DescentBB

I have some Descent dem files and want to convert them to videos, in order to upload them on youtube or somewhere else.
Going to playback a demo in a game (under Rebirth, not DOSBox!), and record a video from screen. Can you recommend me a decent software to do it?
Tried Hypercam (does not record OpenGL windows), and FRAPS (not free, created 200 MB vid from 30 seconds at 700x500 30 FPS, recording 30-60 min vid from a demo scares me - won't fit my HD for sure).
Basically what I need :
1) Easy to use (some hotkey to start and finish recording); it would be nice if I could set maximum time for recording, so I can start it and go away, then just cut off the part I don't need when it will stop.
2) Freeware if possible, or at least proven solution (preferably with demo version so I can try before buying).
3) Some of the demos are long, so it should handle them somehow and create reasonable sized videos. Preferably writing video with desired window size and compression factor on the fly.
I am planning to put the videos on youtube and have relatively slow Internet connection, so please also recommend me how to reduce video size (window size, compression options) without making the vids unpleasant to view.
Also could you recommend me simple video editing software so I can cut the video and probably add text comments over it?

I use Bandicam, but I think you have to pay to remove a watermark on it.

Here's the results (posting some videos of my own): https://www.youtube.com/playlist?list=P ... Xe9fNVzhDq

Do you have a semi-recent AMD or Nvidia video card? If so, you may be able to do it via desktop capture options in Radeon ReLive or Nvidia Shadowplay.

I recommend trying out OBS.
https://obsproject.com/

Forgot to tell that I have a Windows laptop with AMD Radeon HD 7600 built-in video card. Although I can do it on other machine (desktop with some better video card, but definitely not top-notch one). kakhome, thanks for video links. But I see that it is around 150 MB for 7 min video, for 60 min it will be more than a gigabyte, any suggestions to make it smaller while keeping reasonable quality?

1 gigabyte per hour is small for video recordings. (For example, 1 hour of Netflix in their main 1080p streaming format is roughly 2 gigabytes.)

You can recompress it after the initial recording to a more efficient codec and reduce it to standard definition with handbrake or something like that to shrink it after the fact, but doing so usually takes many hours and requires a lot of processing power from the computer. Depending on the codec settings and the performance of the computer, recompressing it could take longer than just uploading the original to youtube in the first place.

2 GB for 1920 x 1080 one hour is not bad, but I think for Descent even 640 x 480 will suffice, and it will be around 6-7 times smaller. That is what I aim at. Or do you think I still need higher res for the videos? And I don't think shrinking the vid will take that long, in my work (which is computer vision algorithm design and implementation) I do a lot of video processing in C++ (with OpenCV library), and it reads and writes those HD vids in real time... Also I have a 30 GB per months traffic limitation on my internet connection at home, so I'd consider recompressing to lower res.

Raw recording is much bigger (often >1 GB beyond 15 min or so). But with compression (VirtualDubMod) I got it down to ~220 MB for ~22 min. I don't know if Krom is referring to uncompressed or compressed size being good, but by extrapolation, if it was an hour I'd expect ~600-800MB.

It's not 1920x1080 though. These smaller ones I was recording in 800x600 window. Recording full screen doesn't work in Bandicam for me. Level 7 I recorded in larger window, but compressed size was also larger.

If you capture at D2's original 640x400 resolution then re-compress it to h264 main profile in fast quality with a higher crf value it should be possible to get the size down significantly without eating too much time. Depending on the content, standard definition videos with these settings can run down as low as 300 MB/hour.

And do you think such 300 MB/hour vids will have enough quality for Descent play-through? Without being painful to look at?

It's hard to say - Descent has a lot of motion in it. It's probably worth some trial-and-error though, since most of the time taken will probably be in uploading the thing... depending on your connection speed anyway.
At 640x480, though, I think you have a reasonable chance of it being watchable, I just can't guarantee it.

Descent, and first person shooter videos in general are one giant pan and zoom, compression is really good at both of those so it should be possible.

At last I found a good solution.
https://obsproject.com/download
it is totally free and records in full screen and window mode, and already in compressed format (and you can select the format and compression, too!). And has a lot of other useful capabilities, too. Needless to say, it does not introduce any sound lags or slowdowns during recording, too. With default compression and 480x360 Descent window (it matches the height of usual youtube window) video size is around 250-300 MB per hour. Compressing 640x480 vids to this size introduce blurring artifacts during fast motion, however.
EDIT : compression options that seems to work best for uploading on Youtube, are 640x480 VBR 800 kbps MP4 with AVC video codec. Decent compression and no blurring artefacts like in CBR mode. Unless you want to upload HD quality, of course.