A few months back a friend asked me to edit the 'dead space' out of some long avi files he took with a mounted cam placed near a watering hole on this property. Starting from zero, but with the help of a few of the members here I was able to figure out how to do it. This thread has that background (and the MediaInfo output for one of the the source files) but the short version is that I installed the Xvid codec and used virtual dub.
So now he's asked me to do it again with a new set of files. The good news is that he did finally turn the camera, so there is no longer the requirement that the image be rotated. The bad news is that he complained that some of the video that results from my edits is darker than the source. I did a side by side comparison of a few samples and he's definitely right. For the daytime footage it doesn't seem to make too much of a difference but for the stuff shot at dusk, the difference is pretty noticeable. Where some of the animals in the original footage are clearly distinguishable, they really just look like shadowy blobs in the versions encoded by VDub.
So, I'd like to end up with more identical copies this time. Based on my really limited understanding of this stuff, there are two avenues I can pursue. The first is to tweak the configuration settings for the XVid MPEG-4 coded. Unfortunately, I have no idea what any of them mean even after the better part of a day spent researching them. So if anyone can provide any guidance there that would be great.
The other option seemed to be to edit the files without reencoding them. Based on what I've read, avidemux should do that. I tried this by setting but video and audio output to 'copy' making a few edits (all edits are simply deleting chunks of video) and saving the file. This 'worked' in the sense that the output file was produced, but it was twice as big (4g vs 2g) as the input file. I'm assuming that that means that the file was reencoded, no? So, is there some trick to get avidemux to save without reencoding?
Thanks in adavnce for any thoughts anyone might have.
+ Reply to Thread
Results 1 to 3 of 3
How did you do the side-by-side comparison? You very well may have used different renderers on playback.
Simply cutting in Virtualdub should not change colors at all, so there's a good chance this is a playback issue rather than encoding issue. Posting short samples might help.