Need help writing dvr-ms -> wmv transcoder

[bgowland]

If I start with Graphedit, I can build a graph to connect a dvr-ms source file to a WM ASF Writer (via audio/video decoders). If I select the properties of the WM ASF Writer and choose a profile, some profiles work but others just produce a 6KB file which looks (to me) like an asf/wmv 'wrapper'. The properties show the right bitrate and resolution but duration is 00:00:00.

Anyone got any ideas what causes this little stub file to be produced? I've written a program to do this but even using one of the profiles that work in Graphedit, I get a 6KB file as mentioned above. I really want to use a custom profile of my own but that does the same thing.

Scratching my head and fresh out of ideas - searching the net doesn't help. Any experts on wmv/asf out there?

Cheers,
Brian

PS This isn't GB-PVR specific so I didn't put this on the Developers forum.

[pBS]

you say you connected a ms-dvr source to the decoders and then to an asf writer? then you're sending it a raw video stream with no compression..
you need to send from the decoders,to another encoder,then to the asf writer..
[usually i found you have to use an asf 'mux' then a standard file writer]

i have been using the ati avivo codecs this way with graphedit also..works great...also has mpeg,avi,asf,psp,ipod,hdmpeg muxes too..
if you want Windows Media 9 files,you'd have to use a WMV9 encoder and send that to a asf muxer..then to a file writer if not built in [some muxers do have file output built in also,2in1...i've even seen mpegencoders that encode,mux and output files in one filter]

i find almost all graphs need a source,a decoder of that source,an encoder,then a mux,then a file output...
unless i understood the problem wrong...

i'd be very interested to see your code too.. i'm wanting to get filter configurability into the software recorder plugin..[among other things]
mainly just need a way to pop-up a filter's properties,set it...and save the settings for subsequent runs...i was using the .xgr graphs format..[text]
my little encoder is out there somewhere and works fine but you have to edit the graph manually to change settings..
other possible causes are wrong version profiles for the wmv encoder,[some come with windows and are old] user security, and have you tried the profiles from the command line?
hope that helps some..
maybe post a pic of your graphs or the xml version?

[pBS]

also,because ms-dvr is basically just mpeg in a funky asf-like wrapper,you could skip decoding and encoding and just change containers..
haven't tried it but there are programs out there that can already..
try just demuxing and then remuxing with asf writer...
depends on what your purpose is...have to be WMV?

[bgowland]

Thanks for the response - some useful points there but it's 6:50AM and I;m going to bed now - brain hurts.

Cheers,
Brian

[bgowland]

Thanks - I've played around some more...

In answer to the question about whether I need to go to WMV or not, the answer is yes for the moment at least. I'm trying to write an automated transcoder for some people who currently need WMV for what they do - at the moment they manually transcode stuff.

The code I'm using is really just a variation of the dvr-ms to wmv transcoding in 'Fun with DVR-MS' (Steve Toub available on MSDN). He gets his graph to just render the dvr-ms source to the WM ASF Writer and reads a custom profile from a prx file. His screen shot pretty much just shows the SB Source through Decrypt/Tag filters to audio/video decoders to the asf writer.

I can get this to work in Graphedit by manually plugging the SB Source to an Intervideo NonCSS Audio Decoder and an Elecard MPEG-2 Decoder then from them to the WM ASF Writer. I set the profile for the writer befor connecting the filter pins. In Graphedit, I can get some of the profiles to work (not all) but if I take the GUID of a working profile from C:\Windows\WMSysPr9.prx and feed that to the writer when I do it programatically, I get these 'stub' 6KB files - the properties of these files do show the bitrate and resolution of the profile however - this is my confusion.

Moving on from that, I've had better success if I start with an MPEG2 source file. The transcode seems to work and I end up with a playable WMV file...until I fully close my application, i.e., deconstruct my graph. At this point, the file shrinks back to the usual 6KB stub. It's as if I'm not 'flushing' the written data but I can see it is there in Windows Explorer and play it with WMP. As soon as I close my app., however, the file becomes 6KB in size.

Any ideas? This could be the same cause as the 6KB files when I'm transcoding from dvr-ms.

Cheers,
Brian