Removing Black Borders (Another FFmpeg XviD Trick)

[BTJustice]

Here is another FFmpeg trick when using XviD encoding. You can remove those black borders from over-scanning by using a command such as this...

Code:

[b]<Conversion name="XviD Cropped" cmd="-y -i {SOURCE_FILE} -ab 128k -ac 2 -acodec mp3 -ar 44100 -cropbottom 6 -cropleft 26 -cropright 46 -croptop 6 -deinterlace -f avi -qmin 3 -qmax 5 -threads auto -vcodec xvid -vtag XVID {DEST_FILE}" targetExtension=".avi" />[/b]

The secret is the crop values. The values are in pixels. You will have to experiment with these. Remember the values used have to be divisible by 2.

The easiest way I could find to figure out the values for my setup was to take a screen shot of a 4:3 frame, open it with a picture editing program (I use Paint.NET), and carefully use the selection tool to select the borders for bottom, left, right, and top in order to get an idea of what I needed to shave off. Originally, my videos were saved at 720 x 480. Now they are 648 x 468.

Now my videos look really nice. I am not really concerned with 16:9 as everything is broadcast at 4:3 with my set up and GBPVR can remove letterbox borders.

[BTJustice]

Here's an example of what you will get...

http://www.youtube.com/watch?v=VRVGsK9qmTs

Remember, the black borders you will see on the left and right on the video above are just where there is no video. The command above just removes the black borders from over-scanning.

[4zm4r3d02]

You can use VirtualDubMod to determine the cropping values. Open the mpeg file, then go to "Video > Filters" in the menu. Press the "Add" button, select the first one in the list, then press "OK" to get back to the Filters window, where the "Cropping" button will now become active. In the cropping window, there is a slider, so you can search through the video to find a frame with a lot of white at the edges, to make it easy to see the black bars. Once you pick the best values, copy them down, exit VirtualDubMod, and put the values in your ffmpeg command line.

Remember the values used have to be divisible by 2.

I thought they had to be evenly divisible by 16?

[BTJustice]

I thought they had to be evenly divisible by 16?

Nope. Just 2 in FFmpeg.