Hi!

I have been playing with active track today and I recorded two videos. Both show a strange issue:

• When I play the cached video on my phone, it plays in 720p just fine.
• When I play the original 1080p stored on the Mavic through the DJI Go 4 app, it plays in slow motion!
• I downloaded the original video from the SD card to my PC and opened it in three different video players on Windows. They all play it in slow motion.
  

Any ideas?

was you recording at 96fps?

SLiWooDy Posted at 2017-1-28 07:55
was you recording at 96fps?

My original setting was 4k/30fps. Then I started Active Track. I do not remember what the app showed then. But the video on the SD card is 1080/25fps. I think I'll have to go outside and try this out again.
Update: I went outside, started Active Track and this time the video looked good. No idea what happend before. :-/


Edit: I probably was not in 4k/30 mode when the recording started. Maybe it was 1080/96.

Dronoob Posted at 2017-1-28 07:59
My original setting was 4k/30fps. Then I started Active Track. I do not remember what the app showed then. But the video on the SD card is 1080/25fps. I think I'll have to go outside and try this out again.
Update: I went outside, started Active Track and this time the video looked good. No idea what happend before. :-/

I had the same problem today.. First flight so i used 1080p 96fps and its all in slo mo...
How can i fix this?? got some good video today but no good if its in slomo..

Thanks for any help..

fans8b782c4f Posted at 2017-1-29 09:15
I had the same problem today.. First flight so i used 1080p 96fps and its all in slo mo...
How can i fix this?? got some good video today but no good if its in slomo..

Hi.

Slovmotion when playing back a video recorded at 96 FPS mode is because there is a bug in the format it is written in. If you use the program MediaInfo https://mediaarea.net/uk/MediaInfo  to read the video format you see the file is written as a 1080p 24 FPS with a bit rate of 15 Mbps. The last figures explain the miserable video quality.

It can only fixes in post production or playing in a player that can display video back at 4x speed. Hope DJI will have corrected the error in the next update.   

Regards Leif.

Landbo Posted at 2017-1-29 10:21
Hi.

Slovmotion when playing back a video recorded at 96 FPS mode is because there is a bug in the format it is written in. If you use the program MediaInfo https://mediaarea.net/uk/MediaInfo  to read the video format you see the file is written as a 1080p 24 FPS with a bit rate of 15 Mbps. The last figures explain the miserable video quality.

That's it! I checked another video on the SD card that has been recorded with 1080/96. And it also plays in 23fps. The transmitted video (cached video) plays just fine here too. It should be easy to reproduce this issue and fix it now.

I am still not sure if I had selected 1080/96. I know I set the format to 4k/30. But I cannot remember exactly when. Let's assume I switched to 4k afterwards.

PS: Would be nice to get some better video quality at 1080/96. The moiré patterns are horrible.

Dronoob Posted at 2017-1-29 11:06
That's it! I checked another video on the SD card that has been recorded with 1080/96. And it also plays in 23fps. The transmitted video (cached video) plays just fine here too. It should be easy to reproduce this issue and fix it now.

I am still not sure if I had selected 1080/96. I know I set the format to 4k/30. But I cannot remember exactly when. Let's assume I switched to 4k afterwards.

Well.

If you use the same program on the second video, you will see the number of Mb/s is higher if you have recorded 24 or 30 FPS.

DJI should be able to write a 96 FPS 1080p video with a bit rate of up to 60 Mb/s, which is that of an 4K video.

Regards Leif.

Dronoob Posted at 2017-1-29 11:06
That's it! I checked another video on the SD card that has been recorded with 1080/96. And it also plays in 23fps. The transmitted video (cached video) plays just fine here too. It should be easy to reproduce this issue and fix it now.

I am still not sure if I had selected 1080/96. I know I set the format to 4k/30. But I cannot remember exactly when. Let's assume I switched to 4k afterwards.

I think I have this issue. My osmo will not read the SD card but the files are there and I played them in VLC and they are all slow and garbled

Dronoob Posted at 2017-1-29 11:06
That's it! I checked another video on the SD card that has been recorded with 1080/96. And it also plays in 23fps. The transmitted video (cached video) plays just fine here too. It should be easy to reproduce this issue and fix it now.

I am still not sure if I had selected 1080/96. I know I set the format to 4k/30. But I cannot remember exactly when. Let's assume I switched to 4k afterwards.

@the DJi guys here: Can you forward this to the engineers please to make sure this is not forgotten in the next update?

Landbo Posted at 2017-1-29 10:21
Hi.

Slovmotion when playing back a video recorded at 96 FPS mode is because there is a bug in the format it is written in. If you use the program MediaInfo https://mediaarea.net/uk/MediaInfo  to read the video format you see the file is written as a 1080p 24 FPS with a bit rate of 15 Mbps. The last figures explain the miserable video quality.

Hey,

do you have an idea how to fix that in postproduction? Would be very thankful for some advices.

Thx and best regards,
Moritz

mojoe2342 Posted at 2017-10-16 03:22
Hey,

do you have an idea how to fix that in postproduction? Would be very thankful for some advices.

No more than you set the speed 4x up for that cut. But 1080p is not nice in any way due to the low bitrate.

Regards Leif.

Hi, the slow-motion video will be generated when shooting 1080P 96fps and 720P 120fps, and they will be played at 23fps and 30fps. If you don't want the slow-motion video, please adjust the settings.

DJI Thor Posted at 2017-10-17 01:17
Hi, the slow-motion video will be generated when shooting 1080P 96fps and 720P 120fps, and they will be played at 23fps and 30fps. If you don't want the slow-motion video, please adjust the settings.

What setting is that?

Dronoob Posted at 2017-10-18 22:38
What setting is that?

Except for 1080P 96fps and 720P 120fps, other video settings like 2720x1530 25fps etc. are the normal version, try changing it on the video size settings.

DJI Thor Posted at 2017-10-19 00:22
Except for 1080P 96fps and 720P 120fps, other video settings like 2720x1530 25fps etc. are the normal version, try changing it on the video size settings.

OK, I misunderstood. I thought there was a setting to record e.g. 1080/96 in slow motion or regular speed. But I understand, that there is no such setting and if you do not want slow motion, you have to select a different frame rate.

It still feels like a bug that a 96FPS video is stored as 24fps video and if you want to get the normal play back speed (at a high frame rate) you have to edit the video. :-/

Dronoob Posted at 2017-10-20 03:30
OK, I misunderstood. I thought there was a setting to record e.g. 1080/96 in slow motion or regular speed. But I understand, that there is no such setting and if you do not want slow motion, you have to select a different frame rate.

It still feels like a bug that a 96FPS video is stored as 24fps video and if you want to get the normal play back speed (at a high frame rate) you have to edit the video. :-/

It is the design of Mavic Pro, if you need to play it at the normal speed, you might need to speed up 4 times.