Gentoo Archives: gentoo-user

From: Mick <michaelkintzios@×××××.com>
To: gentoo-user <gentoo-user@l.g.o>
Subject: Re: [gentoo-user] Re: ffmpeg video+audio capture question
Date: Fri, 27 Sep 2019 08:19:16
Message-Id: CAGOe-ezxW_B9-dbFXSux6PaNycVmWktJ3U3TxoqX8ixt6qsChA@mail.gmail.com
In Reply to: [gentoo-user] Re: ffmpeg video+audio capture question by Ian Zimmerman
1 On Tue, 24 Sep 2019 at 04:56, Ian Zimmerman <itz@××××××××××××.org> wrote:
2 >
3 > On 2019-09-23 16:22, Walter Dnes wrote:
4 >
5 > > There appear to be "media-sound/jack" and "media-sound/jack2" ebuilds.
6 > > Both of them are tagged "~amd64". There's also
7 > > media-sound/jack-audio-connection-kit Which one(s) do I use?
8 >
9 > It's the last one, I'm pretty sure.
10
11 media-sound/jack is an old CD ripping application, so this is not what you want.
12
13 media-sound/jack2 is the C++ coded jack daemon for multi-processor PCs.
14
15 media-sound/jack-audio-connection-kit is (I think) the jack1 daemon coded in C.
16
17 For Jack1 Vs Jack2 features have a look here:
18
19 https://github.com/jackaudio/jackaudio.github.com/wiki/Q_difference_jack1_jack2
20
21
22 > > Youtube is a bad example to use. There are various other HTML5
23 > > streaming websites, which don't work with youtube-dl. Plus I also want
24 > > to be able to record video games and any other desktop app in general.
25 > > What I want is to "tee" the audio output so that I can record while
26 > > monitoring it.
27 >
28 > Long ago, I digitized my vinyl and audio tape collection this way, with
29 > the input coming over good old analog audio cable. I did it with pure
30 > ALSA, no jack was needed. I _think_ there was a knob either in
31 > alsamixer or in arecord to do the "tee", but I don't really remember.
32
33 For streaming websites which do not offer a download button, you can
34 launch the browser developer tab, select Network/Media and keep an eye
35 on the traffic as you click on the website to start streaming the
36 video. The developer tab will list the actual path of the video file.
37 Open another tab in the browser and paste the full URL to download it,
38 or you could try curl/wget et al.
39
40 tee-ing the audio output of desktop applications/windows may be doable
41 with dmix and asoundrc syntax, but I wouldn't know what this looks
42 like today with any certainty - last time I used dmix was in the mid
43 00s. Anyway, you tried this and it didn't work.
44
45 Jackd was created for the very purpose of plumbing I/O audio into
46 various configurations, so tweaking it to do the recording you require
47 should be eminently doable and using one of the various Gtk/Qt front
48 ends makes it even easier/quicker.
49 --
50 Regards,
51 Mick