Introduce compatible-merge operators for format selection (was: Need a bestvideo+bestcompatibleaudio format selector)

[ghost]

I have

• Verified and I assure that I'm running youtube-dl 2016.08.01
• At least skimmed through README and most notably FAQ and BUGS sections
• Searched the bugtracker for similar issues including closed ones

The purpose of this issue

• Bug report (encountered problems with youtube-dl)
• Site support request (request for adding support for a new site)
• Feature request (request for a new functionality)
• Question
• Other

Description

This request follows this question.

I need something like -f bestvideo+bestcompatibleaudio, where 'bestcompatibleaudio' is the selector for the best audio file which is compatible with the desired video file (so that the files don't need to be muxed into an mkv.) Or, if you all find this cool, maybe even 'worstcompatibleaudio'

Until it is implemented, anyone who is in dire need of this feature can use this script.

[dstftw]

No, compatible-shortcuts is not a way to do. Compatibility is the characteristic of the merging operation not a particular format. Thus instead of introducing another n shortcuts an alternative compatible-merge-operator should be introduced.

[ghost]

Compatibility is the characteristic of the merging operation

I guess you're referring to the compatibility of codecs. Yes, that's not wrong. I already see a TODO here. Maybe a codec-compatible-formats-selection feature would be great to have. And that's essentially what I am referring to. Introducing more operators would only add to confusion. It'd be better instead if the checking is smartly taken care of keeping the user interface unchanged.

[dstftw]

I'm not referring to codecs. codec-compatible-formats-selection will make it impossible to mix standard-merge and compatible-merge in single format selection expression.

[ghost]

I'm too lazy to scour the source. Mind sharing a link to the code you're referring to?

[dstftw]

I'm not referring to any code. It's not implemented.

[ghost]

Oh, my bad. Anyway, the point is, I am not talking specifically about the implementation of such a format selector. Rather, I am suggesting that we need a feature (maybe a new interface option) that lets us make youtube-dl automatically choose (if possible) the audio and video formats, based on their codecs, such that they are compatible and don't need to be muxed into matroska.

[weedy]

You can already "block" mkv. You're just not reading the docs.
From my mplayer config:

ytdl-format=298+bestaudio[ext=m4a]/137+bestaudio[ext=m4a]/bestvideo[ext=mp4][height<?1080]+bestaudio[ext=m4a]/best

[ghost]

Wow! Either I am horrible at explaining things or you are not that great at understanding things. I read the docs and I am aware of that "blocking" strategy. My focus is NOT on blocking mkv, rather, it is on ensuring that video and audio files of compatible extensions are downloaded - for example, an m4a DASH video along with an mp4 DASH audio or a WebM DASH video along with a WebM DASH audio, NOT an mp4 DASH video along with a WebM DASH audio along, even if it is the best available audio format (which is usually the case with YouTube videos.) Preventing the muxing of incompatible files into an mkv is just the side effect. Did you at least read the title of the issue before commenting?

This is what I am talking about, in pseudo-code:

bestvideo = getbestvideo()
bve = extension(bestvideo)
bestcompatibleaudio = Nothing
for a in sort_in_descending_order_of_quality(audiofiles):
    if iscompatible(extension(a), bve):
        bestcompatibleaudio = a
        break
selected_formats = (bestvideo, bestcompatibleaudio or getbestaudio())

[yan12125]

@dstftw Did you mean something like this: bestvideo$bestaudio (forgive me for the naive selection of $)? How to know whether it's the best video with the best compatible one among audio formats, or best audio with the best compatible one among video formats?

[dstftw]

Did you mean something like this: bestvideo$bestaudio

Yes, that's the general idea.

How to know whether it's the best video with the best compatible one among audio formats, or best audio with the best compatible one among video formats?

For instance, by introducing another audio-plus-compatible-video-merge operator.

[yan12125]

Sounds good.

[ghost]

@dstftw,

For instance, by introducing another audio-plus-compatible-video-merge operator.

Actually, video-plus-compatible-audio-merge is what I had in mind when I opened this issue, rather than audio-plus-compatible-video-merge. (Or maybe we can have both ways?)
BTW, the introduction of an operator was a smart idea.

@yan12125,
May I suggest the usage of * rather than $?
And thanks for listening and adding the label!

[dstftw]

Obviously we should have both since both scenarios are viable.

[videonerd]

Any plans to realize this awesome feature directly in the program?

[endquote]

Also wishing for this. The merging of incompatible formats into mkv is great, but I'm finding that those files playback incorrectly in Chrome (but work fine in VLC).

Of course this is not ytdl's fault, but still.