#487 DV captures video only on certain MiniDV tapes

[David Powell]

I'm capturing from a JVC GR-DX107 MiniDV camcorder, with a Kalea Informatique PCIE - IEEE1394 a+b - FW4/800 (Texas Instruments XIO2213BZAY chipset) FireWire to DV AVI in VirtualDub 2 under Windows 11, using Windows 11's built in FireWire drivers.

I'd successfully captured 7 tapes using the above setup with audio using DirectShow as the source, then I came across a MiniDV tape that VirtualDub 2 refused to capture or preview audio for, which was odd. I switched back to one of the tapes I successfully captured, and the audio was previewed again. This suggests that there is something about the format of the audio on the tape that is preventing audio playback and capture.

Using GraphStudioNext (https://github.com/cplussharp/graph-studio-next) I was able to manually construct DirectShow filter graphs for both playback and capture (attached) that did successfully capture audio from this tape.

I also used GraphStudioNext to look at VirtualDub 2's filter graph when in preview mode (also attached), but I could not look at its capture filter graph as this was private, but I used the dialog in VirtualDub 2 to get some limited details about this:

Filter graph 0CC13148:
Reference clock: unknown
Filter 0C8A427C [Audio sink]:
Pin "In" (input): connected to pin "Output" of filter "Audio pulldown"
Filter 08063A4C [Video Mixing Renderer 9]:
Pin "VMR Input0" (input): connected to pin "XForm Out" of filter "DV Video Decoder"
Filter 081862FC [Audio pulldown]:
Pin "Input" (input): connected to pin "Output" of filter "ACM Wrapper"
Pin "Output" (output): connected to pin "In" of filter "Audio sink"
Filter 08205D7C [DV Video Decoder]:
Pin "XForm In" (input): connected to pin "Output" of filter "Video pulldown"
Pin "XForm Out" (output): connected to pin "VMR Input0" of filter "Video Mixing Renderer 9"
Filter 0C9F593C [ACM Wrapper]:
Pin "Input" (input): connected to pin "AudOut00" of filter "DV splitter"
Pin "Output" (output): connected to pin "Input" of filter "Audio pulldown"
Filter 08185A8C [Video pulldown]:
Pin "Input" (input): connected to pin "DVVidOut0" of filter "DV splitter"
Pin "Output" (output): connected to pin "XForm In" of filter "DV Video Decoder"
Filter 0CAAAA5C [DV splitter]:
Pin "Input" (input): connected to pin "DV A/V Out" of filter "Capture device"
Pin "DVVidOut0" (output): connected to pin "Input" of filter "Video pulldown"
Pin "AudOut00" (output): connected to pin "Input" of filter "ACM Wrapper"
Filter 00B6A7E4 [Capture device]:
Pin "DV Vid Out" (output): unconnected
Pin "DV A/V Out" (output): connected to pin "Input" of filter "DV splitter"
Pin "DV A/V In" (input): unconnected

It appears that one or more of the additional filters inserted by VirtualDub 2 into the capture graph have an issue with the audio format on this tape.

I tested a playback graph with ACM Wrapper, and that worked, which leaves the Audio pulldown or audio sink filter as the likely culprit.

[Anonymous]

Did you find a solution to the audio issue? I am getting the same thing. First MiniDV tape worked fine. Part way through the second one, after a change in scene, the audio stops working.

[David Powell]

No, I'm afraid not. I had to manually capture the problem tape with GraphStudioNext instead in the end, which was doable for me, but would prove tricky for a lot of people.