[Module/5D3] SMPTE experiment, not usable

[AnotherDave]

I still can't get any of the smart slate apps to read it.

I did read somewhere that you could put a time stamp in the header of the file, which could be read and interpreted into TC by the conversion program (mlv2dng).

[g3gg0]

even when inverted, no sync?

[AnotherDave]

Still nothing showing up for me on the smartslate apps...

*Just a thought.  I know it would be more difficult to create a module that reads TC audio, but would it be possible?  If you could create one that read the signal, and sync the camera's internal clock with to it (it'd have to be free run tc) that would be even better as it would allow you to eliminate the need to output the signal (and whatever hardware you would use to do it).

That'd also have the added advantage of allowing people to sync multiple 5D3s with and iPhone running TC Toolbox.

[g3gg0]

another try

[g3gg0]

Still nothing showing up for me on the smartslate apps...

*Just a thought.  I know it would be more difficult to create a module that reads TC audio, but would it be possible?  If you could create one that read the signal, and sync the camera's internal clock with to it (it'd have to be free run tc) that would be even better as it would allow you to eliminate the need to output the signal (and whatever hardware you would use to do it).

That'd also have the added advantage of allowing people to sync multiple 5D3s with and iPhone running TC Toolbox.

as said. i would prefer to first have the output working, then i want to integrate it.
and then we can talk about such stuff

[g3gg0]

had any time to test the new version yet?

[stevefal]

I have a variety of LTC gear, but I'm getting no output from the module. 5D3.

[EDIT] Ah, movie mode I'll give it a try.

[stevefal]

No lock at all. The LTC audio is not a clean square wave.

[AnotherDave]

Sorry this update totally got past me.

Just tested it out with BAD, but GOOD results too!  It is outputting a signal the TC Toolbox can read... but... it's all garbled.  :-/

https://dl.dropboxusercontent.com/u/21985365/IMG_1426.MOV

Took a video of the iPad screen so you can see what it is doing.

[stevefal]

Clean timecode


Output from SMPTE module

[mageye]

@stevefal

Looks like it's being LPF'd 

[stevefal]

Looks like it's being LPF'd 

Yep, but it's nothing I'm doing. I've double-checked by looking at the 5D3 output directly on a scope. Same thing.

[g3gg0]

thanks a lot, this maybe helps finding the problem.
stay tuned

[g3gg0]

this one any better?

[AnotherDave]

Nope.  Still coming through garbled for me... just the same as before.

[g3gg0]

you tried toggling the inversion options in the menu?

[AnotherDave]

yep.  doesn't make a difference.  looks just like the video I posted earlier...

[tob]

The waveform looks more like square, with the latest module.



I recorded 4 files with the module posted for 1 hour ago. The files are around 13s each, 44100khz, mono, 32-Bit depth. With all settings VSYNC <-> ASIF offset = 40, output volume = 127.

smpte_test_OFF_OFF.wav   Invert output [OFF], Invert parity [OFF]
smpte_test_OFF_ON.wav   Invert output [OFF], Invert parity [ON]
smpte_test_ON_OFF.wav   Invert output [ON], Invert parity [OFF]
smpte_test_ON_ON.wav   Invert output [ON], Invert parity [ON]

https://dl.dropboxusercontent.com/u/34148361/test/smtpe_test.zip

[stevefal]

Same for me - the waveform is much closer but still no lock

[stevefal]

Maybe useful if you're not already using it:

http://github.com/x42/libltc
http://github.com/x42/ltc-tools
http://github.com/x42/libtimecode

[g3gg0]

once again

[AnotherDave]

Same deal for me.... TC is all over the place.  Just like in the video, no change when flipping through settings.

[stevefal]

I haven't tried to decode the datastream visually, but I can see that there are issues with the first few bits after the sync word. The issues seem to vary, but here's one example. The highlighted area starts at bit 76. You can see that bit 79, which should be a 1, transitions at its midpoint, but at its endpoint it does not transition. It continues on to the next bit at the same level. It also has invalid transitions in the next few bits.

Here's another with the same issue, and another mix-up in the next few bits:

[stevefal]

The signal envelope also pulses on a 15 frame interval. I suppose it shouldn't affect decoding, but maybe it's a clue:

[g3gg0]

Aaah damn... i know what is wrong.
Will fix tonight.
Thanks