[Portaudio] using portaudio : play multiple file at the same time

[kaolite]

Hi,

I plan to use Portaudio (+ libsndfile) to replace quicktime sdk (x32 only
...) in my video mixing application. I have a timeline where I can mix
several video ( out of topic) and several audio files . Is it easy to be
able to play multiple file at the same time and do a crossfade ?
Is there any sample to see how to use portaudio and libsndfile together ...
I am starting to use portaudio and I am a little bit lost :)

Best regards,

Kao
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[Gordon Gidluck]

Hello Kao,
portAudio examples use internally generated signals so that there are no
external dependencies on data.

I don't know of any specific examples with libsndfile.

What you would have to do to get started is to work through some test
examples and then take one program and add to that something that fills
it's buffer by reading an external file. The job of the program then
would be to keep the buffer full from data in the file. You have to
develop a process of signaling when the buffer needs more data and so
forth. And also define what happens when there is no more data.

A quick search turned up that there is a fade out used in
patest_stop_playout.c

patest_record.c has an example of playing back using a buffer. That
might be a good example to start from.

Gordon

Post by kaolite
Hi,
I plan to use Portaudio (+ libsndfile) to replace quicktime sdk (x32
only ...) in my video mixing application. I have a timeline where I
can mix several video ( out of topic) and several audio files . Is it
easy to be able to play multiple file at the same time and do a
crossfade ?
Is there any sample to see how to use portaudio and libsndfile
together ... I am starting to use portaudio and I am a little bit lost :)
Best regards,
Kao
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Portaudio at music.columbia.edu
http://music.columbia.edu/mailman/listinfo/portaudio

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[kaolite]

Hello,

thanks a lot for your help ... I am trying to mix both api ... a good point,
the library is very easy to build even in x64 ....

best regards

2009/12/24 Gordon Gidluck <gidluck at windstream.net>

Post by Gordon Gidluck
Hello Kao,
portAudio examples use internally generated signals so that there are no
external dependencies on data.
I don't know of any specific examples with libsndfile.
What you would have to do to get started is to work through some test
examples and then take one program and add to that something that fills
it's buffer by reading an external file. The job of the program then
would be to keep the buffer full from data in the file. You have to
develop a process of signaling when the buffer needs more data and so
forth. And also define what happens when there is no more data.
A quick search turned up that there is a fade out used in
patest_stop_playout.c
patest_record.c has an example of playing back using a buffer. That
might be a good example to start from.
Gordon

Post by kaolite
Hi,
I plan to use Portaudio (+ libsndfile) to replace quicktime sdk (x32
only ...) in my video mixing application. I have a timeline where I
can mix several video ( out of topic) and several audio files . Is it
easy to be able to play multiple file at the same time and do a
crossfade ?
Is there any sample to see how to use portaudio and libsndfile
together ... I am starting to use portaudio and I am a little bit lost :)
Best regards,
Kao
------------------------------------------------------------------------
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Portaudio mailing list
Portaudio at music.columbia.edu
http://music.columbia.edu/mailman/listinfo/portaudio

_______________________________________________
Portaudio mailing list
Portaudio at music.columbia.edu
http://music.columbia.edu/mailman/listinfo/portaudio

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