libmpeg2dec-0.5.1 problems

Hi,

I compiled the 'mpeg2dec' for my PC, but it can't decode the beautiful sand art 'Welcome.mpg' of SLS's demo. Of course, I don't know why.

www.sls (http://www.%3cb%3esls%3c/b%3e)corp.com/LG/bsp/ug_uclinux_neek_bsp_1.5.pdf

Kazu

Hi,

Can you provide a link to the mpeg bitstream? Maybe it's a strange format, which is not recognized by mpeg2dec.

Are you able to build the mpeg2dec also for a nios system?

Cheers,

WK

Hi,

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Can you provide a link to the mpeg bitstream? Maybe it's a strange format, which is not recognized by mpeg2dec.

--- Quote End ---

Please refer the site

http://www.slscorp.com/pages/neekbsp.php

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Are you able to build the mpeg2dec also for a nios system?

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Not yet. Would you tell me the method of compilation? Can we do it only by selecting in the 'menuconfig'?

Kazu

Hi,

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Please refer the site

http://www.slscorp.com/pages/neekbsp.php

.

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Hmm, looks like they want some login & password, which i don't have to download anything from there... :( Any other link avaliable?

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Not yet. Would you tell me the method of compilation? Can we do it only by selecting in the 'menuconfig'?

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I have no idea, wheater it's now in a uCLinux environment. I'm using a pretty old uCLinux, where it was not included (but it looks like my uClinux uses the same gcc: V3.4.6).

So i took the tarball directly from the sourceforge link (see my 1st Post, followed "Download" link and took the newest Version 0.5.1) , untarred it (tar -xzvf libmpeg2-0.5.1.tar.gz) and used the mentioned commandline to configure and build it. It doesn't change anything outside its directory if you dont do a "make install". After configuring and building, i just copied the mpeg2dec binary from libmpeg2-0.5.1/src/ to a directory, wich i'm able to access from my nios system via nfs.

It's a self designed custum board, doing some MPEG-TS processing on a EP2C35, and it would be a really nice feature, to be able to decode some pictures. Of course it's far from realtime, but a single picture every 10-20 sec or so would be totally sufficient.

I've already tried older versions of mpeg2dec and different (also no) optimizations for gcc - result looks always the same.

Meanwhile i also build it with a crosscompiler for a coldfire processor, which like nios doesnt have any MMX or SSE extentions - the resulting binary worked fine! I'm getting really confused now...

Cheers

WK

Hi,

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Hmm, looks like they want some login & password, which i don't have to download anything from there... :( Any other link avaliable?

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Maybe, you can easily resister your e-mail account and get the password from here.

http://www.slscorp.com/pages/login.php?login=login_again

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I have no idea, wheater it's now in a uCLinux environment. I'm using a pretty old uCLinux, where it was not included (but it looks like my uClinux uses the same gcc: V3.4.6).

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It seems that we can select 'libmpeg2' from the menuconfig, so let me see it.

Kazu

Hi,

About 'Welcome.mpg', I'm sorry that it includes audio data. So with the switch '-t'

./mpeg2dec -t Welcome.mpg

we can see the beautiful sand art.

For Nios CPU, we already have the directory '/uClinux-dist/lib/mpeg2dec', and we can select it from the 'menuconfig'. So.

make menuconfig
Kernel/Library/Defaults Selection  ---> <Select> 
 
 Customize Application/Library Settings  < Exit >  < Exit > 
 
 Library Configuration  --->  <Select>
   
 Build libmpeg2 < Exit >  < Exit > 

.

