ffmpeg interlaced source detection

[bigcat]

Hi people. A few days ago i found out that Cuttermaran in the "Encoding mode" does not re-encode the whole file but only the first and the last GOP. Yes, it was stupid of me not to know that.
I used TMpegEnc free edition (which is free for 21 days only) for reencoding, but there're also 2 options for "Temp AVI encoding" in Cuttermaran: one is "YV12" for which the special codec is needed and another one is "RGB24". I wanted more quality but didn't want to install that special codec. In fact, i don't know what codec i need. But without it the resulting temp AVI is just black.
So I wrote ffmpeg provider for Cuttermaran. It works great with YV12 option but as I think ffmpeg doesn't detect interlacing in AVI. Even if the source is interlaced, the resulting mpeg has progressive chunks. Is there interlace autodetect option in ffmpeg?

[leoenc]

Not AFAIK, but berrinam wrote an AVIsynth detection algorithm, maybe you can use it somehow with ffmpeg?
http://avisynth.org/mediawiki/Interlace_detection

[bigcat]

Thanx for help, luckily Cuttermaran gives information about interlacing, so autodetection is not needed anymore. The problem is inside ffmpeg. The latest build for Windows i could find (SVN-r11143) does not encode interlaced at all! Flags +ilme+ildct make no difference, the output is still progressive. Previous build encodes interlaced fine however. SVN-r11143 is quite buggy at all, e.g. when i change sws_flags, output bitrate gets locked to 90 kb/s.
In the attachment there's provider I wrote (if you use it, change all path to ffmpeg.exe, xmlparse.py and python.exe for yourself and put extracted files into Provider\encode folder). Needs Python.

[leoenc]

Yes, I agree - the latest build is buggy.
I posted earlier today a question regarding a different issue (speed\quality), hoping to get an answer from Celtic Druid.