Re: dvd authoring

On 04/01/2011 09:19 AM, jdd wrote:
> Le 31/03/2011 22:25, Dave Plater a écrit :
>
>
>> DVDStyler, as I have found with the other dvdauthor frontends, falls
>> short on the initial conversion to mpeg2 so I always convert with
>> ffmpeg using -target pal-dvd
>
> dvdstyler is said to be able to recompress too large mpeg2 video (and it's a very usefull feature), but at least as I tried just now simply
> crash with segfault :-(
This would be one of the ffmpeg package libs :libavcodec52,libavformat52, libavutil50 or libswscale0. When you update ffmpeg always make 
sure that all of the libs also get updated from the same repo, this is the complete list :
libavcodec52
libavdevice52
libavfilter1
libavformat52
libavutil50
libpostproc51
libswscale0
Looking at the spec file they should be pulled in by an ffmpeg update from packman. Install all of the debug packages for them if you want 
to get a backtrace from the crash : ffmpeg-debugsource and the -debuginfo versions of all of the above.

I never use dvdstyler to reduce the size of a video or any other type of conversion it fails 80% of the time, the aspect ratio is very 
often wrong ie. elongated and it takes about four times longer than ffmpeg usually before it fails. In other words if you want to stay calm 
don't use it. I check the box that says "do not transcode" in the properties window obtained by right clicking on the video file for the 
context menu also the configuration button (with a spanner) in the upper right side select 16:9 instead of auto. Use "ffmpeg -i inputfile 
-target pal-dvd -aspect 16:9 outfile" to reduce the size of the outfile reduce the bit rate with "-b 4000k" to get about a 10% reduction 
and reduce 5.1 to stereo ("-ac 2") also audio bitrate reduction is useful for reducing by a small amount eg."-ab 128k still gives good 
sound and you can go as low as "-ab 32k" for mostly speech remember 128k is considered cd quality. For inputfiles with a size less than 
720x400 (720x395 will look ok but dvb of 720x308 definitely needs two stages 16:9 is 720x405) you need to do a two stage conversion :
"ffmpeg -i inputfile -target pal-dvd -s "inputfile video size" -vf pad=720:404:0:"404 minus horizontal size divided by two":black pipe: 
|ffmpeg -i pipe: -target pal-dvd -aspect 16:9 outfile" The pipe: name for infile and outfile makes ffmpeg use stdin and stdout. The pad 
filter adds space to the left and right or top and bottom of the frame to correct the aspect the last part :black allows you to specify the 
colour of the space.

>
> I will have to follow all this in bugzilla, but don't have time right now as I have a dvd to deliver :-() - so I have to go back to Windows
> (no so glad, the windows Magix editor is good for linear editing but not so good as dvd maker :-()
>
> thanks
> jdd
>
Packman doesn't have a bugzilla you have to use their mailing list or irc, I haven't even subscribed to the list yet but I would be happy 
to help you sort your problem out here. ffmpeg-0.6.201103092102git-1.pm.2.2 is the latest version, dvdauthor-0.6.18-1.pm.3.1 and
DVDStyler-1.8.2.1-5.pm.9.1. All of the ffmpeg libs mentioned above must have the same version as ffmpeg.

Regards
Dave P