28 Jan
28 Jan
11:41 p.m.
On Sat, Jan 28, 2012 at 5:35 PM, Alfs Kurmis <kallipygos(a)inbox.lv> wrote:
Hi Experts.
For my small multimedia audio project i wanna use mplayer as external
decoder.
As usually via pipe , for example so
mplayer -af resample=44100:0:1,channels=2,format=s16le -ao
pcm:nowaveheader:file=/dev/stdout -quiet -really-quiet 'saund_file.ext' |
nextprog -options ...
you're just resampling and reformatting?
Is here another decoder progs/libs with easy-to-use C
API ?
sndfile-resample and sndfile-convert can both be given "-" as the name
of their output or input. they are much simpler programs that mplayer
and will also likely do a better job.
--p
1:33 a.m.
On Sun, Jan 29, 2012 at 01:31:00AM +0200, Alfs Kurmis wrote:
Problem is that, for example mpg123 any messages put
to stderr, so that with
option -s we gotta pure RAW to stout,
but mplayer put all messages to stout
sox/play will definitely do the job with "-" as the parameter. I'm not
sure about the possible codecs.
If nothing helps, fire up jackd (-d dummy should be fine for your case),
tell mplayer to output to jack (-ao jack) and use jack-stdout to pipe
raw audio samples to your later stages or implement whatever you have to
do as a jack program.
Though jackd might be overkill for the use case at hand.
HTH
--
mail: adi(a)thur.de http://adi.thur.de PGP/GPG: key via keyserver
9:12 a.m.
sox/play will definitely do the job with "-"
as the parameter. I'm
Both sox and mplayer are amenable. I've used both in shutlp, a gapless
loop player with a count-in metronome (sox being used as a decoder and
beat generator, and mplayer to output to various back-ends -- pulse,
jack, alsa),
http://danmbox.github.com/shut-audio-tools/
(the programs are unnecessarily complex because I really wanted to see
if POSIX sh could control multiple processes reliably)
For mplayer, I used -quiet -noterm-osd -demuxer rawaudio -rawaudio;
you may want to actually SEE some of mplayer's messages, e.g. in case
the files to be played are corrupt. Oh, and mplayer can also read
control commands from a FIFO, via -input file=/tmp/fifo.
-- Dan
1:37 a.m.
On 01/28/2012 11:35 PM, Alfs Kurmis wrote:
Hi Experts.
For my small multimedia audio project i wanna use mplayer as external decoder.
As usually via pipe , for example so
mplayer -af resample=44100:0:1,channels=2,format=s16le -ao
pcm:nowaveheader:file=/dev/stdout -quiet -really-quiet 'saund_file.ext' |
nextprog -options ...
or so
http://martini.pudele.com/radio/programming/audio/mplayerdecso01.c
I prefer output to pipe, not FIFO.
It seems that mplayer also all messages put to stdout :(
That's probably why mplayer devs recommend using mkfifo (named pipe)
instead of stdout.. 'mencoder' can do it.
If you need to support a variety of unknown formats and codecs: ffmpeg
is an alternative and gstreamer might be one.
ffmpeg -i /some/file -f u16le -acodec pcm_s16le -ar 44100 - \
| jack-stdin system:playback_1 system:playback_2
on that note, `jack-stdout` can capture and pipe raw PCM data from any
JACK-application including `mplayer -ao jack /some/file`. YMMV.
HTH,
robin
1:41 a.m.
Hi Alfs, *,
sorry, a typo slipped in:
On 01/29/2012 01:37 AM, Robin Gareus wrote:
On 01/28/2012 11:35 PM, Alfs Kurmis wrote:
I forgot a the "-c 2" option to enforce stereo.
The line should have read:
ffmpeg -i /some/file -f u16le -acodec pcm_s16le -ar 44100 -c2 - \
Hi Experts.
For my small multimedia audio project i wanna use mplayer as external decoder.
As usually via pipe , for example so
mplayer -af resample=44100:0:1,channels=2,format=s16le -ao
pcm:nowaveheader:file=/dev/stdout -quiet -really-quiet 'saund_file.ext' |
nextprog -options ...
or so
http://martini.pudele.com/radio/programming/audio/mplayerdecso01.c
I prefer output to pipe, not FIFO.
It seems that mplayer also all messages put to stdout :(
That's probably why mplayer devs recommend using mkfifo (named pipe)
instead of stdout.. 'mencoder' can do it.
If you need to support a variety of unknown formats and codecs: ffmpeg
is an alternative and gstreamer might be one.
ffmpeg -i /some/file -f u16le -acodec pcm_s16le -ar 44100 - \ | jack-stdin system:playback_1 system:playback_2
on that note, `jack-stdout` can capture and pipe raw PCM data from any
JACK-application including `mplayer -ao jack /some/file`. YMMV.
HTH,
robin
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participants (5)
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Adrian Knoth -
Alfs Kurmis -
Dan Muresan -
Paul Davis -
Robin Gareus