[FFmpeg-cvslog] random thoughts about SoC (was: Re: random thoughts about refactoring)

[Diego Biurrun]

On Sun, Jan 10, 2010 at 11:13:31PM +0100, Michael Niedermayer wrote:
> On Sun, Jan 10, 2010 at 10:45:16PM +0100, Diego Biurrun wrote:
> > On Sun, Jan 10, 2010 at 10:23:34PM +0100, Michael Niedermayer wrote:
> > > On Sun, Jan 10, 2010 at 02:48:00PM -0500, compn wrote:
> > > > 
> > > > i'll paste some relevent irc chat:
> > > 
> > > thank you!
> > > while not as usefull as i thought, it is usefull.
> > > 
> > > some comments below
> > > 
> > > > [17:49] <DonDiego> Dark_Shikari: we have no students who reach the patch review phase, so this is not a problem
> > > 
> > > ehm? there are plenty who did reach patch review, theres even a patch laying
> > > around that i should review. You make it look quite a bit worse than it is
> > 
> > SoC is not going too well and what's worse, it's not improving year over
> > year..
> 
> Thats not ffmpeg specific.

I was not talking about any other projects, I know no statistics for
others.  For FFmpeg it's less than stellar and not improving.  Clearly
something we must work on.

> Also if u ask for little you get little, if you ask for alot you get alot
> and some failures.
> Itd be certainly possible to make qual tasks and soc projects so simple
> that we had a maybe 70% success rate but the code that would come out of
> this would be less than what we get now.

You are missing the point.  Students and tasks should be evenly matched
for optimal results.

> > > > [17:51] <Dark_Shikari> For example, if you were writing an h264 decoder, you would have to write a header + bitstream parser
> > > > [17:51] <Dark_Shikari> that printed dct coefficients for cavlc streams
> > > > [17:51] <DonDiego> yes, i notice that many people from there apply and i suspect that money could be a motivation, there's $4500 to earn, i can live off that kind of money for 1/2 year in germany..
> > > > [17:51] <Dark_Shikari> that kind of thing is _useful for your actual project_
> > > > [17:51] <kierank> the x264 qualifications are meatier than ffmpeg ones
> > > > [17:51] <DonDiego> mru: jai has just taken money and done nothing in return :-/
> > > > [17:52] <Dark_Shikari> 2) You must be on IRC often, and get to know the community
> > > > [17:52] <Dark_Shikari> you must be involved
> > > > [17:52] <Dark_Shikari> you must respond to pings
> > > > [17:52] <Dark_Shikari> If I ping you and say "there's a bug in your code here", you should be able to respond
> > > > [17:52] <Dark_Shikari> obviously, I can't control timezones/sleep schedules/etc
> > > > [17:52] <mru> DonDiego: jai has done stuff though
> > > > [17:52] <Dark_Shikari> but in general, you shouold be available.
> > > > [17:52] <kierank> 22:42] <@Dark_Shikari> you must respond to pings --> like janihan ;)
> > > > [17:52] <Dark_Shikari> lol
> > > > [17:52] <DonDiego> mru: that was last year, this year it was money for nothing..
> > > > [17:53] * mru takes the chicks for free...
> > > 
> > > > [17:53] <Dark_Shikari> I don't think the x264 requirements are harder than ffmpeg
> > > > [17:53] <Dark_Shikari> the ffmpeg qual tasks are really hard
> > > > [17:53] <Dark_Shikari> and don't even relate to the main project often
> > > > [17:53] <Dark_Shikari> I think the main thing is that we create a community and force people to be involved
> > > > [17:53] <Dark_Shikari> and if they can't stay online and involved, they don't get in
> > > > [17:53] <mru> that's how communities work
> > > > [17:53] <mru> _saying_ you're in doesn't make it so
> > > > [17:54] <Dark_Shikari> yup
> > > > [17:54] <Dark_Shikari> having a qual task that leads into the main project is the best idea of mine IMO
> > > > [17:54] <Dark_Shikari> it gives people a feeling that they're actually part done with the project
> > > > [17:54] <Dark_Shikari> before SOC even starts
> > > > [17:54] <Dark_Shikari> and people are less likely to quit in the middle
> > > > [17:55] <Dark_Shikari> as opposed to simply bullshitting and quitting after getting nothing done
> > > > [17:55] <DonDiego> we need to work on our soc, it's in a sad state and not improving
> > > 
> > > > [17:55] <DonDiego> also, our tasks are *much* too hard
> > > > [17:55] <Dark_Shikari> well, here's my advice for improving ffmpeg SOC
> > > 
> > > > [17:55] <DonDiego> basically the only student that ever finished a decoder is kostya
> > > 
> > > complete nonsense
> > 
> > Absolutely not.  There is only one non-Kostya-implemented decoder that
> > made it into FFmpeg start to finish during SoC: MPEG-4 ALS.
> 
> Thats nonsense, just count how many we just got as a qualification task

This is nonsense, they're much easier than the ones that make up SoC
tasks of course.

