[FFmpeg-devel] [PATCH v9 2/3] libavcodec/jpeg2000dec.c: Add support for PPT marker

Michael Niedermayer michael at niedermayer.cc
Fri Apr 3 00:34:58 EEST 2020


On Thu, Apr 02, 2020 at 08:24:13AM +0530, Gautam Ramakrishnan wrote:
> On Thu, Apr 2, 2020 at 12:58 AM Michael Niedermayer
> <michael at niedermayer.cc> wrote:
> >
> > On Wed, Apr 01, 2020 at 08:01:48AM +0530, Gautam Ramakrishnan wrote:
> > > On Wed, Apr 1, 2020 at 6:17 AM Michael Niedermayer
> > > <michael at niedermayer.cc> wrote:
> > > >
> > > > On Tue, Mar 31, 2020 at 05:32:41PM +0530, gautamramk at gmail.com wrote:
> > > > > From: Gautam Ramakrishnan <gautamramk at gmail.com>
> > > > >
> > > > > This patch adds functional changes to support the
> > > > > PPT marker.
> > > > > ---
> > > > >  libavcodec/jpeg2000dec.c | 85 +++++++++++++++++++++++++++++++++++-----
> > > > >  1 file changed, 76 insertions(+), 9 deletions(-)
> > > >
> > > > can you explain why the jpeg2000_decode_packet* function is / needs to be
> > > > split for this ?
> > > > iam asking as it duplicates quite some code in the previous patch
> > > >
> > > so, if we can represent packet header as H and data as D,
> > > without a PPT marker, the packet data is represented as
> > > HDHDHDHD.....
> > > However, with the PPT marker, this is changed to
> > > HHHHHHHHHDDDDDDD.....
> > > The jpeg2000_decode_packet() decodes a packet in the HD format.
> > > However, to decode packets in packed form (this change should apply
> > > even if PPM marker support is added), I thought it would be better if we
> > > break the function to decode header and data separately.
> >
> > Is there any plan/need to call the 2 functions differently than always
> > first one and immedeatly the 2nd ?
> Hmm, I did not think of this. At the moment, I do not think so. Imo, even the
> PPM marker addition should not make a difference. I really doubt that the
> calling order will change. Does it look like a good idea to merge the function
> back?

i think so, it would be less duplicated code

thx

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

In fact, the RIAA has been known to suggest that students drop out
of college or go to community college in order to be able to afford
settlements. -- The RIAA
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