need to add black bars on all four sides

[ginahoy]

My rear projection TV is out of adjustment so the edges of the picture are cut off (~4% overscan). Until I get around to finding someone I trust to work on it, I've been putting up with it.

In most cases, it's not a big deal but I recently downloaded a foreign language movie with English subs embedded right at the bottom of the image. The movie is DIVX/AVI format, and the image is 640x352. I use the Plex media server through a Roku set top box.

Is there an editing tool that would allow me to add small black bars on all four sides in order to force the original image onto my TV screen? In other words, the opposite of crop.

I'm grateful for your assistance.

[jagabo]

My rear projection TV is out of adjustment so the edges of the picture are cut off (~4% overscan).

That's probably not a maladjustment, it's a normal amount of overscan for a TV.

In most cases, it's not a big deal but I recently downloaded a foreign language movie with English subs embedded right at the bottom of the image.

The problem is the video was improperly subtitled. Anyone who knows what they're doing will leave enough room at the bottom of the frame to compensate for the normal overscan of TVs.

Is there an editing tool that would allow me to add small black bars on all four sides in order to force the original image onto my TV screen?

Lots (for example VirtualDub and its resize filter). But why not just set up your graphics card to compensate for the overscan of your TV? You'll get to see the edges of all your videos.

[ginahoy]

Thanks for reply. I knew a small amount of overscan is normal for CRT based displays, but mine must be more than I said. When I used to subscribe to TV service (prior to 2008), I recall some network feeds with text that was cut off. For example, I remember the titles (cast) of Saturday Night Live were cut off slightly on the left or right.

...why not just set up your graphics card to compensate for the overscan of your TV? You'll get to see the edges of all your videos.

Not sure what you mean. What does my computer's graphics card have to do with rendering output through Plex? I was under the impression that my graphics card is only involved in producing images for my computer monitor.

[jagabo]

Sorry, I missed that you were using a Roku and was thinking HTPC.

You can use VirtualDub to reencode your video with extra black borders. Apply the Resize filter. Leave the size (in the top section) set to 100 percent. In the framing options section enable the Letterbox option and set the frame size large enough to compensate for the TV's overscan. Then select a video compression codec, configure it, and File -> Save as AVI.

[ginahoy]

You can use VirtualDub to reencode your video with extra black borders...

Thanks for the tip and the instructions. I'm downloading now!

[ginahoy]

I would appreciate some advice on the compression settings. My initial thought was not to add further compression since the file is already compressed. However, when I select "uncompressed" I get a huge file -- 1.5 gB for a 60 second test clip!

The original file is DivX, 24 bit depth, 132 kbps, 24 fps. So I selected the DivX compression option... "DivX Codec (2 Logical CPU's)".

There are a number of configuration options. Since I have no idea what I'm doing, through trial and error I selecting "1 Pass" Rate Control. My objective is to end up with a file of the same compression level, type and size as the original. Using the pop-up bit rate calculator, I came up with 949 kbps (2:02 length, 948 MB). I set the Speed/Quality slider as high as it would go, at 8. The result looks good, but I'd feel better if I knew what I was doing. Any advice?

[jagabo]

Processing video requires that the frames be decompressed. When VirtualDub is done adding borders you have uncompressed video. You need to recompress the video if you want a small file again. You could use 2-pass mode and use a bitrate at least as high as the source video. But I would just use Divx 1-pass quality-based mode with a Target Quantizer of 3 (2 if you want higher quality and larger file, 4 if you want lower quality and smaller file). The Encoding presets determine how much time the encoder spends looking for ways to compress the video. In 2-pass mode you get higher quality with higher quality settings. In 1-pass quality based mode the difference shows up as smaller files. Ie, the higher you set the preset the smaller the file will be. The differences aren't that big once you get to 5 or so.

[ginahoy]

Thanks jagabo. One more question. Is there a way I can use VirtualDub to convert to H.264 when I add the letterbox?

The Plex channel on Roku transcodes AVI files in real time, but FastForward/Rewind often hangs the app. Sometimes it gets so bad I have to covert the file to Roku's native format (MP4/H.264) to avoid transcoding. I've been using iWisoft's video converter.

If I'm going to use VirtualDub to letterbox a video, I might as well go ahead and convert to H.264. I read elsewhere in this forum that Handbrake is recommended, but I'm just trying to see if I can do both tasks in a single run.

I noticed VirtualDub doesn't include any codecs, but rather it uses the ones it finds on the computer. For some reason, it doesn't show the H.264 codec that iWisoft uses. I just tried downloading a couple of H.264 encoders, but VirtualDub didn't pick up either one. I feel like I'm grasping at straws.

[jagabo]

VirtualDub requires VFW codecs. You can download and install x264vfw to get h.264 output from VirtualDub. It will still produce an AVI file though. But you could then quickly remux into another container (MP4? MKV?). Or you could try using the export plugins for VirtualDub. That will let you export to another container. Lastly, it might be possible to frame serve from VirtualDub to Handbrake or another encoder. Frame serving is the passing of uncompressed frames from one program to another. I don't know if Handbrake accepts frame served video though.