[Ffmpeg-devel] lzw compression in tiff encoder (qualification task for GSoC)

[Michael Niedermayer]

Hi

On Sat, Apr 07, 2007 at 02:33:00PM +0200, Bartlomiej Wolowiec wrote:
> Hi,
> On Saturday 07 April 2007 01:50, Michael Niedermayer wrote:
> > > +/**
> > > + * Init LZW encoder (allocate memory)
> > > + * @param s LZW state
> > > + */
> > > +void ff_lzw_encode_open(LZWEncodeState ** s){
> > > +    *s = av_malloc(sizeof(LZWEncodeState));
> > > +    (*s)->tab = av_malloc(LZW_HASH_SIZE * sizeof(Code));
> > > +}
> >
> > why _init and _open ? it seems one would be enough
> 
> I've changed functions _open/_close to _alloc/_free. I use _alloc/_init 
> functions, because allocated memory can be used many times (e.g. in TIFF 
> encoder can compress every strip separately).

could you post benchmarks (START/STOP_TIMER) if its faster by a non neglgible
amount iam ok with it, though maybe exporting the size and letting the user
allocate it like md5.c doex:
const int av_md5_size= sizeof(AVMD5);

would be simpler and more flexible?

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

The educated differ from the uneducated as much as the living from the
dead. -- Aristotle 
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