flac dev - Sep 2004 - flac command line usage (was: the road to 1.0...)

On Tue, May 01, 2001 at 12:28:40PM -0700, Josh Coalson wrote:
> OK, I kind of like Matt's usage idea best.  I think there are only
> two minor downsides:
> 
> 1. You won't be able to do basename renaming within the command
> anymore, i.e. 'flac 01.wav songname.flac', you have to do a
> 'flac 01.wav && mv 01.flac songname.flac'
Or: flac 01.wav - > songname.flac

This modification would make flac behave more like gzip, which is a pretty good
model of how a unix-style compressor should behave.  The addition of a -c
option to force output to stdout, and a default input file of stdin would make
flac command-line compatible with gzip for basic compression and decompression
tasks.  Whether or not this is a good idea is another matter.
> 2. This one's way out there, but I guess if someone were on DOS then
> .flac will be too long and there's no way to get around that unless
> I add some option to specify a default extension.
Like gzip's -S option? ;-)  And/Or, the default extension could be different
on
DOS than when a real filesystem is available, set at compile time.
> So unless there's a really big objection I think I'll go and make
> the changes so that the output file name is automatically determined and
you
> can specify multiple input files.
Goodie.  Maybe the default decoding output filename should be set based on the
-f[urw] flags?  So if raw output is selected, the output file would not be
named .wav.  This is probably unnecessary, though; I imagine most batch
compressing/decompressing would be done with WAV.

-- 
 - mdz

On Tue, May 01, 2001 at 02:01:04PM -0700, Josh Coalson wrote:
> Now, that I've gone to implement it, there's a problem it creates
with
> piping, that flac doesn't know what to name an output file when the
input is
> stdin, and there would be no clean way to tell to write a decoded file to
> stdout.  Any suggestions?
The logical thing to do is to output to stdout...what is the complicating
factor?  Is it because you leave the filenames in argv[]?  It's hard to
tell at first glance...

(while I'm here...why in POSIX's name don't you use getopt(3)?  I
could
gladly supply a patch if you're interested...)

-- 
 - mdz

OK, I have checked in the changes to the command-line handling
if anyone wants to try it out.  Hopefully it's more intuitive.

Also, I added the WAVE autodetection Mark was asking about.

The flac usage and documentation.html should be up-to-date also.

Josh


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I may be a bit behind, since I haven't looked at the latest documentation
in CVS.  My apologies if these problems have already been solved.

I think having a default file name is a good idea, but it should be just
a default.  There should also be a '-o' option to specify the output
file name.  This option would only apply if there is one input.  '-o'
should also accept a "file name" of '-' (as in '-o-')
to specify stdout.
The default output when input is stdin should be stdout.

I think this option would solve the four problems listed below.

Larry Fenske
> > > I think the easiest way to make all of this "just work"
would be to
> > provide
> > > a default output filename for both encoding and decoding, e.g.:
> > > 
> > > flac file.wav
> > > 
> > > would produce file.flac, and
> > > 
> > > flac -d file.flac
> > > 
> > > would produce file.wav.  That way, flac *.wav and flac -d *.flac
> > are
> > possible,
> > > and their behavior easily understood.
> > > 
> > 
> > OK, I kind of like Matt's usage idea best.  I think there are only
> > two minor downsides:
> > 
> > 1. You won't be able to do basename renaming within the command
> > anymore, i.e. 'flac 01.wav songname.flac', you have to do a
> > 'flac 01.wav && mv 01.flac songname.flac'
> > 
> > 2. This one's way out there, but I guess if someone were on DOS
then
> > .flac will be too long and there's no way to get around that
unless
> > I add some option to specify a default extension.
> > 
> > So unless there's a really big objection I think I'll go and
make
> > the changes so that the output file name is automatically determined
> > and you can specify multiple input files.
> > 
> Now, that I've gone to implement it, there's a problem it creates
> with piping, that flac doesn't know what to name an output file
> when the input is stdin, and there would be no clean way to tell
> to write a decoded file to stdout.  Any suggestions?
> 
> Josh

> > I think the easiest way to make all of this "just work"
would be to
> provide
> > a default output filename for both encoding and decoding, e.g.:
> > 
> > flac file.wav
> > 
> > would produce file.flac, and
> > 
> > flac -d file.flac
> > 
> > would produce file.wav.  That way, flac *.wav and flac -d *.flac
> are
> possible,
> > and their behavior easily understood.
> > 
> 
> OK, I kind of like Matt's usage idea best.  I think there are only
> two minor downsides:
> 
> 1. You won't be able to do basename renaming within the command
> anymore, i.e. 'flac 01.wav songname.flac', you have to do a
> 'flac 01.wav && mv 01.flac songname.flac'
> 
> 2. This one's way out there, but I guess if someone were on DOS then
> .flac will be too long and there's no way to get around that unless
> I add some option to specify a default extension.
> 
> So unless there's a really big objection I think I'll go and make
> the changes so that the output file name is automatically determined
> and you can specify multiple input files.
> 
Now, that I've gone to implement it, there's a problem it creates
with piping, that flac doesn't know what to name an output file
when the input is stdin, and there would be no clean way to tell
to write a decoded file to stdout.  Any suggestions?

Josh


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> > > It would be easier if FLAC understand the following command:
"flac *.wav
> > > *.flac" or "flac -d *.flac *.wav"
> > > 
> > > for now I have to use some shell "tricks".
> > > 
> > I assume you're using the DOS shell?  because all unix shells I
know will
> > expand the globs first so this syntax cannot work anyway.
> > 
> > but I know what you're saying.  something 'flac -d *.flac'
would be
useful...
> > I'll keep it in mind.
> 
> I think the easiest way to make all of this "just work" would be
to
provide
> a default output filename for both encoding and decoding, e.g.:
> 
> flac file.wav
> 
> would produce file.flac, and
> 
> flac -d file.flac
> 
> would produce file.wav.  That way, flac *.wav and flac -d *.flac are
possible,
> and their behavior easily understood.
> 
OK, I kind of like Matt's usage idea best.  I think there are only
two minor downsides:

1. You won't be able to do basename renaming within the command
anymore, i.e. 'flac 01.wav songname.flac', you have to do a
'flac 01.wav && mv 01.flac songname.flac'

2. This one's way out there, but I guess if someone were on DOS then
.flac will be too long and there's no way to get around that unless
I add some option to specify a default extension.

So unless there's a really big objection I think I'll go and make
the changes so that the output file name is automatically determined
and you can specify multiple input files.

Josh


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