quote: Sam D. Chavez

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I just said that two posts back.

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No Sam, you didn't mention free tools ;-)

Aside from that, Studio Six Digital are currently working on an A/V Sync module for their iPhone tool-suite http://studiosixdigital.com/audiotools/
using the iPhone video recording function.

- Carsten

- Carsten

- Carsten
 

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Posted by Paul H. Rayton (Member # 1817) on 03-07-2012, 04:23 PM:
 
I'm not sure if this would apply to ALL digital still cameras, but if I were to use mine for such a visual "sync check" comparison (as described by Carsten), there might be an issue because there is a slight latency in my camera's video output, due to image stabilization. So the visual pop might be offset a bit from the audible pop.

All we really want and need is a sync "pop" sound of some sort, that is precise and well-defined, and an absolute visual reference -- and have it loop. Then, we can set it to running, go out and listen, see if it's in sync or not, and then dial up (or down) the system.

(And then, **hope** that when we get festivals in, with tapes and other video content from all manner of diverse sources, that the "kids" made their movies properly!)
 

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Posted by Carsten Kurz (Member # 5396) on 03-07-2012, 06:00 PM:
 
There's all sorts of strange gear around, but still even cheap digicams should be able keep video and sound in sync to within one frame or so. And that should be much more accurate than 'guessing' on a loop. If there is an inherent delay in a cameras video processing pipeline, the developers should know this and compensate for it.
I'm not talking about live video anyway, but looking at the recording.

There are sync check videos with a visual pendulum and the sync pop at the center transition, like a musical metronome. Or more elaborate ones like this with multiple visual sync cues:

http://www.youtube.com/watch?v=bCPEidaVzQU

They are certainly good to align a system by direct sensing that is way out of sync, but around +/- one or two frames, it gets difficult. Not that it is really THAT important to be precisely on the spot, but if a cheap gizmo can help you, why not use it.

You can check your cameras sync capabilties easy with a clapperboard. Or simply two sticks or a clap of your hands.

- Carsten
 

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Posted by Jussi Siponen (Member # 5572) on 03-20-2012, 01:32 PM:
 
Inspired by the BBC sync test video linked by Carsten.

I took the sound from the BBC video and adapted the scale for 24fps.



This is frame 7 (upper) and frame 12. The "tick" sound occurs half way through frame 12 being visible.

BTW, is this the right thing to do -- should it be timed to the "leading edge" of frame 12?

If the timing is determined to be correct and I do a QC pass on a real D-Cinema system (in stead of a software DCP player) I can post a download link later this week if there are any takers.
 

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Posted by Paul H. Rayton (Member # 1817) on 03-20-2012, 02:40 PM:
 
Hi, Jussi -- Yes, great. Please consider this at least one "vote of encouragement" to proceed with your plan. I'd be happy to try it (when you finish it), utilizing my somewhat "antique" Quvis server.
 

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Posted by Ian Freer (Member # 1940) on 03-20-2012, 04:02 PM:
 
I have a DCP clip that is almost identical to this that must have come included on some other content I received. I don't recall ingesting in directly, but came as part of something for a film festival so I was ingesting 'everything' to make sure I had the correct versions of DCP's available. I haven't looked at it for a few months but from memory it has the logo of a London, UK post house or something on it. I'll have a look how big it is and see if I can upload it or send it to Brad to put up on the site somewhere. Saves everyone having to re-invent the wheel as it were...

Cheers,
Ian
 

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Posted by Jussi Siponen (Member # 5572) on 03-21-2012, 01:22 PM:
 
DropBox is still uploading as I write this. The download link will start to work as soon as the upload is complete (shouldn't take more than 30 minutes):

SyncTest DCP (340 MB, runtime 1:30)

The delay scale now shows also milliseconds.

Re-inventing the wheel is kind of fun, but also potentially embarrassing, given the audience. I hope I didn't mess up somewhere
 

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Posted by Marco Giustini (Member # 4544) on 03-22-2012, 01:34 PM:
 
Jussi, this looks very good, thanks!
 

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Posted by Dave Macaulay (Member # 813) on 03-28-2012, 08:34 AM:
 
Thanks a bunch! I haven't run this yet (waiting for projector power) but the DCP did ingest OK into the Doremi server.
 

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Posted by Carsten Kurz (Member # 5396) on 03-31-2012, 04:32 PM:
 
Jussi - I just though over it, and it might be useful to have a DCP with the same sync beep at exactly the same time in ALL channels. You might even want to compile a 7.1 version. As all tracks are the same, this could be used on 5.1, 7.1 and SDDS layouts just as well.

I guess I could rewrap it myself from the existing file, but as you have posted a DropBox link, you might just replace the file with a surround version. All that's needed is to place the same mono wave file into all surround channels instead of using only a stereo file for L/R.

I know usually sync is most important for center speaker, but having the sync beep on all channels will enable people to also check various L/R and surround delay issues e.g. by turning down individual channels/amps.

- Carsten
 

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Posted by Jussi Siponen (Member # 5572) on 04-01-2012, 04:57 AM:
 
Hi Carsten,

Good point with the 7.1 - and why didn't I think of that myself?!?

*headdesk*

I'm going to be busy with work for the next couple of days, I'll get to it later this week.
 

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Posted by Jussi Siponen (Member # 5572) on 04-01-2012, 01:31 PM:
 
Had some free time in the evening after all

SyncTest DCP, 7.1 channel version (337 MB, 1:30)

DropBox is still uploading - if the link doesn't work, wait 30 minutes and try again.
 

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Posted by Carsten Kurz (Member # 5396) on 04-01-2012, 07:17 PM:
 
Great Jussi, thanks again.

