Annotate the video in 30 frame rate?

[faj2007]

This tool annotate the video in 20 frame rate, does any one know how to change the frame rate? like 30 in my videos. Thanks

[antingshen]

The tool doesn't care about frame rate, it annotates by timestamp instead of frame number. Perhaps something in your post-processing script assumes 20 fps? (maybe the export_annotations script?)

[faj2007]

I don't know what is the export_annotations scripts. I have video in 30 frames rate, and I want to annotate each frame. Do you mean I can change the timestamp? or maybe I can only do it by imagelist option.

[antingshen]

the tool should just work with 30 fps videos. What problem are you having? Why do you say the tool only annotates at 20 fps?

[clayshieh]

The max fps this tool can edit is restricted by the SAME_FRAME_THRESHOLD value in annotation.js which by default is 0.01 seconds and because it's calculated as an absolute difference in frame times the max fps at default settings is 50 fps for videos. During video playback you can stop at whichever frame you want but if the timestamp for that frame is close enough to the timestamp of another already annotated frame then your annotations will be stored with that closest frame instead.

If you are experiencing issues where annotations aren't appearing where they should be on playback, try lowering the value of SAME_FRAME_THRESHOLD.

[faj2007]

Thanks for the answers, I finally do it in image lists option instead. Also downloading the images a little bit slow, but I can annotate each frame. Maybe I would try SAME_FRAME_THRESHOLD later. My SAME_FRAME_THRESHOLD is 0.01, and it turns out that it annotate the video in 20 fps.

[torresalyssa]

I found that the issue for me was not with SAME_FRAME_THRESHOLD, but with the frame rates that are hard-coded into the VideoFramePlayer class in annotator/static/views/framePlayers.js.

If you go to the class functions nextFrame() and previousFrame(), you'll see that frameRate is hard-coded as 1/20 for nextFrame() and 1/10 for previousFrame(). This also means that as it is written, moving forward one frame and moving back one frame will not result in the same frame sequences.

I was able to make this step through a 30fps, constant frame rate video by setting both frameRate to 1/30.

Ideally this would be something that could be dynamically set, or pulled from the video metadata. The idea would be that when I upload a video to be labeled, I can include a frame rate at which I want the video to be labeled and then the video player will pull in this information and use it to know how much to skip forward or backward by when traversing through frame-by-frame.