16 Jun
2018
16 Jun
'18
9:47 p.m.
Hi,
I'm looking for a tool to mix two audio. My requirement is
given two identical audio inputs say A1 & A2.
A1 is ahead of A2 by t sec, when switch from A1 to A2
it should be seamless and vice versa.
Please help if you know of any open source tool.
-ben
16 Jun
16 Jun
10:06 p.m.
On Sat, 16 Jun 2018 17:47:21 +0000, Benny Alexandar wrote:
I'm looking for a tool to mix two audio. My
requirement is
given two identical audio inputs say A1 & A2.
A1 is ahead of A2 by t sec, when switch from A1 to A2
it should be seamless and vice versa.
Hi Ben,
this is a vague description of the task. What is the reason that signal
1 is ahead of signal 2? What apps do you want to use, resp. do those
apps support plain alsa or jack or pulseaudio?
Perhaps a simple delay is what you are looking for, but maybe you need
resampling.
Regards,
Ralf
10:14 p.m.
> What is the reason that signal
1 is ahead of
signal 2?
For various reason, one audio receiving from network and
other thru air.
> Perhaps a simple delay is what you are looking
for, but maybe you need
resampling.
Yes delay estimation is required as the delay is not known upfront.
In addition to re-sampling stretching also required.
________________________________
From: Linux-audio-user <linux-audio-user-bounces(a)lists.linuxaudio.org> on behalf of
Ralf Mardorf <ralf.mardorf(a)alice-dsl.net>
Sent: Saturday, June 16, 2018 11:36 PM
To: linux-audio-user(a)lists.linuxaudio.org
Subject: Re: [LAU] Audio seamless switch
On Sat, 16 Jun 2018 17:47:21 +0000, Benny Alexandar wrote:
I'm looking for a tool to mix two audio. My
requirement is
given two identical audio inputs say A1 & A2.
A1 is ahead of A2 by t sec, when switch from A1 to A2
it should be seamless and vice versa.
Hi Ben,
this is a vague description of the task. What is the reason that signal
1 is ahead of signal 2? What apps do you want to use, resp. do those
apps support plain alsa or jack or pulseaudio?
Perhaps a simple delay is what you are looking for, but maybe you need
resampling.
Regards,
Ralf
_______________________________________________
Linux-audio-user mailing list
Linux-audio-user(a)lists.linuxaudio.org
https://lists.linuxaudio.org/listinfo/linux-audio-user
10:31 p.m.
On Sat, Jun 16, 2018 at 2:13 PM, Benny Alexandar <ben.alex(a)outlook.com>
wrote:
that turns it into a totally different problem. You originally said:
two identical audio inputs say A1 & A2.
why would you need to resample/stretch them?
> What is
the reason that signal
1 is ahead of signal 2?
For various reason, one audio receiving from network and
other thru air.
> Perhaps a simple delay is what you are
looking for, but maybe you need
resampling.
Yes delay estimation is required as the delay is not known upfront.
In addition to re-sampling stretching also required.
17 Jun
17 Jun
12:16 p.m.
>>why would you need to resample/stretch them?
As mentioned earlier the two audio are identical but one will be ahead/delayed than
other.
The user who is listening to it should not notice the switching, and this
switching happens when the quality of one audio is degraded compared to other.
-ben
________________________________
From: Paul Davis <paul(a)linuxaudiosystems.com>
Sent: Sunday, June 17, 2018 12:01 AM
To: Benny Alexandar
Cc: Ralf Mardorf; linux-audio-user(a)lists.linuxaudio.org
Subject: Re: [LAU] Audio seamless switch
On Sat, Jun 16, 2018 at 2:13 PM, Benny Alexandar
<ben.alex@outlook.com<mailto:ben.alex@outlook.com>> wrote:
> What is the reason that signal
1 is ahead of signal 2?
For various reason, one audio receiving from network and
other thru air.
> Perhaps a simple delay is what you are looking
for, but maybe you need
resampling.
Yes delay estimation is required as the delay is not known upfront.
In addition to re-sampling stretching also required.
that turns it into a totally different problem. You originally said:
two identical audio inputs say A1 & A2.
why would you need to resample/stretch them?
2:18 p.m.
On Sun, 2018-06-17 at 08:16 +0000, Benny Alexandar wrote:
Hi Ben,
"ahead/delayed" could be caused by different sync issues. And
"identically" as well as "degraded" could be interpreted in different
ways.
You mentioned "one audio receiving from network and other thru air".
For example a single CD player's audio signal is send wireless to an
audio interface and by a network cable the same audio output of this CD
player is send to a network interface, you are not using two CD players
playing the same CD.
I don't have knowledge about wireless audio and audio by network, but I
suspect that it's similar to using two sound cards. To avoid "degraded"
sound quality two sound cards needs to be synced by a single clock
source e.g. word clock or you need to workaround this sync issue by
using software such as zita-ajbridge. That's one kind of sync issue.
Another kind of sync issue could be caused by e.g. distance. For
example, one audio cable is 10 meters short, the other is as long as
from Earth to Mars and back. To workaround this time difference you
could use a delay effect, to delay the signal provided by the short
cable.
