The default codec

[Zuldek1994822]

Hello, I have compiled the manifest.

<?xml version="1.0" encoding="utf-8"?>
<MPD xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xmlns="urn:mpeg:dash:schema:mpd:2011"
     xmlns:xlink="http://www.w3.org/1999/xlink"
     xsi:schemaLocation="urn:mpeg:DASH:schema:MPD:2011 http://standards.iso.org/ittf/PubliclyAvailableStandards/MPEG-DASH_schema_files/DASH-MPD.xsd"
     profiles="urn:webm:dash:profile:webm-on-demand:2012,urn:mpeg:dash:profile:isoff-on-demand:2011"
     type="static"
     mediaPresentationDuration="PT18.7S"
     maxSegmentDuration="PT9.0S"
     minBufferTime="PT9.0S">
	<Period id="0" start="PT0.0S">
		<AdaptationSet id="0" contentType="video" startWithSAP="1" segmentAlignment="true" bitstreamSwitching="true" frameRate="24/1" maxWidth="1280" maxHeight="720" par="16:9">
			<SegmentTemplate timescale="1000000" initialization="init-$RepresentationID$.webm" media="sg-$RepresentationID$-$Number%05d$.webm" startNumber="1" duration="9000000" />			
			<Representation id="1" mimeType="video/webm" codecs="vp09.00.11.08" bandwidth="60000" width="256" height="144" sar="1:1" />
			<Representation id="2" mimeType="video/webm" codecs="vp09.00.20.08" bandwidth="150000" width="427" height="240" sar="1280:1281" />
			<Representation id="3" mimeType="video/webm" codecs="vp09.00.21.08" bandwidth="276000" width="640" height="360" sar="1:1" />
			<Representation id="4" mimeType="video/webm" codecs="vp09.00.30.08" bandwidth="512000" width="853" height="480" sar="2560:2559" />
			<Representation id="5" mimeType="video/webm" codecs="vp09.00.31.08" bandwidth="1024000" width="1280" height="720" sar="1:1" />
		</AdaptationSet>
		<AdaptationSet id="1" contentType="audio" startWithSAP="1" segmentAlignment="true" bitstreamSwitching="true">
			<SegmentTemplate timescale="1000000" initialization="init-$RepresentationID$.webm" media="sg-$RepresentationID$-$Number%05d$.webm" startNumber="1" duration="9000000" />
			<Representation id="0" mimeType="audio/webm" codecs="opus" bandwidth="96000" audioSamplingRate="48000"/>
		</AdaptationSet>
		<AdaptationSet id="2" contentType="video" startWithSAP="1" segmentAlignment="true" bitstreamSwitching="true" frameRate="24/1" maxWidth="1280" maxHeight="720" par="16:9">
			<SegmentTemplate timescale="1000000" initialization="init-$RepresentationID$.mp4" media="sg-$RepresentationID$-$Number%05d$.m4s" startNumber="1" duration="9000000" />			
			<Representation id="1" mimeType="video/mp4" codecs="avc1.64000c" bandwidth="95000" width="256" height="144" sar="1:1" />
			<Representation id="2" mimeType="video/mp4" codecs="avc1.640016" bandwidth="250000" width="426" height="240" sar="640:639" />
			<Representation id="3" mimeType="video/mp4" codecs="avc1.64001f" bandwidth="500000" width="640" height="360" sar="1:1" />
			<Representation id="4" mimeType="video/mp4" codecs="avc1.640028" bandwidth="1000000" width="854" height="480" sar="1280:1281" />
			<Representation id="5" mimeType="video/mp4" codecs="avc1.640032" bandwidth="2500000" width="1280" height="720" sar="1:1" />
		</AdaptationSet>
		<AdaptationSet id="3" contentType="audio" startWithSAP="1" segmentAlignment="true" bitstreamSwitching="true">
			<SegmentTemplate timescale="1000000" initialization="init-$RepresentationID$.mp4" media="sg-$RepresentationID$-$Number%05d$.m4s" startNumber="1" duration="9000000" />
			<Representation id="0" mimeType="audio/mp4" codecs="mp4a.40.2" bandwidth="128000" audioSamplingRate="48000">
				<AudioChannelConfiguration schemeIdUri="urn:mpeg:dash:23003:3:audio_channel_configuration:2011" value="2"/>			
			</Representation>
		</AdaptationSet>
		<AdaptationSet id="4" contentType="image" mimeType="image/webp">
			<SegmentTemplate media="tile_$RepresentationID$_$Number%01d$.webp" duration="50" startNumber="1" />
			<Representation id="250" bandwidth="2000" height="1250" width="4440">
				<EssentialProperty schemeIdUri="http://dashif.org/thumbnail_tile" value="10x5" />
			</Representation>
		</AdaptationSet>
	</Period>
</MPD>

(this.dsh = dashjs.MediaPlayer().create()).initialize(
	this.v = el('video', {poster: `/h720.webp`, preload: `auto`},
				el('source', {src: `/file/1.mp4`, type:"video/mp4"})
		    ), '/video/1/manifest.mpd');

this.dsh.updateSettings({
	streaming: {
		preferVideoCodec: "vp9",
		preferAudioCodec: "opus",
	}
});

I set the settings for VP9 and OPUS, but the player still plays MP4 in Chrome.
What's the problem here and is the configuration built correctly?

It is preferable to play VP9, MP4 is a backup option if vp9 is not supported by the browser.

[dsilhavy]

There is no setting called preferVideoCodec or preferAudioCodec. You need to use the initial track selection functionality. More information can be found here: https://dashif.org/dash.js/pages/usage/track-selection.html. Note that the documentation is based on dash.js version 5.

If you are on a platform that does not support VP9 or Opus these tracks will be filtered.

[Zuldek1994822]

I don't understand, here's my mpd, how to set it so that priority is on VP9, and h264 as a last resort if VP9 could not be played.
Chrome can play VP9, but dash ignores the preset preferVideoCodec setting: "vp9", and starts loading .m4s instead.webm files

[wschidol]

This conversation has me intrigued. You are quoting a preferVideoCodec setting yet I don't see that setting in the dash.js source code (and @dsilhavy says the same). So where is that setting coming from?
I went into bing and searched for "dash.js preferVideoCodec". The bing AI was quite confident that the setting exists and can be used for what you say. Is this an AI hallucination?

[dsilhavy]

I don't see a setting such as preferVideoCodec in version 4 or 3 of dash.js either so I would also be interested to know where you got this from.

To select the desired track based on your example you can do something like this:

        function init() {

            var video,
                player,
                url = 'yourmpd.mpd';

            var getCustomTrack = function (trackArr) {
                const webMTrack = trackArr.find((track) => {
                    return track.mimeType === 'video/webm'
                })

                return webMTrack ? webMTrack : trackArr[0]
            }

            video = document.querySelector('video');
            player = dashjs.MediaPlayer().create();
            player.initialize(video, url, true);
            player.setCustomInitialTrackSelectionFunction(getCustomTrack);

        }

[Zuldek1994822]

I probably have the old version, but there is no such setting on the new version..