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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 / vp8 player for java

does anyone know of a java library that plays vp8 or webm videos? thanks!
clamp
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Convert mp4 to webm with transparency?

I know how to convert mp4 to webm with ffmpeg: ffmpeg -y -i me939371029.mp4 -r 30 out3.webm But I'd like to use webm transparency. That guide uses Blender, but Blender's a desktop tool that's not easily automated and only outputs PNGs that must be…
mikemaccana
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How to (feature) detect if browser supports WebM alpha transparency?

I'm integrating a *.webm Video with alpha transparency. At the moment, the transparency is only supported in Chrome and Opera. (Demo: http://simpl.info/videoalpha/) Firefox for example plays the video as it supports the WebM format, but instead of…
chaenu
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ffmpeg options that work with Chrome

I am trying to find the magic options that make mp4 work in Chrome. I think my videos were working, but don't seem to any more after Chrome updated. Chrome, Version 41.0.2272.101 (Windows) I tried some other machines and found some of the videos…
James
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How to join two video files using Python?

Here I tried to cut first and second 30sec long video file from "path/connect.webm" to the strings out and out1. It works. But what I need to do is to concatenate these two strings and write that to a file "path/final.webm". So that I get a 60sec…
rash
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How come HTML5 video plays inconsistently in Firefox 11?

I have the following HTML5 video code on my homepage and it acts strange in Firefox 11.
DecafJava
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Adaptive video encoding with alpha channel

I've created a WebM media file with transparent background in Adobe After Effects. Due to Widevine specs, I have to encode this file to an adaptive format for playing. With the following command I've successfully created a webm file with…
Peter Bartha
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MediaRecorder's Webm blobs produce a broken video

I'm trying to emit webm Blobs (Base64-encoded and generated by MediaRecorder) to my Phoenix backend via WS, where I Base64-decode them and append them to a file. What I end up with is a defective webm video, I can see the first frame when I open it…
Milan Velebit
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How to edit .webm Blobs captured by Chrome MediaRecorder

In Chrome. I'm using MediaRecorder and canvas.captureStream() to create a webm file of the canvas. let recorder = new MediaRecorder(document.querySelector('canvas').captureStream(), {mimeType: 'video/webm'}); let chunks = []; let…
Bobby
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Downloading YouTube to mp3 and writing metadata (artist/song title) to mp3 file using youtube-dl

I am extracting audio only from youtube videos using youtube-dl. I would like to write the metadata (i.e. Artist Name and Song Title) into the mp3 file after downloading. My attempt to accomplish this starts with this code: @echo off set…
IRNotSmart
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Full-width Background Videos in Internet Explorer

I am designing a website that uses a self-hosted background video in a 100% width container. Works flawlessly in Chrome and Firefox but fails miserably in IE (tested in IE 11). The video is supposed to stretch width-wise to fill the container -…
digitalJE5U5
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Finding duration/number of frames of WebM using FFMPEG/libavformat

I'm trying to retrieve the duration and number of frames from a WebM file using FFMPEG and libavformat. I'm adapting some code that was initially written to work with MP4s, and when passing an MP4 it seems to work fine. I have FFMPEG 2.1 compiled…
gcgrant
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Splitting webm video to png with transparency

I need to split a webm encoded video into png frames, without losing transparency. I use the following ffmpeg command: ffmpeg -i dancer1.webm -pix_fmt rgba frames/%04d.png This produces a directory of pngs, but why is each output frame is missing…
Stephen Emslie
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Video with transparency, how to display alpha channel of webm files correctly on every device; VP9 or VP8 encoding?

About how to get a transparent background with a webm video via alpha channel, here is one person that says you should encode with VP8 and not VP9. WebM Alpha only displayed in Chrome? And here is another person who says it's the opposite thing,…
HolyResistance
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ffmpeg in "streaming mode" suddenly stops writing output file and resumes after several minutes

I'm using ffmpeg to convert chunks of media in webm format to a wav file in a "continuous stream" mode. Using a python wrapper, I'm feeding ffmpeg a webm chunk (let's say 1 chunk each second) and ffmpeg continuously writes the output wav (then, in a…
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