Inside the MediaFoundationCaptureDevice, there's the following call let availible = mf_device.compatible_format_list()?;. Compatible format list generates all possible combinations of frame rates and resolutions, then returns them. On my system, this method spins and deadlocks. If I try and break the process, I can step through until index 334.
I think this is caused by the following chunk:
let frame_fmt = match guid_to_frameformat(fourcc) {
Some(fcc) => fcc,
None => continue,
};
In my case, frame_fmt does not match anything and triggers a 'continue', but the index is not incremented, leading to an endless loop while evaluating the same fourcc value.
EDIT: I made a patch, but I defer to the owner if it's better to increment index in this part or at the top of the block. Both are good.
===
Complete digression:
It feels slightly wasteful (though cleaner) to exhaustively enumerate camera formats before passing them in to the fulfill method on camera_fmt. Perhaps it's possible to do one of the following to speed up the detection process?
Create a method get_compatible_format_list that takes the requested format and breaks on a match.
Use some kind of callback to check for valid formats?
Obviously, this is inconceivable if the user requests the MAX_WHATEVER. In that case we need to enumerate the formats no matter what, but it's possible we can still do some early-out by skipping the later parts of the inner loop if the resolution is less than the min or the framerate is less than the best we've found.
This was a strange one.
Inside the MediaFoundationCaptureDevice, there's the following call
let availible = mf_device.compatible_format_list()?;. Compatible format list generates all possible combinations of frame rates and resolutions, then returns them. On my system, this method spins and deadlocks. If I try and break the process, I can step through until index 334.I think this is caused by the following chunk:
In my case, frame_fmt does not match anything and triggers a 'continue', but the index is not incremented, leading to an endless loop while evaluating the same fourcc value.
EDIT: I made a patch, but I defer to the owner if it's better to increment index in this part or at the top of the block. Both are good.
===
Complete digression:
It feels slightly wasteful (though cleaner) to exhaustively enumerate camera formats before passing them in to the fulfill method on camera_fmt. Perhaps it's possible to do one of the following to speed up the detection process?
Obviously, this is inconceivable if the user requests the MAX_WHATEVER. In that case we need to enumerate the formats no matter what, but it's possible we can still do some early-out by skipping the later parts of the inner loop if the resolution is less than the min or the framerate is less than the best we've found.