Using AVS with large DV AVI files

[fvisagie]

Hi All,

The DV Type 1 AVI source files in my projects are typically 15 - 18GB each and 90GB+ in total. As I understand it, to steer away from the apparently infamous DirectShow interface the alternatives are either OpenDML or AVIFile. But the AVIFile handler doesn't work >2GB.

OpenDML doesn't provide sound with DV Type 1 so I'd either have to convert to Type 2 or extract and source audio separately. Converting to Type 2 isn't much of an option space-wise.

So the question then is: assuming good source material, how accurately does AVS maintain relative sync when processing and serving separate DV AVI video via OpenDML with PCM WAV audio? Is this even worth considering or should I just find a way to convert to Type 2? Any any other things to watch out for?

Many thanks,
Francois

[Gavino]

Converting to Type 2 isn't much of an option space-wise.
Since this is a lossless operation, you can afford to delete the Type 1 files after conversion.

[fvisagie]

Since this is a lossless operation, you can afford to delete the Type 1 files after conversion.

That is true. Although if you add the time it would take to convert 90GB+ as well as my fear of deleting anything, I start becoming distinctly uncomfortable at the prospect ;).

[Gavino]

In that case, your best bet is probably to demux the audio and source it separately with WavSource, using AudioDub to combine with the video in your script. I don't think you should experience any sync problems with this.

[fvisagie]

When working with Trims from the same DV Type 2 file (non-interleaved audio) I hope that UnalignedSplice should generally work? I'm a bit wary of potential silence insertion with AlignedSplice.

If I end up working with audio in separate files, I suspect one would need to AudioDub onto video clips before specifying Trims?

I'm starting to get the feeling it would be less hassle, and safer, to convert to DV Type 2...

[Gavino]

UnalignedSplice should work, and with PAL sources, you have frame-accurate audio samples.

Yes, AudioDub before trim, eg
AviSource(..., audio=false)
AudioDub(WavSource(...))

basically puts you in the same state as if you had loaded a Type 2, and you can then follow that with Trim which will affect video and audio together and in sync.

(And of course you can avoid this hassle in the future by always capturing to Type 2. :))

[DeathWolf]

UnalignedSplice should work, and with PAL sources, you have frame-accurate audio samples.

Yes, AudioDub before trim, eg
AviSource(..., audio=false)
AudioDub(WavSource(...))

basically puts you in the same state as if you had loaded a Type 2, and you can then follow that with Trim which will affect video and audio together and in sync.

(And of course you can avoid this hassle in the future by always capturing to Type 2. :))


You could try ffms2:)

[TheFluff]

OpenDML doesn't provide sound with DV Type 1 so I'd either have to convert to Type 2 or extract and source audio separately. Converting to Type 2 isn't much of an option space-wise.
v = opendmlsource("dv.avi")
a = directshowsource("dv.avi", video=false)
audiodub(v,a)

hth

[tedkunich]

Hi All,

But the AVIFile handler doesn't work >2GB.



I have several 40G+ AVI files that AVIsource loads just fine.... Not sure if yours being DV makes a difference, mine are intermediate files using the Lagarythm (sp?) codec.

T

[2Bdecided]

Full tape (13GB) DV-AVI files load just fine with AVIsource. However, I've only ever used type 2. I'm using WinDV and Cedocida, though I don't think either make a difference in this case.

Cheers,
David.