@Eugen and Jean I have figured out what the problem was. Eugen's suspicions regarding the frame rate being a factor, turned out to be spot on.
When I render the 60FPS project I get the audio pops, however when I switch the profile to 23.96 or 25FPS, they disappear. Obviously the audio is otherwise unusable with multiple silent portions since I switched from a 60FPS to a 23FPS profile mid-project, which you cannot/should'nt do, but it confirms the source of the problem. The pops do not occur right away, it's mostly fine for about 1 - 2 minutes, but after that they start popping up, so the out of synch issue Eugen talked about makes a lot of sense. Unfortunately, I cannot simply use a 23 or 25FPS profile from now on, because I use a lot of Slide animations which I need to be rendered at 60FPS, and I don't see how else this can be achieved, other than using a 60FPS profile. Do you guys have any idea how I can keep exporting the video at 59FPS and still solve the audio/out of synch issue Eugen spoke of? Regards John Sent with [ProtonMail](https://protonmail.com) Secure Email. ‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐ On August 21, 2018 11:13 PM, johnar1 <john...@protonmail.com> wrote: > Hey Eugen! > > Thank you for your great insights. > > Yes, I use a 59.9FPS 1080p video profile and I am almost positive that the > entire audio is 44100 Hz. So you are saying that this is a known issue under > these specific conditions? (I will do my research right now, thank you!) > > I always try to cut audio when there is silence, to be more specific, I make > MMA Youtube videos, and mostly edit interviews. I make my cuts exclusively > during pauses or outro sections. > > But the pops also occur randomly with clips that I did not cut/edit at all or > of which I positively know that they are cut correctly without any lingering > sound pieces at the beginning, but you have already given a good explanation > now. > > I will compile the latest ffmpeg, ffplay and ffprobe and report back. > Is there anything else I should consider regarding this out of synch issue? > > Maybe increase the Hz of the audio that I use? > > Regards > > John > > Sent with [ProtonMail](https://protonmail.com) Secure Email. > > ‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐ > On August 21, 2018 8:53 PM, Eugen Mohr <eugen.m...@gmx.net> wrote: > >> Hi John >> >> It comes 2 things to my mind: >> - Do you cut the audio at the zero point? In Audition (for example) is a >> function that you can cut only at that point (when the wave goes through >> zero) to avoid clicks. >> - When audio frequency (i.e. 44.1kHz) and video frequency (i.e. 60fps) >> interfere each other after a time and from there you get clicks. Video >> rendering is always video frequency driven. This would be a FFMPEG problem. >> >> Merlimau >> >> Am 21.08.2018 um 19:55 schrieb johnar1: >> >>> Hey Jean, thank you for that valuable info. >>> >>> I have tested the 18.08 version that you linked and unfortunately the pops >>> at the beginning of audio clips still occur, but I have made an interesting >>> discovery. >>> When I render the entire project, there are three pops at the beginning of >>> 3 clips, let's say at 01:23, 02:02 and 03:15 in the time line. >>> These audio pops only come up in the rendered output, not during playback. >>> When I only render a small selected zone surrounding the area where I know >>> the pop will be, it does not occur. >>> Only when I render the full project, they appear. >>> I have tried this with all three known audio pops that I have spotted in >>> the fully rendered project, and each time they disappear when I only render >>> a selected area around them. >>> >>> The next thing I have noticed is that switching the playback settings >>> betwen SDL and RTAudio can affect this issue as well. >>> >>> As you know me now, I will now enter full testing mode and report back to >>> you with a more detailed analysis. >>> I will compile the latest melt, ffmpeg and co in order to provide a full >>> report, but I will use the AppImage versio 18.8.0 which you have suggested. >>> >>> Anything else I should consider? >>> >>> Best regards, >>> >>> John >>> >>> Sent with [ProtonMail](https://protonmail.com) Secure Email. >>> >>> ‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐ >>> On August 20, 2018 10:23 AM, Jean-Baptiste Mardelle >>> [<j...