Bugs item #2977716, was opened at 2010-03-27 17:26 Message generated for change (Comment added) made by zmoelnig You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=507079&aid=2977716...

Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: Pixes (pix_ objects) Group: win32 Status: Open Resolution: None Priority: 5 Private: No Submitted By: Matteo Sisti Sette (sistisette) Assigned to: Nobody/Anonymous (nobody) Summary: pix_film with DS eats up cpu in W32

Initial Comment: When I send an [open( message to a pix_film object, if it uses DirectShow (as opposed to QuickTime) to decode the file, it starts consuming an enormous amount of cpu: around 30% of a 2.5GHz Intel Core Duo machine. Furthermore, it never stops eating that much cpu, even if you stop repdorucing the file (by setting auto to 0 and not changing the frame through the right inlet) and even if you disconnect it from the gemhead.

This happens with file encoded with various codecs: DV-PAL, H.264, Animation+, and I suspect everything else.

Note that if I open the files with QuickTime instead of DS (by appending the proper number to the open message), then this does not happen: the impact of opening the file on the CPU is minimal, almost impossible to note, and it only consumes cpu during few seconds after opening the file, and when _actually_ playing it (i.e. a gemhead connected to it and changing frame). That is, with quicktime pix_film only consumes CPU when it is supposed to, and it is much much less CPU: you can easily read 6 full-size DV-PAL files actually rendering some portion of them on the screen, and you can have a dozen of pix_film with [open(ed files without impact on CPU (or even many more, then the impact won't be on CPU but on performance in general due to the memory trashing).

This can't be normal: DirectShow is supposed to be much faster than QuickTime on Windows; also, any given media player will open a video file using DirectSHow and without eating up nearly as much cpu, especially when not playing. There must be something wrong in GEM.

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Comment By: IOhannes m zmlnig (zmoelnig)

Date: 2010-08-22 20:16

Message: i meant to say, that this is a "tough" one, rather than touching...

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Comment By: IOhannes m zmlnig (zmoelnig) Date: 2010-08-22 20:16

Message: that's a touch one. there might be a problem with Gem using frame accurate seeking for playback, which might be handled better by QT than by DS.

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You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=507079&aid=2977716...