Hi Brion, In addition to automated bitrate adjustments, can there be a way for users to manually adjust their bitrates or quality settings on the fly without changing resolutions or file formats?
Not meaning to be ungrateful, but I think that improving HD video playback in IE and Safari should take precedence as a priority. I tried watching one of Victor's HD WEBM fundraising videos on a 4K display in Safari, and my user experience went from amazing to awful as soon as playback started in low-def OGV. Thanks, Pine On May 24, 2016 09:44, "Brion Vibber" <bvib...@wikimedia.org> wrote: > In the past, we've had a mixture of fixed bitrates and quality-based > settings for producing video transcodes. > > Each has its advantages: fixed bitrates are more predictable for watching > while streaming, while fixed quality settings allow for reducing the > bitrate on low-complexity scenes to save bandwidth (and increasing it on > high-complexity scenes to keep quality up!) > > Since "download and watch it later" is less of a thing on today's internet > than "stream it right now!", I'd been leaning for a while towards moving > more things to fixed bitrates. However, I'm starting to come down on the > side of a fixed quality setting with a variable bitrate... > > Overall variable rate encoding should lead to lower bandwidth usage for > most parts of most files, while still maintaining high quality on scenes > that need it. > > > The downside is that a high-complexity scene encoded at a higher bitrate > might cause buffering to run out during playback that had been working ok > on earlier scenes at a lower bitrate. > > Once we support adaptive streaming (using MPEG-DASH, or something like it) > the system should be able to provide a detailed enough manifest[1] to show > which segments of the file are low-bandwidth and which are high-bandwidth, > so if there's a bandwidth limitation that stops us from viewing one > particular segment at the current resolution, we can bump down and then > bump resolution back up again when the bandwidth usage goes down. > > If there's no strong objection, I'm going to tinker with the quality > settings for WebM and Ogg Theora video transcodes to try to find quality > settings I'm happy with that result in reasonable bandwidth averages. > > > [1] An MPEG-DASH manifest (.mpd) specifies a target bitrate on each > resolution representation, but the actual segments can be different sizes. > When they're specified as byte ranges of a source file, the exact segment > size is conveniently available! > > -- brion > > > _______________________________________________ > Multimedia mailing list > Multimedia@lists.wikimedia.org > https://lists.wikimedia.org/mailman/listinfo/multimedia > >
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