jit.qt.movie & preroll crashing consistently

Jan 7, 2013 at 1:19am

jit.qt.movie & preroll crashing consistently

Hi Everyone,

The fast read: using preroll crashes Max if sending stop and start messages in high rates. (look at the demonstrative patch)

The long one: This might be a useful post for many people willing to play simultaneously some big videos.
I have a big patch which is playing 5 videos (720×405 in PhotoJPEG at 50fps) at the same time and jumping frames here and there. I started trying many options and the most responsive was to use loadram (loading the entire videos to ram) this option never gave any problem, it works great.
But my project grew up and now I can’t load the entire thing.. I badly need to use preroll and asyncread. Then my application started to crash. I wanted to know what was exactly the reason and found out that basically I cant stop and start a video in preroll mode. More precisely, max will crash if I try to stop and start the movie in a fast framerate (faster than the movie). This is the most obvious and ugly example I found, but of course it was also crashing if I jumped frames and done other “strange” things.

Any solution to my dilemma?
Here you have a demonstrative patch. If you need a video just let me know.
Any help will be awesome!

Max Msp 5.1.9 (and same crash in many different computers)

– Pasted Max Patch, click to expand. –
#65946
Jan 8, 2013 at 10:34am

Hi,

I think it would be important to get some feedback on this bug.. Was my example clear enough?

Thanks!

#237480
Jan 8, 2013 at 1:37pm

hi jordi,

preroll never worked for me. its buggy and simply sometimes it does not work.
perhaps someone got it to work ?

my workarond is:
dont use this function and use a internal ssd harddisk for the clips you want to play.
it is amazingly fast !!

best,
lee

#237481
Jan 9, 2013 at 4:51pm

FWIW, this does not crash on my system — os 10.8, max 6.08. If the rate of the qmetro is too high relative to the framerate of the video, it simply freezes. This makes sense, since you’re sending a stop message at a rate faster than a new frame gets loaded, so I wouldn’t expect that to work. Trying something else fairly intense — random frame jumping — I still don’t have any problem. You might want to try working with a different codec. And why do your movies have a framerate of 50 fps?

I suspect that preroll is not the culprit here — the main issue probably has to do with the rate at which you are accessing your disk.

M

– Pasted Max Patch, click to expand. –
#237482

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