Dear Friends,

We have a thread going in our nanoFlash forum.

http://www.dvinfo.net/forum/convergent-design-nanoflash/489656-sony-nex-vg10-nanoflash-working.html#post1604028

Using the nanoFlash, one can achieve 1080p24 out of a standard NEX-VG10.

The 1080p24 includes synced audio.

Please post comments on our thread in the nanoFlash forum.

This post is to only inform you that the other thread exists.

Very interesting Dan and many thanks for posting. Just responding to keep this from slipping down the list.

Dear Henry

This is very nice as the nanoFlash greatly expands upon the NEX-VG10's capabilities.

Many have wanted to be able to record in 24p.

And High-Bit-Rate Codecs are certainly nice to have.

How is a 60i camera recording 24p in a NanoFlash?

the camera records 30 or 25p depending on region, then puts it in a 50 or 60i wrapper.

Dear Friends,

While Sony lists the camera as being 1080i59.94, it is actually putting out 1080psf29.97.

The nanoFlash is capable of converting the 29.97 Progressive Segmented Frames to
29.97 true progressive frames per second.

And the nanoFlash is capable of Over and Under-Cranking, thus allowing one to obtain 1080p23.976.

Thanks very much Dan; this setup plus an HDMI splitter and field monitor settling one of the most oft quoted criticisms of the VG10 on the forum even without the framerate fix.. I think the cam is taking a little too much flak for not offering more pro features, which seems strange considering it's price point and consumer cam designation. It's great that we can use it for pro applications but we need to appreciate that it's a few thousand less than an af100 and cut it a bit of slack.

Dear Friends,

When one adds a nanoFlash, you get simultaneous HD-SDI and HDMI outputs.

Thus for the NEX-VG10, you can feed the nanoFlash with HDMI in, then get HD-SDI and HDMI outputs. You can use one, both, or neither.

So the 24p is not usable with audio? Or the audio has to be recorded elsewhere? What scenario can we use this capability? It seems like a slight slow-motion effect would be obtained.

Dear William,

Yes, the audio will be in perfect sync in you are using the nanoFlash and 24p or 25p.

Just set the Crank On, with 24/24 or 25/25.

Curious, makes the camera seem viable again to me. So "crank" effectively changes the frame rate of the camera to a true 24p if I understand correctly.

Dear William,

The camera actually put out 29.97 Progressive Segmented Frames per second.

Then the nanoFlash discards just enough frames, in an appropriate manner, to obtain 23.976 frames per second.

This is a process where we take x number of frames then skip one, then repeat,

This is not very sophisticated. 30p down to 24p means 1 frame is removed every five frames. Without frame blending, this causes motion to appear choppy. And 30p (which the NX10 is producing) is notoriously difficult to frame blend into 24p. There is nothing in the nanoFlash spec sheets that indicates frame blending is part of the hardware. The example here is of a still life, we need to see real motion.

Dear William,

No, we do not do frame blending.

Gerado posted a video with motion. I will go find it.

William has it right. The time between frames for 29.97 simply can NOT be be made to be the time between frames for 23.976.

The math doesn't work. This is Sony Cineblah all over again. The software chooses the nearest in time frame to record. It will look just like 24fps with the Z1. (Please don't let me ever see this Sony demo again!)

Only if motion compensation -- a huge computational task (think hours per minute) -- is done by Twixter can this be done. And, there is in no way certain the new series of frames will look PERFECT.

If you want 24p, I don't know why folks ignore the real solution: Twixter. It never gets mentioned, yet for several years it keeps doing the job.

Now could 25 be converted to 24 -- I doubt by the nano.

Dear Steve,

We are in complete agreement: "The time between frames for 29.97 simply can NOT be be made to be the time between frames for 23.976."

We cannot adjust the time between frames, that is up to the camera.

The NEX-VG10 puts out 1080psf29.97.

The best we can do is record 1080p29.97, or using cranking to achieve 23.976, but we can not change the time between the frames.

If you want 24p, I don't know why folks ignore the real solution: Twixter. It never gets mentioned, yet for several years it keeps doing the job.

Now could 25 be converted to 24 -- I doubt by the nano.

