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Questions tagged [webm]

WebM is an open video encoding standard by Google. It consists of video streams compressed with the VP8 or VP9 video codec, audio streams compressed with the Vorbis or Opus audio codecs, and WebVTT text tracks. It may contain alpha planes for transparency.

For the purposes of the video tag introduced by HTML5, there was a need for an open (royalty-free) video codec which could be incorporated into free open source projects. WebM is Google's answer to this challange. An other possibility is Theora (also royalty-free).

Other vendors are voting for H.264 (mostly Apple and Microsoft), for which they already bought the licenses to incorporate into their web browsers.

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webm to mp4 conversion using ffmpeg

When I try to convert a webm file to mp4 the output is very very choppy and it appears as if many frames have been dropped by ffmpeg I used the following commands to convert ffmpeg -i movie.webm movie.mp4 ffmpeg -i movie.webm -vcodec libx264…
Pavan K
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How to create a WebM video file?

After looking around the web, I found no way to generate a WebM video. I see drivers for Windows and QuickTime, but no evidence that the most common utility FFmpeg is being supported. Is there any open source converter that produces WebM?
Marneau
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How to minimize the delay in a live streaming with ffmpeg

i have a problem. I would to do a live streaming with ffmpeg from my webcam. I launch the ffserver and it works. From another terminal I launch ffmpeg to stream with this command and it works: sudo ffmpeg -re -f video4linux2 -i /dev/video0 -fflags…
Pasquale C.
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WebM vs. Ogg Theora

How would one compare Ogg Theora and WebM against the following parameters:- Efficiency of compression Efficiency of computation Issues in Wider adaptability (why wouldn't someone make a hardward chip that does Ogg or WebM transcoding; like it is…
caleb531
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Can I record video in Android Studio in another format, instead of WebM?

I'm developing an app in Android Studio, and it's useful to be able to record video from the emulator (via the button in the Logcat tab). However, in recent versions of Studio (I'm now on 3.4.1) the default video format has changed to WebM. WebM…
Iain Merrick
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ffmpeg concat produces DTS out of order errors

I'm following the documentation on how to concatenate files with ffmpeg but during the process I'm seeing lots of warning and the output video stops after the first chunk but the audio keeps on playing. This is the command I'm using to concatenate…
Andy
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Do I need both WebM and ogv formats when using HTML5 video?

From videojs.com's documentation, I had the impression that I needed to include both ogv and webm file formats (in addition to mp4). Then I read http://www.htmlgoodies.com/html5/client/how-to-embed-video-using-html5.html#fbid=erNepglDbZl, from…
nitech
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Batch script to convert, youtube-dl webm file to mp3 with ffmpeg

I'm using youtube-dl to extract the best possible audio quality from youtube videos. However the best quality audio usually turns out to be the webm format, which isn't useful. I would like to write a batch script that converts the webm file to an…
SneakyShrike
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Error "Transparency encoding with auto_alt_ref does not work" when converting a .mov with Alpha to .webm with alpha with ffmpeg

I am trying to convert a .mov file with alpha transparency into a .webm file and have been following this thread for help: Convert mov with Alpha to VP9 Webm with Alpha Using ffmpeg The command line I have been using is ffmpeg -r 24/1 -i…
ThomTTP
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Encoding FFMPEG to MPEG-DASH – or WebM with Keyframe Clusters – for MediaSource API

I'm currently sending a video stream to Chrome, to play via the MediaSource API. As I understand it, MediaSource only supports MP4 files encoded with MPEG-DASH, or WebM files that have clusters beginning with keyframes (otherwise it raises the…
Chris Nolet
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Is WebM for audio too, or just video?

I've seen mentions of WebM being used for audio, but reading the WebM Project site and googling convert mp3 to webm has led me to believe that WebM is just for video. I definitely see lots of WebM to mp3 conversion utilities, but not the reverse. I…
Brian FitzGerald
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Video with transparency on Android

Is there any way to have Android play video with transparent areas? When I try to play a WebM video containing transparent areas in VideoView, the background of the view remains black. Instead of black I'd expect to see the background of the parent…
hleinone
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Convert PNGs to webm video with transparency

I would like to use avconv to convert a series of PNG images to a WebM video, preserving transparency. I understand that the pixel format used in the output video must support transparency. So I tried: $ avconv -framerate 25 -f image2 -i…
sebastian
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Real Time Streaming to HTML5 (with out webrtc) just using video tag

I would like to wrap real time encoded data to webm or ogv and send it to an html5 browser. Can webm or ogv do this, Mp4 can not do this due to its MDAT atoms. (one can not wrap h264 and mp3 in real time and wrap it and send it to the client) Say I…
Evren Bingøl
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WebM and Opus in Safari

Using patent-free audio and video codecs on the web has always been problematic due to poor support in Safari. According to the Safari 15 release notes, though, this might be starting to change. WebM video is apparently now supported in MSE on…
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