[alsa-devel] [RFC] compress: add support for gapless playback

[Takashi Iwai]

At Tue, 05 Feb 2013 20:44:42 -0600,
Pierre-Louis Bossart wrote:
> 
> >   /**
> > + * struct snd_compr_metadata: compressed stream metadata
> > + * @encoder_delay: no of samples inserted by the encoder at the beginning
> > + * of the track
> > + * @encoder_padding: no of samples appended by the encoder at the end
> > + * of the track
> > + */
> > +struct snd_compr_metadata {
> > +	 __u32 encoder_delay;
> > +	 __u32 encoder_padding;
> > +};
> 
> You need to pad this structure with reserved bytes for future 
> evolutions. Things like ReplayGain, etc, might be of interest for some 
> implementations. Let's not be cheap here

Or, make it a single key/value.  User-space can call the ioctl
multiple times with different key/value pairs.

(BTW, don't you need get_metadata?  IMO, it was a mistake that we
 didn't provide get_* variants for PCM parameters.)


thanks,

Takashi