dvr-ms header states NTSC resolution although its stream is PAL

So here is the post I mentioned to make in this thread.

Summary: When capturing from TV to dvr-ms-file via Win XP MCE, the header of
the dvr-ms file signifies that the stream’s resolution is 720x480, while the
real stream resolution is 720x576, MCE configured for PAL country and
Hauppauge 150 MCE a PAL version. This can have complications for playback.

For example, when playing back in WMP (directly or through avisynth) with
ffdshow as MPEG2 decoder, the lowest part of the picture (I assume some
576-480 = 96 lines) is missing. When I consult the ffdshow info and/or
avisynth’s info()-function it says the resolution is 720x480. When I switch
back to my old nvidia decoder, the picture is displayed correctly in WMP and
in file-preferences the correct 720x576 resolution was displayed. This led me
to investigate the real resolution of the stream. After consulting various
websites and making sure my Hauppauge MCE150 was configured correctly (i.e.
to capture in PAL format), I went on to investigate the file itself. Gspot
said it was an asf container, so I downloaded asfviewer
(http://www.microsoft.com/windows/windowsmedia/forpros/format/ASFViewer.aspx)
and opened the dvr-ms file. Under Header object “Stream Properties†one finds
the following data:

Stream Properties Object [1] (297 bytes)
Property Value
File Position 9005 ( 0x232D )
Object ID B7DC0791-A9B7-11CF-8EE6-00C00C205365
Object Size 297 ( 0x129 )

Stream Number 1
Version 1
Offset 0
Encrypted False
Security ID 18873916 ( 0x11FFE3C )
Stream Type Specific
Stream Type Video Media
Window Width 720
Window Height 480
Flags 2
Bitmap Info Header
biSize 208
Width 720
Height 480
Planes 1
Bits 0
Compression TEXT: DVR
0000: 44 56 52 20 DVR
Image Size 0
X Pels / Meter 0
Y Pels / Meter 0
Colors Used 0
Colors Important 0
Extra Data Size 168
Extra Data 0000: 00 00 00 00 00 00 00 00-00 00 00 00 00 00 00 00

0010: 00 00 00 00 00 00 00 00-00 00 00 00 00 00 00 00
0020: 00 00 00 00 00 00 00 00-63 17 05 00 00 00 00 00 c
0030: 00 00 00 00 00 00 00 00-04 00 00 00 03 00 00 00
0040: 00 00 00 00 00 00 00 00-28 00 00 00 D0 02 00 00 (
0050: E0 01 00 00 01 00 00 00-4D 50 45 47 00 00 00 00 MPEG
0060: 00 00 00 00 00 00 00 00-00 00 00 00 00 00 00 00
0070: 00 00 00 00 00 00 00 00-02 00 00 00 02 00 00 00
0080: 00 00 00 00 00 00 00 00-D0 C4 C4 C4 49 00 2B 4E I +N
0090: 98 FB 95 37 F6 CE 51 6D-D1 C4 C4 C4 49 00 2B 4E 7 Qm I +N
00A0: 98 FB 95 37 F6 CE 51 6D 7 Qm

This led me to try to change the headerdata (all instances of 480 to 576)
and see whether this is causing the playback problems. After I changed the 3
values (those emphasized), the ffdshow codec stated displaying the dvr-ms
file correctly (with lower part of the picture displayed and acknowledging it
as a 720x576 stream) Further testing showed that changing only the binary
data under “extra dataâ€-property from “E0 01†to “40 02†was enough to make
it work as it should.
When I tried to play back the file in MCE, there was no change, except the
picture was stuttering. (As if the “fps†didn’t match with the refresh rate.)
I have no explanation for the stuttering.

I need this to work with ffdshow because nvidia decoder doesn’t work with
avisynth, and I need to use avisynth for a script I am writing to automatize
transcoding dvr-ms to h264.

So, the question is: am I the only one or is everyone having this issue AND
IF SO, how can one force MCE to write down the header of dvr-ms-files
correctly? Help would be appreciated.