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Questions tagged [video-processing]

Video processing deals mostly with filtering video frames. Most common filters are noise removal, contrast and color modifications. For questions related to trimming and modifying videos use [video-editing], and [video-encoding] for questions related to editing videos into any format.

Video processing is a particular case of signal processing, which often employs video filters and where the input and output signals are video files or video streams. Video processing techniques are used in television sets, VCRs, DVDs, video codecs, video players, video scalers and other devices.

Most common filters are noise removal, contrast and color modifications. Relevant questions should include specific filters.

See also:

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How to detect if a video file was recorded in portrait orientation, or landscape in iOS

I am using AlAssetsGroup enumerateAssetsAtIndexes to list the assets in the Photos (Camera) app. For a given video asset I want to determine whether it was shot in portrait or landscape mode. In the following code, asset is an AlAsset and I have…
George C.
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How to split video or audio by silent parts

I need to automatically split video of a speech by words, so every word is a separate video file. Do you know any ways to do this? My plan was to detect silent parts and use them as words separators. But i didn't find any tool to do this and looks…
TermiT
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FFMPEG: chroma key / greenscreen filter for images / video

I need for a video to use chroma key filter / greenscreen filter and overlay it over another video and output it as new video. Are there any existing libraries, scripts, filters or solutions for this purpose?
user753676
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Writing a video file using H.264 compression in OpenCV

How do I write a video using H.264 compression with the VideoWriter class in OpenCV? I basically want to get a video from the webcam and save it after a character is pressed. The ouput video file is huge when using MPEG4 Part 2 compression.
kauDaOtha
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How to get Bytes from CMSampleBufferRef , To Send Over Network

Am Captuing video using AVFoundation frame work .With the help of Apple Documentation http://developer.apple.com/library/ios/#documentation/AudioVideo/Conceptual/AVFoundationPG/Articles/03_MediaCapture.html%23//apple_ref/doc/uid/TP40010188-CH5-SW2…
Vasu Ashok
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playing a specific interval of a video in mplayer using command line option

I am using mplayer to play videos... I wanted to know if there are command line options to play a specific interval of a video in mplayer? For example, if I want to play a video file from 56 secs for a duration of 3 secs, then what would the command…
assassin
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Fetching the dimensions of a H264Video stream

I am trying to fetch the dimensions (Height and width) from a H264 stream. I know that to fetch the same details from a mpeg2 stream you have to look at the four bytes following the sequence header start code ((01B3)). Will the same logic work for…
DRT
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How do I get a Video Thumbnail in .Net?

I'm looking to implement a function that retrieves a single frame from an input video, so I can use it as a thumbnail. Something along these lines should work: // filename examples: "test.avi", "test.dvr-ms" // position is from 0 to 100 percent…
Sam Saffron
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ffmpeg in python script

I would like to run the following command in a python script, I also want to make it loop over several videos in a folder. This is the command I want to run. ffmpeg -i mymovie.avi -f image2 -vf fps=fps=1 output%d.png I want to fit it in something…
jawwe
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Select the camera while using navigate.getUserMedia()

I am using navigate.getUserMedia() method to capture video on my mobile and do further processing on it. But as of now it is capturing the video using the front camera. How do i make it to access the rear facing camera?? Below is some sample code…
Vinay C
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How do I add a custom thumbnail to a .mp4 file using ffmpeg?

I am trying to find the proper ffmpeg command to add a .png or .jpg image to a .mp4 video as a thumbnail. The command will eventually automatically be executed by a C# program. This is what I have so far: # This does not work. It only removes the…
cooder_one
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How can I make a video from array of images in matplotlib?

I have a couple of images that show how something changes in time. I visualize them as many images on the same plot with the following code: import matplotlib.pyplot as plt import matplotlib.cm as cm img = [] # some array of images fig =…
Salvador Dali
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How to Add Font size in subtitles in ffmpeg video filter

I'm using this command to crop,scale, and then add subtitles as overlay ffmpeg -i input.avi -vf "[in]crop=in_w:in_h-20:0:0 [crop]; [crop]scale=320:240 [scale];[scale]subtitles=srt.srt" -aspect 16:9 -vcodec libx264 -crf 23 oq.mp4 how can we set…
khizar ansari
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How to expose a virtual camera on macOS?

I want to write my own camera filters for videochat, and ideally apply them in any/all of the popular videochat applications (Zoom, Hangouts, Skype, etc.). The way I imagine this working is to write a macOS application that reads the camera feed,…
user18184
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Can ffmpeg burn in time code?

I have a need to burn in a time code to a video and am wondering if this is something that ffmpeg is capable of?
spinon
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