GSoC 2008

Hi,
I'm interested in applying to FFmpeg under GSoC this year.
As my
qualification task, I'd like to work on the BFI playback
subsystem. Is it
possible for me to update the wiki entry for this task as
'claimed'?
Thanks,
Sisir K.

------
Sisir Koppaka
Undergraduate Student
IIT Kharagpur
India
_______________________________________________
ffmpeg-devel mailing list
ffmpeg-develmplayerhq.hu
https://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel

Sisir Koppaka wrote:
> Hi,
> I'm interested in applying to FFmpeg under GSoC this
year. As my
> qualification task, I'd like to work on the BFI
playback subsystem. Is it
> possible for me to update the wiki entry for this task
as 'claimed'?
> Thanks,
> Sisir K.

Tell me what username you would like to use for the Wiki
(letters,
numbers, spaces, caps, all okay). I will create the account
and you can
update the Wiki yourself.

We're running out of qualification tasks. I need to go
create some more!

-- 
	-Mike Melanson
_______________________________________________
ffmpeg-devel mailing list
ffmpeg-develmplayerhq.hu
https://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel

Thanks! I'd like to have 'Sisir Koppaka'  as the username
for the Wiki.

On Thu, Mar 20, 2008 at 1:44 AM, Mike Melanson <mikemultimedia.cx> wrote:

> Sisir Koppaka wrote:
> > Hi,
> > I'm interested in applying to FFmpeg under GSoC
this year. As my
> > qualification task, I'd like to work on the BFI
playback subsystem. Is
> it
> > possible for me to update the wiki entry for this
task as 'claimed'?
> > Thanks,
> > Sisir K.
>
> Tell me what username you would like to use for the
Wiki (letters,
> numbers, spaces, caps, all okay). I will create the
account and you can
> update the Wiki yourself.
>
> We're running out of qualification tasks. I need to go
create some more!
>
> --
>        -Mike Melanson
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-develmplayerhq.hu
> https://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel

>



-- 
-----------------
Sisir Koppaka
_______________________________________________
ffmpeg-devel mailing list
ffmpeg-develmplayerhq.hu
https://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel

Hello,

Mike Melanson wrote:
> We're running out of qualification tasks. I need to go
create some more!

How about this one: Finish G.722.1 and siren decoding.

This patch works for siren, but I haven't tested with the
G.722.1. It 
should work the same though.

Basically it'd involve (in separate patches):
- Split G.722.1 tables from cookdata.h into g7221data.h;
- Rename divergent tables as g7221_... and cook_...;
- Split G.722.1 functions from cook.c to g7221.c;
- Cleanly make cook call G.722.1's decoder instead of
mono_decode;
- Clean all the #if 0 and // hacks;
- Fix the *22.0f hack;
- Implement a faster 320-point iMDCT.

I've sent a sample to /MPlayer/incoming/siren/msnsiren.wav

Ramiro Polla

_______________________________________________
ffmpeg-devel mailing list
ffmpeg-develmplayerhq.hu
https://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel

Ramiro Polla <ramirolisha.ufsc.br> writes:

> Hello,
>
> Mike Melanson wrote:
>> Ramiro Polla wrote:
>>> Hello,
>>>
>>> Mike Melanson wrote:
>>>> We're running out of qualification tasks. I
need to go create some more!
>>> How about this one: Finish G.722.1 and siren
decoding.
>> 
>> Not bad...
>> 
>>> This patch works for siren, but I haven't
tested with the G.722.1. It
>>> should work the same though.
>>>
>>> Basically it'd involve (in separate patches):
>>> - Split G.722.1 tables from cookdata.h into
g7221data.h;
>>> - Rename divergent tables as g7221_... and
cook_...;
>>> - Split G.722.1 functions from cook.c to
g7221.c;
>>> - Cleanly make cook call G.722.1's decoder
instead of mono_decode;
>>> - Clean all the #if 0 and // hacks;
>> 
>>> - Fix the *22.0f hack;
>> 
>> Can you explain this step better?
>
> Something like adding qscale to CookContext, set it to
1.0 on Cook and 
> 22.0 on G.722.1. Then change the line
> f1 = quant_centroid_tab[index][subband_coef_index[i]];
> to
> f1 =
quant_centroid_tab[index][subband_coef_index[i]]*q->qscal
e;
>
>>> - Implement a faster 320-point iMDCT.
>> Seems a bit out of scope without more guidance.
Otherwise, log it.
>
> FFmpeg's imdct only works with 2^n input. In this
hacked-up patch, I 
> used imdct_ref from some other part of FFmpeg. It's
painfully slow.

I notice that mpegaudiodec.c has a custom imdct as well.

>>> I've sent a sample to
/MPlayer/incoming/siren/msnsiren.wav
>> 
>> I suppose a more pertinent question is: Why aren't
*you* doing this for
>> a qual task?  (You are
aiming for SoC, right?)
>
> Hey, I got Mimic in =)
>
> The problem is that I halted in the imdct part =(. My
math is not that 
> good, and after some time fighting with math books I
saw that I'd study 
> this thoroughly next semester at University. So I
decided to first learn 
> to have some idea of what I was supposed to achieve,
then implement it.

