libmpeg2-devel — main mailing list for libmpeg2 development

Re: [mpeg2-dev] SDL

[Gernot Z. <gz...@ly...>]

Hej Paul !

> > I also need to scale the video to 800x600, can I use sdl to upscale to do
> > this using hardware scaling?  Any pointers would be great :)
>
> I think this is possible, but I dont know how to do this myself.
Yes, it's possible ... SDL is able to use XVideo, which is the XServer's
extension to scale in hardware - talk with the SDL guys to see how it
works, you have to feed it with the separate YUV-buffers, I think ... our
mjpeg_tools at mjpeg.sf.net, and the program lavplay (with  software
playback) contain some example code (but it is maybe buried long
down there ;) )

Servus,
  Gernot

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Re: [mpeg2-dev] Error concealment of libmpeg2

[Michel L. <wa...@zo...>]

On Fri, Oct 05, 2001 at 11:29:02PM -0700, Lu Xiaoxiang wrote:
> Hi Michel,
>    Thank you for your answer. Yes, I am interested in the error
> concealment stuff. Now I am working on mpeg2 video over IP network. I use
> libmpeg2 package as the decoder. I concern the video quality degradation
> after transmission across the network.So actually I will implement some
> error concealment algorithms.I think the first step is how libmpeg2
> detects errors. 

Are you thinking about LAN or WAN applications ?

I suppose for IP networks the first layer of error correction should
be on the coded stream itself - using some kind or redundancy in the
packet transmission. I had sent an email to the videolan mailing list
not long ago about that subject, I also recommended people to have a
look at http://www.csl.sony.co.jp/person/morelos/ecc/codes.html and
http://www.iet.unipi.it/~luigi/fec.html

You probably knew some of that already but I figure extra information
never hurts :)

As for the error detection in libmpeg2. The most common cause of
problems (segfaults) right now is when we get an incorrect motion
vector and we try to use pixels outside of the prediction frame and
boom! I've started some work to detect that but I need to finish
it. The second step would be to detect parsing errors like invalid
huffman codes. I suppose after that we'll have a quite reliable
detection of fscked up slices.

-- 
Michel "Walken" LESPINASSE
Of course I think I'm right. If I thought I was wrong, I'd change my mind.

Re: [mpeg2-dev] Error concealment of libmpeg2

[Lu X. <lxi...@so...>]

Hi Michel,
   Thank you for your answer. Yes, I am interested in the error
concealment stuff. Now I am working on mpeg2 video over IP network. I use
libmpeg2 package as the decoder. I concern the video quality degradation
after transmission across the network.So actually I will implement some
error concealment algorithms.I think the first step is how libmpeg2
detects errors. 

 Xiaoxiang Lu
 ICS department of UC,Irvine
 phone:(949)8246374

On Fri, 5 Oct 2001, Michel LESPINASSE wrote:

> On Fri, Oct 05, 2001 at 03:03:43PM -0700, Lu Xiaoxiang wrote:
> >    What have you implemented in the libmpeg2 concerning error
> > concealment? Could you please suggest me something about that? Thanks.
> 
> This is currently unimplemented. Actually right now the error handlig
> is so bad that we can crash on bad streams sometimes.
> 
> When we solve the crash problems error concealment can probably be
> implemented outside of libmpeg2 - like you would get a list of slices
> that were not properly decoded, and you'd have to do whatever you want
> with these slices. Maybe we could try to also extract more information
> like motion vectors from the slices above and below to help the error
> concealment algorithms. But as I said we have nothing of that yet.
> 
> Are you interested in error concealment yourself ?
> 
> -- 
> Michel "Walken" LESPINASSE
> Of course I think I'm right. If I thought I was wrong, I'd change my mind.
> 

Re: [mpeg2-dev] Error concealment of libmpeg2

[Michel L. <wa...@zo...>]

On Fri, Oct 05, 2001 at 03:03:43PM -0700, Lu Xiaoxiang wrote:
>    What have you implemented in the libmpeg2 concerning error
> concealment? Could you please suggest me something about that? Thanks.

This is currently unimplemented. Actually right now the error handlig
is so bad that we can crash on bad streams sometimes.

When we solve the crash problems error concealment can probably be
implemented outside of libmpeg2 - like you would get a list of slices
that were not properly decoded, and you'd have to do whatever you want
with these slices. Maybe we could try to also extract more information
like motion vectors from the slices above and below to help the error
concealment algorithms. But as I said we have nothing of that yet.

