Decoding pcm s16l from pipe?

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thomasa88
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Decoding pcm s16l from pipe?

Postby thomasa88 » 12 Jan 2009 18:59

Is it possible to pipe raw pcm s16le data to vlc?

I tried this but it does not work:

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cat /var/run/pulse/fifo_output | cvlc - -v

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[00000001] main libvlc debug: translation test: code is "C" [00000375] dummy interface: using the dummy interface module... libdvdread: Using libdvdcss version 1.2.10 for DVD access libdvdread: Can't stat - No such file or directory [00000385] dvdnav demux warning: cannot open dvdnav [00000393] ps demux warning: this does not look like an MPEG PS stream, continuing anyway [00000001] main libvlc error: option sub-original-fps does not exist [00000384] main input error: demux doesn't like DEMUX_GET_TIME [00000384] main input error: demux doesn't like DEMUX_GET_TIME [00000384] main input error: demux doesn't like DEMUX_GET_TIME
When adding --demux=wav I get this: (but it is listed as a demuxer :S)

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[00000388] main demux warning: no demux module matching "wav" could be loaded [00000384] main input error: no suitable demux module for `/wav://-'

Jean-Baptiste Kempf
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Re: Decoding pcm s16l from pipe?

Postby Jean-Baptiste Kempf » 12 Jan 2009 20:59

demux raw?
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thomasa88
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Re: Decoding pcm s16l from pipe?

Postby thomasa88 » 12 Jan 2009 21:17

demux raw?

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[00000388] main demux error: no demux module matched "raw" [00000384] main input error: no suitable demux module for `/raw://-'
:(

edit.
Are there any other flags I could specify to set the format?

Rémi Denis-Courmont
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Re: Decoding pcm s16l from pipe?

Postby Rémi Denis-Courmont » 13 Jan 2009 22:28

There is no raw PCM demux, although it would be easy to implement.

As I infer you're using PulseAudio as input, you can always:
- stream L16 over RTP/UDP/IP over the loopback interface, or
- echo a binary .WAV file header, before you cat the FIFO into VLC:
(echo XXXX; cat /var/run/pulse/fifo_output) | cvlc -v- -
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thomasa88
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Re: Decoding pcm s16l from pipe?

Postby thomasa88 » 13 Jan 2009 22:49

It works! Thank you! :D

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ffmpeg -f s16le -ar 192000 -i /var/run/pulse/fifo_output -vn -acodec copy -f wav - | cvlc -
(It's a bit choppy but I have to look at all the rate settings for ffmpeg and caching in vlc)

edit.
Ie the second option, the first spills to much multicast traffic ;)


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