[Ffmpeg-devel] Last jpeg patch to support multiple-scan JPEGs

[Kostya]

On Mon, Nov 20, 2006 at 06:56:08PM +0100, Cyril Russo wrote:
> Michael Niedermayer a ?crit :
> >Hi
> >
> >On Mon, Nov 20, 2006 at 02:26:34PM +0100, Cyril Russo wrote:
> >  
> >>Hi,
> >>
> >>
> >>    
> >>>>Worse, the patch from Kostya doesn't solve the multiple scan JPEG   
> >>>>decoding errors as (s)he pretends. The problem is fully unrelated.
> >>>>Interleaved JPEG != Progressive JPEG != Multiple scan JPEG
> >>>>        
> >>> 
> >>>  kostya posted a second patch which adds Multiple scan JPEG sipport
> >>>  by removing 6 lines and chagning 2, while yours duplicates a whole 
> >>>      
> >>  function (which btw ive complained about in my review and you ignored
> >>    
> >>>  it)
> >>>      
> >>   
> >>No, it's wrong. Kostya's patch doesn't add multiple scan JPEG support. 
> >>He (I make the assumption he is a male)
> >>added progressive support. There is a big difference with multiple scan 
> >>support.

Actually, progressive JPEG uses multiple scans too so after integrating it
was easy to add proper support for multiple scans.

> >>    
> >
> >kostya did send 2 patches one for progressive and one for multiple scan
> >jpeg
> >
> >
> >  
> >>Again, try to decode the JPEG I've posted before with kostya version, it 
> >>will fail.
> >>    
> >
> >kostya said it works so ill trust him considering that you seem to be
> >a little confused about which patch i speak off
> >
> >[...]
> >  
> Ok, let's make things clear. I, and I suppose, all of us too, want to be 
> able to decode all standard JPEGs.
> I've found both patch from kostya, and only the last one got applied.
> Anyway, the previous patch from /Mon Nov 20 06:51:15 CET 2006 /doesn't 
> work either (the index in the scan is not used for decoding the scan 
> while it should)/

No, you have missed it (it was posted in your thread 'Incorrect JPEG decoding
with patch').

> 
> /Of course you can trust anyone older than me, I'm new here, but I'm not 
> new in image processing.
> Again, if you don't want to believe me, believe yourself by compiling 
> lastest kostya version, and launch :
> wget http://xryl669ny.free.fr/MyFile000.jpg && mv MyFile000.jpg 
> test.mjpeg && ffmpeg -i test.mjpeg -vframes 1 -f mjpeg output.jpg
> 
> You'll get a very beautiful (and uniform) grey picture in output.

Try SVN r7143, it is already there.

> Then, still don't believe me, apply my patch in a separate directory to 
> the last SVN version, build, and try the same command line.
> You'll get a good image as output. That's all.
> 
> Then trust who you want, the kostya version works for progressive jpeg, 
> not multiple scan jpegs, my version add multiple scan jpeg support
> but as nothing to do with progressive jpeg (it doesn't break anything at 
> all).
> 
> Anyway, hope you don't take it as a personal attack, what I want is my 
> stream correctly decoded.
> If it's already done and working, it's great, whoever made it.
> Currently it's not, so I've added it, I've provided all the materials to 
> check if it's working.
> I've corrected the patch so it is like the devs said it should be, so 
> what next ?
> 
> Regards,
> 
> -- 
> Cyril RUSSO
> 
> 
>