weirdness with 120 fps

Sal Ferrari · Mar 27, 2016

Hello,

I was so excited to see that the P4 supports 120 fps. However I'm running into strange issues

1. I'm not getting any preview/proxy videos in the Library tab for these shots.
2. Sometimes I'm getting corrupt video files when I import them to my mac. They are several GB in size but QT can't open them.
3. The times that I am able to open the files, QT plays that at 29.97 fps. I select "get info" inside of QT and it reports that the file is at 29.97. To compare I looked at the shots I took at 60 fps and they report 59.94 in the info panel and play reasonably correct.
4. The video quality at 120 fps is awful. I see blockiness throughout the entire video. NOT GOOD.

Can anyone confirm these issues? I have a support call logged into DJI at the moment and will report back once I get more information. Thanks.

DroneDestination · Mar 27, 2016

Maybe a) your computer can't play 120fps files or b) your monitor is only 60hz and cannot display 120fps.
Just shots in the dark here, no hate please.

isopro · Mar 27, 2016

anyone tryed the 120 fps, without any issue here ?

Sal Ferrari · Mar 27, 2016

its definitely not my computer. the file is stamped incorrectly as 29.97. If I speed it up it plays at the right speed. Still looks like *** tho.

isopro · Mar 27, 2016

Sal Ferrari said:
its definitely not my computer. the file is stamped incorrectly as 29.97. If I speed it up it plays at the right speed. Still looks like *** tho.

I think i read about this issue in another thread, i believe you could fix that in premiere pro or after effect, by changing clip properties, but i dont know how to properly fix the file in windows without 3rd party programs, such as those mentioned above

mirrorimage · Mar 27, 2016

Sal Ferrari said:
Hello,

I was so excited to see that the P4 supports 120 fps. However I'm running into strange issues

1. I'm not getting any preview/proxy videos in the Library tab for these shots.
2. Sometimes I'm getting corrupt video files when I import them to my mac. They are several GB in size but QT can't open them.
3. The times that I am able to open the files, QT plays that at 29.97 fps. I select "get info" inside of QT and it reports that the file is at 29.97. To compare I looked at the shots I took at 60 fps and they report 59.94 in the info panel and play reasonably correct.
4. The video quality at 120 fps is awful. I see blockiness throughout the entire video. NOT GOOD.

Can anyone confirm these issues? I have a support call logged into DJI at the moment and will report back once I get more information. Thanks.

What happens if you play them back in VLC on the mac?

m0j0 · Mar 27, 2016

I'm just guessing but I'm betting the cam is shooting the higher frame rate like the Panasonic gh4 shoots it. It is truly 29.97 Overcranked. Just a guess. Simply put it is 29.97 sped up to 120

Sent from my iPad using PhantomPilots mobile app

m0j0 · Mar 27, 2016

Just to add to the convo. When I shoot 96 fps on the GH4 I can choose to overcrank from 24 or 29.97.. It then plays slowed down in the timeline .

Sent from my iPad using PhantomPilots mobile app

Sal Ferrari · Mar 28, 2016

mirrorimage said:
What happens if you play them back in VLC on the mac?

The bad files do not work.

The ones that I'm able to play in QT play the same in VLC (slowed to quarter speed and crappy looking).

Sal Ferrari · Mar 29, 2016

Has ANYONE else tried 120 fps or am I the only one?

If so, please let me know if they work properly for you thanks.

Ramphex · Mar 29, 2016

Please report back with the memory card you are using to write these files to on your aircraft.

Sal Ferrari · Mar 29, 2016

i am using the stock card that came with the unit. 16 GB Lexar 633x U1, HC1

I filmed more today in both 60 fps and 120 fps.

the 60 fps files worked perfect.

the 120 fps files were blurry (only 12.5 Mbps, unlike the 60 fps at 60 Mbps) and they did not show up in the Library (the proxy file icons did not automatically show up like they are supposed to). I loaded these onto my Mac and they played at quarter speed. They are stamped at 29.97 fps.

I expect better. this is kinda bullsh&%^$&# right?

Sal Ferrari · Mar 29, 2016

I found another related thread

Filming 120FPS

Ramphex · Mar 29, 2016

Have not tried recording in 120fps. Quick question, what are you trying to record that you need 120fps?

mirrorimage · Mar 29, 2016

Sal Ferrari said:
Has ANYONE else tried 120 fps or am I the only one?

If so, please let me know if they work properly for you thanks.

It seems to work properly. It seems like the SD card you used wasn't fast enough and it wrote a corrupted file that you can't open. You said all the other videos at 120fps came out fine correct? Just this one. Try using a better SD card and see if new videos have this problem. It sounds like it's only on that one file correct?

Ramphex · Mar 29, 2016

mirrorimage said:
It seems to work properly. It seems like the SD card you used wasn't fast enough and it wrote a corrupted file that you can't open. You said all the other videos at 120fps came out fine correct? Just this one. Try using a better SD card and see if new videos have this problem. It sounds like it's only on that one file correct?

Seems as he's having issues with all of this 120fps files. Only the 60fps ones are good.

mirrorimage · Mar 30, 2016

Ramphex said:
Seems as he's having issues with all of this 120fps files. Only the 60fps ones are good.

Apologies for misunderstanding. Can someone else confirm that 120fps videos play back on Mac using quicktime correctly? As far as the quality of 120fps they won't be impressive. Videos will be darker, and look grainer than you would expect.

Can you please share one of your 120fps raw videos? Then I'll see if I can figure it out.

Ramphex · Mar 30, 2016

Why are we using QuickTime instead of something more powerful like VLC?

Fallguy · Mar 30, 2016

I reported this problem right after I got my P4 2 weeks ago. The 120fps is nothing like the 120fps I was used to on my Gopro. You could play those files back on any player at normal speed without having to speed it up yourself in the player.
The reason you should need the 120fps in your video is because then you could slow the video down yourself when you render it for a smooth looking slow motion effect. The 120fps was a contributing factor in me getting this quad , and it sucks. 60fps works just fine.
As far as sd cards , I would make sure you get a quality U3 card from a reputable dealer if you intend to use 4k video. IMO

StevenQX · Mar 30, 2016

Fallguy said:
I reported this problem right after I got my P4 2 weeks ago. The 120fps is nothing like the 120fps I was used to on my Gopro. You could play those files back on any player at normal speed without having to speed it up yourself in the player.
The reason you should need the 120fps in your video is because then you could slow the video down yourself when you render it for a smooth looking slow motion effect. The 120fps was a contributing factor in me getting this quad , and it sucks. 60fps works just fine.
As far as sd cards , I would make sure you get a quality U3 card from a reputable dealer if you intend to use 4k video. IMO

Was one of the strong point of P4 also for me but after reading how 120fps is on the p4 (fake 120fps with looow bitrate) it's not anymore.