How to crop h.264 video?

zqbobs

macrumors newbie
Original poster
Mar 10, 2009
7
1
I have some MPEG2 stream video captured by EyeTV from VHS tapes. After transcoding to h.264 for AppleTV using Streamclip, there is a bar of noise along the bottom (about 10-20 lines). I don't use EyeTV to transcode VHS because it doesn't de-interlace and results in "combed" output.

I know it's possible to crop the video in the initial transcoding, but is it possible AFTER transcoding, in Streamclip or Handbrake or another program, to simply crop the h.264 video without re-encoding it. i.e. to do it relatively quickly?
 

lannister80

macrumors 6502
Apr 7, 2009
490
17
Chicagoland
I don't think you can crop the source without re-encoding.

You could crop the *playback*, but otherwise you'll need to re-encode.

Anyone else have a better idea? :confused:
 

fpnc

macrumors 68000
Oct 30, 2002
1,927
96
San Diego, CA
You can do this by applying a mask to the movie using QuickTime Pro or perhaps with a free QuickTime utility. Basically, you create a picture with the same dimensions of the video and with the area you want covered either painted black or white (I can't remember which, but you must create an image with black and white areas). Then you add that picture as a mask within the movie. You can probably Google to find the exact procedure.
 

sandman42

macrumors 6502a
Oct 23, 2003
955
57
Seattle
I used to use MPEG Streamclip to convert MPEG2 files (from EyeTV) to DV for use in iMovie. When doing those conversions, and probably when doing the conversions you're doing, you can crop, resize and re-center the image. You might have to experiment with the settings a little, but you should be able to do what you want during that step. Doesn't help you for files you've already converted, unless you're willing to transcode them again.
 

fpnc

macrumors 68000
Oct 30, 2002
1,927
96
San Diego, CA
You can do this by applying a mask to the movie using QuickTime Pro or perhaps with a free QuickTime utility. Basically, you create a picture with the same dimensions of the video and with the area you want covered either painted black or white (I can't remember which, but you must create an image with black and white areas). Then you add that picture as a mask within the movie. You can probably Google to find the exact procedure.
You don't need to re-encode the video if you use a QuickTime mask as I outlined above. The only requirement is that the original file be in a QuickTime movie format or a QuickTime compatible H.264 stream which can then be passed through using the QuickTime Pro application (or a similar QuickTime utility -- some of which are free).

In case you aren't aware, the QuickTime Pro application allows you to add masks and to pass through both H.264 video and AAC audio streams to create a duplicate of the video and/or audio that just has a new QuickTime movie wrapper. No re-encoding required.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.