Reliable way of getting video and audio containing formats from JSON

[christoph-heinrich]

Checklist

• I'm asking a question and not reporting a bug or requesting a feature
• I've looked through the README
• I've verified that I'm running yt-dlp version 2022.06.29 (update instructions) or later (specify commit)
• I've searched the bugtracker for similar questions including closed ones. DO NOT post duplicates
• I've read the guidelines for opening an issue

Please make sure the question is worded well enough to be understood

I am currently working on the ytdl_hook from mpv.
It runs yt-dlp with -J and then parses the JSON.
Currently it just assumes that everything that doesn't have a vcodec set (== null or == 'none') is an audio format. The problem with that is that things like storyboards from YouTube also get recognized as audio formats.

The README says:

ba, bestaudio: Select the best quality audio-only format. Equivalent to best*[vcodec=none]

Indicating that logic to be true.
But the README also says:

ba*, bestaudio*: Select the best quality format that contains audio. It may also contain video. Equivalent to best*[acodec!=none]

Implying that all formats that have audio are guaranteed to have acodec != null and acodec != 'none'.

The README however never states that != null and != none are guaranteed for vcodec or acodec if the format contains video or audio respectively.

Is there a reliable way of getting all the formats containing video and all the formats containing audio without also getting any other formats (e.g. storyboards from YouTube) from the JSON? Also it would be good to know if you know that solution to also work for youtube-dl.

P.S. I'm not a native english speaker, so maybe I'm wrong on this.
The README contains

b*, best*: Select the best quality format that contains either a video or an audio

but I think the word 'either' indicates xor, where as this should be a logical or. I suggest changing it to 'video and/or audio' to make it less ambiguous.

Provide verbose output that clearly demonstrates the problem

• Run your yt-dlp command with -vU flag added (yt-dlp -vU <your command line>)
• Copy the WHOLE output (starting with [debug] Command-line config) and insert it below

Complete Verbose Output

No response

[pukkandan]

if acodec!='none', the format has an audio. Similar for video

Eg:
video-only = vcodec!='none' && acodec=='none'
audio-only = vcodec=='none' && acodec!='none'
pre-merged = vcodec!='none' && acodec!='none'
storyboard = vcodec=='none' && acodec=='none'

PS: null represents that we don't know what the codec is, and is not the same as 'none'

---

Don't close the issue. I'll take a look at your suggestions about the README later

[christoph-heinrich]

Wow that was fast, thank you.

[christoph-heinrich]

I just tested it, and unfortunately this still recognizes non video formats from this json as videos. But I guess that just means that yt-dlp just doesn't know that they are not videos.

As a solution to that, I ended up also checking resolution != null and resolution != "audio only", but I guess that wouldn't be a good general solution then.

[pukkandan]

According to the json given in the issue, yt-dlp thinks they are videos. But I cannot reproduce their result and would need more info to say what exactly is hapenning