Are you interested in error concealment yourself ?

-- 
Michel "Walken" LESPINASSE
Of course I think I'm right. If I thought I was wrong, I'd change my mind.

Re: [mpeg2-dev] SDL

[Michel L. <wa...@zo...>]

On Sat, Oct 06, 2001 at 03:02:01PM +1000, Paul wrote:
> I also need to scale the video to 800x600, can I use sdl to upscale to do 
> this using hardware scaling?  Any pointers would be great :)

I think this is possible, but I dont know how to do this myself.

-- 
Michel "Walken" LESPINASSE
Of course I think I'm right. If I thought I was wrong, I'd change my mind.

Re: [mpeg2-dev] SDL

[Paul <kr...@ip...>]

I also need to scale the video to 800x600, can I use sdl to upscale to do 
this using hardware scaling?  Any pointers would be great :)

On Sat,  6 Oct 2001 05:28, you wrote:
> On Fri, Oct 05, 2001 at 09:01:27PM +1000, Paul wrote:
> > Can I use libmpeg2 to display to an SDL surface?  I'm searching for a
> > quick way to implement Mpeg2 in an application.
>
> the mpeg2dec test program has an SDL output mode - I think it does work.
>
> Try running mpeg2dec -o sdl foo.mpg
> (maybe with the -s option too if foo.mpg is multiplexed)
>
> The corresponding source code is in libvo/video_out_sdl.c

[mpeg2-dev] Error concealment of libmpeg2

[Lu X. <lxi...@so...>]

Hi,
   What have you implemented in the libmpeg2 concerning error
concealment? Could you please suggest me something about that? Thanks.

 Xiaoxiang Lu
 ICS department of UC,Irvine
 phone:(949)8246374

Re: [mpeg2-dev] SDL

[Michel L. <wa...@zo...>]

On Fri, Oct 05, 2001 at 09:01:27PM +1000, Paul wrote:
> Can I use libmpeg2 to display to an SDL surface?  I'm searching for a quick 
> way to implement Mpeg2 in an application.

the mpeg2dec test program has an SDL output mode - I think it does work.

Try running mpeg2dec -o sdl foo.mpg
(maybe with the -s option too if foo.mpg is multiplexed)

The corresponding source code is in libvo/video_out_sdl.c

-- 
Michel "Walken" LESPINASSE
Of course I think I'm right. If I thought I was wrong, I'd change my mind.

[mpeg2-dev] SDL

[Paul <kr...@ip...>]

Hi

Can I use libmpeg2 to display to an SDL surface?  I'm searching for a quick 
way to implement Mpeg2 in an application.

Any help would be appreciated :)

Thanks

Paul

[mpeg2-dev] mpeg2

[Philip S. <br...@bi...>]

hello,
       I tried to download mpeg2 with decss but when it came through =
there was nothing in the file.

                                 phil

[mpeg2-dev] program Stream Documentation

[Vijay K. S <vij...@wi...>]

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[mpeg2-dev] aspect ratio

[Anuj D. <an...@ja...>]

hi,
i was wondering how anybody is able to get the right aspect ratio
on the screen since it is unused in the code and not given to the vo
layer? is there a clean solution or just pass the picture struct ??

(btw congrats on the clean compile on OS X, out of the box !!)

[mpeg2-dev] sf trackers, bug report, and api updates

[David I. L. <dl...@vt...>]

Sigh... walken has disabled the sourceforge trackers for libmpeg2 and
liba52.  A very useful feature to keep bugs and features requests and
patches and so on organized.  Response on IRC: "<walken> use the ML !"

Ok, bug report: trackers are disabled.

More serious bug report: vektor (working on movietime) and Xine project
are thinking of and/or have branched libmpeg2 because it does not offer
enough features to be useful in their projects.  There is quite a bit of
stream info that needs to be passed to the output API or else complex
duplicate stream processing code must be added to applications.  walken:
if you don't know how to proceed on development let other developers
have a CVS branch to play around in until the code is worthy to merge
back to HEAD.  That's what CVS is for, use it.  You've disabled the only
other way to provide patches, the Patches Tracker (which vektor posted a
patch to already).  You can have all activity on the trackers sent to
mailing list if that's the only issue.  Hard to develop cross-project
libraries like this.  Please help to cooperate, I want to see movietime
released and vektor is waiting on this stuff.  Thanks.

