[gst-devel] Ogg and GStreamer

in7y118 at public.uni-hamburg.de in7y118 at public.uni-hamburg.de
Thu Jul 31 03:56:06 CEST 2003

Zitat von Ronald Bultje <rbultje at ronald.bitfreak.net>:

> doesn't GST_BUFFER_DURATION(buf) suffice here? It's the actual reason why
> I added it... And well, not all plugins use it or fill it in perfectly, but 
> it works, mostly.
> If GST_BUFFER_DURATION(buf) isn't good enough, could you please explain
> what more it should do? We could then remove GST_BUFFER_DURATION() in
> favour of something else. We shouldn't add something, I think, they look
> too much alike...
Duration is the length value of the time format.
Let me do a little matrix:

format\position |   start   |  length  | end
          bytes |           | size     |
           time | timestamp | duration |
         frames | offset    |          |  ?
    [any other] |           |          |

This matrix summarizes for every format GStreamer uses what information about 
the buffer is available directly as a value inside the buffer struct. The value 
marked with the question mark is the only value that is available in ogg.
How do I
- get this value when encoding in oggmux?
- store this value when decoding in oggdemux?
(Please keep in mind that in the future ogg might be used for loads of formats 
and not only audio or video.)
The suggested - and currently possible - ways to do this are
- use gst_pad_query for encoding
- discard the value when decoding
and those don't look like best (and not like the fastest either).
That's why I was asking for addition of a field inside the buffer struct for 
the frames/length combination.


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