[FFmpeg-devel] JPEG2000 decoder

[rukhsana afroz]

Hi Michael,

On Fri, Jun 3, 2011 at 10:36 AM, Michael Niedermayer <michaelni at gmx.at>wrote:

> On Fri, Jun 03, 2011 at 02:25:26AM -0700, rukhsana afroz wrote:
> > Hi Michael,
> >
> > On Wed, Jun 1, 2011 at 3:42 AM, rukhsana afroz <rukhsana.afroz at gmail.com
> >wrote:
> >
> > > Hi Michael,
> > >
> > >> maybe jaspers and ours advance the pointer at a slightly different
> > >> spot in the implementation
> > >>
> > >>
> > > As per the discussion on IRC chat, I checked where s->bit_index gets
> > > modified. I see, in our decoder that s->bit_index has been manually set
> to 8
> > > at the beginning of decoding packet. whereas, in jasper, I did not see
> this.
> > > Also, jasper always reads the entire byte to check present bit even for
> > > other files, like file1.jp2 etc. Whereas, our decoder does not do so. I
> need
> > > your suggestion on this as i do not find any clue in the doc for this.
> I am
> > > waiting for you on the IRC chat.
> > >
> > >
> > >
> > >
> > >
> > I have rebased the codebase against ffmpeg and also decode_packet
> function
> > works properly comparing with jasper. However, it gets segmentation fault
> > somewhere in decode_cblk function for adding new code. Tomorrow I will be
> in
> > chat to discuss this code. My new code rebased with ffmpeg is in:
> >
> > https://github.com/rukhsana/ffmpeg_j2k
>
> thanks
>
> btw
>
> floor_log2() can be replaced by av_log2()
>
>
I have pushed another branch r2 now. Could you please help check whether the
initialization of contexts (which has been done for every codeblock segment)
is ok compared with jasper? I think, there some problem in this. I am
checking as well. There are some problems in decode_cblk function, i need to
debug thoroughly.

Thanks

-- 
Rukhsana Ruby
Phd Student
Department of Electrical & Computer Engineering
The University of British Columbia
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