Re: [mediacapture-record] Add replaceTrack method to MediaStream (#167)

Note, the origin of this issue is the code at https://github.com/guest271314/MediaFragmentRecorder/blob/master/MediaFragmentRecorder.html which outputs the expected result of a WebM video which encodes the individual track pixel dimensions at Mozilla Firefox, does not output the expected result at Chromium, Chrome browser. Would suggest to run the code to observe the output at the respective browsers. That lead to attempting to compose code which output the same result at each browser https://github.com/guest271314/MediaFragmentRecorder/branches, observing several different issues at each browser due to implementations of APIs, methods during testing code.

Was able to encode variable resolution at Chromium browser using the codec `"video/<x-matroska|webm>;codecs=h264"` or `"video/<x-matroska|webm>;codecs=avc1"` https://plnkr.co/edit/Axkb8s?p=info. Mozilla Firefox does not playback the video, for reasons described in issues relating to codecs in WebM and Matroska file output by `MediaRecorder` 
at Firefox and Chromium, for example https://bugs.chromium.org/p/chromium/issues/detail?id=980822. Mozilla Firefox already does output expected result using that browsers' implementation of VP8, VP9, and related encoders and decoders and HTML `<video>` element. 

Without using `"video/<x-matroska|webm>;codecs=avc1"` `mimeType` at `MediaRecorder` at Chromium have not been able to playback WebM files containing variable resolution which output the expected pixel dimensions at HTML `<video>` element, which for reasons unknown here, does output variable width and height when the codec is `h264` or `avc1`.  

The purpose of this issue is not to simply have methods for each browser that still output dissimilar results, for example, arbitrary track order, which require more than one version of code to achieve similar output.

The purpose of this issue is for the capability to compose the same code for each browser and achieve the same output at each browser, to the extent possible, uniform implementation of any extended method specification which is intended to not stop `MediaRecorder` recording and encoding replacement track properties (for example, width and height) when replacing, adding and removing tracks and streams at `MediaRecorder` while not stopping recording.

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Received on Friday, 30 August 2019 03:11:42 UTC