Audio bug/desync
212 7 5-2 05:04
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DaLyR
lvl.3
Flight distance : 1105322 ft
Romania
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Hi, yesterday I tried to use lightcut to render a full video of 9 minutes which has more files of 2 minutes each but in the second clip of the 2 minutes I got some weird problem with the audio. It's not right after the split of the file but after few seconds... but if you play the original second clip directly from the splitted file there will be audio disruption for like 2 seconds and after that everything looks ok and normal, but those 2 seconds makes impossible to join all clips directly in lightcut without getting the sound delay on the ENTIRE VIDEO, which is very frustrating!
I recorded in 2.7k, loop mode (20 minutes), rocksteady on, pro mode on


This problem made impossible to render it directly in Lightcut app because from that second clip all audio becomes waaaay unsyncronized, like 2-3 seconds of delay between the image and the audio.

I uploaded the 2 clips here: https://drive.google.com/drive/f ... frpftQb?usp=sharing

In the second clip (DJI_20240501160503_0011_D_002.MP4) at 0:10 seconds you can hear the sound problem
5-2 05:04
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Andreas Dueck
Second Officer
Switzerland
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Did you record with the lowest shutter speed? If so, then the audio track has probably a faster "FPS" than the video file. The solution in this case would be to slow down the audio tracks.
5-2 11:33
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DaLyR
lvl.3
Flight distance : 1105322 ft
Romania
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Andreas Dueck Posted at 5-2 11:33
Did you record with the lowest shutter speed? If so, then the audio track has probably a faster "FPS" than the video file. The solution in this case would be to slow down the audio tracks.

There it's a moment where the sound stops completely and then "restarts". In the source file it's ok after this weird moment but in the lightcut everythings become delayed from that moment.
I used auto shutterspeed with the min. of 1/200 and 30fps so there was no chance to be the shutter speed under 1/100 atleast and also If i remember correctly I had max ISO 800 or even 400 but the light was enough to not auto set the shutter under 1/100...

For sure the problem it's no related to shutterspeed, but could be related even to the SD Card or something on the writing part, I THINK but DJI knows better that, for sure
5-3 00:36
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DJI Gamora
Administrator

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Hi, DaLyR. Thank you for reaching out. The problem cannot be confirmed due to incomplete information. Please provide us with the following information:
1. Have similar problems occurred in other shooting scenes and what is their frequency?
2. Device firmware version number;
3. Photo of the front of the SD card used;
4. Camera log and specific shooting time.

How to export a Log File?
1. Reproduce the abnormal process.
2. Go to camera unit System Settings - Device Info. Tap “Export Logs”.
3. Mount the camera unit and front touchscreen module/power module. Connect to Osmo Action 4 in a computer using a USB cable.
4. Select “File Transfer” on the Osmo Action 4 screen. Go to “My Computer”. Find the corresponding disc for the Osmo Action 4 (internal storage).
5. Export all log files and zip them. Send the entire zip file back for analysis and confirmation (Also check the time point when the abnormality occurred to determine the log position).

Please keep us posted.
5-3 05:52
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DJI Gamora
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DaLyR Posted at 5-3 00:36
There it's a moment where the sound stops completely and then "restarts". In the source file it's ok after this weird moment but in the lightcut everythings become delayed from that moment.
I used auto shutterspeed with the min. of 1/200 and 30fps so there was no chance to be the shutter speed under 1/100 atleast and also If i remember correctly I had max ISO 800 or even 400 but the light was enough to not auto set the shutter under 1/100...

Hi, DaLyR. We have sent you a DM, please check. Thank you.
5-5 21:52
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Andreas Dueck
Second Officer
Switzerland
Online

DJI Gamora Posted at 5-5 21:52
Hi, DaLyR. We have sent you a DM, please check. Thank you.

@DJI Gamora

Please make such answers public so that others who have the same problem can benefit from them.

Thank you very much for your efforts.
5-6 02:27
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osmonauta
Second Officer
Hungary
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The audio seems to be fine. If you extract the audio (from clip 2) and open it in an audio editor, there are no skips or silence. It plays fine.

However, I noticed when you encode the video (the 2nd clip) to H264, it skips about 87 frames starting at frame 390. So once you reach frame 390 (timecode 16:07:21;26) and you advance to the next frame, it will jump to frame #477 (16:07:24;23). Again, this is only after an H264 conversion of clip #2.

Something must've happened at that time and for some reason the video doesn't sync correctly with the audio at that point.


I used LosslessCut to extract the audio, and HandBrake to convert the video to H264. I tried both hardware and software encoding and in both cases the H264 version skips 87 frames.

5-6 07:09
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DJI Gamora
Administrator

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Andreas Dueck Posted at 5-6 02:27
@DJI Gamora

Please make such answers public so that others who have the same problem can benefit from them.

Hi, Andreas. The issue has not been analyzed yet as the needed details are not forwarded. If you are experiencing the same issue, please provide the needed info and files from this post.
5-8 07:56
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