Hello,
I'm trying to understand the logic behind the frame rate that Avid MC sets for the plugin. I'm testing with a session that uses 720p video at 23.98 fps, and OpenIO sets the plugin's frame rate to 59.94 for some reason. It would be preferrable to use the session's frame rate, no?
Can someone describe the logic that MC uses to set the frame rate, and what a plugin needs to do to convince it that it supports 23.98 fps?
Thanks,
Ori
when you created the project, what frame rate did you choose?
Dave S.
23.98.
oripessach: Can someone describe the logic that MC uses to set the frame rate, and what a plugin needs to do to convince it that it supports 23.98 fps?
Check the specs of your video I/O hardware. Many do not support 720p/23.976 as a tranmission signal. It is over 59.94p.
Blackmagic UltraStudio and Decklinks do not list that format.
Is it even an SMTPE standard?
DQS
www.mpenyc.com
Ori,
Because Open I/O was originally developed to support hardware I/O devices, it does restrict any formats to standard broadcast formats. So for 720p/23.976 and 720p/29.97, it selects 720p/59.94 as the output format.
Jeremy
Thanks - for this, and the other issues you've responded to.
The one showstopping issue we're still having is that based on the sample plugin code, it's not clear how a plugin can maintain A/V sync. To the best of my understanding, a plugin is supposed to read and play one frame's worth of audio at each TOF, if audio is playing. This doesn't seem to work and results in a pretty big gap between the video and audio.
I was able to make things slightly better by only reading audio when m_bIsPlaying is set to true, but even then, the audio will eventually get out of sync (it takes longer, though - maybe an hour.)
How is this supposed to work? Any insignt into how the NDI plugin does it, for example, would be extremely helpful.
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