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Re: sox - package is broken


On Mar 16 00:00, David Stacey wrote:
> On 10/03/2014 11:14, Corinna Vinschen wrote:
> >Does anybody feel up to the task to debug this issue in the Cygwin DLL?
> >The DSP code is practically only in a single file called fhandler_dsp.cc.
> 
> I've started looking at this, but it is at the very bottom of my
> priority queue so progress might be slow. Thus far, I've determined
> that the last 1.5s are missing from *all* wav files piped to
> /dev/dsp. If your wav file happens to be less that 1.5s then you get
> nothing. This hasn't been noticed to date because most audio files
> (e.g. songs) contain an amount of silence at the end of the file to
> separate the tracks.
> 
> The code mentioned above maintains a circular buffer that holds 1.5s
> worth of sample data, so it is probable that this buffer isn't
> getting flushed properly. I've spent an evening debugging the code,
> but haven't turned up anything yet. It doesn't help that the code is
> rather sparsely commented.
> 
> I'll post again if I learn more.

Cool, many thanks for looking into this.

If there are always samples at the end missing, maybe there's just some
"flush audio queue" call missing in fhandler_dev_dsp::close_audio_out?

I'm just glancing at this part of the code and what makes me a bit wary
is the call

  audio_out_->stop (immediately);

This is called from fhandler_dev_dsp::close, just a few lines later
like this:

  close_audio_out (exit_state != ES_NOT_EXITING);

Doesn't that mean that, if the application calls exit without calling
close implicitely, the buffer will not be flushed?  That sounds wrong to
me.

OTOH, I don't know if that's really the case here.  I'm just musing.


Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Maintainer                 cygwin AT cygwin DOT com
Red Hat

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