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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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Decode video frames on iPhone GPU

I'm looking for the fastest way to decode a local mpeg-4 video's frames on the iPhone. I'm simply interested in the luminance values of the pixels in every 10th frame. I don't need to render the video anywhere. I've tried ffmpeg, AVAssetReader,…
simon.d
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why DCT transform is preferred over other transforms in video/image compression

I went through how DCT (discrete cosine transform) is used in image and video compression standards. But why DCT only is preferred over other transforms like dft or dst?
mrsatish
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OpenCV: reading frames from VideoCapture advances the video to bizarrely wrong location

(I will put a 500 reputation bounty on this question as soon as it's eligible - unless the question got closed.) Problem in one sentence Reading frames from a VideoCapture advances the video much further than it's supposed to. Explanation I need to…
timgeb
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OpenCV doesn't report accurate frame rate/count

I have a 33 second video that I'm trying to process with OpenCV. My goal is to determine what instance in time (relative to the start of the video) each frame corresponds to. I'm doing this in order to be able to compare frames from videos of the…
mpenkov
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Reverse video in android

I have recorded a video from camera in my app and saved in device storage.Now I want to reverse the video such that it plays from backwards.i.e. if video is of 10 seconds then the last frame at 10th second will become first frame and it starts…
Android Developer
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Why does video resolution change when streaming from Android via WebRTC

I'm trying to stream at 640x480 from Chrome on Android using WebRTC, and the video starts off at that, but then the resolution drops to 320x240. Here are the getUserMedia parameters that are sent: "getUserMedia": [ { "origin":…
Jay Prall
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how to use AVCaptureSession to read a video from a file?

I am writing an app that does some real-time video processing using an AVCaptureSession with a AVCaptureVideoDataOutput as output and an AVCaptureDeviceInput with the video file (it no longer needs to be in real-time) as input. Is it possible to use…
kunal
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Concatenate mp4 files in Android using halfninja ffmpeg

I've manage to compile halfninja ffmpeg scripts for Android NDK using NDK version r5c. (Unfortunately any attempt to compile with earlier NDK generated some error), also I'm not very knowledgeable on the whole NDK process, so it's a bit hit-n-miss…
Budius
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Superimposing two videos onto a static image?

I have two videos that I'd like to combine into a single video, in which both videos would sit on top of a static background image. (Think something like this.) My requirements are that the software I use is free, that it runs on OSX, and that I…
Archagon
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People Counting System

I want to develop a "People Counting System" using OpenCV (or Emgu CV). Please guide me on how to implement or lead me to some examples or open source projects. (I have done some work: extracting diff then threshold to delete background, using…
Kaveh Shahbazian
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Getting "TypeError: must be real number, not NoneType" whenever trying to run write_videofile to a clip in moviepy

Example code: from moviepy.editor import * clip = VideoFileClip('video.mp4') clip.write_videofile('video2.mp4', fps=30) After showing the following messages, showing that the video is being built and written, Moviepy - Building video…
Sato
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What's a good Python library to manipulate frames of a video file?

I'm looking for a Python video processing library, similar to PIL, where I can iterate through all the frames of a source video, access the pixel data for each frame, draw onto each frame and save the result as a new video file. I've found a couple…
Tom
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Use Kalman filter to track the position of an object, but need to know the position of that object as an input of Kalman filter. What is going on?

I am trying to study how to use Kalman filter in tracking an object (ball) moving in a video sequence by myself so please explain it to me as I am a child. By some algorithms (color analysis, optical flow...), I am able to get a binary image of…
John
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Video Capturing + Uploading + Processing + Streaming back - .NET & C#

We are trying to find out any technologies/libraries available in .NET stack (even wrappers on top of 3rd party dlls) that'll help us to build an app that can 1 - Capture an image from a user's video device 2 - Upload it realtime to a server 3 -…
amazedsaint
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Most used Python module for video processing?

I need to: Open a video file Iterate over the frames of the file as images Do some analysis in this image frame of the video Draw in this image of the video Create a new video with these changes OpenCV isn't working for my webcam, but python-gst…
Tarantula
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