video – Page 18 – Tarik Billa

Getting a thumbnail from a video url or data in iOS

March 19, 2023 by Tarik

-(UIImage *)generateThumbImage : (NSString *)filepath { NSURL *url = [NSURL fileURLWithPath:filepath]; AVAsset *asset = [AVAsset assetWithURL:url]; AVAssetImageGenerator *imageGenerator = [[AVAssetImageGenerator alloc]initWithAsset:asset]; imageGenerator.appliesPreferredTrackTransform = YES; CMTime time = [asset duration]; time.value = 0; CGImageRef imageRef = [imageGenerator copyCGImageAtTime:time actualTime:NULL error:NULL]; UIImage *thumbnail = [UIImage imageWithCGImage:imageRef]; CGImageRelease(imageRef); // CGImageRef won’t be released by ARC return thumbnail; } … Read more

How can I set preview of video file, selecting from input type=’file’

March 12, 2023 by Tarik

@FabianQuiroga is right that you should better use createObjectURL than a FileReader in this case, but your problem has more to do with the fact that you set the src of a <source> element, so you need to call videoElement.load(). $(document).on(“change”, “.file_multi_video”, function(evt) { var $source = $(‘#video_here’); $source[0].src = URL.createObjectURL(this.files[0]); $source.parent()[0].load(); }); <script src=”https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js”></script> … Read more

JavaScript: Extract video frames reliably

March 10, 2023 by Tarik

[2021 update]: Since this question (and answer) has first been posted, things have evolved in this area, and it is finally time to make an update; the method that was exposed here went out-of-date, but luckily a few new or incoming APIs can help us better in extracting video frames: The most promising and powerful … Read more

Get video dimension in python-opencv

March 9, 2023 by Tarik

It gives width and height of file or camera as float (so you may have to convert to integer) But it always gives me 0.0 FPS. import cv2 vcap = cv2.VideoCapture(‘video.avi’) # 0=camera if vcap.isOpened(): # get vcap property width = vcap.get(cv2.cv.CV_CAP_PROP_FRAME_WIDTH) # float `width` height = vcap.get(cv2.cv.CV_CAP_PROP_FRAME_HEIGHT) # float `height` # or width = … Read more

Android intent for playing video?

March 9, 2023 by Tarik

Use setDataAndType on the Intent Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(newVideoPath)); intent.setDataAndType(Uri.parse(newVideoPath), “video/mp4″); startActivity(intent); Use “video/mp4” as MIME or use “video/*” if you don’t know the type. Edit: This not valid for general use. It fixes a bug in old HTC devices which required the URI in both the intent constructor and be set afterwards.

This code to write video+audio through AVAssetWriter and AVAssetWriterInputs is not working. Why?

March 8, 2023 by Tarik

In startVideoRecording I call (I assume you are calling this at some point) [_capSession startRunning] ; In stopVideoRecording I do not call [_videoWriterInput markAsFinished]; [_videoWriter endSessionAtSourceTime:lastSampleTime]; The markAsFinished is more for use with the block style pull method. See requestMediaDataWhenReadyOnQueue:usingBlock in AVAssetWriterInput for an explanation. The library should calculate the proper timing for interleaving the … Read more

GPU-accelerated video processing with ffmpeg

March 5, 2023 by Tarik

FFmpeg provides a subsystem for hardware acceleration, which includes NVIDIA: https://trac.ffmpeg.org/wiki/HWAccelIntro In order to enable support for GPU-assisted encoding with an NVIDIA GPU, you need: A supported GPU Supported drivers for your operating system The NVIDIA Codec SDK ffmpeg configured with –enable-nvenc (default if the drivers are detected while configuring)

What’s the maximum length of a youtube video id?

March 5, 2023 by Tarik

It’s almost certainly going to stay at 11 characters. The individual characters come from a set of 64 possibilities (A-Za-z0-9_-). 64^11 is somewhat more than 2^64. (10 characters would not be enough.) So basically each youtube ID is actually a 64bit number. And I quite doubt they will ever run out of those. If you … Read more

Automatic height when embedding a YouTube video?

March 4, 2023 by Tarik

This article contains a good answer, copied below. CSS: .video-container { position: relative; padding-bottom: 56.25%; /* 16:9 */ height: 0; } .video-container iframe { position: absolute; top: 0; left: 0; width: 100%; height: 100%; } Example Html <div class=”video-container”> <iframe width=”560″ height=”315″ src=”https://www.youtube.com/embed/_TyJeKKQh-s?controls=0″ frameborder=”0″ allow=”accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture” allowfullscreen></iframe> </div> How this works: The … Read more

Create thumbnail from video file via file input

March 4, 2023 by Tarik

Canvas.drawImage must be based on html content. source here is a simplier jsfiddle //and code function capture(){ var canvas = document.getElementById(‘canvas’); var video = document.getElementById(‘video’); canvas.getContext(‘2d’).drawImage(video, 0, 0, video.videoWidth, video.videoHeight); } The advantage of this solution is that you can select the thumbnail you want based on the time of the video.