[FFmpeg-soc] Support for JPEG 2000 image files

[Michael Niedermayer]

On Sun, Dec 13, 2009 at 05:09:47PM +0100, Peter B. wrote:
> Thanks for the tip!
> 
> I must admit that I haven't focused on JPEG-LS, because according to
> information about it I've found on the web, it seemed that JPEG-LS is
> less known/supported/used than JPEG 2000.

well ffmpeg supports jpeg-ls encoding & decoding, the code for that is
just ~1000 lines:
   89   397  2977 jpegls.c
  377  1397 11414 jpeglsdec.c
  395  1534 12249 jpeglsenc.c
   41   193  1266 jpeglsdec.h
  111   396  3014 jpegls.h
 1013  3917 30920 total

compare that to our unfinished jpeg2000 implementation:
   384   1498   9557 dwt.c
   389   1558  14122 j2k.c
  1075   3923  36767 j2kdec.c
  1045   3862  36837 j2kenc.c
   108    445   2975 mqc.c
    93    343   2396 mqcdec.c
   119    381   2738 mqcenc.c
    63    297   2038 dwt.h
   234    901   7335 j2k.h
    75    287   1902 mqc.h
  3585  13495 116667 total

or libopenjpeg through which ffmpeg supports jpeg2000 currently
   187    695   4491 bio.c
   125    608   3956 bio.h
   190    729   4872 cio.c
    86    478   3106 cio.h
    40     63    682 CMakeLists.txt
   661   3146  19332 dwt.c
   113    681   4514 dwt.h
   121    547   3827 event.c
    58    367   2455 event.h
    64    366   2384 fix.h
    87    378   3038 image.c
    48    288   1854 image.h
   119    605   3554 int.h
  2630   9970  77828 j2k.c
   525   2548  17030 j2k.h
    76    421   2730 j2k_lib.c
    75    389   2632 j2k_lib.h
   700   2398  18777 jp2.c
   176    800   5752 jp2.h
   155    701   4659 jpt.c
    75    390   2701 jpt.h
   132    700   3859 mct.c
    98    571   3860 mct.h
   542   1757  13951 mqc.c
   197    903   5952 mqc.h
   307    905   8443 openjpeg.c
   751   3311  24093 openjpeg.h
   102    380   2957 opj_includes.h
  1078   3585  32188 pi.c
   152    837   5503 pi.h
    87    372   2653 raw.c
   100    538   3514 raw.h
  1210   4372  30369 t1.c
   295   1246   7667 t1_generate_luts.c
   147    680   5198 t1.h
   402   6209  27167 t1_luts.h
   721   2724  19951 t2.c
   102    586   3901 t2.h
  1409   6049  51062 tcd.c
   270   1293   8793 tcd.h
   213    740   5180 tgt.c
   114    608   4012 tgt.h
 14740  64934 460447 total


> 
> Theoretically it seems a valuable alternative to JPEG 2000 by offering
> faster processing and better compression [1] in many cases, but there
> are some issues that I'd have to evaluate about JPEG-LS:
> 
> - lack of applications/tools that support it (e.g. ImageMagick can't do
> JPEG-LS [2])

As you can see above jpeg-ls is quite a bit simpler thus also simpler to
add. And we have a jpegls implementation while we dont have a finished
jpeg2000 one not counting the use of external libs like libopenjpeg.
imagemagick surely could use ours ...


> - partial data retrieval for thumbnail previews (possible with JPEG-LS?)

you can decompress the whole frame and scale it down, you can also store
that image in the video file in some user data or in a seperate file
for faster access.
You can even store the whole video as lossless jpeg-ls + in a seperate file
some lossy codec like mjpeg, h263 or mpeg4 or h264 (maybe at a lower
resolution). The options are many

Also as you mentioned support, how many jpeg2000 implementations support
retrieving lower resolution content? ive not checked but i would suspect
that not all support this.
ffmpeg supports btw, decoding most DCT based codecs in lower resolution.


> 
> For a long-term archive it is important to use open standards that are
> as widespread as possible. I was even surprised that given the age of
> JPEG 2000 it's still not supported as seamlessly as I'd expected. :(

j2k is complex, we had 2 students during SOC fail getting the code in
useable shape.


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

it is not once nor twice but times without number that the same ideas make
their appearance in the world. -- Aristotle
-------------- 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-soc/attachments/20091213/86339c30/attachment.pgp>