Problem with AVC/AAC file and DirectShowSource

[pooksahib]

Hi. I regularly use MeGUI and when I encounter a file (usually a wmv) that won't load properly or results in out of sync A/V, I use avspmod to create a script like this:

DirectShowSource("F:\video.wmv", fps=29.970, ConvertFPS=True)
EnsureVBRMP3Sync()

I have an mp4 file here (AVC video and AAC audio) which plays perfectly on all players – no sync problems. When loaded onto MeGUI, I have a choice of two Indexers, L-SMASH and FFMS. L-SMASH gives an error message ('couldn't make a frame' if I recall rightly) and the encode done with FFMS is out of sync.

I want to try my DirectShowSource solution on this file but it won't load in avspmod: 'Could not open as video or audio. The source filter for this file could not be loaded'

Googling this was not successful. I read that installing ffdshow was needed but I got nowhere with that.

Can anyone suggest why the sync issue arises when the source file is in sync? And is there a way of opening this AVC/AAC file with DirectShowSource? My thanks in advance.

[davexnet]

Of course you can open it with FFDshow but you need the haali splitter also.
Otherwise you can install the LAV filters

[sneaker]

and the encode done with FFMS is out of sync.

Did you set fpsnum/fpsden?

a=ffaudiosource("source")
v=ffvideosource("source", fpsnum=30000, fpsden=1001)
AudioDub(v, a)

[Marsia Mariner]

Yes, some weeks ago I did find a file which was driven out-of-sync when decoded by FFMS.
OTOH, DirectShowSource() through LAV Filters ran flawlessly. My "recipe" was build two .GRF files and combine them with AudioDub().
But I don't use MeGUI. And no, I don't recommend Haali Media Splitter to anyone.

[LigH.de]

MeGUI does not use Haali anymore. It uses an FFMS2 version which got rid of this dependency. And it also supports L-SMASH Works, which never needed Haali. Try to use the "File Indexer" instead of DirectShowSource.

And apart from that...

Your example shows that you want to open a WMV file. Why do you believe it contains AVC+AAC? Now you got me confused. Please provide facts now, using MediaInfo.

[davexnet]

And no, I don't recommend Haali Media Splitter to anyone.

I somewhat agree I think FFDshow/haali were more popluar in Windows XP and the OP did not state his OS

It was widely used for many years, why do you have animosity towards it?

[LigH.de]

Because LAV Filters are the superior DirectShow filter team these days, decoders and splitters written by the same author, in a much better supplement than the previous one.

But anyway, regarding AviSynth, always prefer native decoder plugins when possible, avoid DirectShow until it is the last hope.

[pooksahib]

I began with an example of how I've previously encoded a problem file - it just happened to be wmv. This current file is definitely AVC/AAC so no need for any confusion, LigH.de!

Installing LAV filters finally allowed me to create a script with DirectShow Source but, unfortunately, the encoded file was still out of synch. Given that Indexing it also fails, I'm either going to do a simple edit using Avidemux or I might convert it at placebo quality using Handbrake and then use avisynth on that new file (a bit of a pain but it's worked in the past).

Thanks for all the suggestions.

[LigH.de]

"Placebo" is not quality, but a waste of time and electricity.

Much simpler: Use a rather small CRF; to preserve the quality of a lossy compression, you will most probably need a copy with higher bitrate, no matter how long it takes to encode it.

[pooksahib]

I may have used the wrong word - if I do use Handbrake, it'll be with a CQ of about 14-16.

Did you set fpsnum/fpsden?

Yes, thanks - MeGUI does that automatically.

[pooksahib]

I've had to uninstall LAV filters - it was preventing the preview window in MeGUI from working properly.

[LigH.de]

That's quite incredible. In which way did it interfer? The preview window will only display uncompressed (raw) video, the only reason for issues could be that processing raw video is enabled but unnecessarily restricted afterwards.

[pooksahib]

The preview window appeared but was stuck on one frame - I couldn't navigate. But it only happened with a script using DirectShowSource.

[jagabo]

If ffVideoSource gives you A/V sync errors try using LSmashVideoSource or LWlibavVideoSource (and vice versa). Both are part of the LSmash package.

http://avisynth.nl/index.php/LSMASHSource

[pooksahib]

Thanks, jagabo. As mentioned in post #1, LSmash has it's own problem ('couldn't make a frame'). I tried LWlibavVideoSource but the sync issue persists. Must be something odd with this particular video. I'm not bothered, I've just done a simple avidemux edit.

[LigH.de]

I doubt that LAV Filters was a reason of issues with MeGUI in the first place. Instead, it is probably the source file, and LAV Filters just reacted on media errors in its own way.

Often it helps to re-multiplex a file into a fresh container, without re-encoding any content. For MP4 => MP4, you could use a tool based on MP4Box (there are several UI's available, e.g. YAMB, My MP4Box GUI, BOX4); for many formats => MKV, try MKVToolnix. And furthermore, many ffmpeg based tools would work as well.

If there is a serious issue in the original file already, most probably already such a remultiplexer will complain.