View Full Version : Black bars in 16x9?

09-07-2010, 05:58 PM
We're getting small, but not unnoticeable black bars when working in 16x9 with 16x9 cameras on the finished mpg files. What might we check or change to remedy this?

09-07-2010, 06:30 PM
Where are these black bars showing up?

09-08-2010, 09:36 AM
Another way of putting it is that we are getting slight letterboxing along the top of the image, even though we are shooting with 16:9 cameras in a 16:9 project.

09-08-2010, 09:40 AM
I think what Josť is asking is where are these 'bars' showing up? Do you see them in the TriCaster preview monitors, on output (what sort - VGA, 'video' or stream), in captured files, or perhaps when viewing the full overscan area only? I might also ask, which model TC, and what is the source - i.e., is it HD, or 16:9 SD, and connected how?

09-08-2010, 10:21 AM
Yes and I'll add in a NLE?

09-08-2010, 11:41 AM
I think you mean black bars on the sides of the picture right?

These bars are not related to the TC but to your cameras that have not the full resolution. On some SD cameras it is often the fact that not the whole picture is recorded. The black bars are in the underscan section and should be not visible when viewing on a monitor that is NOT in underscan mode.

Allthough you will see these bars in any fullscreen app like Internetplayers or beamers. If you are streaming then try to tweak the settings of Adobe Flash Media Encoder. You can specify a crop value to exclude the bars from your final stream.


09-08-2010, 11:47 AM
We're shooting in 16:9 SD, from Sony HDR-FX1 camcorders, connected to the Tricaster with component cables (with component to BNC adapters to actually connect directly to the tricaster).

There are equal-sized black bars in the Tricaster preview window, but my complaint isn't about that (I figured that the preview monitors might not be exactly 16:9, since they don't look it). The slight letterboxing, which is on the top part of the image, can be seen when I open the MPEG2 file the Tricaster creates (or an AVI file exported from the Tricaster) in Premiere Pro (CS3 and CS5).

I am trying to figure out how to create a true 16:9 image from the Tricaster.

09-08-2010, 07:04 PM
Have you tried using the interpret footage and force 16:9 aspect in Premiere?
Choose File > Interpret Footage.
Select an option in the Pixel Aspect Ratio section, and click OK.
Select one of the following:
Conform To Lets you choose from a list of standard aspect ratios.

09-13-2010, 08:25 AM
I should specify that this isn't a problem that only occurs in Premiere. If I open the file created by the Tricaster in a video player, you can see the black bar along the top of the image. The solution is likely in the Tricaster.

09-13-2010, 08:32 AM
Definitely not to be smart-alecky, but you do realize that there can be a small section at the top of a video file that constitutes unviewable signal, and which is normally unseen, on output, but can appear on a computer or stream, right? And it's not that?

09-14-2010, 08:52 AM
Let me put it this way, to quell any doubts. Using the same exact cameras as I am now using, and shooting 16:9 footage from the camera, and recording to tape or hard drive, I get a perfectly filled up 16:9 image when viewed in any player, and Adobe Premiere, and when uploaded to youtube or any other site.

However, when connecting these cameras to the Tricaster and recording using the Tricaster, the recorded video has a thin black bar along the top of the image, which can be seen in the Tricaster's editor, in a video player, or when importing in (and exporting from) Adobe Pr.

This is clearly aTricaster issue because I can record in the Tricaster and view the file in the Tricaster, and see this problem.

09-14-2010, 09:59 AM
No worries, I'm not trying to wiggle out of this, just asking questions to diagnose it. A screenshot might be useful.

09-14-2010, 01:40 PM
It could be that your camera is cropping the image only on the outputs that you use. I had this issue with several DV cameras.

Do you have a monitor that supports you camera connection and can be switched to underscan?

Then try the following:

Connect the camera to the monitor by using the same interface (Component or Composit or SDI) as you use with the TC.

Place a mark at the upper picture position.

Connect the monitor and your camera to your TC. Switch the camera to live output and compare the picture and the mark.

If the picture and the mark is the same with the TC it is related to your camera. If not then it is an issue with the TC. Make sure that no liveset is selected.


12-12-2013, 06:49 PM
I am curious what you ended up doing to fix this, because my Tricaster Broadcast is doing the same thing. The mpg file that the Tricaster creates has a black bar at the top that is 4 pixels thick. I have to edit out the top 4 pixels in order to have a full screen. I'm using a Canon XL2 set to 16:9, and the Tricaster is also set to 16:9.

12-12-2013, 07:31 PM
This is because of the analog connection between the systems. You will find that all analog equipment will have black edge(s) somewhere on the left/top/right sides of the frame. This is normal and you find that different analog devices will have their black edges in different locations. This is why there is overscan on monitors to hide this.

This issue doesn't happen with digital devices, SDI sources plugged into your TriCaster will fit the entire frame perfectly. This also wouldn't be a problem with DV (since that is also digital), but TriCaster doesn't have DV inputs.

12-13-2013, 06:31 AM
Ok, so if I use overscan, it will go away?

12-13-2013, 07:31 AM
Its not so much it goes away as its hidden under the edge of your monitor.

This is why we have things like safe title and safe action. You didn't want to place your titles to close to the edge because they would be half on half off the screen.

CRT monitors had bezels that covered up the edge of the tube because there was all types of 'garbage' that would show up on the edges of the display and this hid it so you looked like you have a nice picture when you looked at the screen. Today's HD displays so the same thing, typically small part of the edge of the video isn't shown. Most HD displays so have an aspect ratio option to show edge to edge picture (typically needed when you connect up a computer), but this usually isn't enabled for normal video watching.

These issues can come into play when viewing video on a computer display. Unlike a video monitor that has overscan, your computer display does not. So you see everything. In these cases if the main playback is designed for computer playback you will have to do whatever you can to clean up the image.

12-13-2013, 07:56 AM
The issue is not with the live video monitor. The issue is with the mpg file that the Tricaster creates when a production is recorded. We have a live web stream of our production every week, and there have never been any black bars in the live video feed. After the production is over, we upload the recorded video file for people to watch after the fact. That video file is where the black bar at the top comes in to play.

12-13-2013, 08:12 AM
These 'non-image' parts of the frame are inherent to analog video, which was never really designed to be displayed as 'pixels', but rather as interlaced 'lines' of video. Certain information relevant to the display of the signal is carried in specific lines that do not make up part of the picture, and in older times were hidden behind the display device's bezel.

TriCaster records the full video frame, and unless you take steps to eliminate it, you will see this 'noise' at times, for example when the image is scaled down or transposed within the frame (say, to serve as a picture-in-picture element). You will also see it on any display device that doesn't mask the edges. I think some streaming encoders provide settings to do a little automatic cropping to deal with this issue, but there are other ways of handling it as well.

12-13-2013, 08:23 AM
Thank you for the explanation. I need to get digital cameras to get rid of the black bars produced by my analog cameras, right? In the mean time, I guess my only option is to keep cropping out the dead space.

12-13-2013, 08:44 AM
You can crop, or you might run the whole thing through a Virtual Input (or under a DSK) to superimpose a thin black border.