[FFmpeg-devel] [PATCH] Some ra144.c simplifications

[Michael Niedermayer]

On Thu, May 15, 2008 at 09:44:51AM +0200, Vitor Sessak wrote:
> Hi
> 
> Michael Niedermayer wrote:
> > On Wed, May 14, 2008 at 09:12:07AM +0200, Vitor Sessak wrote:
> >> On Tue, May 13, 2008 at 2:13 PM, Michael Niedermayer <michaelni at gmx.at> wrote:
> >>> On Tue, May 13, 2008 at 11:05:45AM +0200, Vitor Sessak wrote:
> >>>  > Michael Niedermayer wrote:
> >>>  >> On Sun, May 11, 2008 at 05:45:29PM +0200, Vitor Sessak wrote:
> >>>  >>> Michael Niedermayer wrote:
> >>>  >>>> On Sat, May 10, 2008 at 04:50:03PM +0200, Vitor Sessak wrote:
> >>>  >>>>> Hi,
> >>>  >>>>>
> >>>  >>>>> libavcodec/ra144.c really needs some cleanup. I'll start with the
> >>>  >>>>> following:
> >>>  >>>>>
> >>>  >>>>> ra144_indent.diff: Reindent the whole file. Since there was no
> >>>  >>>>> substantial change in this file since it inclusion in 2003, I don't
> >>>  >>>>> think there is any problem in making its indentation inline with the
> >>>  >>>>> rest of FFmpeg.
> >>>  >>>>>
> >>>  >>>>> ra144_unpack_rewrite.diff: Rewrite completely unpack_input()
> >>>  >>>>>
> >>>  >>>>> ra144_simp{1,2}.diff: minor simplifications
> >>>  >>>> all ok if you have tested your code
> >>>  >>> Next round:
> >>>  >>>
> >>>  >>> ra144_simp{3,4}.diff: minor simplifications (FFSWAP, unused stuff
> >>>  >>> removal)
> >>>  >> ok
> >>>  >>> ra144_sqrt.diff: remove ff_sqrt reimplementation and its corresponding
> >>>  >>> big table (output is not anymore binary-identical but this function is
> >>>  >>> more accurate, not less). Nice thing we have now a fast ff_sqrt :-)
> >>>  >> by how much does the output differ?
> >>>  >
> >>>  > According to tiny_psnr for drummers.14.ra
> >>>  > stddev: 28.84 PSNR:18.92 bytes:5369856
> >>>  >
> >>>  > which looks a lot to me (even if playing the file I can't hear any
> >>>  > difference). I suggest to leave this for after the rest of the cleanup.
> >>>  >
> >>>  >>> ra144_split_val.diff: glob->val is unrelated with the rest of the
> >>>  >>> unpacked buffer. This patch split its table out of the others
> >>>  >> ok
> >>>  >>> and move
> >>>  >>> it parsing to a more reasonable place.
> >>>  >> not ok, the place does not look reasonable to me
> >>>  >
> >>>  > I don't know if it is this that you mean, but the unpack_input()
> >>>  > function is a bit senseless. It read three unrelated things (10 codebook
> >>>  > indexes, a codebook index for val and 4 4-byte blocks) from the
> >>>  > bitstream and put everything in the same buffer. The attached patch (to
> >>>  > be applied after ra144_rename_valtab.diff) simply remove this function
> >>>  > and move the bitstream reading to where the data is actually needed.
> >>>
> >>>  ok (I assume that every cleanup has been tested and has bit identical
> >>>  output ...)
> >> I do test them.
> >>
> >> More cleanup (to be applied after the previous ok'ed patches):
> >>
> >> ra144_trim_context.diff : Remove a lot of vars from context
> >> ra144_trim_context2.diff: Modify add_wav() to remove another
> >> context var
> >
> > all ok
> 
> Yet some more:
> 
> ra144_const.diff: Make const everything that can be declared so

ok


> ra144_useless_buffers.diff: Remove some useless buffers (and avoid a memcpy)

ok


> ra144_useless_buffers2.diff: More useless buffer removal

see below


> ra144_nopar_ctx.diff: Don't send the context for functions that don't use it

ok


> ra144_rotate_block.diff: Simplify rotate_block()

ok


> ra144_uint8_tables.diff.gz: Declare as (u)int8_t tables that fit in one
> byte (yes, that makes the indentation of ra144.h inconsistent. I'll fix
> the rest of the file later)

ill look at that in a moment


[...]
> --- ../ffmpeg.old2/libavcodec/ra144.c	2008-05-14 18:02:44.000000000 +0200
> +++ libavcodec/ra144.c	2008-05-14 18:24:08.000000000 +0200
> @@ -105,7 +105,7 @@
>  static void do_output_subblock(Real144_internal *glob, const unsigned short  *gsp, unsigned int gval, signed short *output_buffer, GetBitContext *gb)
>  {
>      unsigned short int buffer_a[40];
> -    unsigned short int buffer_d[40];
> +    unsigned short int *block;
>      int e, f, g;
>      int a = get_bits(gb, 7);
>      int d = get_bits(gb, 8);
> @@ -125,13 +125,13 @@
>      else
>          g = 0;
>  

> +    memmove(glob->buffer_2, glob->buffer_2 + BLOCKSIZE, (BUFFERSIZE - BLOCKSIZE) * 2);
> +
> +    block = glob->buffer_2 + BUFFERSIZE - BLOCKSIZE;
> -    add_wav(glob, d, a, g, e, f, buffer_a, etable1 + b*BLOCKSIZE,
> -            etable2 + c*BLOCKSIZE, buffer_d);
> +    add_wav(glob, d, a, g, e, f, buffer_a, etable1 + b*BLOCKSIZE,
> +            etable2 + c*BLOCKSIZE, block);
                                      ^^^^^
> -
> -    memmove(glob->buffer_2, glob->buffer_2 + BLOCKSIZE, (BUFFERSIZE - BLOCKSIZE) * 2);
> -    memcpy(glob->buffer_2 + BUFFERSIZE - BLOCKSIZE, buffer_d, BLOCKSIZE * 2);
> 
> -    final(glob, gsp, buffer_d, output_buffer, glob->buffer, BLOCKSIZE);
> +    final(glob, gsp, block, output_buffer, glob->buffer, BLOCKSIZE);
                        ^^^^^
cosmetics, split!


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

never fix a bug you don't understand. -- Ben Laurie
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: Digital signature
URL: <http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/attachments/20080515/4f112c1c/attachment.pgp>