Splitting f4v

[cool09]

I used avidemux to split an f4v (w/Frame Rate=29.97 and Decoded format=Planar 4:2:0 YUV) and all I did was set the muxer to mp4 and the output to mp4. The file came out with the same parameters as the original and I can hardly tell if there was any quality loss (I use VLC Player) but is there a better way to split f4v to ensure no quality loss? Am I using avidemux correctly for this file?
I split mp4 files using avidemux or Allok Video Splitter and a lot of the times the split file doesn't play well in Windows Media Player (looks very choppy) so I open it with VLC Player and it looks fine. And sometimes the split file size comes out much larger than the original file size. (I can't figure this out.)
Can VLC Player split mp4 and f4v files? I looked at some tutorials to do this and I tried it and it took forever so I aborted it.

[jagabo]

If you had video and audio set to "copy" the streams were simply copied into a different container. So no quality loss. If you didn't use copy mode they were re-encoded, losing quality.

[Secoast]

Output Format is the muxer. If this is all you changed, no encoding occurs, therefore zero quality loss.
If you set Video Output to Mpeg4 AVC(x264) instead of Copy, the output will have been encoded.

[cool09]

If you set Video Output to Mpeg4 AVC(x264) instead of Copy, the output will have been encoded.

If I set the Video Output on an mp4(264) file to "Copy" the split file always comes out as an mkv file. So now I get in the habit of setting the Video Output to mp4(264) to get output as an mp4(264) file.
I just split an mp4 and I set the Video Output to Copy and it came out as an mp4 and looked fine. I can't figure it out.
And I don't know why sometimes when I cut out several minutes from an mp4(264) in avidemux the file size comes out larger than the original.
Sometimes when I look at the VLC Codec Data in an unsplit file the Video Resolution and Buffer Dimensions are different. For example I have a file with Video Resolution as 1280x720 and the Buffer Dimension is 1280x738. What does this exactly mean?
How come split files usually play choppy in Windows Media Player but play okay in VLC Player?

[jagabo]

If I set the Video Output on an mp4(264) file to "Copy" the split file always comes out as an mkv file.

If you set the Output Format to MP4 Muxer you will get an mp4 file.

So now I get in the habit of setting the Video Output to mp4(264) to get output as an mp4(264) file.

If you don't use Copy you will re-encode the video and lose quality.

I just split an mp4 and I set the Video Output to Copy and it came out as an mp4 and looked fine. I can't figure it out.

Isn't that exactly what you want?

And I don't know why sometimes when I cut out several minutes from an mp4(264) in avidemux the file size comes out larger than the original.

That's probably because you were re-encoding the video before, and using a higher bitrate.

Sometimes when I look at the VLC Codec Data in an unsplit file the Video Resolution and Buffer Dimensions are different. For example I have a file with Video Resolution as 1280x720 and the Buffer Dimension is 1280x738. What does this exactly mean?

Buffer Dimension is the size of the memory buffer into which the video is decompressed. You are probably misremembering that, the 738 was probably 736. Some encoders/decoders have a mod 32 requirement -- 736 is a mod 32 frame size, 720 is not. This is nothing you need to worry about unless you are getting an error while encoding or decoding.

How come split files usually play choppy in Windows Media Player but play okay in VLC Player?

WMP is a crappy media player?

[Secoast]

If Output Format is set to MP4 and Video Output set to Copy, no encoding will occur (or quality loss) and there should be no increase in file size.
If you set Video Output to Mpeg4 AVC(x264) the video stream will be encoded. This will cause a loss in quality, mostly negligable, and a change in file size, very possibly larger. You can configure encoding to reduce file size, but this will reduce quality further.

Just use Copy mode (Video Output) and output to MP4 (Output Format) for best results.

[jagabo]

The only real drawback to copy mode is that the video cutting is not frame accurate. You can only cut on keyframes. And there can be 10 seconds or more between keyframes.