screen width when only showing one person. It might not be worth the effort of generating 2 versions of a program like this, but it should be possible.
I work in the Presentation area. We never pan and scan. That level of editing is left to the program producers.
2007-02-14, 11:42 AM
I work in the Presentation area. We never pan and scan.
I understand that. It wouldn't make sense for you to pan and scan during presentation. As you said, that level of editing can only be done during production of recorded (not live) programs.
My question is do you ever show a WS recording on the digital channels and a 4:3 recording that had previously been produced using pan and scan on the analog channels?
My reason for asking this is after the analog shutdown, would there be any benefit for broadcasting a 4:3 SD version on a sub-channel. If the SD version is always either a centre cut or a letterbox the there wouldn't be any benefit for this as this information could be indicated with flags, but if you were to show a separate version that the producers paned and scanned, then there would be some value. Obviously the benefit would have to be weighted against the loss of bandwidth on the HD sub-channel. Optimally it would be nice if the CRTC let you add a sub channel to show a 4:3 P&S version when it is available and remove it when it doesn't.
I've had a look at a CBUT-DT air check tape. I don't see the interleaved black you described. If you see it again, please note the exact date and time and I will have another look.
#1 No, to my knowledge we have never done that.
#2 I don't think you will ever see a multicast channel used for this purpose. Aside from the bandwidth, the added costs of supporting a 2nd format would be a tough sell.
2007-02-14, 05:24 PM
Thanks, you answered my question. Sorry if I wasn't being clear at first.
2007-02-14, 06:58 PM
I notice it quite often. For example, when Arrested Development comes back from a comercial break, the show usually has a white screen for a moment and I notice it flash. I've also observed it on Planet Earth. I guess it could possibly be something on my end but I figured everything comes across converted already so there shouldn't really be an issue on the transitions. I'll try to take a closer look and give you an exact time.
2007-02-20, 03:30 AM
Ok, so I was watching Planet Earth which I recorded Sunday night at 7:00. After each comercial break there was a momentary glitch in both audio and video a split second into the show. It's not always full black frames, sometimes just part of the frame is black. There's a pop in the audio.
CBUT-DT (Vancouver) OTA
Sunday Feb 18
Times are Pacific
hmm, seems to be happening more and more, coming back from commercials. Because I use a PVR, I often miss the first few seconds coming back from commercials.
I've tried to remember to "backspace" on Nat. Geo and I have NOT noticed it on several programmes since I mentioned it to NG, although it could still be happening. I believe I may have noticed it once or twice on Discovery...
See the following thread.
I do not recall any video issues, only audio.
I see it during Planet Earth on the Vancouver transmit path. The same material on Toronto is fine. The following program is fine too. Maintenance is investigating. Thanks for the heads up bwalter.
Marc. Thanks for the feedback. We mentioned in my link (post 331) that we thought it might be a satellite issue, as this has affected a number of programmes, a number of service providers, a number of different channels.
It would be really great if you could track this down.
I cannot speak for other channels, but this case is not a satellite problem. My recording is from an MPEG decoder that monitors the HD signal as it leaves the building on its way to the CBUT-DT transmitter. There is no satellite involved. The same material playing out to CBLT-DT is fine. We're trying to figure out why there is a difference.
2007-02-20, 10:24 PM
Can you please comment on the SD upconversion process for CBUT-DT?
All SD programs are shown upconverted on CBUT-DT. When SD programs are shown, the first few lines of the broadcast are white and black horizontal bars. This occurs for both 16:9 and 4:3 SD programs. While it makes it very easy to tell at a glance if the present program is in HD or not, it is quite distracting at times.
From my research it seems that these are the result of the SD closed captioning lines being shown in 1080i following upconversion.
Should the upconversion process be eliminating these lines?
The VBI information is very likely an affiliate issue. They should not be present if your overcan is 2% or more.
I assume you're not seeing them on other channels (typically) and have you checked your overscan with a setup DVD?
ardsa, you are correct, those lines are closed captioning and they should not be there. Closed captions are handled differently in HD. I found a couple of upconverters that were passing the line. I've asked that they be adjusted. (Due to a monitoring issue, those lines were masked in our control room.)
2007-02-21, 02:16 PM
I'll let you know if the lines disappear.
2007-02-25, 10:52 PM
in a previous post, someone said that if the Toronto feed is in HD and the Ottawa feed is in SD, CBOT-DT will transmit the Toronto feed.
The bottom line is that CBOT-DT transmits the Toronto games during HNIC instead of the Ottawa games.
It it going to be fixed at some point ? Can we get the upconverted Ottawa games instead of the Toronto games ? After all, it's called CBOT-DT (so one would hope that it's the same content than CBOT).
And there's the game in an hour version available late at night for those who want to see the highlights of the Toronto games anyway.
Are you aware of any plans to fix this ?
Quick technical question for you Marc. We understand that Global supplies BEV with a 720P signal and other service providers with a 1080i signal.
Does CBC do something similar for BEV?