Valid ALSA URL in input parameter but not in --input-slave

[richardthiebaud]

I am trying to stream audio and video from a USB2 video capture card. If I put the Alsa device as the main input, it works fine. I get both audio and video.:

dick@dick2:~$ vlcshow1
++ vlc alsa://hw:1,0 --input-slave=v4l2:///dev/video0
VLC media player 3.0.16 Vetinari (revision 3.0.13-8-g41878ff4f2)
QObject::~QObject: Timers cannot be stopped from another thread
d

However, If I put the Alsa device as "--input-slave", I get no sound and and in the log I get:

dick@dick2:~$ vlcshow2
++ vlc v4l2:///dev/video0 --input-slave=alsa://hw:1,0
VLC media player 3.0.16 Vetinari (revision 3.0.13-8-g41878ff4f2)

with error in the log:

main error: Invalid url passed to the "input-slave" option

(This is line 264 of the following log.)

result of "aplay -l"

dick@dick2:~$ aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: Generic [HD-Audio Generic], device 3: HDMI 0 [HDMI 0]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 0: Generic [HD-Audio Generic], device 7: HDMI 1 [HDMI 1]
Subdevices: 0/1
Subdevice #0: subdevice #0
card 0: Generic [HD-Audio Generic], device 8: HDMI 2 [HDMI 2]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 0: Generic [HD-Audio Generic], device 9: HDMI 3 [HDMI 3]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 2: Generic_1 [HD-Audio Generic], device 0: ALC897 Analog [ALC897 Analog]
Subdevices: 1/1
Subdevice #0:

(ALC897 is the speaker driver.)

result of "arecord -l":

dick@dick2:~$ arecord -l
**** List of CAPTURE Hardware Devices ****
card 1: MS210x [MS210x], device 0: USB Audio [USB Audio]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 2: Generic_1 [HD-Audio Generic], device 0: ALC897 Analog [ALC897 Analog]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 2: Generic_1 [HD-Audio Generic], device 2: ALC897 Alt Analog [ALC897 Alt Analog]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 3: acp [acp], device 0: DMIC capture dmic-hifi-0 []
Subdevices: 1/1
Subdevice #0: subdevice #0
dick@dick2:~$

[richardthiebaud]

VLC log:

-- logger module started --
main: Running vlc with the default interface. Use 'cvlc' to use vlc without interface.
main error: Invalid url passed to the "input-slave" option
gl: Initialized libplacebo v4.192.1 (API v192)
-- logger module stopped --

[Rémi Denis-Courmont]

This was already fixed 2.5 years ago. Please update.

[richardthiebaud]

This happens in the most recent version of VLC.
Linux Mint 21.3
VLC media player 3.0.16 Vetinari (revision 3.0.13-8-g41878ff4f2)
Installed from https://community.linuxmint.com/software/view/vlc

[Rémi Denis-Courmont]

The latest release is 3.0.20 (30 Oct 2023). We can't go back in time and apply bug fixes to past releases; if you don't keep up-to-date, you don't get bug fixes.

[richardthiebaud]

And where do you suggest I get it from? This is the latest version, just installed from the website.

[Rémi Denis-Courmont]

What do you expect exactly? The bug is not going away if you don't update. I suppose you could also downgrade to a version before the bug, but either way, you're going to have to change versions if you want the bug fixed.

The official VLC website clearly states that the current release is 3.0.20: https://www.videolan.org/vlc/

[richardthiebaud]

The official website currently installs 3.0.16 for Linux Mint. If you want people to use the latest version, you should fix what the official website installs.

[Rémi Denis-Courmont]

That's a Linux Mint problem. We have no control over Linux Mint.