Can't encode VC-1 videos with avisynth/MeGUI

[WAusJackBauer]

So basically it finishes the encode, however at some point in video it stutters, causing the video and audio to de-sync. It's happened with two movies so doubt its coincidence.

I've tried using DSS2, ffvideosource but neither worked. Does anyone know a source filter that is known to work for VC-1?

[poisondeathray]

DGSource . Requires a compatible Nvidia card and license (not free)

Is it random point that it stutters ? If it's the same point, there might be an issue with your source . Does it play normally in a media player ?

Preview with a directshowsource() script in mpcpc, but set your decoder to windows media decoder. If there are no errors there, likely it will encode ok too.

[WAusJackBauer]

DGSource . Requires a compatible Nvidia card and license (not free)

Is it random point that it stutters ? If it's the same point, there might be an issue with your source . Does it play normally in a media player ?

Preview with a directshowsource() script in mpcpc, but set your decoder to windows media decoder. If there are no errors there, likely it will encode ok too.

The untouched source file played in a media player is fine. The encoded video is the one out of sync and always stutters in the same place. If I preview it in avisynth (even using DSS2) it's fine.

[poisondeathray]

The untouched source file played in a media player is fine. The encoded video is the one out of sync and always stutters in the same place. If I preview it in avisynth (even using DSS2) it's fine.

Look at the log file for clues

If you're 100% certain the avs script preview is ok, then changing the source filter wouldn't help - because it works ok already according to you. If you're not 100% certain then check again

Assuming the dss2 script is ok - that would mean the issue is somewhere downstream, such as video encoding, audio encoding, muxing etc...

(IMO dss2/dss2mod script is "never" ok, because you are almost always missing frames - it typically drops 1 (or more). IMO, plain directshowsource() is better for a plain encode, no filters)

You mentioned a stutter - can you be more specific in the description ?

Have you ruled out a playback problem ? Tried different media players ? VLC, mpchc , smplayer ?

Did you test audio separately , and video separately ? What is causing the "stutter" ?

[jagabo]

Try DirecshowSource("filename.ext", fps=X, ConvertFPS=true). replace X with the correct frame rate. I don't know if VC1 is like older WMV codecs -- but the older ones reduced the frame rate when the action got too intense for the requested bitrate. So, for example, a 24 fps video would drop to 12 fps for those scenes. The above line will convert VFR to CFR.

[WAusJackBauer]

Try DirecshowSource("filename.ext", fps=X, ConvertFPS=true). replace X with the correct frame rate. I don't know if VC1 is like older WMV codecs -- but the older ones reduced the frame rate when the action got too intense for the requested bitrate. So, for example, a 24 fps video would drop to 12 fps for those scenes. The above line will convert VFR to CFR.

That sounds about right, I'll give it a try.

[WAusJackBauer]

Well I tried it and now this encode has more stutters, (always happen in same place, tried potplayer and VLC) but somehow the audio stays in sync.

My script looks like this.

DirectShowSource("E:\Movies\Over the top\Over The Top.mkv",fps=24000.0/1001.0,ConvertFPS=true)
ConvertToYV12
SMDegrain(tr=4, thSAD=600, RefineMotion=True, contrasharp=True, interlaced=False, plane=4, prefilter=0, chroma=True, lsb=False, lsb_in=False, lsb_out=False, Show=False)

Any other ideas?

[sneaker]

If you drop the file into GraphStudioNext (32 bit if you are using 32 bit AviSynth), how does the graph look? I'd try it so that it uses LAV Splitter and LAV Video. In LAV Video test the Microsoft DMO decoder (default for software) and DXVA2 copy-back. You can also export a graph from GraphStudioNext and load the .grf file in DirectShowSource to force a specific graph.

Still, this makes me wonder:

The untouched source file played in a media player is fine. The encoded video is the one out of sync and always stutters in the same place. If I preview it in avisynth (even using DSS2) it's fine.

poisondeathray talked about that prior. Maybe encoding or muxing is broken? Can you share the output file? Does it make a difference whether you choose mkv or mp4 output?

[jagabo]

DirectShow isn't frame accurate when random seeking. Given that you're using a temporal filter along with an (presumably) out-of-order encoder it's likely that is your problem. I would try using DirectShowSource to produce an intermediate with a lossless intra frame codec (frames will be read linearly from the source). If that intermediate file looks ok filter and encode from that.

Also try other source filters like ffVideoSource or LWLibavVideoSource (LSmash).

[sneaker]

ffmpeg's VC-1 decoder is kinda buggy. Your intermediate file suggestion is not the worst idea...

[WAusJackBauer]

So I encoded it with FFVideoSource last night and its all good.

I could've sworn I tried it with the last VC-1 video and it didn't work. Either way thank you for all the responses, will try some of the workarounds if FFVideoSource doesn't work for the next one