@kdenlive.org>](mailto:j...@kdenlive.org) wrote: >>> >>>> On 18.08.2018 14:55, johnar1 wrote: >>>> >>>>> Hey Jean and guys! >>>> >>>> Hello Johnar! >>>> >>>>> I have uncovered a new problem with the latest stable AppImage 18.04.1 >>>>> release of kdenlive which is very troublesome. >>>>> >>>>> Randomly, kdenlive will cause a "click" or "pop" sound at the beginning >>>>> of an audio track. I have observed that this happens the most when two >>>>> audio tracks are overlapping or a cut has been made at the beginning of >>>>> the a clip. >>>>> >>>>> I have also found that audio pops disappear in the same footage disappear >>>>> when switching from SDL to RTAudio in the settings. >>>>> >>>>> I am using a fresh install of Kubuntu 18.04 with updates and >>>>> Mlt and ffmpeg versions all from the Appimage, so this has to be a thing >>>>> in kdenlive or maybe the latest Alsa / Pulseaudio package? >>>>> >>>>> I have tried some stuff suggested in forums such as exporting only the >>>>> audio in wav, but without luck. >>>> >>>> I have just uploaded the 18.08.0 AppImage containing the latest MLT. Could >>>> you check if the problem still happens ? >>>> It is available here: >>>> >>>> https://files.kde.org/kdenlive/release/kdenlive-18.08.0-x86_64.AppImage.mirrorlist >>>> >>>> Thanks for your feedback. >>>> >>>> Jean-Baptiste >>>> >>>>> Any ideas? >>>>> >>>>> Regards >>>>> >>>>> ‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐ >>>>> On July 26, 2018 9:20 AM, Jean-Baptiste Mardelle >>>>> [<j...@kdenlive.org>](mailto:j...@kdenlive.org) wrote: >>>>> >>>>>> On 23.07.2018 00:21, Juku Trump wrote: >>>>>> >>>>>>> Hi, >>>>>> >>>>>> Hello Juku! >>>>>> >>>>>> Thanks a lot for your contribution and sorry for my late reply. Your >>>>>> help is very welcome. I have now merged your contribution. Regarding the >>>>>> tests, they need some work and currently don't all pass and crash. We >>>>>> need to work on that. >>>>>> >>>>>> Regarding other tasks, we really need to make a list of UI improvements >>>>>> that could be done without too much knowledge of the whole code. I will >>>>>> try to spend some time on it tomorrow, help is welcome. But basically, >>>>>> if there is any UI related thing that you want to improve, feel free to >>>>>> ask and we can guide you if needed. >>>>>> >>>>>> Best regards, >>>>>> >>>>>> Jean-Baptiste >>>>>> >>>>>>> My name is Juku. I am a film hobbyist and I have been using Kdenlive >>>>>>> for about 8 years. As I'm also a developer, I thought I would try my >>>>>>> hand on contributing to Kdenlive. >>>>>>> >>>>>>> I have mostly been a web developer so far, so I do not have much >>>>>>> experience with C++ (except for some tutorials) and I have never done >>>>>>> any Qt development. >>>>>>> >>>>>>> I viewed the "Junior Jobs" section in Kdenlive Development Information >>>>>>> page and tried to fix #384511 for start ("New project window does not >>>>>>> fit to laptop screen (1366x768)"). Thanks to a hint by Christoph Feck >>>>>>> in the comments below that bug, I got it fixed and submitted the patch >>>>>>> ([D14281](https://phabricator.kde.org/D14281)) for review. >>>>>>> >>>>>>> Currently I'm having some trouble with the automated tests. Should they >>>>>>> succeed in their current state or are there some known problems with >>>>>>> them? >>>>>>> >>>>>>> It would be helpful if someone would suggest some other tasks which I >>>>>>> could start with. >>>>>>> >>>>>>> Thanks, >>>>>>> Juku
