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| fvisagie |
| Posted: Aug 18 2012, 03:20 PM |
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Advanced Member
Group: Members
Posts: 35
Member No.: 26033
Joined: 19-August 09
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VDXA (Options -> Preferences -> 3d accel -> uncheck Enable 3D...) seems to slow down VirtualDub processing, even when no obvious graphics display process is in progress.
Transcoding a 0:11:38 PAL DV AVI clip to Lagarith with both input and output video displays disabled:
VDXA disabled: 0:03:13
VDXA enabled: 0:03:46
The time ratio remains roughly the same with different file sizes and in/output formats.
VirtualDub 1.9.11 and Windows 7 32-bit Professional SP1, 2.6GHz Intel Core i5-2540M with 4GB RAM.
VirtualDub configuration:
VirtualDub.audio.SetSource(1);
VirtualDub.audio.SetMode(0);
VirtualDub.audio.SetInterleave(1,500,1,0,0);
VirtualDub.audio.SetClipMode(1,1);
VirtualDub.audio.SetConversion(0,0,0,0,0);
VirtualDub.audio.SetVolume();
VirtualDub.audio.SetCompression();
VirtualDub.audio.EnableFilterGraph(0);
VirtualDub.video.SetInputFormat(0);
VirtualDub.video.SetOutputFormat(15);
VirtualDub.video.SetMode(1);
VirtualDub.video.SetSmartRendering(0);
VirtualDub.video.SetPreserveEmptyFrames(1);
VirtualDub.video.SetFrameRate2(0,0,1);
VirtualDub.video.SetIVTC(0, 0, 0, 0);
VirtualDub.video.SetCompression(0x7367616c,0,10000,0);
VirtualDub.video.SetCompData(1,"AA==");
VirtualDub.video.filters.Clear();
VirtualDub.audio.filters.Clear();
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| phaeron |
| Posted: Aug 19 2012, 12:07 AM |
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Virtualdub Developer
Group: Administrator
Posts: 7773
Member No.: 61
Joined: 30-July 02
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Strange, I can't explain this. There is only one use of that flag in the entire codebase: whether 3D accelerated formats are exposed to video filters. All of the other acceleration code only activates if there are filters running in 3D acceleration mode. Obviously, neither code path executes if there aren't any filters.
Any chance you might have done some of the tests differently where one of the tests wrote a fresh file and another test wrote on top of an old one? There will be differences between these two because in one case the OS filesystem has to periodically extend the file whereas in others it simply overwrites in place. File extension is expensive on NTFS because it is a synchronous operation.
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| fvisagie |
| Posted: Aug 19 2012, 02:47 PM |
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Advanced Member
Group: Members
Posts: 35
Member No.: 26033
Joined: 19-August 09
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| QUOTE (phaeron @ Aug 19 2012, 02:07 AM) | | Any chance you might have done some of the tests differently where one of the tests wrote a fresh file and another test wrote on top of an old one? There will be differences between these two because in one case the OS filesystem has to periodically extend the file whereas in others it simply overwrites in place. File extension is expensive on NTFS because it is a synchronous operation. |
You're right. Retesting and writing to distinct files in the two cases produced identical times.
Sorry for the false alarm! |
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