Add a muxer

Question

Add a muxer

sjpotter opened this issue 4 years ago · comments

i.e. I might want to read in a stream, modify it and output the stream.

In fact, I did just that in a project I'm working on where I take the m2ts stream from libbluray, and add in language descriptors (from the buray clipinfo) and then serialize it out.

Quentin Renard · Answer 1 · Tue Apr 14 2020 04:09:41 GMT+0800 (China Standard Time)

you're definitely right, it would mean adding a muxer.

if you feel like contributing, I'm welcoming PRs

ivanjaros · Answer 2 · Sat Sep 19 2020 04:29:51 GMT+0800 (China Standard Time)

you could use https://github.com/nareix/joy4/tree/master/format/ts, since it is not maintained, it would be nice to have some up-to-date library..even if it is only for ts.

BRUHItsABunny · Answer 3 · Mon Nov 16 2020 10:50:43 GMT+0800 (China Standard Time)

I'm currently doing some preliminary research to make a TS muxer to mux small TS files into 1 big TS file. Anyone else working on this or might I be the one to issue a PR?

Quentin Renard · Answer 4 · Mon Nov 16 2020 16:15:32 GMT+0800 (China Standard Time)

I don't think anybody is working on this, go for it! ❤️

Try to reuse as much code as possible in this lib, create the least amount of new .go files and export the simplest and smallest API would be my points of emphasis.

Matt Aimonetti · Answer 5 · Tue Feb 23 2021 12:43:22 GMT+0800 (China Standard Time)

I'm playing with sample-aes encrypted hls streams that I'd like to demux, decode and remux. If this package were to offer a muxer, it would really make it close to complete. I understand nobody's really working on it at this moment and I'm afraid my TS knowledge is too limited but contribute but if maybe if a few of us work together we can get something working decently rapidely.

BRUHItsABunny · Answer 6 · Wed Feb 24 2021 01:59:16 GMT+0800 (China Standard Time)

Sorry I completely forgot about this. I'm probably not going to be working this until I get settled into my new job.

Ilya Barbashov · Answer 7 · Sat Mar 06 2021 10:54:44 GMT+0800 (China Standard Time)

I'm playing with sample-aes encrypted hls streams that I'd like to demux, decode and remux. If this package were to offer a muxer, it would really make it close to complete.

Well you can do this now. You got to handle decoding yourself though. But it's not hard since go std lib offers good crypto API. Just be aware of PKCS7 padding, that one costed me a bunch of grey hairs :)

Matt Aimonetti · Answer 8 · Sat Mar 06 2021 11:25:35 GMT+0800 (China Standard Time)

@barbashov care to share more? I'm not too worried about the crypto (if I understand what data needs to be decoded) but I'm not sure how to rebuild the stream without a muxer.

Ilya Barbashov · Answer 9 · Sat Mar 06 2021 11:42:53 GMT+0800 (China Standard Time)

@barbashov care to share more? I'm not too worried about the crypto (if I understand what data needs to be decoded) but I'm not sure how to rebuild the stream without a muxer.

I've written a muxer :) It's under review currently, but already useful #16

Ilya Barbashov · Answer 10 · Wed Mar 24 2021 22:57:10 GMT+0800 (China Standard Time)

@asticode you may want to close that one as well

Quentin Renard · Answer 11 · Wed Mar 24 2021 23:08:37 GMT+0800 (China Standard Time)

Thanks to @barbashov 's great work, this lib now has a muxer ❤️

Closing this issue

Matt Aimonetti · Answer 12 · Sun Mar 28 2021 08:47:00 GMT+0800 (China Standard Time)

I'm playing with sample-aes encrypted hls streams that I'd like to demux, decode and remux. If this package were to offer a muxer, it would really make it close to complete.

Well you can do this now. You got to handle decoding yourself though. But it's not hard since go std lib offers good crypto API. Just be aware of PKCS7 padding, that one costed me a bunch of grey hairs :)

Thanks @barbashov , I wrote the aes-128 crypto (CBC/PKCS7) code needed to decode the entire files but sample-aes is a bit more tricky since it requires also understanding the transport protocol (only only part of the data is encrypted).

My understanding is that I need to do something similar to your what you have here:
https://github.com/asticode/go-astits/blob/master/cmd/astits-es-split/main.go#L107

That would give me access to the partially encrypted data, then decrypt the data and remux the file by adding the decrypted PES to the new stream. Does that seem right or do I need to copy/add more data to my decrypted stream?

Ilya Barbashov · Answer 13 · Sun Mar 28 2021 08:59:28 GMT+0800 (China Standard Time)

I'm playing with sample-aes encrypted hls streams that I'd like to demux, decode and remux. If this package were to offer a muxer, it would really make it close to complete.

Well you can do this now. You got to handle decoding yourself though. But it's not hard since go std lib offers good crypto API. Just be aware of PKCS7 padding, that one costed me a bunch of grey hairs :)

Thanks @barbashov , I wrote the aes-128 crypto (CBC/PKCS7) code needed to decode the entire files but sample-aes is a bit more tricky since it requires also understanding the transport protocol (only only part of the data is encrypted).

My understanding is that I need to do something similar to your what you have here:
https://github.com/asticode/go-astits/blob/master/cmd/astits-es-split/main.go#L107

That would give me access to the partially encrypted data, then decrypt the data and remux the file by adding the decrypted PES to the new stream. Does that seem right or do I need to copy/add more data to my decrypted stream?

I don't really know how to help you since I haven't implemented SAMPLE-AES at this point in my software.
Though as far as i know, SAMPLE-AES doesn't encrypt the whole packet, it encrypts just the payload. If that's right, what you need to do is to decrypt only the payload. Anyway, I would follow HLS RFC here.