> also, ffmpeg is made of many parts, encoders, decoders, muxers, demuxers
> and alot in between. If you split the students we have over these there arent
> that many left in each category, now saying there are just 2 in one specific
> category is a little weak.
> 
> just a quick grep for a random student name:
> libavcodec/ac3dec.c: * Copyright (c) 2007-2008 Bartlomiej Wolowiec <bartek.wolowiec at gmail.com>
> libavcodec/ac3dec_data.c: * Copyright (c) 2007 Bartlomiej Wolowiec <bartek.wolowiec at gmail.com>
> libavcodec/eac3dec.c: * Copyright (c) 2007 Bartlomiej Wolowiec <bartek.wolowiec at gmail.com>
> libavcodec/eac3dec_data.c: * Copyright (c) 2007 Bartlomiej Wolowiec <bartek.wolowiec at gmail.com>
> libavcodec/lzwenc.c: * Copyright (c) 2007 Bartlomiej Wolowiec
> libavcodec/lzwenc.c: * @author Bartlomiej Wolowiec
> libavcodec/nellymoserenc.c: * Copyright (c) 2008 Bartlomiej Wolowiec
> libavcodec/nellymoserenc.c: * by Bartlomiej Wolowiec
> libavcodec/tiffenc.c: * Copyright (c) 2007 Bartlomiej Wolowiec
> libavcodec/tiffenc.c: * @author Bartlomiej Wolowiec
> libavformat/spdif.c: * Copyright (c) 2009 Bartlomiej Wolowiec
> libavformat/spdif.c: * @author Bartlomiej Wolowiec

That's a straw man.  I mean what I say, not what you put into my mouth.

I never claimed we got nothing out of SoC nor am I unaware that demuxers
are easier to write than decoders.  I was talking about decoders and my
point still stands.

> > Our SoC tasks are too hard, it's a fact.
> 
> thats your oppinion
> and as you consider to apply for this years soc ill surely not consider
> your oppinon as it could be heavily biased due to personal interrest.

Everything is perfect.  You assess reality without flaw.  Nothing needs
to be changed, ever.  FFmpeg must continue in all regards without
adjusting course in the slightest.

I'm sick and tired of these discussions.  First you complain loudly
that you want to hear about all the problems that get talked about
"behind your back", then you shoot at the messenger.

Fuck it.   I'm not making the mistake again.  You know what happened to
Cassandra when she stayed in Troy.  Clearly the wise choice is to leave
before it happens.  I'm out.

> > > > [17:56] <Dark_Shikari> DylanZA was one of our successes last year
> > > > [17:56] <Dark_Shikari> he picked x264 over ffmpeg
> > > > [17:56] <DonDiego> hmm
> > > > [17:57] <DonDiego> qual tasks were started after the first year
> > > > [17:57] <DylanZA> most reasonable students will pick a couple of projects anyway
> > > > [17:57] <DonDiego> to weed out incompetent students
> > > > [17:57] <Dark_Shikari> DonDiego: IMO there are two requirements
> > > > [17:57] <Dark_Shikari> 1) competent/self-motivated
> > > > [17:57] <Dark_Shikari> 2) involved
> > > > [17:57] <DylanZA> but if one is too difficult then they choose another. but the poor students might just stick to one project and try their luck
> > > > [17:57] <Dark_Shikari> unless you have both, you will have a failure
> > > > [17:58] <DylanZA> Dark_Shikari: yuo also need luck
> > > 
> > > > [17:58] <Dark_Shikari> this is why I'm biased against indian/chinese students, they do not tend to be very involved
> > > 
> > > if iam not mistaken our mxf muxer was written by a chinese student together
> > > with his mentor baptiste
> > 
> > Kartikey Mahendra Bhatt and Xiaohui Sun were complete failures, then
> > there's a bunch of incompetent ones that failed during qualification.
> > 
> > > also jai is indian if iam not mistaken and he wrote the alac stuff
> > > jai failed on jpeg2k but kamil who i think was from poland failed on that
> > > before.
> > 
> > Jai worked well one year and milked SoC for the money the next year..
> 
> i think lack of communication was one of the main reasons of jais
> failing in the 2nd year.

That's hard to believe for a student that has been around for such
a long time.

Diego