[FFmpeg-devel] GSoC Qual VQA v3 : patch updated

[Michael Niedermayer]

On Mon, Apr 13, 2009 at 03:18:51PM -0400, The Deep Explorer wrote:
> > kostya already explained that you cannot do it that way.
> > Its basic C knowledge, to know how to read 2 bytes or how to read a littele
> > endian 16bit value.
> 
> code = AV_RB16(&src[src_index]);
> 
> As per Kostya, Ronald, this will read in the big endian format.
> So If I do this now ...
> 
>      code = code_buf >> 13;
>      code = code & 0x0007;
> 
> This is giving me the code I tested in with a sample file, Is this still wrong ?

the text says intel which meaning little endian not big, ronald is a lazy
brat who didnt bother reading the text ;)


> 
> 
> > Its your job to write functioning code not ours, after all thats a
> > qualification, that is we want to find out if you can do it not if we
> > can do it.
> > In the actual SOC project in summer we of course would (or should at least)
> > be more helpfull
> 
> Please I was just trying to understand the document, which is explanatory
> for an expert but not sufficient for a newbie like me :(...

are you sure you are qualified for an actual SOC project this year?


> 
> >> Write block number (Val & 0xff) Count times.
> >>          Count is (((Val/256) & 0x1f)+1)*2. Note that this can only
> >>          index the first 256 blocks.
> >>
> >> As per the document, I found the block no, wrote it to the dest buff
> >> count times...
> >
> > uhm
> > a little bit of common sense is helpfull, really
> >
> > The text
> > "       Write block number (Val & 0xff) Count times.
> >        Count is (((Val/256) & 0x1f)+1)*2. Note that this can only
> >        index the first 256 blocks.
> > "
> > does not mean
> > "Write block_number X"
> > but
> > "Write the block with number X"
> > or shorter
> > "Write block, number X"
> >
> 
> Ok , my next attempt : So val is the short int I read, X is the ==> (Val & 0xff)
> and Count is explicityly stated
>             X = code_buf & 0x1ff;
>             count = (((code_buf / 256) & 0x1f) + 1) * 2;
>             for (index = 0; index < count; index++)
>                 dest[dest_index + index] = X;
> 
>             dest_index += index;
> 
> So what is it wrong in here ..., please help...

You write X not the block X
its like if you tell a taxi driver to bring you to the 5th street
and he throws you out of his car and gives you a piece of paper with
5 written on it

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

Dictatorship naturally arises out of democracy, and the most aggravated
form of tyranny and slavery out of the most extreme liberty. -- Plato
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