MPEG-2 Transport Stream Packaging for Media over QUIC Transport | Hacker News Reader

MPEG-2 Transport Stream Packaging for Media over QUIC Transport

ietf.org

68 pointsmondainx23 comments

Try not to confuse container vs codec. M2TS can carry a plethora of content and is very widely used these days, in the streaming world.

Including IP (over DOCSIS), I believe!

I became aware of RFC4259: https://www.rfc-editor.org/rfc/rfc4259, but is there literature about its use in the wild? Searching on [rfc4259, nanog] comes up snake eyes for me.

DOCSIS would probably not be be specified in RFCs, but see e.g. here: https://account.cablelabs.com/server/alfresco/9b8a9bd8-dea3-...

I suppose the main reason was compatibility with existing cable headend infrastructure, but I'm also curious to know if there were ever actual TV and DOCSIS data sharing a single physical transponder. Would be a nice way of leveraging spare bandwidth due to variable bit rate video encoding!

Is MPEG-2 still used over h264 for things that would justify this RFC in 2026?

MPEG-2 TS is a container. H.264 is a coding specification. They are totally different things.

One can find MPEG-2 TS in surprising places (see: DOCSIS encapsulating Ethernet frames into TS packets).

If I had to guess why MPEG-2 TS, it'd probably be the for the fact it's a well-supported streaming format in both hardware and software. If you tried using QuickTime or MPEG-4 containers, you'd have to rely on hacks like ensuring the moov atom preceeds mdat.

Matroska may be worth considering (especially the subset used by WebM to make it stream-friendly and quicker to seek), but no idea how widespread hardware support is for (de)muxing that.

Before ProRes, we captured HD content at 100Mbps MPEG2 video with PCM audio wrapped in a 302m stream that were muxed together as an MP2TS wrapper. The 302m made it even more difficult as not all MP2TS tools could do it correctly, and some would not allow for custom Program stream IDs and needed to be remuxed by other tools allow for custom PIDs as a post process.

But seeing how many uses people came up with for using MP2TS just shows it's flexibility and resilience.

I don't think MKV is better suited for low-latency streaming production (as opposed to consumption) than MP4. That's really more of the domain of MPEG-TS, RTP etc., and presumably this is a reliable transport alternative to that.

HLS, MPEG-DASH etc. do successfully work around much of that, but they're really mostly that – workarounds to present stream-like semantics over an HTTP + CDN based delivery mechanism.

There are significant gaps on the production/distribution side of things, i.e., everything that happens before the CDN (and for very low latency even beyond), and I suppose this is an attempt at filling those.

Hardware support does not matter for TS, as containers are handled in software.

Fast start is irrelevant because MoQ normally uses fragmented MP4, not progressive.

Sure, but there are a lot of media applicances that don't really have upgradeable software. I suppose it can be pretty useful to just (un)wrap MoQ and feed the result over a local interface into something that just expects M2TS and vice versa.

MPEG-TS is used to contain h264 chunks for HLS. MPEG-DASH and the new CMAF standard use fMP4 containers instead. My personal take is that Media over QUIC (MoQ) should support both.

HLS also supports fMP4 now and no one is making new services that use TS (there are some old ones still around with too much friction to switch)

The nice thing about fMP4 is that it's supported by both HLS and MPEG-DASH, so you can save yourself the effort of duplicating all data at the CDN level (or using a CDN that can just-in-time assemble fMP4 and M2TS files from the same underlying source).

No, but under it ;)

This looks like a kludge that should be used as a last resort. Transport Stream is not for the Internet.

Transport stream is specifically meant for unstable connections vs Program streams used for DVDs with a nice steady data stream. Digital cable signals and other signals use transport streams specifically because they can resync if things do get out of sync.

But yes, working with TS feels kludgy. I haven't had to deal with them in over a decade, but there was one tool that made it all super easy, MP2TSME, that I hear is no longer available

They are still pretty widely use for HLS/DASH streams. You may not be dealing with them, but you're probably watching them.

The Internet you are referring to is not meant for low latency streaming. This is what it takes make it low latency. MPEGTS is proven stable and ubiquitous. If only it has less overhead.

I'm been using MPEG2 transport streams over the internet to broadcast programs to millions of people for over 15 years, and of course over private IP networks.

I'm almost certain you've seen some of that output

> Transport Stream is not for the Internet.

As a rule, strong feelings about issues do not emerge from deep understanding.

Tell that to cable isp's. I don't know if things have changed. but due to the way things fell out when they were trying to transition to internet service on their video lines it ended up being ip encapsulated in mpegts. Something about how all their existing equipment spoke mpegts.

Transport Stream is for everything, which includes the Internet.

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