- Carsten
 

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Posted by Wolfgang Woehl (Member # 6901) on 09-08-2012, 09:22 AM:
 
Jussi, great effort and thanks for sharing.

Here's a conversion to Bluray from your SYNC-TEST_TST_F_20_2K_IND_20120317_DCP_OV package: SYNC-TEST_TST_F_20_2K_IND_20120317_DCP_OV.udf. Get the image and burn it to disc.

We used this in combination with a Syncheck II to debug some issues. So I've stared a lot at this thing in the past days:

I'd probably go for less visual clutter like dropping the upper left title, dropping the "Adjust" note.

The Syncheck II is a straightforward sync checker, has a light sensor and a mic. It goes for white flash so the bigger the white region is on sync flash the easier to catch. Their test material is actually black with 1 full white frame. But you can make do with the flash circle.

We've noted the off-boundary position of the sound pip and, like you, I'm asking myself if that is correct sync. Film sound editors would know. Anyway, we were not chasing half a frame but more so that was not a biggie.

Btw, there is a short and low-volume organ kind of sound just before the first pip.
 

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Posted by Wolfgang Woehl (Member # 6901) on 09-17-2012, 11:19 AM:
 
So I've asked a film sound editor: He says perfect sync sits at the 0 position (my words) of a frame, the opening or starting boundary of a frame.

Duh, right? Well, always good to talk to experts
 

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Posted by Jussi Siponen (Member # 5572) on 09-27-2012, 12:43 PM:
 
Looks like I'll be re-visiting this project next weekend.

The sync test is off by 0.5 frames / 21 ms -- hardly the end of the world, but I'd rather have the DCP right *on* than "close enough for government work"...

Gentlemen, stop your downloads for now. I think I can swap the files under the links with corrected versions and then make a post saying I've done so.
 

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Posted by Jason Raftery (Member # 6291) on 09-27-2012, 03:18 PM:
 
Jussi, thanks for this helpful DCP.

The sync test DCP ingests and runs fine on the Dolby servers I've tested it on but won't ingest on GDC servers. The GDC doesn't even "see" the DCP on the flash drive and thus won't ingest it.
 

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Posted by Wolfgang Woehl (Member # 6901) on 09-27-2012, 03:28 PM:
 
Jussi, great and thanks. The same deprecation note goes for the Bluray version of Jussi's Sync Test package. The link I had posted above is dead for now. I'll post a link to the corrected Bluray version once Jussi's done.
 

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Posted by Jussi Siponen (Member # 5572) on 09-29-2012, 06:03 PM:
 
Here's the latest:

Synctest rev4, combined 2.0 and 7.1 audio versions package (343 MB)

What has changed (both per Wolfgang's feedback):
- corrected the sound timing
- made the white circle on frame 12 larger to make it easier to pick up with measurement tools

The previous URLs now point to a zip file with only a README.txt file with this message:

quote:

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Hi!

This package has been superseded by:

https://dl.dropbox.com/u/12106363/SYNC-TEST_TST_F_71_2K_IND_20120929_DCP_OV.zip

Best regards,

Jussi Siponen

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quote: Wolfgang Woehl

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And the organ-like sound before the first pip is still there, in both sound versions.

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Whisky-Tango-Foxtrot?!?!

The waveform should be a perfectly flat line before the first pip, no DC offset either...
 

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Posted by Wolfgang Woehl (Member # 6901) on 09-30-2012, 07:21 AM:
 
He, right, guess it should. But

asdcp-test -x 2a111bb8 2a111bb8-fc50-456d-98cc-00718a44b450_pcm.mxf ; sox 2a111bb8_1.wav trim.wav trim 0 0.4 ; sox -v 200 trim.wav trim-v200.wav ; play trim-v200.wav

The original (quite faint) signal is clearly audible over a standard auditorium PA @ 7.0. Well, like I said: It kind of has its use
 

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Posted by Carsten Kurz (Member # 5396) on 09-30-2012, 08:40 AM:
 
Yes, I can hear the short 'organ' beep just a fraction ahead of the very first sync click, even on my laptop speakers.

No big deal for the purpose of the sync check DCP, but it IS there in the audio.

Should keep no one from downloading and using it, though.

- Carsten
 

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Posted by Carsten Kurz (Member # 5396) on 09-30-2012, 08:15 PM:
 
(Sorry, can not respond by PM to your PM it seems)
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Oh, and Jussi, I would propose another test pattern as well - a crop test pattern, a 2k full screen image (2048*1080) with numbered rulers on every edge.

Like e.g. this:

http://www.cine4home.de/tests/projektoren/SanyoPLVZ3/cropping_dig2.jpg

- Carsten
 

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Posted by Jason Raftery (Member # 6291) on 10-06-2012, 09:13 PM:
 
Thanks for the new DCP.

I have just one location that uses GDCs right now and am there infrequently at best, but I'll try the new DCP next time I'm there.

The files were in the root directory of my flash drive. The server was able to see and ingest the TI DLP logos from here that were on the same flash drive but curiously could not see or ingest Dolby 3D and Dolby 7.1 DCPs that were on the same drive (as well as the sync check DCP).
 

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Posted by Dave Macaulay (Member # 813) on 10-11-2012, 06:53 AM:
 
I finally downloaded the 7.1 version, and found it won't ingest on the two Doremi servers I have tried. I've been using the original 5.1 version so obviously it ingests fine.
The only difference I can see is that in a directory listing of my usb stick, the original one shows with the usual "UUID" string of a lot of hex numbers. The new one shows up with the DCP name. Should the DCP be in a folder with the UUID? I didin't do anything different between the two, just unzipped the file downloaded from FT.
 

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