If your university is anything like the one I attended,
you'll stand a
much better chance of gaining any useful knowledge from that
course if
you first familiarise yourself with how these transforms are
used in
real life, never mind the precise details of why they work.

-- 
Måns Rullgård
mansmansr.com
_______________________________________________
ffmpeg-devel mailing list
ffmpeg-develmplayerhq.hu
https://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel

On Wed, Mar 19, 2008 at 01:14:56PM -0700, Mike Melanson
wrote:
[...]
> We're running out of qualification tasks. I need to go
create some more!

* the AVPalette cleanup ...

* change the existing avi/mjpeg code so it generates videos
playable on
  my canon digital ixus 30 

* lossy flac encoder using viterbi algorithm

* MPEG-4 GMC encoder

* fix ffserver

* per MB rate control (nice for VBV compliance)

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

Thouse who are best at talking, realize last or never when
they are wrong.

_______________________________________________
ffmpeg-devel mailing list
ffmpeg-develmplayerhq.hu
https://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel

On Wed, Mar 19, 2008 at 11:27:58PM +0100, Michael
Niedermayer wrote:
> On Wed, Mar 19, 2008 at 01:14:56PM -0700, Mike Melanson
wrote:
> [...]
> > We're running out of qualification tasks. I need
to go create some more!
> 
> * the AVPalette cleanup ...
> 
> * change the existing avi/mjpeg code so it generates
videos playable on
>   my canon digital ixus 30 
> 
> * lossy flac encoder using viterbi algorithm
> 
> * MPEG-4 GMC encoder
> 
> * fix ffserver
> 
> * per MB rate control (nice for VBV compliance)

* Rewrite libavcodec/fdctref.c from scratch so that we can
get rid of
  that piece of non-free code.

Diego
_______________________________________________
ffmpeg-devel mailing list
ffmpeg-develmplayerhq.hu
https://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel

On Wed, Mar 19, 2008 at 11:35:28PM +0100, Diego Biurrun
wrote:
[...]
> * Rewrite libavcodec/fdctref.c from scratch so that we
can get rid of
>   that piece of non-free code.

i think this is too easy

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

I am the wisest man alive, for I know one thing, and that is
that I know
nothing. -- Socrates

_______________________________________________
ffmpeg-devel mailing list
ffmpeg-develmplayerhq.hu
https://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel

On Wed, Mar 19, 2008 at 09:57:01PM +0000, Måns Rullgård
wrote:
> Ramiro Polla <ramirolisha.ufsc.br> writes:
> > Hey, I got Mimic in =)
> >
> > The problem is that I halted in the imdct part =(.
My math is not that 
> > good, and after some time fighting with math books
I saw that I'd study 
> > this thoroughly next semester at University. So I
decided to first learn 
> > to have some idea of what I was supposed to
achieve, then implement it.
> 
> If your university is anything like the one I attended,
you'll stand a
> much better chance of gaining any useful knowledge from
that course if
> you first familiarise yourself with how these
transforms are used in
> real life, never mind the precise details of why they
work.

I think that's actually unlikely to depend on the
university. If you did
not really use it before or in parallel to the course you
are unlikely
to learn to much from it.
Though if you are particularly unlucky they will only
explain a few
thousand optimized versions that in any actual
implementation will still
be slower than the stupidest approach... 
_______________________________________________
ffmpeg-devel mailing list
ffmpeg-develmplayerhq.hu
https://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel

Reimar Döffinger <Reimar.Doeffingerstud.uni-karlsruhe.de>
writes:

> On Wed, Mar 19, 2008 at 09:57:01PM +0000, Måns Rullgård
wrote:
>> Ramiro Polla <ramirolisha.ufsc.br> writes:
>> > Hey, I got Mimic in =)
>> >
>> > The problem is that I halted in the imdct part
=(. My math is not that 
>> > good, and after some time fighting with math
books I saw that I'd study 
>> > this thoroughly next semester at University.
So I decided to first learn 
>> > to have some idea of what I was supposed to
achieve, then implement it.
>> 
>> If your university is anything like the one I
attended, you'll stand a
>> much better chance of gaining any useful knowledge
from that course if
>> you first familiarise yourself with how these
transforms are used in
>> real life, never mind the precise details of why
they work.
>
> I think that's actually unlikely to depend on the
university. If you did
> not really use it before or in parallel to the course
you are unlikely
> to learn to much from it.
> Though if you are particularly unlucky they will only
explain a few
> thousand optimized versions that in any actual
implementation will still
> be slower than the stupidest approach... 

Hmm, now why does that ring a bell?  We at least had the
fortune to
have one course taught by someone who actually worked on
audio codecs
for a living (in a company), and did the teaching mostly for
fun.  Of
course, that only happened after the maths department had
tortured us
for a couple of years.

-- 
Måns Rullgård
mansmansr.com
_______________________________________________
ffmpeg-devel mailing list
ffmpeg-develmplayerhq.hu
https://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel