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What's the secret for high FPS?

leo
edited March 2013 in General Discussion
I have somewhat decent CPU (i5-750), but I still can't seem to get more than around 13 FPS when recording at 1920x1080 (just desktop recording, nothing fancy).
And this is with "Capture Frames Every" and "Playback Rate" optimized for higher FPS and CPU usage. I usually keep them at 5 and 200 for smaller files, but even at 1 and 1000 it didn't improve much.

How much FPS do you guys get and with what settings?

I should also mention that I prefer to use the Camstudio Lossless codec, because I like to have good quality. But if some other codec would get me good quality at high FPS, I'll consider it.

Comments

  • leo,

    See this recent thread of the last couple of days:

    http://camstudio.org/forum/discussion/comment/5262#Comment_5262

    Terry
  • Also, some notes to the OP.

    First, I think when the developers of 2.0 set the max playback rate at 200, they were probably considering that most video editors won’t process higher than 200 FPS and most likely can’t even open an AVI with a higher rate, so it may be best not to push past that limit, although the recorder definitely seems to work best on my machine with a “capture frames every” of 3 or 4. Unfortunately, there’s not much that can be done with the resulting video.

    The two things that are causing a low “actual input rate” on your tests are your choice of codecs and the size of the capture area. The “lossless” you’re using is inherently slow and, at that speed, is not actually operating with what we would consider “lossless” qualities at all. What it’s doing is taking some very good still pictures and stringing them together into a poor quality video simulation. Using x264 or Xvid MPEG-4 will speed up the input and produce a better video. The size of the capture area is an absolute limitation. When you try to capture an area as large as you are, you’re pushing resources well past reasonable limits, and there’s going to be a slowdown. The obvious cure for that MIGHT be scaling down the area to be captured and checking the resulting input rate. BTW, shutting down the monitor during the recording process seems to make absolutely no difference whatsoever in the input rate, so I can tell you that’s not worth trying.

    Environmental issues might cause a slowdown as well. Anti-virus programs, aggressive firewalls (like Zone Alarm) and Adobe Flash Player will sap resources needed to run Cam and whatever program you’re using to generate an image to be recorded, at the same time. If you can take your computer offline during recording, you’ll eliminate the possibility of updates and such interfering with the recording process.

    Ken
  • Thanks, guys.

    TerryBritton: Switching to 16 bit did indeed increase the FPS significantly. I also noticed that I can get pretty much the same result if I uncheck "Enable desktop composition" in advanced System settings (while staying at 32bit).
    However, I don't like how it makes windows look. But it's something that I might end up using.

    bmkoreken: Yeah, the resolution thing is obvious, I noticed that too.
    Regarding the codecs: Xvid actually produces lower FPS compared to CamStudio lossless.
    But now I tried x264vfw with the Ultrafast preset and it did get me a couple of FPS more than CamStudio lossless, so that's great.
    But CamStudio lossless retains the actual colors and sharpness, while x264vfw doesn't. You can see it, for example, with the light green text inside the CamStudio window. x264vfw makes that color too saturated, while CS lossless records it exactly as it is. Also the other text is a bit smeared/blurry with x264 (or Xvid).
  • edited March 2013
    leo,

    Are you recording with the quality setting at 1 for both Xvid and x.264?

    I do Photoshop tutorials for folks (here's one public one below) and the color is always perfect with Xvid at quality setting of 1.

    Terry



  • Terry; I certainly agree with you on this one. In my Xvid tests, I captured a video playing on one of my media players and then played them both side by side. I couldn’t tell them apart, and in fact, I had someone else look at both and she couldn’t tell which was the original, in terms of color, sharpness and motion.

    Way back in the thread where I was questioning the viability of x264 vs. Xvid, I was responding to a post which suggested that a bitrate of 900 was sufficient to produce a decent result, and my response was that one needs to throw a lot more at it than that to get something really good. When vopo finally got the settings right, I realized that even my estimates had been low, but even with the higher bitrate, the resulting file is just a tiny fraction of the size of one done with lossless. Of course, the results obtained with Xvid should be comparable, assuming one allows it enough bitrate to work properly.

    What we need for testing the actual input rate is a standardized capture area. I can’t compare any result with those of the OP, because my display isn’t even as large as his capture area. There’s no doubt that doing a capture that large slows down the process, but the question remains as to how much and what compromise is to be made to improve the situation.

    Ken
  • This is an example of what it looks like on my end (I'm on a different PC right now), comparing CamStudio Lossless to Xvid. I get the same color change with both Xvid and x264 on the highest settings:
    http://i45.tinypic.com/1z3tfdy.png

    Then of course this gets compressed lossily once more after editing and once again by Youtube, which makes the artifacts more noticeable.
    Maybe it's not a big deal, but having a better start for editing (lossless) is useful.

    If perhaps you guys don't have this color change with Xvid/x264 let me know, perhaps my settings are wrong.
  • Leo,

    In Xvid, which profile did you use? The darkening is a curious artifact.

    I used the 720HD one for most of mine, but the 2.7 tutorial and review and some earlier than those were done with the 1080HD profile.

    Terry
  • That’s a good graphic, and it shows that Cam lossless is capturing a good image, at least as far as being able to produce screen caps with good clarity. Since I don’t have Cam lossless, I tried the same test using Xvid, x264 with Lagarith and UT video codec as the two lossless types. The Xvid and 264 were indeed somewhat more saturated, and the two lossless were more saturated still. The UT produced the worst image overall.

    What I generally do when I’m making videos for Youtube is to use x264 (or Xvid) at the best quality and then take the result into an editor and adjust the color, value, frame rate etc. before uploading and they look really good to me. I’m always using high bitrate, and am satisfied with the end result.

    But to me, the two problems which are showing up on the caps you posted are the very low input rate and the size of the lossless file (actually much better than Lagarith). The large capture area is almost certainly the cause of both issues. Since I do mostly high motion videos, those input rates would be a real killer for me. I think I’d be considering reducing the recording area to 720 and checking out the result. I really think that there’s a compromise which will have to be made here, and you just have to decide where it should be.

    Ken
  • Terry: I just used the default "unrestricted" for the example. But I also tried another one before (720p, IIRC) and it produced the same saturated colors.


    I also noticed that I can get a slight FPS boost (and much smaller files) if I set the "Set Key Frame Every" to the maximum value of 1000.
    The resulting video seems just fine in VLC. Are there perhaps any downsides that I'm not seeing?
  • leo,

    The only downside of setting high SKFE levels that I've heard tell of is that it can adversely affect the fine scrubbing of the video via the playback progress bar, as it has to "scrub" to a full frame apparently. So, the fewer full frames, the less fine your choices, so when wanting to jump back just a second or so, instead it jumps back 5 seconds.

    I have an article on key frames you may find interesting, but that was the most impressive part I just told you.

    Terry
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