Wrong FPS after cropping with Video Editor

Sebastian_Kloubert · February 26, 2021, 3:26pm

Hello there,

I’m using DLC 2.2b7 on Ubuntu 18.04.
I have a problem with the Video Editor function.

I used the built-in cropping tool to select the area of interest in my videos and cropped them successfully.
The problem is that the cropping changes the video information about the frames-per-second (FPS). The original videos have (for example) 44 FPS with a duration of 10 seconds and the cropped videos have 60 FPS with a duration of 10 seconds.

If only the video information would be changed, this wouldn’t be problematic.
The problem is that DLC uses this video information during the analysis.

The csv of the analysis has 600 rows (and pose estimations for every row) even though the video should only have 440 frames.

How do I tackle this problem?

Best wishes

Sebastian

MWMathis · February 26, 2021, 3:44pm

HI Sebastien,

it may be the meta data is corrupted, then re-corded to defaults. we use ffmpeg under the hood, so you could edit this function as you like! I hope that helps!

github.com

DeepLabCut/DeepLabCut/blob/736bf425e11ba8858e75e9962002a9a28718e367/deeplabcut/utils/auxfun_videos.py#L380



    Windows:
    >>> deeplabcut.ShortenVideo('C:\\yourusername\\rig-95\\Videos\\reachingvideo1.avi', start='00:17:00',stop='00:22:00',outsuffix='brief')

    Extracts (sub)video from minute 17 to 22 and and saves it in C:\\yourusername\\rig-95\\Videos as reachingvideo1brief.avi
    """
    writer = VideoWriter(vname)
    return writer.shorten(start, stop, outsuffix, outpath)


def CropVideo(
    vname,
    width=256,
    height=256,
    origin_x=0,
    origin_y=0,
    outsuffix="cropped",
    outpath=None,
    useGUI=False,
):
    """

(but also, please role up from beta releases, we are at 2.10.2 now, which includes maDLC functions)