Before to 'make', please modify the file '/uClinux-dist/lib/mpeg2dec/mpeg2dec-0.4.1/configure' line 23984 like

echo "$as_me:$LINENO: checking if libtool supports -prefer-non-pic flag" >&5
echo $ECHO_N "checking if libtool supports -prefer-non-pic flag... $ECHO_C" >&6
    mkdir ac_test_libtool; cd ac_test_libtool; ac_cv_libtool_non_pic=no
    echo "int g (int i); static int h (int i) {return g (i);} int f (int i) {return h (i);}" >f.c
    echo "int (* hook) (int) = 0; int g (int i) {if (hook) i = hook (i); return i + 1;}" >g.c
    ../libtool --mode=compile $CC $CFLAGS -prefer-non-pic 
        -c f.c >/dev/null 2>&1 && 
    ../libtool --mode=compile $CC $CFLAGS -prefer-non-pic 
        -c g.c >/dev/null 2>&1 && 
    ../libtool --mode=link $CC $CFLAGS -prefer-non-pic -o libfoo.la 
        -rpath / f.lo g.lo >/dev/null 2>&1 &&
    ac_cv_libtool_non_pic=yes
    cd ..; rm -fr ac_test_libtool; echo "$as_me:$LINENO: result: $ac_cv_libtool_non_pic" >&5
echo "${ECHO_T}$ac_cv_libtool_non_pic" >&6
    if test x"$ac_cv_libtool_non_pic" = x"yes"; then
#    LIBMPEG2_CFLAGS="$LIBMPEG2_CFLAGS -prefer-non-pic" <-- line 23984
    LIBMPEG2_CFLAGS="$LIBMPEG2_CFLAGS -fPIC"
     else
    :
    fi

.

(Without this,we have some relocation bugs that is caused the dynamic linking.)

After the compilation, you can get 'libmpeg2.so.0' and 'libmpeg2convert.so.0' in '/usr/lib' automatically, but copy 'mpeg2dec' in the directory 'uClinux-dist/lib/mpeg2dec/build/src/.libs' by yourself to the adequate directory e.g. '/usr/bin' with 'nokia7_dual.bit'. And please execute

./mpeg2dec -o pgm nokia7_dual.bit

In my NEEK, the result is fine.

Kazu

Moin,

Sorry for the delay, meanwhile i had to do other things.

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So with the switch '-t'

./mpeg2dec -t Welcome.mpg

we can see the beautiful sand art.

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That's good news!

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(Without this,we have some relocation bugs that is caused the dynamic linking.)

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I think, this is the real problem with "my" mpeg2dec. When i do the change with -fPIC in the configure script, "my" mpeg2dec results look a lot better, but still not error-free. Anyway, now i know, where the problems are. Many thanks for that.

What now works ok for me, is a real old mpeg2decoder, which can be downloaded from

http://mpeg2videotools.sourceforge.net/

It compiles and runs on my nios system with almost no tweaks; here's a diff of the Makefile, which just changes the gcc and sets the -elf2flt flag during the link:

--- mpeg2dec/Makefile   2009-12-21 12:26:24.000000000 +0100
+++ orig/mpeg2dec/Makefile      2003-02-02 17:40:32.000000000 +0100
@@ -43,9 +43,8 @@
#  uncomment the following two lines if you want to include X11 support
-#USE_DISP = -DDISPLAY
-#LIBS = -L/usr/X11R6/lib -lX11
-LIBS = -elf2flt
+USE_DISP = -DDISPLAY
+LIBS = -L/usr/X11R6/lib -lX11
#  uncomment the following two lines if you want to use shared memory
#  (faster display if server and client run on the same machine)
@@ -63,7 +62,7 @@
# 
#  GNU gcc
# 
-CC = nios2-linux-uclibc-gcc
+CC = gcc
 CFLAGS = -g -O2 $(USE_DISP) $(USE_SHMEM) $(INCLUDEDIR) $(TRACE) $(VERBOSE) $(VE
RIFY) $(WARNINGS)
 OBJ = mpeg2dec.o getpic.o motion.o getvlc.o gethdr.o getblk.o getbits.o store.o
 recon.o spatscal.o idct.o idctref.o display.o systems.o subspic.o verify.o

Another advantage of the mpeg2decode is, that it can output colored .ppm files, so i don't have to fiddle around with the y and the 2 chroma planes seperatly.

Cheers,

WK