Re: question about standart

Rob Leslie <[email protected]> Tue, 21 Sep 2004 23:14:45 -0700
Newsgroups gmane.comp.audio.mad.devel
Message-ID <[email protected]>
On Sep 21, 2004, at 9:11 PM, Grigory A. wrote:
> Could someone give me answer :
> are mp3 frames independent?
> I mean how current frame depend from previous?
>
> It looks like points of dependences are in
> - overlap procedure
> - synthesis procedure

In addition to these, MP3 frames are also interdependent in the way 
they share the bit reservoir. What this means is that the audio data 
for a Layer III frame is not necessarily contained entirely between 
sync words; some or all of the associated audio data may be stored in 
the free space of the preceding frames.

> so if I skip correctly one or more frames - all "problems" will
> disappear after first newly decoded frame.
> I mean - first frame decoded after skipped - will be wrong (if compare 
> with
> non-skipped sequence)and second become same in both cases?

If the frame you decode after skipping depends on the bit reservoir, 
you may not even be able to decode it. You may have to decode several 
frames before the bit reservoir is fully refilled.

There has been much discussion on the subject of seeking; you may want 
to review:

     http://www.mars.org/mailman/public/mad-dev/2001-August/000321.html
     http://www.mars.org/mailman/public/mad-dev/2001-August/000338.html
     http://www.mars.org/mailman/public/mad-dev/2003-November/000949.html

-- 
Rob Leslie
[email protected]