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[dtc]

I am not a video guy, so bear with me.

I have some mp4 files of a concert that someone shot with their camera - one file for each song.  There is a lot of filler like talking and tuning and clapping that I want to get rid of. When viewing, I can set the video to start and stop at a particular place by setting the playback interval. Now, I would like to make a new file of just that playback interval. I can do that with Convert File, but it seems like I have to select a conversion format and even when I do what I think is the same as the original, it seems to take a long time, like it is doing some sort of conversion.

So, is there a way a create a new file of just the playback interval of a mp4 without doing any conversion of the original format?

Thanks.

[~OHM~]

You need some type of editing program....there are lots to choose from free and pay...no matter what you choose its best to make a copy of the file you want to shorten or cut up....here is a free one that does it right online, it does have a limit of 500mb tho...but you say they are homemade so maybe they are small enough....give it a try and see how it works for you....

http://online-video-cutter.com/

[dtc]

Thanks. I can give it a try. I looked at a couple of others, but they seemed to do file conversions.

Since I have already made the cuts with playback interval in MC I was hoping there was a simple way to write out the cut files without doing any conversions. Is that not possible in MC?

[~OHM~]

I have no clue about using MC for such a task, someone in the know is bound to see your post and answer you....

[dtc]

Thanks. I will try your suggestion.

[dtc]

Well, I tried Video Cutter. I started with a 43 MB file, cut a little bit off the front and ended up with a 77 MB file. Looks like some form of conversion is going on that makes the file larger, unfortunately. Video Convert is set to be Same as Source. Not sure what is going on.

[~OHM~]

I guess I don't know what to tell ya....other than do a google and keep trying....good luck and keep me posted. I use a purchased program but it's installed on another pc. I will boot it up and see whats it's called and update this post!

Update: well the program I use is no longer updated...guess I may be looking also...check this link out.

http://filmora.wondershare.com/video-editor/free-video-editing-software-windows.html

[blgentry]

Way back I used to use virtualdub for this kind of quick and dirty editing task.  I haven't touched it in many many years, though it's still around.  It was never very friendly.

AVIDemux is fairly similar, though a bit more friendly.  I've used AVIDemux recently on Mac.  It's available for Windows, Mac, and Linux, so you can give it a try if you'd like.

For MKV video, I've found that MKVToolNix is pretty good at splitting video.  It's not as easy as AVIDemux, but it's better for multiple simple splits in a single file.

Brian.

[dtc]

Thanks guys. Appreciate the suggestions. I will keep these options available for possible future use.

What I have figured out (I think) is that any of these programs read in the data and manipulate it in some sort of internal format and then write it out. So, they have to go through an output formatting stage. As an analogy, from an audio perspective, it would be like opening  a flac file, lopping off 10 seconds at the start and then writing it out again. The output would go back through the flac compression. If something like that is what is going on when the video is written out, I might was well let MC do it. As I said, I am not video savvy, but that is my "analysis".  I will probably just stick to MC for now.

I did come across an interesting little tool for reading video files form the net, like Facebook. clipconverter.cc takes a url, opens the file and the lets you write it out in all sorts of formats. It also lets you set a start and a stop point. It also has a add-on for browsers. So, using Firefox, whenever viewing something on YouTube, for example, there is an option on the screen to grab the video and write it out in various formats, including adding a start and stop point. Pretty handy. If you want the file in MC, you might as well just use MC to grab a YouTube video and set the start and stop points. But, for files that do not need to be included in MC, clipconverter seems like a nice option.

Thanks again.

[blgentry]

What I have figured out (I think) is that any of these programs read in the data and manipulate it in some sort of internal format and then write it out. So, they have to go through an output formatting stage.

For many video editing programs, this is true.  But not for all.  The three I mentioned all have modes to work without re-encoding the video.

For a proof of concept, I just took a 1:22:00 MP4 video file and cut an approximately 8:00 (8 minute) chunk out of it and saved it to a new file, using AVIDemux.  The process (after I chose the start and stop points and options) took about 8 seconds.  The resulting video file is full quality and was not re-encoded at all.

There are some things to learn about this process, but it's not so bad.  It's also quick and retains full quality.

Brian.

[Castius]

xmedia recode is what i use. It can be a bit crash prone.
Generally that's because you have more control.

[dtc]

Thanks Brian. I will take a second look.  My mp4 files are H.264 video with AAC audio. Are you saying that these programs use that format internally? Or can they simply cut out a portion without decompressing the H.264 video?

That begs the question as to what MC does with that format. When I cut some portion of a H.264 and aac file to the same output format, is there anything lost in the process? My analogy would be converting a DSD to PCM to output a DSD file. Or is it like a flac to PCM to flac conversion. Is the video convert  a "lossless" process.

Again, I am a novice at this and am trying to understand the issues. My current files are not good enough to matter, but I would like to understand the process better.  Thanks.

[blgentry]

My mp4 files are H.264 video with AAC audio. Are you saying that these programs use that format internally? Or can they simply cut out a portion without decompressing the H.264 video?

AVIDemux can copy the video and audio formats when you cut.  Or it can transcode to new formats.  You have the choice.  It defaults to copying both, which means it's just going to cut the audio and video and not re-encode anything.

I have no idea what MC does when you choose to cut video, but if it takes "a long time", then it's almost certainly re-encoding the video (and possibly audio).

Brian.

[dtc]

Thanks Brian. I will keep looking into this "lossless" issue, although as I said, it is purely academic at this point.