Hi,

On Tue, Apr 10, 2012 at 1:49 PM, Diego Biurrun <[email protected]> wrote:
> On Tue, Apr 10, 2012 at 01:27:59PM -0700, Ronald S. Bultje wrote:
>> On Tue, Apr 10, 2012 at 1:23 PM, Diego Biurrun <[email protected]> wrote:
>> > On Tue, Apr 10, 2012 at 12:49:20PM -0700, Ronald S. Bultje wrote:
>> >> On Tue, Apr 10, 2012 at 12:40 PM, Diego Biurrun <[email protected]> wrote:
>> >> > On Tue, Apr 10, 2012 at 11:37:30AM -0700, Luca Barbato wrote:
>> >> >> On 10/04/12 09:24, Diego Biurrun wrote:
>> >> >> > On Tue, Apr 10, 2012 at 07:30:30AM -0700, Ronald S. Bultje wrote:
>> >> >> >> On Tue, Apr 10, 2012 at 7:12 AM, Diego Biurrun <[email protected]> 
>> >> >> >> wrote:
>> >> >> >>> On Fri, Mar 30, 2012 at 02:08:22AM +0200, Diego Biurrun wrote:
>> >> >> >>>> ---
>> >> >> >>>>  libavcodec/Makefile  |    2 +-
>> >> >> >>>>  libavcodec/h264.c    |  358 
>> >> >> >>>> +++-----------------------------------------------
>> >> >> >>>>  libavcodec/h264.h    |    5 +
>> >> >> >>>>  libavcodec/h264dec.c |  349 
>> >> >> >>>> ++++++++++++++++++++++++++++++++++++++++++++++++
>> >> >> >>>>  4 files changed, 375 insertions(+), 339 deletions(-)
>> >> >> >>>>  create mode 100644 libavcodec/h264dec.c
>> >> >> >>>
>> >> >> >>> ping
>> >> >> >>
>> >> >> >> You told me on IRC it did not significantly decrease compile time, 
>> >> >> >> so
>> >> >> >> I don't see the point of the patch.
>> >> >> >
>> >> >> > That's not the only reason I went for implementing this patch.  It 
>> >> >> > also
>> >> >> > reduces the size of h264.c by 350 lines, which is not huge, but more
>> >> >> > than nothing, and it reduces the size of libavcodec if the H.264 
>> >> >> > decoder
>> >> >> > is disabled but some other part that requires h264.c is enabled.
>> >> >>
>> >> >> Good point, if it doesn't break anything and doesn't hinder people
>> >> >> working on h264.c seems a good patch.
>> >> >
>> >> > Size difference before and after while configuring with
>> >> > "--disable-everything --enable-decoder=svq3":
>> >> >
>> >> > before:
>> >> > biurrun@passion:~/src/priv/libav $ ls -l libavcodec/libavcodec.a
>> >> > -rw-rw-r-- 1 biurrun src-pisa 33880296 2012-04-10 20:47 
>> >> > libavcodec/libavcodec.a
>> >> >
>> >> > after:
>> >> > -rw-rw-r-- 1 biurrun src-pisa 33852434 2012-04-10 21:36 
>> >> > libavcodec/libavcodec.a
>> >> >
>> >> > This amounts to a saving of 32kB.
>> >>
>> >> I still don't think the split makes sense. Please re-read my earlier 
>> >> comment.
>> >
>> > There is no earlier comment to re-read, you only mentioned the effect of
>> > this patch on compile time.  Since some miscommunication seems to be
>> > going on, let me quickly reiterate the goals of this patch:
>> >
>> > 1) Reduce line count of h264.c,
>> > 2) reduce compile time of h264.c and
>> > 3) reduce libavcodec size in certain configurations.
>> >
>> > Unfortunately the split did not quite have the effect on 2) that I
>> > had hoped for, but there are modest improvements in 1) and 3).
>> >
>> > Could you please quickly state why you think this patch is not worth
>> > the improvements in 1) and 3)?
>>
>> I wonder how you think the patch manages to accomplish (3), given that
>> it doesn't add or remove code? Sorry to sound like an asshole, but I'm
>> a bit sceptical over this claim.
>
> Read what I write :)
>
> Let me repeat:
>
>  Size difference before and after while configuring with
>  "--disable-everything --enable-decoder=svq3":
>
>  before:
>  biurrun@passion:~/src/priv/libav $ ls -l libavcodec/libavcodec.a
>  -rw-rw-r-- 1 biurrun src-pisa 33880296 2012-04-10 20:47 
> libavcodec/libavcodec.a
>
>  after:
>  -rw-rw-r-- 1 biurrun src-pisa 33852434 2012-04-10 21:36 
> libavcodec/libavcodec.a
>
>  This amounts to a saving of 32kB.
>
> h264.c is currently not only required by the H.264 decoder, but also by
> the SVQ3 decoder and the H.264 parser.  After my patch the common code
> remains in h264.c and the decoder-only code is in h264dec.c.  Configurations
> that disable the H.264 decoder while enabling parts that require the common
> code in h264.c thus end up smaller because h264dec.c is no longer compiled.

So by removing H264 specific code from a binary that only contains a
SVQ3 decoder, you manage to save 32kB out of 34MB? Isn't that a little
... Ehm, how shall I put this kindly... Lame? Wouldn't you expect
more?

How's speed and size of the binary containing both decoders? Does it
change after this patch?

Ronald
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