Hi, I have captured video over firewire to Kdenlive 0.7.7.1.
I can't render my project to DVD, or Mpeg2 but I can render to RAW DV or Mpeg4.

Rendering of /home/coudy/lacike.vob aborted, resulting video will probably be corrupted.
Rendering of /home/coudy/lacike.vob crashed.
I can't find any other errors.

My system is Ubuntu 9.10 64bit with KDE 4.3.5.
Kdenlive is installed from sunab repository (deb http://ppa.launchpad.net/sunab/ppa/ubuntu karmic main).

coudy@coudy:~$ dpkg -l kdenlive-*
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Cfg-files/Unpacked/Failed-cfg/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Názov Verzia Popis
+++-==================================-==================================-====================================================================================
ii kdenlive-data 0.7.7.1-0ubuntu0~karmic1 a non-linear video editor (data files)
ii kdenlive-dbg 0.7.7.1-0ubuntu0~karmic1 a non-linear video editor (debugging symbols)

coudy@coudy:~$ dpkg -l kdenlive
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Cfg-files/Unpacked/Failed-cfg/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Názov Verzia Popis
+++-==================================-==================================-====================================================================================
ii kdenlive 0.7.7.1-0ubuntu0~karmic1 a non-linear video editor

coudy@coudy:~$ dpkg -l *mlt*
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Cfg-files/Unpacked/Failed-cfg/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Názov Verzia Popis
+++-==================================-==================================-====================================================================================
ii libmlt++-dev 0.5-0ubuntu0~karmic1 MLT multimedia framework C++ wrapper (development)
un libmlt++0.2 <žiadna> (popis nie je k dispozícii)
un libmlt++1 <žiadna> (popis nie je k dispozícii)
ii libmlt++2 0.5-0ubuntu0~karmic1 MLT multimedia framework C++ wrapper (runtime)
ii libmlt-data 0.5-0ubuntu0~karmic1 multimedia framework (data)
ii libmlt-dev 0.5-0ubuntu0~karmic1 multimedia framework (development)
un libmlt0.2 <žiadna> (popis nie je k dispozícii)
un libmlt0.2.5 <žiadna> (popis nie je k dispozícii)
ii libmlt1 0.5-0ubuntu0~karmic1 multimedia framework (runtime)
ii libxmltv-perl 0.5.56-1 Perl libraries related to the XMLTV file format for TV listings
in mlt <žiadna> (popis nie je k dispozícii)
rc mlt-python 0.4.7f-0ubuntu4~ppa1k Python Bindings for MLT Video Framework
un openshot-mlt <žiadna> (popis nie je k dispozícii)
un python-mlt <žiadna> (popis nie je k dispozícii)
un sgmltools-2 <žiadna> (popis nie je k dispozícii)
un xmltv <žiadna> (popis nie je k dispozícii)
un xmltv-gui <žiadna> (popis nie je k dispozícii)
ii xmltv-util 0.5.56-1 Utilities related to the XMLTV file format for TV listings

I confirm the bug with
- kdenlive 0.7.8 from svn (rev 4370)
- Built and used with Kde 4.4.2 (to avoid timeline issue)

When rendering with vcodec=mpeg4, the process "melt" eats all memory in a few minutes when the "s" option is used. (I have 4GB RAM)
In my case:

It DOES crash (no more memory) with
f=mp4 hq=1 acodec=libfaac ab=128k ar=44100 vcodec=mpeg4 minrate=0 b=2000k s=1280x720 aspect=%dar mbd=2 trellis=1 mv4=1 subq=7 qmin=10 qcomp=0.6 qdiff=4 qmax=51 pass=2

It does NOT crash (no more memory) with
f=mp4 hq=1 acodec=libfaac ab=128k ar=44100 vcodec=mpeg4 minrate=0 b=2000k aspect=%dar mbd=2 trellis=1 mv4=1 subq=7 qmin=10 qcomp=0.6 qdiff=4 qmax=51 pass=2

I did not find any bug opened on that topic. Should we ? Is it a melt ou kdenlive bug ? If melt, where should we report this bug ?

Thank you!
I understand my problem a little better now.
http://www.kdenlive.org/mantis/view.php?id=1197

Fixed in MLT git - see the mantis bug. The next release that will contain this fix is MLT 0.5.4. I do not have a projected date yet. I need to spend a little time looking at other bugs prior to the next release.