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It's great that VirtualBox has a built-in video capture ability but the problem is, it saves two small .WEBM files when I do a video capture. I went to convert one of the .WEBM files (using Xilisoft video converter) which was only like 802KB's big and the output file was nearly 1GB big! Something is wrong with that picture so I had to find out if Vbox can save them as a normal video file.

Is there any possible way to get it to save them as an MP4 or an otherwise more commonly known file? I've looked in the Preferences and Settings but don't see an option to change the output file type.

My host is Win7 and my guest is also Win7, and I'm using v4.3.1.0 of VirtualBox.

Thanks!

WebM is a pretty well known (although new) container for movies. Its biggest advantage is that it's libre (free). Think of it as the PNG of videos. For more information, head over to Wikipedia. If you ended up with 1GB video, when you started from less than 1MB source, then you should be asking Xilisoft.

MP4 would be a poor choice for a screen presentation. Transformation into the frequency domain works well for natural video but it isn't designed for all those sharp edges and flat filled areas of a PC screen, which is possibly why it gets bigger. It will also get blurrier. Sometimes the video coder also transforms the color model, e.g. from 256 color palette based to 24bit or 32bit color, because MPEG can't support a palette color model. Obviously that's a data increase too. Finally, the most common reason for a big size increase from an MPEG coder is user error: e.g. selecting a silly high constant bitrate output.

socratis wrote:WebM is a pretty well known (although new) container for movies. Its biggest advantage is that it's libre (free). Think of it as the PNG of videos. For more information, head over to Wikipedia. If you ended up with 1GB video, when you started from less than 1MB source, then you should be asking Xilisoft.

Thanks socratis. That's some good info to know. It still doesn't make sense why Vbox creates two separate small WebM files. Why not just one file like a normal program would? I'm looking into trying out some of those free screen recording programs instead, don't suppose you can recommend me a good one?

Lee48 wrote:don't suppose you can recommend me a good one?

Sorry, I'm not running Windows natively and I never had that need.

mpack wrote:MP4 would be a poor choice for a screen presentation. Transformation into the frequency domain works well for natural video but it isn't designed for all those sharp edges and flat filled areas of a PC screen, which is possibly why it gets bigger. It will also get blurrier. Sometimes the video coder also transforms the color model, e.g. from 256 color palette based to 24bit or 32bit color, because MPEG can't support a palette color model. Obviously that's a data increase too. Finally, the most common reason for a big size increase from an MPEG coder is user error: e.g. selecting a silly high constant bitrate output.

Thank you for that detailed response, you obviously know your stuff. When I tried to convert that less than 1MB file into another format last night, I tried many different types for the output and they all were around the 1GB size which was very odd. But today, I did another video capture for close to two minutes (1m46s) and the file size (of the bigger of the two created files) was 3.24MB's (the other file was only 291 bytes) so again I put it in Xilisoft to convert it and surprisingly, trying different output file types (no HD, just general formats), the file size was not much more than the original size, they were between 5 and 6MB's.

Not sure of why the sudden change but it must be an Xilisoft issue. I'd still like to be able to change the video output type when doing a video capture, it creates two separate files for some strange reason and I have a feeling that when I put the bigger of the two files in Xilisoft to convert it, it somehow affects the quality of the output file. I'm just guessing here but it seems that something is not right with that.

So I take it that there's no possible way to change the output file type when doing a video capture?

socratis wrote:Sorry, I'm not running Windows natively and I never had that need.

I see, well thank you though. I'll just download a bunch of them, install them in my VM, and see what happens. I'll find a decent one soon enough.

the only reson you would get two or more webm files is if you start a video capture, stop it, start it again, etc.

loukingjr wrote:the only reson you would get two or more webm files is if you start a video capture, stop it, start it again, etc.

Thanks loukingjr. I understand what you're saying there but I never stopped and restarted the video capture. The two files came from the same recording. Both files had the exact same date and time stamp. Both had the same filename but one had -1 at the end of it and the other had -2. Since apparently there's no way to change the output type, I guess I'll just have to find some kind of screen recording program. Can you recommend to me some decent programs to use?

Lee48 wrote:

loukingjr wrote:the only reson you would get two or more webm files is if you start a video capture, stop it, start it again, etc.

Thanks loukingjr. I understand what you're saying there but I never stopped and restarted the video capture. The two files came from the same recording. Both files had the exact same date and time stamp. Both had the same filename but one had -1 at the end of it and the other had -2. Since apparently there's no way to change the output type, I guess I'll just have to find some kind of screen recording program. Can you recommend to me some decent programs to use?

the reason there was a -1 after the name is because it is a second video capture so it wouldn't write over the first one. if you leave Video Capture checked, it will start a new recording every time you launch your guest.

as far as screen recorders for Windows, I have no reason to record my screen so I never looked for one. The only time I've ever recorded a screen was to see how video capture works in VirtualBox after reading your post.

loukingjr wrote:as far as screen recorders for Windows, I have no reason to record my screen so I never looked for one. The only time I've ever recorded a screen was to see how video capture works in VirtualBox after reading your post.

Well, I certainly appreciate your taking the time to try out the video capture to help me out here. I've seen lots of video tutorials on YouTube where people have recorded their screens in a VM so I was trying to figure out how to make mine work with just one file for the output so I could edit it. I've d/l'd a few screen recorders and will try them out in my VM. Thanks again.

you're welcome.

Regarding the file names (-1 and -2): This does not happen if you start and stop video capturing. Stopping capturing will not close the file but will stop writing more frames into the file. If you view such a file with a video player application you will notice that the time jumps when it reaches the location where you stopped capturing.

The -1 and -2 file names come from capturing the 1st guest screen, the 2nd guest screen and so on. So if you have 4 guest screens configured, you will get four file names (-1 ... -4) for one recording.

If for some reason the captured file is already there (e.g. from a previous VM session with capturing enabled), the new file name is automatically renamed to include a time stamp.

Frank Mehnert wrote:Regarding the file names (-1 and -2): This does not happen if you start and stop video capturing. Stopping capturing will not close the file but will stop writing more frames into the file. If you view such a file with a video player application you will notice that the time jumps when it reaches the location where you stopped capturing.

The -1 and -2 file names come from capturing the 1st guest screen, the 2nd guest screen and so on. So if you have 4 guest screens configured, you will get four file names (-1 ... -4) for one recording.

If for some reason the captured file is already there (e.g. from a previous VM session with capturing enabled), the new file name is automatically renamed to include a time stamp.

interesting. I got the -1 with one guest screen configured but I just tried it again and this time I got the date stamp instead. Perhaps it's because the first time I tried I enabled video capture before I launched the guest, launched the guest, stopped video capture, started it again, then stopped it again.

thanks for the info Frank.

Frank Mehnert wrote:The -1 and -2 file names come from capturing the 1st guest screen, the 2nd guest screen and so on. So if you have 4 guest screens configured, you will get four file names (-1 ... -4) for one recording.

That explains it! I read this and it clicked. I had my VM setup for two monitors (being new to this program, not knowing any better, so since I have dual-monitors, I figured I had to) so I changed it to one monitor, did a video capture, and it created just one file, no more of the -1 and -2 files. Now if only there was a way to change the output file type to a more commonly known, better quality, and editable, video file. (hint, hint)

Thank you Frank for clearing that mystery up for me.