VideoIntervals

VideoIntervals[video,crit]

returns time intervals of video for which the criterion crit is satisfied.

VideoIntervals[video,crit,n]

evaluates criterion crit on partitions of n video frames.

VideoIntervals[video,crit,n,d]

evaluates crit on partitions with offset d.

VideoIntervals[{video1,video2,…},crit,…]

applies crit to a list of inputs extracted from each videoi.

Details and Options

  • VideoIntervals can be used to detect time intervals of interest in a video, such as constant frame, silent audio intervals, intervals containing a specific object, etc.
  • A criterion crit of a single argument gets applied to image frames or a list of image frames.
  • A pure function crit can access video and audio data as well as time using the following arguments:
  • #Imagevideo frames as Image objects
    #Audioa chunk of the audio as an Audio object
    #Timetime from the beginning of the video
    #TimeIntervalbeginning and end time stamps for the current partition
    #FrameIndexindex of the current output frame
    #InputFrameIndexindex of the current input frame
  • In VideoIntervals[{video1,video2,…},crit,…], data provided to each of the arguments is a list where the i^(th) element corresponds to the data extracted from videoi.
  • By default, partitions are offset by one frame.
  • VideoIntervals supports video containers and codecs specified by $VideoDecoders.
  • The following options can be given:
  • AlignmentCenteralignment of the time stamps with partitions
    MaxItems Infinitymaximum number of intervals to return
  • By default, measurements are returned at the center of each partition. Using the Alignment option, measurements can be returned at the beginning (Left) or end (Right) of each partition.

Examples

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Basic Examples  (2)

Find video intervals with constant frames:

Find video intervals with loud audio:

Scope  (5)

Specify the criterion as a pure function:

Specify the criterion as a normal function:

The input to the criterion function is an association with keys "Time", "TimeInterval", "Image", "FrameIndex", "InputFrameIndex" and "Audio" (if present):

Evaluate the criterion on a buffer of five frames:

If the partition size is not Automatic, the value for "Image" and will be a list of images:

The value for "Audio" is always a single Audio object of the appropriate duration:

Evaluate the criterion on non-overlapping partitions of five frames:

Specify partition size and offset using time quantities:

Options  (1)

MaxItems  (1)

By default, using MaxItems∞, the whole input is evaluated for possible intervals of interest:

Stop the computation once n complete intervals have been detected:

Applications  (2)

Find the intervals that contain the most motion in a video:

Extract the corresponding frames:

Find the intervals that contain constant frames:

Delete such intervals from the video:

Compare the duration of the original and resulting videos:

Wolfram Research (2020), VideoIntervals, Wolfram Language function, https://reference.wolfram.com/language/ref/VideoIntervals.html.

Text

Wolfram Research (2020), VideoIntervals, Wolfram Language function, https://reference.wolfram.com/language/ref/VideoIntervals.html.

CMS

Wolfram Language. 2020. "VideoIntervals." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/VideoIntervals.html.

APA

Wolfram Language. (2020). VideoIntervals. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/VideoIntervals.html

BibTeX

@misc{reference.wolfram_2024_videointervals, author="Wolfram Research", title="{VideoIntervals}", year="2020", howpublished="\url{https://reference.wolfram.com/language/ref/VideoIntervals.html}", note=[Accessed: 23-November-2024 ]}

BibLaTeX

@online{reference.wolfram_2024_videointervals, organization={Wolfram Research}, title={VideoIntervals}, year={2020}, url={https://reference.wolfram.com/language/ref/VideoIntervals.html}, note=[Accessed: 23-November-2024 ]}