Assuming two CD player's should play the same CD, or better let's assume
two different professional audio recorders are individually playing the
same recording, instead of just using the signal of a single
professional audio recorder, you need to sync the two machines by a
timecode, such as SMPTE, to avoid drift.
You should be more detailed about the issue. What is the source of the
audio signal/s? What is "wireless" for? In what way is the audio quality
"degraded"? Is always the same sample rate etc. used? What software are
you using for mixing/switching the signals?
Regards,
Ralf
>>why
would you need to resample/stretch them?
As mentioned earlier the two audio are
identical but one will be ahead/delayed than other.
The user who is listening to it should not notice the switching, and this
switching happens when the quality of one audio is degraded compared to other.
3:08 p.m.
So you want to stretch/shrink the newly-switched-to audio so that it
"catches up" with the just-switched-from audio and then runs at normal
speed?
This strikes me as madness, but hey, good luck!
On Sun, Jun 17, 2018 at 4:16 AM, Benny Alexandar <ben.alex(a)outlook.com>
wrote:
>>why
would you need to resample/stretch them?
As mentioned earlier the two audio are identical but one will be
ahead/delayed than other.
The user who is listening to it should not notice the switching, and this
switching happens when the quality of one audio is degraded compared to
other.
-ben
------------------------------
*From:* Paul Davis <paul(a)linuxaudiosystems.com>
*Sent:* Sunday, June 17, 2018 12:01 AM
*To:* Benny Alexandar
*Cc:* Ralf Mardorf; linux-audio-user(a)lists.linuxaudio.org
*Subject:* Re: [LAU] Audio seamless switch
On Sat, Jun 16, 2018 at 2:13 PM, Benny Alexandar <ben.alex(a)outlook.com>
wrote:
> What is the reason that signal
1 is
ahead of signal 2?
For various reason, one audio receiving from network and
other thru air.
> Perhaps a simple delay is what you are
looking for, but maybe you need
resampling.
Yes delay estimation is required as the delay is not known upfront.
In addition to re-sampling stretching also required.
that turns it into a totally different problem. You originally said:
two identical audio inputs say A1 & A2.
why would you need to resample/stretch them?
4:28 p.m.
Yes Paul, your understanding is right.
Rubber band audio is meant for this I guess
(Rubber Band Library is a high quality software library for audio time-stretching and
pitch-shifting. )
-ben
________________________________
From: Paul Davis <paul(a)linuxaudiosystems.com>
Sent: Sunday, June 17, 2018 4:38 PM
To: Benny Alexandar
Cc: Ralf Mardorf; linux-audio-user(a)lists.linuxaudio.org
Subject: Re: [LAU] Audio seamless switch
So you want to stretch/shrink the newly-switched-to audio so that it "catches
up" with the just-switched-from audio and then runs at normal speed?
This strikes me as madness, but hey, good luck!
On Sun, Jun 17, 2018 at 4:16 AM, Benny Alexandar
<ben.alex@outlook.com<mailto:ben.alex@outlook.com>> wrote:
>>why would you need to resample/stretch them?
As mentioned earlier the two audio are identical but one will be ahead/delayed than
other.
The user who is listening to it should not notice the switching, and this
switching happens when the quality of one audio is degraded compared to other.
-ben
________________________________
From: Paul Davis
<paul@linuxaudiosystems.com<mailto:paul@linuxaudiosystems.com>>
Sent: Sunday, June 17, 2018 12:01 AM
To: Benny Alexandar
Cc: Ralf Mardorf;
linux-audio-user@lists.linuxaudio.org<mailto:linux-audio-user@lists.linuxaudio.org>
Subject: Re: [LAU] Audio seamless switch
On Sat, Jun 16, 2018 at 2:13 PM, Benny Alexandar
<ben.alex@outlook.com<mailto:ben.alex@outlook.com>> wrote:
> What is the reason that signal
1 is ahead of signal 2?
For various reason, one audio receiving from network and
other thru air.
> Perhaps a simple delay is what you are looking
for, but maybe you need
resampling.
Yes delay estimation is required as the delay is not known upfront.
In addition to re-sampling stretching also required.
that turns it into a totally different problem. You originally said:
two identical audio inputs say A1 & A2.
why would you need to resample/stretch them?
5:41 p.m.
On Sun, Jun 17, 2018 at 12:28:22PM +0000, Benny Alexandar wrote:
Rubber band audio is meant for this I guess
(Rubber Band Library is a high quality software library for audio time-stretching and
pitch-shifting. )
This doesn't make any sense at all.
If the delay between the two signals isn't fixed, there is no point in
comparing their quality (unless the difference is so big that it's
obvious from the start). Whatever you do to stretch the signals will
produce so much artefacts that any subtle quality difference is lost.
And if the time difference is fixed, just adjust a delay plugin
manually, then crossfade. Any DAW will do that.
--
FA
2380
days inactive
2381
days old
linux-audio-user@lists.linuxaudio.org
8 comments
4 participants
participants (4)
-
Benny Alexandar -
Fons Adriaensen -
Paul Davis -
Ralf Mardorf