Unable to set --merge-output-format

What is your operating system (Windows, Linux, OSX, etc.)?
Ubuntu 21.10

What is your web server (Apache, IIS, etc.)?
nginx/1.21.5

What version of AllTube are you using?
Master branch

How did you install AllTube (with Git or with a release package)?
Git clone + composer

What version of PHP are you using?
PHP 7.4.27 (cli)

What version of Python are you using?
Python 2.7.18 for youtube-dl or Python 3.9.7 for yt-dlp

What version of youtube-dl are you using?
Included

Do you get any PHP-related errors in your webserver's logs?
No.

What is the content of your config/config.yml file?

---
# Path to your youtube-dl binary
#youtubedl: vendor/ytdl-org/youtube-dl/youtube_dl/__main__.py
youtubedl: vendor/yt-dlp/yt_dlp/__main__.py

# Path to your python binary
#python: /usr/bin/python
python: /usr/bin/python3

# An array of parameters to pass to youtube-dl
params:
    - --no-warnings
    - --ignore-errors
    - --flat-playlist
    - --restrict-filenames
    - --no-playlist
    - --merge-output-format
    - mp4

# True to enable audio conversion
convert: false

# True to enable advanced conversion mode
convertAdvanced: false

# List of formats available in advanced conversion mode
convertAdvancedFormats: [mp3, avi, flv, wav]

# Path to your ffmpeg binary
ffmpeg: /usr/bin/ffmpeg

# ffmpeg logging level.
ffmpegVerbosity: error

# Path to the directory that contains the phantomjs binary.
phantomjsDir: /usr/bin/

# True to disable URL rewriting
uglyUrls: false

# True to stream videos through server
# Set to "ask" if you want to allow it but not enable by default.
stream: true

# True to enable remux mode (merge best audio and best video)
remux: true

# MP3 bitrate when converting (in kbit/s)
audioBitrate: 128

# App name
appName: AllTube Download

# Generic formats supported by youtube-dl
genericFormats:
    best/bestvideo: Best
    bestvideo+bestaudio: Remux best video with best audio
    worst/worstvideo: Worst

# Enable debug mode.
debug: false

# True to enable audio conversion mode by default
defaultAudio: false

# False to disable convert seek functionality
convertSeek: true

Please provide the URL of a video that causes the issue.
Any.
https://www.youtube.com/watch?v=5oxDwxkOAXI

I'm trying to set --merge-output-format mp4 in config, but get an error:

'/usr/bin/python' 'vendor/ytdl-org/youtube-dl/youtube_dl/main.py' '--no-warnings' '--ignore-errors' '--flat-playlist' '--restrict-filenames' '--no-playlist' '--merge-output-format mp4' '--dump-single-json' 'https://www.youtube.com/watch?v=5oxDwxkOAXI' '-f' 'best/bestvideo' failed with this error:
Usage: main.py [OPTIONS] URL [URL...]
main.py: error: no such option: --merge-output-format mp4

How can i fix this? Do i need to modify any other sources to make remux produce mp4 files instead of mkv's?
Trying with installation from GIT or in Docker, with youtube-dl or yt-dlp - everything returns the same error.

Please don't remove the issue template.

I assume you are doing this:

params:
    - --merge-output-format mp4

The correct syntax is this:

params:
    - --merge-output-format
    - mp4

Sorry. I've edited the template back.

That fixed the error i was getting but alltube still offers mkv file as a result, despite merge-output-format set to mp4.
Is it possible to make remux output files in mp4 container? Or should i make another issue for that question?

The remux format is hardcoded here.
I suppose we could add an option to allow changing the format.
However, very few formats support muxing streams and MP4 is not one of them:

[mp4 @ 0x559e6d37d940] muxer does not support non seekable output

Oh, i see.
Could -movflags frag_keyframe+empty_moov help with the problem?
It seems that it can make the resulting file incompatible with some software, but it would produce a file usable in Premiere Pro (i've just checked) that does not support mkv.

We do use that for M3U streams so I guess it could work.

Should i try changing the hardcoded matroska and adding -movflags frag_keyframe+empty_moov to see if it helps, or are there more variables in play, apart from one linked above?
UP: nevermind, it's not a class git can clone anyway.

You will also need to change the MIME type here:

alltube/classes/Controller/DownloadController.php

Line 249 in 835170f

$response = $response->withHeader('Content-Type', 'video/x-matroska');

And the file extension here:

alltube/classes/Controller/DownloadController.php

Line 256 in 835170f

'attachment; filename="' . $this->video->getFileNameWithExtension('mkv') . '"'

If i put modified Downloader.php into alltube classes folder, will it work?

You will need to edit it in vendor/rudloff/alltube-library/classes/Downloader.php.

Thank you!
It worked!
I've also had to edit genericFormats section in config to make it download video and audio streams compatible with mp4 container:
bestvideo[ext=mp4]+bestaudio[ext=m4a]: Remux best video with best audio
I'm now getting a proper mix of 1080P video and m4a audio using the remux option.

And for my fellow Adobe Premiere enthusiasts, the better option is
bestvideo*[height<=1080][vcodec^=avc1]+bestaudio[ext=m4a]: Remux best video with best audio
...because Premiere Pro is not working with av1 as of today.