20 Apr
2015
20 Apr
'15
5:47 a.m.
I would like to make a video of a performance
of acoustic music. I have a webcam on my computer,
but rather than use the microphone that is
on the webcam, I would prefer to use my
ART USB Dual TubePre microphone preamp
plugged into the S/PDIF of my M-Audio 2496.
Is there any application that can record video
from a webcam but use an audio input other than
the built-in mic on the cam?
Thanks;
20 Apr
20 Apr
6:24 a.m.
Hello Ivan,
Am 20.04.2015 um 05:46 schrieb Ivan K:
This can be done very easily using gstreamer. You can construct
pipelines from single elements. Here's an example that might work for
your application:
gst-launch-1.0 v4l2src ! video/x-raw,width=640,height=360,framerate=30/1
! vp8enc deadline=30000 threads=4 ! queue ! matroskamux name=mux !
filesink location=test.mkv jackaudiosrc ! audio/x-raw,channels=2 !
audioconvert ! opusenc ! queue ! mux.
This will grab raw video from your cam, encode it, mux it and save it to
a file. Furthermore, audio will be grabbed from jack, encoded and also
muxed to the same file. If your webcam supports it, you can also take an
encoded stream from the device and add audio without re-encoding:
gst-launch-1.0 v4l2src !
video/x-h264,width=640,height=360,framerate=30/1 ! h264parse ! queue !
matroskamux name=mux ! filesink location=test.mkv jackaudiosrc !
audio/x-raw,channels=2 ! audioconvert ! opusenc ! queue ! mux.
Here's some docs if you need further info:
http://docs.gstreamer.com/display/GstSDK/Basic+tutorial+10%3A+GStreamer+too…
Best regards,
Jannis
9:25 p.m.
Thank you for your help; this is a lot to take in, though I am not
adverse to working on the command line, and many times I prefer it.
In your first example, it seems I need to substitute something
for "jackaudiosrc". What might I put there?
Also, I am surprised to see the use of the "!" character as
opposed to the pipe "|". Is the "!" particular to bash?
I am taking a look at the documentation. Thanks again.
Jannis Achstetter <jannis_achstetter(a)web.de> wrote:
21 Apr
21 Apr
6:50 a.m.
Am 20.04.2015 um 21:25 schrieb Ivan K:
Thank you for your help; this is a lot to take in,
though I am not
adverse to working on the command line, and many times I prefer it.
Good to hear that :)
In your first example, it seems I need to substitute
something
for "jackaudiosrc". What might I put there?
Right, I was assuming you are using the JACK audio server. If not you
can use "alsasrc" or "pulsesrc", depending on your setup. You can
always
get a list of available elements using "gst-inspect-1.0".
Also, I am surprised to see the use of the
"!" character as
opposed to the pipe "|". Is the "!" particular to bash?
The "!"s are not specific to bash but to gstreamer. It's not several
processes that are started and piped together by bash but it's several
gstreamer elements that are piped together by gstreamer. Hence, the "|"
doesn't work here.
I am taking a look at the documentation. Thanks
again.
You're welcome.
Best regards,
Jannis
23 Apr
23 Apr
6:17 p.m.
Thank you for your responses, Mr. Achstetter.
Sorry about the delay in my response.
Jannis Achstetter <jannis_achstetter(a)web.de> writes:
"gst-inspect-1.0" is a very useful utility. Thank you for
introducing it to me. I was hoping to use Jack, but "jackaudiosrc
does not show up in my "gst-inspect-1.0" output. Among other things,
I found:
alsa: alsasrc: Audio source (ALSA)
pulseaudio: pulsesink: PulseAudio Audio Sink
when using either of these, I get the message:
WARNING: erroneous pipeline: could not link opusenc0 to queue1
I will continue to work with gst-launch-1.0, though
it seems that there is a bit of a learning curve.
---
To others who may be reading this thread: how are people
recording the audio to their video at live events? Keep in mind
that I am recording chamber music, not rock or electronic music.
I am thinking that my best bet may be to use my Nikon camera for
the video, and at the same time use qtractor for the audio, and
then sync up the two in a video editor.
My Nikon camera takes excellent video, probably better than
my webcam anyways.
24 Apr
24 Apr
5:42 p.m.
2015-04-23 18:17 GMT+02:00 Ivan K <ivan_521521(a)yahoo.com>om>:
If you have some portable field recorder like Zoom H2, H4 or similar, you
can record several inputs inside this device (mics incorporated and some
XLR/combo inputs as well). Or you can do the same but less portable with a
laptop and some interface with so many inputs as you need, and the mics,
cables, stands and stuff needed for this.
Then use some multimedia editor like Cinelerra, Kdenlive, Kino... to synch
audio and video, or even inside Ardour that supports audio and video synch
(I have not use this function but I think it was introduced in Ardour v3,
now v4 is out).
Hope it helps.
--
C. sanchiavedraZ:
* NEW / NUEVO: www.sanchiavedraZ.com
* Musix GNU+Linux: www.musix.es
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