DRD Team

question about recording a gameplay session

While GZDoom gameplay works without problem, I ran into something odd while recording the gameplay.
Since I know only 0.5% of rudimentary C++ programming and OpenGL and how it interacts with the hardware,
I thought I should ask about it here.

I recorded the gameplay with Fraps 3.2.3
http://www.mediafire.com/watch/v4qrm8ry ... _fraps.mp4
No problem with that.

Recording with Camtasia 8.4.2, the game started and played without problem, but Camtasia recorded this
http://www.mediafire.com/watch/77r9igbc ... /1080p.mp4
Here, the resolution was set to 640x480 fullscreen.

What could be the cause for the result with Camtasia?

Spoiler:

---

Because it's recording a buffer that has nothing to do with where OpenGL draws to. You will usually see similar results with DirectX programs in full screen as well. Fraps is designed to hook into the program had capture the screen buffer directly, hence why it has no such problem.

So there are two buffers, one which receives the information to play the game and another which sits there and recycles the game startup over and over in a loop until the game is terminated.

Why isn't the buffer with the game always dominant? Seems to be counterproductive somehow.

No, not like that. Camtasia seems to recycle its own recorded stream here because it can't get its hand at the fullscreen buffer, writes nothing and stores whatever was there before, meaning the last few frames from the desktop which then get written out over and over again.

My guess is that it tries to get its hands at a handle of the desktop window then tries to read from it which fails in fullscreen mode and doesn't check for errors. A clear case of badly written software.

Kappes Buur wrote:question about recording a gameplay session

While GZDoom gameplay works without problem, I ran into something odd while recording the gameplay.
Since I know only 0.5% of rudimentary C++ programming and OpenGL and how it interacts with the hardware,
I thought I should ask about it here.

I recorded the gameplay with Fraps 3.2.3
http://www.mediafire.com/watch/v4qrm8ry ... _fraps.mp4
No problem with that.

Recording with Camtasia 8.4.2, the game started and played without problem, but Camtasia recorded this
http://www.mediafire.com/watch/77r9igbc ... /1080p.mp4
Here, the resolution was set to 640x480 fullscreen.

What could be the cause for the result with Camtasia?

Spoiler:

---

I see that you hava a GTX 660. Have you tried to record with ShadowPlay in the nvidia driver? It´s in the nvidia experience software included with the driver. I think it's excellent to record GZDoom with it. The only thing i noticed is that you have to enable desktop recording and start recording before launching GZDoom. I haven´t seen any flaws so far. And it´s free for all nvidia users.

Same as FRAPS, ShadowPlay files are enormous in size. Plus, after having used ShadowPlay
once, my desktop icons were all rearranged.

Now, that I know what to expect, I will use Camtasia to record GZDoom in windowed mode.
The only drawback is that I have to install two versions of GZDoom, since I do not want to
change the ini file back and forth from fullscreen true to false and vice versa every time.

Kappes Buur wrote:Same as FRAPS, ShadowPlay files are enormous in size.

Then turn down the bitrate?

The file sizes are big because there is very little or no compression. If you have enough space to record them but want them to be smaller, you can load them into a video editing program (the one that comes with windows does it) and save them in a smaller/more compressed format. That does, of course, make it a longer and two stage process but it also means that you can trim, add titles, join videos or do whatever other "post production" tricks you might fancy.

Shadowplay is actually encoded H.264 video, but the default settings use 50Mbps. It's smaller then what Fraps would ever be, even at that bitrate, but you still don't want to lower it due to how you'll need to reencode the video at least twice more (editing + youtube encoding).