[gst-devel] release?

[Benjamin Otte]

On Mon, 2 Feb 2004, Jérémy Simon wrote:

>   Let's take an example (vorbis tag) :
>
>     REPLAYGAIN_TRACK_GAIN=-7.03 dB
>     REPLAYGAIN_TRACK_PEAK=1.21822226
>     REPLAYGAIN_ALBUM_GAIN=-6.37 dB
>     REPLAYGAIN_ALBUM_PEAK=1.21822226
>
>   1/ REPLAYGAIN_TRACK_GAIN and REPLAYGAIN_ALBUM_GAIN type should be
> STRING. Is it the Gstreamer role to remove the 'dB' string and store the
> data as double ?
>
The GStreamer tagging system doesn't care about the xyntax used inside
tags. We take the type that makes the most sense and it's the element's
job to convert it to that type.

To give you an example:
tracknumber and track count are both unsigned int in GStreamer, because
that makes the most sense for a tracknumber.
Vorbiscomments often use TRACKNUMBER=3/7 which obviously needs conversion
inside the vorbiscomment code.

There's even a reason why I made it that way (in fact 2):
1) App developers (and plugin developers using those tags) have a much
simpler time working with those values, because they have clear semantics.
2) Conversion between types of tags must only be done once: on extraction.
It would be a tough thing if you wanted to encode an asf and got the
tracknumber as a vorbis encoded string...

>   2/ REPLAYGAIN_TRACK_PEAK and REPLAYGAIN_ALBUM_PEAK should work. But it
> doesn't. I tried : gst-launch -t filesrc location=foo.ogg ! oggdemux !
> vorbisdec ! alsasink. These tag aren't detected.
>
Did you add the code to detect and parse those tags to the voprbiscomment
extraction code?
Vorbis (and ID3, too) only detect and parse tags they have been made aware
of.


Benjamin