mediacapture-record VS MediaFragmentRecorder

Courtesy of this GitHub thread, my currently working, but very inconvenient strategy to capture the video is to use mediaCapture(0) on the canvas element with MediaStreamTrackProcessor to pipe frames into WebM muxer from a package called webm-muxer.

WebRTC's RTCRtpSender.replaceTrack() method achieves "seamless" replacement of a MediaStreamTrack. I proposed the same be added to MediaRecorder, see Add replaceTrack method to MediaRecorder., Add replaceStream to MediaRecorder.

I guess this could be used to remux the broken files that are spitted by the MediaRecorder API, which have missing metadata that prevents from seeking and thus far has been ignored / sweeped away in Chrome [1], Firefox [2], and even the standard itself [3], which ignored in its design the basic fact that encoding any file should include a "closing" stage (where metadata is written) before yielding it as a finished file.

[1]: https://bugs.chromium.org/p/chromium/issues/detail?id=642012

[2]: https://bugzilla.mozilla.org/show_bug.cgi?id=1283464

[3]: https://github.com/w3c/mediacapture-record/issues/119

See also https://developer.chrome.com/en/articles/webcodecs/. FWIW Some experiments (see branches) I did creating media fragments in the browser https://github.com/guest271314/MediaFragmentRecorder.

There are multiple ways to achieve the requirement, see the branches of this repository https://github.com/guest271314/MediaFragmentRecorder/.

The requirement is pssible. You can use RTCRtpSender.replaceTrack(), among other options. This repository is dedicated to that purpose https://github.com/guest271314/MediaFragmentRecorder.

You can use Image Capture API to get images from a MediaStreamTrack https://github.com/guest271314/MediaFragmentRecorder/tree/imagecapture-audiocontext-readablestream-writablestream.

You can use Media Fragment URI https://www.w3.org/TR/media-frags/ to play specific time slices of videos, or RTCRtpSender.replaceTrack() to merge specific time slices of discrete videos into a single media stream, see https://github.com/guest271314/MediaFragmentRecorder/blob/webrtc-replacetrack/MediaFragmentRecorder.html.

No. It can't. I can capture anything on my screen with navigator.mediaDevides.getDisplayMedia({video: true}) alone https://github.com/guest271314/screenshot, or other means. If I wanted to, I can capture audio as well, with several different approaches, respectively https://github.com/guest271314/captureSystemAudio; and both in a single video, or multiple vides merged into one https://github.com/guest271314/MediaFragmentRecorder.