Let me start off by saying that I know that there are many threads on this already, however, I still haven't figured out a good way to do this.

So I have a gem video that is driven by a lot "real-time" midi data. I play the midi "live" through a DAW, but I can generate a midi file for it (it's not really live).

Now I want to record the video, and I've tried all the above methods and nothing quite works. pix_write gives a horrible frame rate. Plus it seems to skip frames randomly. Same with screen capture software. I never got pix_record to work either.

It's been suggested in other threads that one can record the live actions and then do the rendering offline. I guess the logical way to do this is to play a midi file in pd and use pix_write. I have no idea how to play a midi file in pd. Any help would be appreciated.

By the way, I'm on Windows.

Thanks!

i dont think pix_write does offline rendering.
i use this screencapture app and it works quite good
http://camstudio.org/
give it a try

I've tried CamStudio. It works, but it gives a pretty bad frame rate. And my video is not even that complicated. My PC is a few years old, so maybe it's time to upgrade.

So I guess, the common practice is to use video capture software?

I'll try a few optimizations, but it just feels wrong to use video capture for this.

the good thing about using a external video capture software is that it is a different thread and so can be performed by another processor than pd. i tried pix_record, wich seems buggy to me (on winXP) so i ended up with cam studio. results vary very much with the codec you choose.

use a video card output plugged into some sort of external recorder, then just record in realtime. i'm considering using this random VCR my roommate left here to do this, but some realtime dvd recorder would be ideal. unless you have a serious powerhouse it's kinda ridiculous to put your system through all the realtime rendering as well as recording to HD. although nowadays machines are way more powerful. a few years ago i had a 1.5 ghz athlon with a geforce 3 and the method i ultimately settled on was recording the audio separately to .wav, dumping each frame of the gemwin to a jpg (which on this machine had to be a smaller resolution and TERRIBLE terrible quality), then i had a complex script system to use mencoder and ffmpeg to put the stills together to a video then add the audio. eventually it somewhat worked, took LOTS of trial and error, but ultimately it never captured the true potential of what i was trying to record. recording externally will let you save ALL your overhead for realtime audio/visuals, at as high a resolution and complexity as you machine will allow (and ultimately the recording resolution of the device).
just my 2 cents, i really know nothing about external dvd recorders and have a crappy machine that can't handle the 3d i need it to so i haven't recorded in a while. but here's an example of my old method recording (and if you notice, the sync is off almost a whole beat, it's supposed to trigger changes only when notes are triggered, i got it sync'd but realized after the fact it was off a beat)

another similar video, sync is way better on this one

but ultimately these had to be dumbed down to be able to record via this backwards ass method.
record externally, then upload some HD for us!

slvmchn, I think external recording is definitely an option. Of course one would need a good video card that is capable of digital output (DVI, HDMI, or something like that).

I don't really care for sound because I only use pd for the visuals. The approach I'm currently exploring is offline rendering with pix_write. I'm exporting my score as a midi file and then loading it using [ midifile ]. This is still work in progress but it seems doable. One thing I'm concerned about is getting the timing right.

In terms of converting jpegs to a movie file, I'm not sure why you had to jump through hoops. VirtualDub can do this easily for you.

I'll report back once I have something working.

Alright, finally got everything working. This was unnecessarily hard. Exported the track into midi. Created my own notein_sim and used pix_write to render the jpegs. Used a free program called PhotoLapse to convert the jpegs into avi and then combined the sound and the visuals in MovieMaker. This required a lot of trial and error, but--hey--it worked

Final product:

Nice video! I dig it. I have recently run into a very similar problem (although on mac) and wonder if you can give any advice. I control an audio patch on one processor using a midi keyboard+modwheel+knobs/faders+computer keyboard. This patch then sends values using netsend to the other processor which is running the patch with the gem window.

I've tried using pix_write but the framerate issue is really throwing me for a loop. I end up creating a whole bunch of jpgs but then when I tell quicktime to open the list of jpgs as a movie the length is usually off by almost a factor of .5 (but not quite!). Syncing then becomes really annoying to say the least.

Thank you for the kind words I can't believe it's been almost exactly one year since I last looked into this! Regardless of whether you're using a Mac or a PC, I think the same idea applies. You need to somehow record your live actions, and then "replay" them in the same processor. Any midi software should allow you to record live data from a midi device (this may even be possible with pd). Then once you save that into a midi file, you would have to replay it in your patch where gem is running. You can then trigger pix_write every 40 milliseconds or so. Pd's concept of time is virtual, and everything will run much slower, but will appear in sync because both the screen snapping and the replay of the midi file will be slowed down equally.

Unfortunately I can't provide much more info because I haven't look at Pd in a long time. But hopefully, this will steer you in the right direction. Good luck and don't give up!

It took me forever to find a good solution for this (Windows), but I have been using https://obsproject.com/ for this. Open Broadcaster Software.
You can adjust the framerate and the audio sampling rate, its pretty customisable and so far the results look good.

Yeah, what @Coalman said.

OBS is kind of the standard solution for screen recording on Windows. Most streamers, youtubers and such use it as well. It's quite capable and free, which is nice.

I once tried to record PD with it and got a solid 7 FPS and horrible audio crackling, but that's because my crap computer is on the verge of dying haha

Edit: Also, I'm glad you got it working using your creative solution, @orsk!
I might have to try something like that myself.

you can set the framerate manually with [gemhead] and then match it in obs. this stuff is noisy and crackly but that was on purpose (it doesnt have to look and sound like this, its a choice, ha ha)