jit.record: writer input not ready for media data (bug?)
Hi dear people
In avf mode, the jit.record object doesn't accept many frames in rapid succession. After about 4 frames triggered by an uzi, it posts the message 'writer input not ready for media data'. In quicktime mode all's fine.
Mac Pro, osx 10.9.5, Max/MSP 7.2
to reproduce, please paste this bit & click button.
anybody got easy workarounds apart from working with delays and such?
merci! -t
hey tarik.
this is not so much a bug, as it is a limitation of the AVF engine. lots of things like this, that used to work with quicktime, don't work with avf due to the asynchronous nature of so much of the library.
i've registered a feature request to output a notification from jit.record when it's ready to accept media data, which could be used to trigger the next frame.
in the meantime, some sort of delay is your only option. i did it like this (adjust the delay time for your setup and processing needs):
Thanks Rob!
Yes, that feature would be really handy. Until then, the delay method will do.
! t
One thing I've noticed is that the choice of codec has some influence over the occurrence of this 'writer input not ready for media data' error. If I use h264, the Max console rains full of errors. If I use prores4444 I only have a very occasional 'writer input not ready for media data', and they do not occur at all with prores422 on my MBP running 10.10.3. Which is a perfect codec for the experimental nonsense I output from jitter.
good point, thanks for the sharing!
fyi I get the same error under avf when trying to export movs from jit.matrixset
I still encounter this problem with jit.record & jit.matrixset on OSX nowadays.
Using jit.vcr instead of jit.record solved the problem for me (using OSX 10.13.6 & Max 7.3.5).
for exporting from jit.matrixset, try switching the video engine preference to viddll
I'm in the weeds with this too...
I'm using an uzi to export a matrixset to a prores4444 file through a jit.qt.record object
Interestingly it works fine on my machine but all the people who have tested my standalone have the problem. their 48 frame videos end up exporting only 2 or 3 frames.
I tried switching to viddll but that didnt seem to help, nor did switching to prores422...
for me jit.vcr just crashes max instantly on export
Super strange
For dumping frames into a jit.record you pretty much have to use viddll engine. I just mocked up a quick test and it seems to work fine. You can use jit.matrixset exportmovie, but I think it's less user friendly as it locks up the GUI. In my patch, you can still abort the recording by clicking the toggle, so it seems like a better option.
The default codec of jit.record with viddll is h264, so if you want prores4444 you have to dive into the dictionary options for specific codecs, as demonstrated in the viddll specific tab of the jit.record help patch. This is also how you can increase the bit rate of the h264 export.