[Vorbis-dev] Urgent Doubt in VORBIS

[Sumit Chatterjee]

Hi Conrad..
    Actually no, I am not using the wrote(0) function. Its a live stream, so
basically the data feed never stops. I basically need to maintain synch
between the raw sample and decoded stream.
   By the way I can try using vorbis_analysis_wrote(&vd, 0) retreive the
correct granulepos value and then continue with my encoding. Will I get
continuous encoded stream by doing this?

Thanks
Sumit

2009/8/29 Conrad Parker <conrad at metadecks.org>

> 2009/8/28 Sumit Chatterjee <getsumit at gmail.com>:
> > Hey Mike,
> >        Sorry its actually 4am in the morning, so my brain isnt working
> that
> > much. Here goes the explanation:
> >       Step 1: raw sample --> encode. Here while encoding , as I get
> packets,
> > I record the granulepos used up for that packet, which gives me the pcm
> > consumed.
> >       Step 2: The packet and pcm are sent to another program through
> > sockets, wherein the received packet is decoded.
> >       Step 3: The decoded pcm size is matched with the  pcm size sent
> > corresponding to the encoded packet.
> >
> >       Also to add to the details: I have changed the buffering mechanism
> of
> > OGG container to 2KB from 4KB
> >
> >
> > The basic problem is in Step 1, where I feel, I may have to deduct an
> offset
> > in the beginning before using the granulepos structure element - is it
> so?
>
> no, the granulepos returned in the ogg_packet structure is correct.
>
> During the stream, the granulepos represents the number of decodable
> frames, which will lag behind the number of frames consumed (due to
> overlap-add). That is normal.
>
> At the end of the encode this will be fixed. Are you calling
> vorbis_analysis_wrote(&vd, 0) at the end of the input data?
>
> Conrad.
>
> >
> > 2009/8/28 Michael Smith <msmith at xiph.org>
> >>
> >> On Thu, Aug 27, 2009 at 3:09 PM, Sumit Chatterjee<getsumit at gmail.com>
> >> wrote:
> >> > Hi Mike,
> >> >     I was having a big problem earlier as there was a mismatch of over
> >> > 16-20KB sometimes.
> >> >     I have solved that problem now. After lot of debugging I could
> find
> >> > out
> >> > that granulepos wasn't being used at the correct place for identifying
> >> > the
> >> > pcm size of the data encoded.
> >> >
> >> >     BUT, currently I have a minor issue still left on the same lines.
> If
> >> > I
> >> > send the pcm size of the encoded data to another machine, and decode
> the
> >> > encoded stream, there is "always" a mismatch of 4096 bytes :(
> Regarding
> >> > your
> >> > suggestion currently my mearsurement is on the same base(integer).
> >>
> >> I can only assume you have a bug in your code then. I can't help much
> >> more specifically than that - you haven't provided any information
> >> about what you're doing.
> >>
> >> Mike
> >
> >
> > _______________________________________________
> > Vorbis-dev mailing list
> > Vorbis-dev at xiph.org
> > http://lists.xiph.org/mailman/listinfo/vorbis-dev
> >
> >
>
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