Support for Live Video Stream (Non-Terminating) Processing Mode

[Breakthrough]

PySceneDetect should have a mode that allows for an OpenCV VideoCapture object that doesn't terminate (e.g. a webcam, or live internet stream) and continually provides updates for when a new scene is detected. This should work fine with both of the currently implemented scene detectors (ThresholdDetector and ContentDetector), although the main detection loop function scenedetect.detect_scenes() will need to be changed.

Using the set format, a timecode should be printed, followed by a newline, at the discovery of each new scene. This should allow other programs monitoring the process output a notification that a new scene was found. Additionally, for integration with other Python programs, an incremental version of detect_scenes() should be created that allows the user to pass one frame per call, with the function returning the current frame number if a scene change was detected, or None otherwise.

[Breakthrough]

Giving this issue a bump, as the implementation of this feature will affect some parts of the upcoming API changes. Much of the original issue information is the same, with the exception that a specific SceneManager context will need to be initiated before performing live detection (with respect to the upcoming v0.5 API).

[Breakthrough]

This is now supported natively in v0.5 via the Python API by passing a cv2.VideoCapture object instead of a scenedetect.VideoManager object.

However, I'm not sure how to go about adding this feature to the command line - is there a use case for this, and if so, does anyone have any suggestions for how it should be implemented (e.g. what options/flags should be provided, what the output should be, and how to determine when to terminate? [can use the time command to do this, but other questions need investigation]).

[x-techlabs]

When I checked the documentation , they didn't say about the option for live. Kindly can you show me where this documentation is?

[Breakthrough]

Hi @x-techlabs;

This feature is only available from the Python API. Instead of using a VideoManager class, you can instead use a native OpenCV VideoCapture object. For example, see this page and replace the video_manager with an open VideoCapture (be sure to set the end time when detecting scenes, or it will run indefinitely).

For additional details, see the detect_scenes method documentation from the StatsManager.

Thanks!

[mhashim6]

@Breakthrough
How is it possible to set an end time for a live-stream?
Our use case is: We have a continuous camera feed from a raspberry pi, and we need to trigger an action when the scene change.
so perhaps something like a callback or a blocking python generator to iterate upon detected scenes would be ideal.

[Breakthrough]

Hi @mhashim6;

Sorry for taking so long to get back to you! You can accomplish this as follows:

vm = VideoManager([0])   # Open Device 0
time_zero = vm.get_base_timecode()
vm.set_duration(time_zero + 5.3)    # Limit to 5.3 seconds
# or alternatively: vm.set_duration(500)  # limit to 500 frames
vm.start()

Is this what you were asking for, or were you looking for a different functionality? My apologies again for the delay in responding to this comment!

[mhashim6]

Hi @mhashim6;

Sorry for taking so long to get back to you! You can accomplish this as follows:

Hi! no problem, the whole world is kind of frozen right now.

vm = VideoManager([0])   # Open Device 0
time_zero = vm.get_base_timecode()
vm.set_duration(time_zero + 5.3)    # Limit to 5.3 seconds
# or alternatively: vm.set_duration(500)  # limit to 500 frames
vm.start()

Is this what you were asking for, or were you looking for a different functionality? My apologies again for the delay in responding to this comment!

I hope this is not a dumb question, but doesn't that make the video finite?