-dave
-- 
David I. Lehn <dl...@vt...>  | http://www.lehn.org/~dlehn/
Computer Engineering Graduate @ Virginia Tech in sunny Blacksburg, VA

Re: [mpeg2-dev] compile error

[Michel L. <wa...@zo...>]

Hmmm sorry for the late response...

On Mon, Sep 24, 2001 at 07:10:14PM +0200, ma...@li... wrote:
> /usr/X11R6/lib/libXxf86dga.so: undefined reference to `atexit'

Where did you get your libXxf86dga.so from ? Normally you should only
have a .a file... I suspect the problem is in the .so file, it should
not exist and if it did exist it should contain dependancies to
whatever lib atexit is defined in (I thought it was libc, but I'm not
positive)

Regards,

-- 
Michel "Walken" LESPINASSE
Of course I think I'm right. If I thought I was wrong, I'd change my mind.

[mpeg2-dev] compile error

[<ma...@li...>]

maybe lame, but when compiling mpeg2dec i get the following:

Making all in src
make[1]: Entering directory
`/home/marek/utils/multimedia/tools/mpeg2dec/mpeg2dec/src'
/bin/sh ../libtool --mode=link gcc  -g  -O3 -fomit-frame-pointer
-mcpu=pentiumpro -Wall -Werror   -o mpeg2dec  mpeg2dec.o
.../libmpeg2/libmpeg2.la 		 ../libvo/libvo.la 		 libmpeg2dec.la 
gcc -g -O3 -fomit-frame-pointer -mcpu=pentiumpro -Wall -Werror -o
mpeg2dec mpeg2dec.o  ../libmpeg2/.libs/libmpeg2.a ../libvo/.libs/libvo.a
-lSM -lICE -L/usr/X11R6/lib -lX11 -lXext -lXv -L/usr/lib -lSDL -lpthread
../.libs/libmpeg2dec.a
/usr/X11R6/lib/libXxf86dga.so: undefined reference to `atexit'
collect2: ld returned 1 exit status
make[1]: *** [mpeg2dec] Error 1
make[1]: Leaving directory
`/home/marek/utils/multimedia/tools/mpeg2dec/mpeg2dec/src'
make: *** [all-recursive] Error 1

I use RH 7.1 massively updated 'by hand' (including XFree version which
may be the cause of this problem.

I must note that I have no such problems with other software, including
mplayer, which uses some old version of your lib as well (and I _do_
play
movies using DGA, so the lib seems not to be bogus).

can someone help me on this?

regards

-- 
Marek Pętlicki <ma...@li...>
Linux User ID=162988

Re: [mpeg2-dev] macintosh os9 opengl port of lib_vo module

[Wade K. <li...@ma...>]

>=C0 (At) 9:03 -0800 19/09/01, Wade Kamkoff =E9crivait (wrote) :
>
>>  - the color is weird. greenish?
>
>Perhaps a problem with the YUV transform (green picture means U and 
>V coordinates are 0).
>
>>  - the frames seem to play out of order..like f1..f3..f2..f4..f6...etc
>
>The vout layer is supposed to reorder the frames coming from the 
>decoder. I,P and B pictures are inverted in the stream, so they must 
>be re-inverted by your module.
>
>
>--
>Christophe Massiot.


-- 
Thanks, Care to help? Do you have a mac running os9? I have both osx 
and os9 but have been a little lazy today. Im sure it would not be 
hard to make is osxable since the code is not that big...

I did figure out the opengl part to get the frame upside right.

Thats what I was thinking in the module. add a frames list and invert 
their playback...

The YUV transform ill read into. I was at a loss there. Absorbed too 
much information in 2 days..heh.

Wade
li...@ma...

Re: [mpeg2-dev] macintosh os9 opengl port of lib_vo module

[Christophe M. <ma...@vi...>]

À (At) 9:03 -0800 19/09/01, Wade Kamkoff écrivait (wrote) :

>  - the color is weird. greenish?

Perhaps a problem with the YUV transform (green picture means U and V 
coordinates are 0).

>  - the frames seem to play out of order..like f1..f3..f2..f4..f6...etc

The vout layer is supposed to reorder the frames coming from the 
decoder. I,P and B pictures are inverted in the stream, so they must 
be re-inverted by your module.


-- 
Christophe Massiot.

