W7 + AviSynth + VC-1 = problem?

[follz20]

Hi all

I'll try to be concise as possible with this post but there are a few variables so bear with me. Here are my specs & installed programs:

quad cpu @ 3.78ghz
2gb RAM
ATI 5850
Windows 7 pro
ffdshow rev 3342
mpc-hc rev 1774
Standalone filters registered: Matroska muxer; Matroska source; Matroska splitter; MPC - Mpeg source (gabest); MPC - Mpeg splitter (gabest); MPC - Mpeg-2 video decoder (gabest); MPC - Video decoder
Sources: blu-ray m2ts files

Recently I thought I had a problem with MeGUI encodes, where the video would playback slow & choppy (like playing a game with low fps). But I also had several successful encodes with MeGUI, which confused me until I realised all the successful encodes were AVC videos. Turns out the problem is the VC-1 video sources. The end result was always choppy, regardless of settings.

I then noticed that if I demuxed just the video with tsmuxer into a m2ts container, the playback would be the same as the encode. I fixed this, however, by enabling the vc-1 transform filter inside mpc-hc. Smooth playback was the result so the source isn't a problem.

(As an aside, if I demux the vc-1 video and an audio track with tsmuxer and remux with mkvmerge, there is no stuttering/jittery playback whatsoever. Weird?)

I can load the vc-1 source in avisynth script creator in MeGUI perfectly fine. I save it, then I see what the result is when I play the .avs file with mpc-hc. The choppy playback resumes, regardless of the decoder used: have tried it with libavcodec or wmv9 with ffdshow; or with mpc-hc's internal transform filters. So, having played around and tested this, I can safely say this is a encoding problem with the vc-1 source and avisynth in W7 (I never had a problem in XP).

Doing a bit of net searching, some people believe that there is indeed a problem with vc-1 & avisynth in W7 but there appears to be no apparent solution (as far as I can see).

So, attempting to sum up the problem: can't properly encode vc-1 sources without slow/choppy playback (via avisynth & megui); libavcodec & wmv9 via ffdshow won't smoothly playback vc-1 video inside m2ts container, seems fine with mkv container though; no errors whatsoever when making avisynth script or during encoding; all other video encodes (avc, x264 etc) turn out fine.

Here is a sample of an vc-1 encode, it's only 18mb:

http://rapidshare.com/files/375278056/problem_encode_-_intro_.mkv

It might just be better to take a look to see what I mean. This is basically what all my vc-1 encodes turn out like.

Any help appreciated!

PS- My simple avisynth script for *most* encodes (depends on aspect ratio):

DirectShowSource("E:\Blu-Ray Rips\tbe.m2ts", fps=23.976, audio=false, convertfps=true)
#deinterlace
#crop
#resize
#denoise

My x264 encoding settings:

program --profile high --pass 2 --bitrate 10000 --stats ".stats" --thread-input --keyint 240 --min-keyint 24 --bframes 5 --ref 6 --me umh --direct auto --partitions all --output "output" "input"

[-Sandro-]

it would be helpful if you posted the original file you encode, cause I had a similar problem and solved. But I don't remember how so I have to test directly

[jagabo]

Your video has lots of duplicate frames. Hence the jerkiness. DirectShowSource() isn't very reliable. It leaves you at the mercy of whatever DirectShow filters are installed. It's not uncommon to see problems like this.

[follz20]

Your video has lots of duplicate frames. Hence the jerkiness. DirectShowSource() isn't very reliable. It leaves you at the mercy of whatever DirectShow filters are installed. It's not uncommon to see problems like this.

Thanks for reply.

Ok, if DSS isn't reliable, what is an alternative option for encoding x264/vc-1 sources in mkv or m2ts containers?

[creamyhorror]

DSS relies on whatever the default VC-1 decoder is on your system. The issue is either that that decoder isn't working correctly, or DSS is mishandling the frames.

You may be able to see the default VC-1 decoder using GraphStudio. I'm not sure, as I've never used Win 7. You may also be able to change the priority of the decoders to use another one that works properly.

The other thing to try is DSS2() or FFVideoSource(). The latter is available via the FFMS2 Avisynth package. These are frame-accurate source filters, but I'm not sure if that's the problem with your source. (I don't even know if FFVideoSource will load VC-1 video...)

[-Sandro-]

One thing you could try is to use MS decoder