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| Unofficial VirtualDub Support Forums > Testing / Bug Reports > Max Fps |
| Posted by: evropej Mar 22 2011, 12:07 AM |
| Change frame rate to (FPS) What is the maximum number here? I find that after 300, there seems to have no effect for me. v1.10 thanks |
| Posted by: stephanV Mar 22 2011, 08:48 AM |
| The highest frame rate in AVI would be FFFFFFFF/00000001 which is 2^32/1 fps. The reason why you don't see an effect higher than 300 fps can be due to CPU or drive speed limitations. |
| Posted by: evropej Mar 22 2011, 07:42 PM |
| You bring up a good point so I did a little test. I am running core i7 at 4.14GHz and I have an SSD at 295/285 MB transfer rates. I was watching the load usage and it never seemed to peg any core at any time. The average load at 400 FPS for example was about 50%. I am not sure how to measure the transfer rate on the SSD though for a single thread or application. Side note, should the software play frames rates outside the LCD display capabilities or in fact the capability of the eyes? How do I export the file then with this frame rate? I tried saving the file but I am not sure if the media players are handling this issue correctly. |
| Posted by: stephanV Mar 23 2011, 08:05 AM | ||
You can see the average bitrate in the new file in VirtualDubs file information. That will give you an indication if it is out of your harddrive's spec.
If you have a 60 Hz monitor and you have a 300 fps file, normally the display will only show 1 out of 5 frames. |
| Posted by: evropej Mar 23 2011, 01:33 PM |
| Thanks for the suggestion, I will try that when I get home. I guess my question was why bother rendering all the frames? Why not convert it to an equivalent 30FPS video? Or am I missing something. |
| Posted by: stephanV Mar 23 2011, 03:36 PM | ||
For non-keyframe only files this is not possible because a delta frame depends on all previous frame up to the first previous key frame to be decoded. Of course, you can always enforce this yourself by using VirtualDub's decimation options if you don't mind losing frames in the resulting file and re-encoding it. |
| Posted by: evropej Mar 23 2011, 05:34 PM |
| I tried the suggestion with negative results. So how can a TV play these files? I tried uploading to facebook with errors. The work around right now is to capture the video with Camtasia at 30FPS. |
| Posted by: stephanV Mar 23 2011, 05:58 PM |
| I don't know what "negative results" are, or what you tried. |
| Posted by: evropej Mar 24 2011, 06:23 PM |
| I tried to decimate the video but the result was choppy. I think the best thing now is just to capture the video output from vdub with a capture software. I was hoping to eliminate this step but I dont an answer at this time. |
| Posted by: ale5000 Mar 24 2011, 06:45 PM |
| VirtualDub is also a capture software, you can use it directly. |
| Posted by: evropej Mar 25 2011, 03:59 AM |
| I dont have much luck doing captures with vdub. I was hoping for someone to explain how to convert things the right way so a newbie like me can understand.  |
| Posted by: stephanV Mar 25 2011, 08:00 AM | ||
Are you using Direct Stream Copy with an already compressed stream? |
| Posted by: evropej Mar 25 2011, 01:27 PM |
| No direct stream copy, I was using xvid compression. |
| Posted by: stephanV Mar 25 2011, 02:11 PM |
| That is strange. Works fine here. |
| Posted by: evropej Mar 26 2011, 07:59 PM |
| Max data rate is 87MB/S which is not even close to what the SSD can do. I tried with new xvid or and camtasia compression and I still get a horrible output file. Anyone have any suggestions here on how to bypass this? |
| Posted by: phaeron Mar 26 2011, 10:46 PM |
| You are not going to max the SSD for modern video compression algorithms before you hit other bottlenecks. 87MB/sec, or 696Mbit/sec, is a staggeringly high bitrate for a compression method like MPEG-4 or H.264. I'm not even sure they can produce that much compressed data for common resolutions even with everything maxed out. Usually at that rate you'd either be working uncompressed or with a low ratio, lossless format. There is another bottleneck which you can hit for this kind of frame rate, which is the graphics card. Past a certain point the graphics driver may not be able to issue commands quickly enough to churn through that many frames; it may either have an internal throttle, or it simply might have a timing limitation. It can also be for compatibility reasons, since older games may blow up if the frame rate is too high. Usually there isn't a use to playing videos with so high of a frame rate relative to the display, so the video player won't have logic to work around this. I guess we'd need more detail to help you further on what you're trying to do. No regular video capture device will produce 300 fps when the input signal is 25 or 29.97 fps; no screen capture software can produce 300 fps when the desktop composition system is capped at refresh rate. I'm not clear on what you're trying to do with these high frame rates. |
| Posted by: evropej Mar 27 2011, 02:45 PM |
| I have a video which is recorded at 30 fps and I want to Play it back at 300 fps. I want to basically speed up the video. Msu has a Plugin which does the opposite or slow down the video as slow motion effect. This is all I want to do lol. Thanks |
| Posted by: evropej Mar 29 2011, 02:55 AM |
| This is baffling me. So, I played back a video at 300 FPS and captured it using camtasia. Go into file information and it tells me its 30 FPS video. Sweet, so now I can play back on vdub at 300 FPS again to really speed it up. The great surprise, it plays only at the rate it was originally recorded. Seriously, what is going here? http://www.evropej.com/renia.zip  |
| Posted by: phaeron Apr 3 2011, 12:19 AM |
| It's a bit of a tall order to expect an HD file to play back at 10x normal speed, particularly without hardware acceleration. My quad core Core i7 definitely wasn't up to it. |
| Posted by: evropej Apr 3 2011, 04:04 AM |
| I am not interested in the playback if i can just produce the results shown on the video. I wanted to play a video, like the one shown, at much higher speed. Thats all. Any suggestion on how to proceed would be appreciated. The method I cam currently using is to play a video in vdub at 10x and capture the output with a second program. |
| Posted by: ale5000 Apr 3 2011, 10:57 AM |
| You can use "Decimate by" in addition to "Change frame rate" so it will speed up the video without get a frame rate too high. |