25 can be converted to 24, it's done a lot by video to film facilities. One to one frame transfer with professional audio work to slow down and frequency compensate the audio just as 24f film has been sped up in PAL countries to 25f for decades now. It was the one reason PAL video equipment was in demand here in the US by aspiring film-makers.

The question is.... why do we want to shoot anything destined for film with anything but true 24p equipment anymore now that it's so available? Soon film will be a non-issue anyway as all cinemas will have quality digital playback and will be able to play any frame rate.

I think the confusion is that the nano can do under and over crank. So yes, 30 can be come 24. But it means the video simply plays faster, like a silent movie plays 18 as 24.

Or maybe it plays slower. Which ever it is, it's a speed change not a frame rate conversion.

Which might mean the nano could speed change 25 to 24 which might be very nice!

Dear Steve,

If one uses our Crank feature, so that the baseline (first number) is 24, and the Crank Number is 30, then you will have the effect that your described: 24 Frames will play out in 1 second, and the full 30 frames will take longer than 1 second.


But, if one uses our Crank featue, with 24 and 24, one will record 24 frames per second, and one will playback 24 frames per second.

The nanoFlash will take in 30 frames per second, then discard appropriate frames so that only 24 frames are recorded.

"... then discard appropriate frames so that only 24 frames are recorded."

Unfortunately, there are few or no "appropriate" frames because the TIME each 30fps frame is captured does not match the TIME each 24fps SHOULD HAVE BE captured.

All that can be done to get a 24fps stream is to choose from the 30fps stream 24 frames where each of these frames has the least time ERROR. This creates two problems:

1) Jitter. Since sometimes an EARLIER in time frame is selected from the 30fps stream and sometimes a LATER in time frame is selected from the 30fps stream, the timebase of the 24fps stream is unsteady.

2) Since the same selections are made each second, the pattern of selection creates a cadence that may be visible.

The only way 30 can become 24 is for 30 frames to be broken into 2 million pixels, each of which has a calculated motion vector (obtained from several previous frames).

Now each vector is adjusted to represent 1/24th rather than 1/30th second.

Next, each pixel is moved by the modified motion vector to a new location in what will be the NEXT frame. In this way, 24 new frames are CREATED.

The problem is that unlike MPEG-2/-4 compression there is no frame the CREATED frame can be compared to, hence no ERROR compensating information can be created. Thus, IF an error is made for one or more pixels, these errors can propagate until a computed frame perfectly lines up in time with a 30fps frame. Now, the errors can be found.

Then, the errors must be carefully backed-out of the appropriate previously computed frames.

This is why the conversion process is so slow unless implemented in hardware as they are in 120Hz and 240Hz HDTVs. (Although this is a simpler process because motion vector times are always the same.)

I believe you can download a demo version of Twixtor. When I tried it many years ago it would occasionally drop a frame. I assume it is now much better.

Dear Steve,

As I said above:

We are in complete agreement: "The time between frames for 29.97 simply can NOT be be made to be the time between frames for 23.976."

Then I responded to your comments that we are creating slow or quick motion, which we are not.

As you properly state, it takes a lot of computing power to do as you suggest.

What we are offering is a solution that may not be for everyone.

If someone wants to record 1080p29.97 out of the nanoFlash, with the proper time per frame, then they can do it.

If they want 1080p24 (without each frame occupying the precise 1/24th of a second time), then they can do it.


And of course one can use Twixtor.

My only issue with the claim that 24p can be recorded is that very few understand the fine line between getting 24fps with frames each captured at their correct time and simply getting 24fps.

Sony tried this with their Z1.

The problem is that I predict, since I cannot see it, that it's got to look really really bad. There is a huge error every time a the system tries to pick a frames that should be 1/24 th second apart from frames that are actually 1/30 the second apart. No time to calculate the percent error, but it is going to be RELATIVE to the timebase large and not consistent.

I think the average error is 25% in capture time.

Just realized that I didn't consider thar somewhere in every 30 frames 6 have to be dropped.So when a frame goes away there is a gap of 1/60th second which means one or more of the new frames is going to be a long way from where it was captured.

One good thing about the VG10 is that even in the 30fps world the shutter speed can be set to 1/50th.

yes a downloadable ProRes 23.976 file would be perfect!

Dear Friends,

I think the next step would be to record some video, with motion, to see how it looks.