Re: [Alsa-user] Send a *.wav into a input device

[Rene H. <ren...@ke...>]

On 05-11-07 02:16, Carlos Hernandez wrote:

> I'm sorry. I will try to say it again...
> 
> sure you know Mp4live, the live encoder and broadcaster from the MPEG4IP 
> project. Mp4live only can read audio from OSS or ALSA devices...  I got 
> one "file.wav" pcm 16 bits, 44100 hz stereo,  I want to  send the audio 
> from this file to mp4live.
> 
> The question is....:  is there any way to send the audio from this 
> "file.wav" to an ALSA o OSS device and thus read the data with mp4live 
> from this device?

Yes, you can use the "file" plugin for this purpose. You will need to feed 
the plugin from a raw file, so first make sure you have one:

aplay -D file:foo.raw foo.wav

foo.raw is basically foo.wav minus its 44 byte header; any size difference 
beyond those 44 bytes is caused by alignment. You can listen to this file with:

aplay -f cd foo.raw

Ofcourse, replace "-f cd" with the correct format parameters if your foo.wav 
was not 44100/16/2.

Then, you'll need a PCM that reads from this file. Create a ~/.asoundrc (or 
add to an existing one) with:

pcm.infile {
         @args [ FILE ]
         @args.FILE {
                 type string
         }
         type file
         slave {
                 pcm null
         }
         file /dev/null
         infile $FILE
}

You can now record from the "infile:foo.raw" device, specifying the same 
format parameters again:

arecord -D infile:foo.raw -f cd bar.wav

Note that arecord will not end itself after the input file is depleted or 
anything; it will happily wait around for more data to appear. Simply 
interrupt it (Ctrl-C)...

I don't know mp4live. You need to know how to specify the "infile:foo.raw" 
device, format parameters and how to tell it the input has dried up...

HTH.

Rene