- Posts: 1
- Joined: Tue Mar 19, 2019 3:52 pm
- Real Name: Annette Wilson
Tue Mar 19, 2019 4:45 pm
I'm trying to use the retime controls to have a fast-forward effect on portions of my clip. I've found that the audio remains in sync if I speed up or slow down a segment of the clip, but goes out of sync only when I return to 100% speed in that clip. Specifically 100%. If I use the curves view to set a speed of 99% it is in sync. Is this a bug?
Here's what I did to test this out precisely:
1. Recorded video of me counting slowly from one to ten.
2. Imported it into a fresh timeline.
3. Added two speed points between numbers.
4. Speed up the audio in that middle segment to 200%.
The result is that the audio and video remain in sync in the 100% segment up to the first speed point, and in the 200% segment up to the second speed point, but after the second speed point, the video runs as expected at 100% with no discontinuity, but the audio jumps back and replays from an earlier portion of the audio at 100% speed.
If I do the same, but add:
5. Slow down the audio in the last segment to 75%.
Now the result is that the audio remains in sync with the video, as expected. I can use the retime curve to set the retime speed for the last segment extremely close to 100% (e.g. 100.80% or 99.60%) and the audio remains in sync with the video. It's only when set to exactly 100% that it loses sync.
It appears that any segments with 100% speed are playing audio from the source as if the entire clip had been playing at 100% speed up until that point. So if they are preceded by a high-speed section they will replay some of the audio, and if they are preceded by a low-speed section they will skip some audio.
I should also note that the audio waveforms shown on the timeline for the clip appear to bear little relation to either what is playing or what I would expect to be playing, but I have little idea what's going on there and it's not my main concern.
I'm running Davinci Resolve 15.3.0.008 on a Windows 10 laptop.
Processor Intel(R) Core(TM) i7-8750H CPU @ 2.20GHz, 2201 Mhz, 6 Core(s), 12 Logical Processor(s)
Installed Physical Memory (RAM) 16.0 GB
Video cards:
1. Intel(R) UHD Graphics 630
2. NVIDIA GeForce GTX 1060
Let me know if there are any other details that would help figure this out.
Is this a known issue? It reproduces reliably for me, but perhaps it's related to the particular way I'm recording video and audio? (I'm using OBS and recording three stereo tracks - mixed, voice only, desktop audio only - and then discarding the mixed track for editing.) Is there some setting that might affect it?
I can work around this by using 99% speed segments, but it's frustrating. I could also just split into lots of clips and adjust the speed of each individually, but so far I've found that to be very difficult to edit - once anything moves it's hard to keep consecutive clips seamless. The retime controls appear to be just what I want, if only they did what I expected.
Here's what I did to test this out precisely:
1. Recorded video of me counting slowly from one to ten.
2. Imported it into a fresh timeline.
3. Added two speed points between numbers.
4. Speed up the audio in that middle segment to 200%.
The result is that the audio and video remain in sync in the 100% segment up to the first speed point, and in the 200% segment up to the second speed point, but after the second speed point, the video runs as expected at 100% with no discontinuity, but the audio jumps back and replays from an earlier portion of the audio at 100% speed.
If I do the same, but add:
5. Slow down the audio in the last segment to 75%.
Now the result is that the audio remains in sync with the video, as expected. I can use the retime curve to set the retime speed for the last segment extremely close to 100% (e.g. 100.80% or 99.60%) and the audio remains in sync with the video. It's only when set to exactly 100% that it loses sync.
It appears that any segments with 100% speed are playing audio from the source as if the entire clip had been playing at 100% speed up until that point. So if they are preceded by a high-speed section they will replay some of the audio, and if they are preceded by a low-speed section they will skip some audio.
I should also note that the audio waveforms shown on the timeline for the clip appear to bear little relation to either what is playing or what I would expect to be playing, but I have little idea what's going on there and it's not my main concern.
I'm running Davinci Resolve 15.3.0.008 on a Windows 10 laptop.
Processor Intel(R) Core(TM) i7-8750H CPU @ 2.20GHz, 2201 Mhz, 6 Core(s), 12 Logical Processor(s)
Installed Physical Memory (RAM) 16.0 GB
Video cards:
1. Intel(R) UHD Graphics 630
2. NVIDIA GeForce GTX 1060
Let me know if there are any other details that would help figure this out.
Is this a known issue? It reproduces reliably for me, but perhaps it's related to the particular way I'm recording video and audio? (I'm using OBS and recording three stereo tracks - mixed, voice only, desktop audio only - and then discarding the mixed track for editing.) Is there some setting that might affect it?
I can work around this by using 99% speed segments, but it's frustrating. I could also just split into lots of clips and adjust the speed of each individually, but so far I've found that to be very difficult to edit - once anything moves it's hard to keep consecutive clips seamless. The retime controls appear to be just what I want, if only they did what I expected.