Re: [mpeg2-dev] macintosh os9 opengl port of lib_vo module

[Wade K. <li...@ma...>]

>On Wed, Sep 19, 2001, Wade Kamkoff wrote:
>
>>  Hello. I have made a small module for running the mpeg2dec program
>>  with the libmpeg2 .0.2.0 source on MacOS9 with OpenGL. Its a not
>>  fully complete. It does mostly work though. Let me know if you are
>>  interested.
>
>I _am_ interested, for the VideoLAN project :-). How come you chose to use
>OpenGL, and not QuickTime overlay support ?
>
>--
>Christophe Massiot.


-- 
Good morning.

Well, I am an amateur programmer. This is my first week ever working with
video on the Mac. I did mess with the quake1 source a bit. But it wasnt
too extensive.

The libvo module was very difficult at first. Here is its status.
  - the code is based off the nullrgb32 module
  - it does display at around 20 fps full 720x480 32 bit m2v files.
  - the demuxer does work.
  - the color is weird. greenish?
  - the frames seem to play out of order..like f1..f3..f2..f4..f6...etc
  - thats a guess though on the frame order..?!

I only really modified 2 files to get the whole thing to run in OS9.
  - mpeg2dec.c
  - cpu_accel.c

Not counting the modifications made to add a video_out_macos9gl.c file.

Well, im off to the store right now. hacking all night learning opengl.
I probably could get my stuff in order today and submit the source..? If
I can stay awake.

Wade
li...@ma...

[mpeg2-dev] macintosh os9 opengl port of lib_vo module

[Wade K. <li...@ma...>]

Hello. I have made a small module for running the mpeg2dec program 
with the libmpeg2 .0.2.0 source on MacOS9 with OpenGL. Its a not 
fully complete. It does mostly work though. Let me know if you are 
interested.

li...@ma...
-- 

Re: [mpeg2-dev] How to use the libmpg2

[Michel L. <wa...@zo...>]

On Fri, Sep 07, 2001 at 01:04:04AM +0200, Karsten Fuhrmann wrote:
> Hello i am trying to use your lib, to get some rgb frames out of an
> mpg2 stream. So i hacked another video_out module called raw. this
> is working and i can get out data from the vo_frame_t structure !
> But this does not seem to be an rgb picture in the fields base[0] to
> base[2] ? so what is in these field yuv or something or what ?

Yes, the frames at the libmpeg2 output are in yuv format.
(note the pgm output is already pretty raw too - it just adds a small
header before the image bytes)

> So my Question is how to get pure rgb frames out of the stream using
> libmpg2

Well you need to convert from yuv to rgb format. There is an example
routine for that in libvo, its called yuv2rgb

> Another Question : Who is the maintainer for MacOs X in this project ?

There is not specific macos maintainer. This list is the right place
to ask most questions.

Do you have any specific problems or features you'd like to see
implemented ?

Regards,

-- 
Michel "Walken" LESPINASSE
Of course I think I'm right. If I thought I was wrong, I'd change my mind.

[mpeg2-dev] How to use the libmpg2

[Karsten F. <kar...@we...>]

Hello i am trying to use your lib, to get some rgb frames out of an mpg2 stream. So i hacked another video_out module called raw. this is working and i can get out data from the 
vo_frame_t structure ! But this does not seem to be an rgb picture in the fields base[0] to base[2] ? so what is in these field yuv or something or what ?

So my Question is how to get pure rgb frames out of the stream using libmpg2

Another Question : Who is the maintainer for MacOs X in this project ?


Thanks,
Karsten
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[mpeg2-dev] Re: Cannot compile mpeg2dec!

[Michel L. <wa...@zo...>]

> /usr/include/string.h:259: parse error before `)' token
> /usr/include/string.h:264: parse error before `)' token
> /usr/include/string.h:267: parse error before `)' token
> In file included from decode.c:29:
> ../include/video_out.h:36: parse error before `this'
> ../include/video_out.h:37: parse error before `this'
> ../include/video_out.h:38: parse error before `this'
> ../include/video_out.h:56: parse error before `this'

> I would appreciate it very much if anybody could offer some
> idea. Thanks a lot.

Does it still do this with the CVS version from
http://libmpeg2.sourceforge.net/files/mpeg2dec-snapshot.tar.gz ?

Also if it does, can you run gcc -v and send us the output ?

It looks like you're using a c++ compiler instead of c, but I'm not
totally sure.

-- 
Michel "Walken" LESPINASSE
Of course I think I'm right. If I thought I was wrong, I'd change my mind.

[mpeg2-dev] test !

[Michel L. <wa...@zo...>]

Just ignore me...

-- 
Michel "Walken" LESPINASSE
Of course I think I'm right. If I thought I was wrong, I'd change my mind.