Re: [?]Are Realtek Audio Drivers for Linux available for use
On Fri 12 Mar 2021 at 23:00:47 (-0500), Stefan Monnier wrote:
> > But nowadays, there are some audio links that play quite happily
> > without leaving any trace that I can find. Which leaves only the
> > option of recording the soundcard output. Some computers have both
> > LineOut and LineIn, and these can be connected together, but that's
> > not a very good solution in terms of noise.
>
> I must admit that I haven't looked at ALSA for quite some years and
> I consider computers to be devices which should ideally stay silent,
The only CD/DVD player that we have in the house (that's not a
computer) is one of those devices for strapping to the back of
front seats in a car. The slave screen is as yet unpackaged, and we
only use the device for playing CDs. Everything else comes off a
computer, connected either to hifi (3.5mm) or a TV (HDMI, or via USB).
> so
> my knowledge of audio is quite limited, but I've recorded the "Monitor"
> of the output with good success when recording a Jitsi session (using
> `vokoscreen`, IIRC).
AFAICT, for video, that just records the screen. I do that with
Shift-Alt-F12 start, Shift-Alt-F11 stop (fvwm bindings to customised
ffmpeg commands). But the disadvantages of that method (it gets
polluted by all sorts of screen clutter, it's uses up CPU, you're
recording a resampled image) is precisely why I steal from the
browser's cache. The image is at the original resolution, it's as
clean as when it arrives from the site, it just copies files with
cp, so it doesn't load the CPU.
> Admittedly, I was using pulseaudio, so maybe this is a PA feature not
> available in ALSA?
That's my point: you might have it, but perhaps not. Stealing from
the cache solves this problem, as you normally get Transport Stream
segments of Audio/Video, or you get MPEG transport streams with
the streams in separate files. Most sites put start times on the
segments, a few don't. That makes assembly trickier, particularly
for audio because video is easier to check for glitches. (Often,
there are time codes within frame, too.)
So, yes, PA may be a solution for recording the audio, both
standalone, and when the screen is being captured simultaneously.
But I've still no idea of what this new, cache-less technology is
that browsers play.
Cheers,
David.
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