Video+Audio Best leads to AAC Audio instead of OPUS

[Tanatsuko]

Using the Video+Audio best setting, I downloaded a video that has the YouTube codecs (248) and (251), so it should be 1080p (Google's V9 codec) and OPUS for audio. However, the file I end up with has the correct video codec but uses AAC for audio (see screenshot I took from VLC of the downloaded file).

Steps to reproduce the behavior:

1. Type in "https://www.youtube.com/watch?v=UT3yC-4_YBU" and click the [+].
2. Make sure that at the bottom "Video + audio" and "Best" are selected.
3. Click the green "Download" button.
4. Navigate to the file, open it in your media player of choice, and check the codec.
5. See that the audio is AAC instead of OPUS.

Expected behavior:

In a video that uses the (248) video codec and the (251) audio codec, the audio should be in OPUS, not AAC.

If applicable, add screenshots to help explain your problem.

Additional info (please complete the following information):

• OS: Windows 10
• Application version: 2.5.4
• Application type: I believe it's installer? I downloaded the .EXE from some page I found on Google.

(Edit: I apologize that the VLC screenshot is in German, but I believe it's understandable, even without knowing German.)

[StefanLobbenmeier]

Can you try enabling the option to list audio formats in settings? Should be under advanced.

Apart from that could you elaborate on why you would expect OPUS as the default?

[StefanLobbenmeier]

From yt-dlp, this would mean setting this setting:

--prefer-free-formats           Prefer video formats with free containers
                                over non-free ones of same quality. Use with
                                "-S ext" to strictly prefer free containers
                                irrespective of quality

[Tanatsuko]

Thank you. I managed to download my video in .webm with OPUS audio now.

If you check out my test video on YouTube, set the settings to 1080p, and go to "Stats for Nerds," it will show that the video codec is 248 (VP9) and the audio codec is 251 (OPUS). In fact, if you go through all different video resolutions, the audio codec always stays 251 (OPUS), so I'm surpised to see AAC audio at all as I wouldn't know where "Open Video Downloader" gets the AAC audio track from. My best guess would be that the program converts OPUS to AAC for compatibility purposes?

I have never worked with the command line tools before, but before I had to reinstall my OS, I've used a different program (I can't remember the name, though) that automatically gave me the VP9/OPUS combo. I like this program's design a lot better, though. I'm just a little surprised why the video + audio combo ends up giving me AAC for audio.

Oh, a little addendum: Out of curiosity, I just used the same video I linked above and went with "audio only" and "best" without fumbling around with any other settings - this way, I'm getting OPUS audio, too.

[MadDog443]

Can you try enabling the option to list audio formats in settings? Should be under advanced.

Apart from that could you elaborate on why you would expect OPUS as the default?

Besides Opus being open source it is also probably the leading competitor in terms of quality per byte, this is quite important for streaming services (if you plan to host a jellyfin server). Some data: https://opus-codec.org/comparison/

[XPRAMT]

left aac right opus