More selective frame rate.

[HiroshiYAMA]

In cases where the fastest frame rate is not always required, the processing time of discarded frames is wasteful.
In that case, it is better to be able to set a more suitable frame rate.
That's why I made it possible to specify the frame rate as a real number with a command line option.
If there is no matching value in the list of configurable frame rates, select the closest value.

[dusty-nv]

Thanks @HiroshiYAMA - I prefer to keep a single frameRate value in the videoOptions as opposed to nominator/denominator. Does it not work like that with just using float frameRate in the pipeline?

[HiroshiYAMA]

@dusty-nv
Of course, I wanted to do that.
I tried float frameRate in the pipeline.
... ! video/x-raw, ... , framerate=29.97/1 ! ...

But, I got the following error.

[gstreamer] gstCamera failed to create pipeline
[gstreamer]    (could not link v4l2src0 to mysink, v4l2src0 can't handle caps video/x-raw, format=(string)YUY2, width=(int)1920, height=(int)1080, framerate=(string)29.97/1)
[gstreamer] gstCamera -- failed to create device v4l2:///dev/video0

Therefore, I implemented a fraction(nominator/denominator) in the pipeline.
for example,
cmd-line option: --input-rate=29.97
--> pipeline, ... ! video/x-raw, ... , framerate=2997/100 ! ...
others, 59.94 --> 7013/117(not work 5994/100)