Have you tried an SVN build?
Maybe use cra...err fraps?

What's the difference between an SVN build and regular DOSBox?

Also, I don't have FRAPS, And I do believe you have to pay for it, soooo that's kinda not an option right now. Besides, if it's "craps", then why would I want to? 😜

Svn is current code of Dosbox.
On the plus side the video recording issupposed to be fixed in svn.
On the other hand svn builds can be unstable.

Hmm... I'll give that a go for the next episodes.

I'll let you guys know how it goes.

I also discovered the async audio issue the other day.

Used 0.74 for video recording and Audacity for recording the audio. But just as you I found that the audio would grow out of sync the more time went by.

However I don't have these "lag" issue. Can you describe it in more detail?

Regarding fraps, yes it costs money but the license doesn't expire. It works quite well with DOSBox and allows you record from the line-in which makes all the videos in sync.

However something inside DOSBox makes the sound go slow when you use Double Buffering or Vsync or Fraps at anything lower than 60fps.

Even at 60fps fast paced animations (e.g. PQ3 introl) will slow down the music. But many games are great to record!

To keep the file size down, I play at 320 x 200 (I use a low resolution and Windows 7s disability zoom) and that way the files stay quite small and performance to the HDD is not an issue.

If DOSBox had a feature to record from line-in or mic that would be awesome!

I would also like to know what capturing related things have been changed in that svn build...

Revision 3627
Update the rendering output even when only the refresh rate changed. Previously there might have been problems with video recording under some rare circumstances.

Among other things, depends on your svn build version.

and writing the index too often has been fixed as well.

Mau1wurf1977 wrote:

I also discovered the async audio issue the other day.

Used 0.74 for video recording and Audacity for recording the audio. But just as you I found that the audio would grow out of sync the more time went by.

Here are my suggestions in another thread instead of using Audacity (it did work for me)
Capturing KQ7 and KQ6 music in DOS-Box
DosBox does record digital audio directly in the video, so that leaves the music as being the only problem (if using GM or such).

Yea I'm using Camtasia now...

Captures video and audio from line-in (MT-32 for example).

Your method is interesting, though quite time consuming.

If DOSBox would sync their recordings to a timer, I guess then we wouldn't have this issue. But it seems like it's not doing that so as time goes on the audio track will run more and more ahead of the video.

I'm sure there is a solid reason why it got implemented that way in DOSBox. And having a capture function is better than none at all. It works perfect for Sound Blaster or Adlib. ScummVM has no capture function whatsoever, so no complaints there...

I didn't get such issues on my tests, then again, I didn't record for that long...
also, I am using a self-built SVN err..build.
The method I suggested, if time consuming was to fix the lack of responsiveness.
X-Fi cards have the ability to do time synched recordings, but I haven't delved that much into it, a hardware solution could work instead of a software one, maybe some day I'll get to it 😜
Linux offers some possibilities with XVidCap too.
I made some Ubuntu demos for a friend and they went really well, maybe it works for DosBox too without that much overhead, thing here is amount of ram and amount of disk access...

Does your SVN have a different video capture code?

I can't find the right words for the issue, but DOSBox isn't "capturing" the screen output as such, it writes the images to the HDD but not all of them. So as time goes on, the DOSBox images written to the HDD are less compared to if the out screen output would have been captured.

It seems that screen transitions (with black screens) cause this issue. I found that in a ~ 20m gameplay recording, when in sync at the start you would be out of sync ~ 4s at the end.

What responiveness issues did you have? I never encountered any of that, just the audio out of sync when recording through line in.

Also where is Zachski? Seeing he complained that his other thread didn't get solved 🤣

No, just the SVN code that got fixed, for that test I used...lemme see SVN 3658. What *could* be different is that I build it with VC++ and not mingw.
My recording ended up being ~40megs
I didn't have any responsiveness issues, I was trying to help the guys in the other thread that complained about audio lag in KQ7/6 video after finding out that (quite logically) the midi commands don't get rendered in the video and looking for a solution that didn't involve recording the music with an external app, at least not running it while DosBox is.
I started the recorders (MIDI and video) before I started the game, so it would record everything, I ended up with 4 files:
A 4dos video (I use 4dos as a shell, so it gets recorded)
A kq7 video (the game itself and the ~40 meg video)
Another 4dos video (after exit, same reason as above)
And a midi file of the whole process (hence the need to edit it)
I stopped the recorders *after* exiting the game.
The audio didn't lag and I didn't notice frames getting dropped, I recorded a good chunk of the intro video (no midi sound, digital, for obvious reasons), and some gameplay (midi sound for the music, but digital audio for the hare jumps, Vallanice's voice, dress ripping, the scorpion walk).
I don't know who Zaschi is 😜 ahh yes, I see...he was using 0.73...bad start.
Now from what I gather, DosBox indeed doesn't capture the video in the traditional sense...because it doesn't need to! (The audio is a bit of a different issue) actually, that would be, I believe, inneficient: DosBox composes a frame using what the games ask it to draw (changing only what has "moved"), puts it in your output and does so n times to get the animation going, that rendered frame can also be written directly to a video or screenshot, without the need for capturing it (like a video capture card would), that would be redundant.
I used output=opengl, that could have something to do with it.
I just recorded another test, this time LSL7 and I started the recorder after starting the game, in that game all the audio is digital, the video works fine. (ended with a 37.5 mb clip).
I am curious, though, which games are you trying to record? I might own at least one so I can test.

I used Monkey Island 2 for testing...

Though my next project will be capturing the footage from a real Retro PC (I have one and a ton of parts and bits and peaces).

There are so many DOSBox videos on YouTube, not hardly any real / Bare Metal DOS videos which act as a reference so to speak.

I will use a AWE64 Gold as it has excellent signal quality (even SPDIF if you want to use that) and line-in and mic in so I can capture music from a Roland Midi module (Be it MT-32, CM32L or Sound Canvas) and use a mic to have some commentary going.

DOSBox is great but I always run into these "hmm I wonder if that was the same on a real machine" cases and hoping that there is some interest on YouTube...

That sounds great! (The recording part)
I do have that game...so, I'll check to see if I run into the lag and such.
I for one would like to see comparison videos, DosBox does agree with what my mind remembers (at least most of the time and when it doesn't involve pc speaker), but hard evidence would be better, so, let me know when you have some videos up 😀

*Update*: I just checked recording with MI2 (Soundblaster sound, VGA) and didn't notice any problems...

Oh yea it works no worries. The only issue I had was that audio recorded via Audacity would go out of sync as time goes on.

Doesn't apply to Sound Blaster, Adlib and PC speaker of course...

One game where I noticed a difference was "The Heart of China". On the real machine the scrolling is super smoth, as if someone would move the painting. Under DOSBox it's a different story 😀

Another game is "Indiana Jones and the last Crusade" in Game Blaster mode. The music would sometimes get stuck...

Digital speech quality is also better on a real AWE64 Gold. I have a video that compares digtal speech in Wing Commander and it's the only sound card that avoids a tiny "cut off" sound whenever someone stops talking. Even DOSBox has this 🤣

feel free to make list of those tiny bugs.

I don't want to be a pain. These little issues are really really little and I doubt anyone would even notice 🤣

I'm sure there are more pressing issues!

If you take the time to notice the tiny bugs, why not make a list as well. The more specific you are the easier it is for the devs to look into it. And valid bug reports are mostly welcome in open source projects 😀

Okido I will work on a list and keep on eye on any other things I notice...