I have just ccrashed DaVinci 16

[Terence Christopher]

George Thanks for your comment. I have made progress with that project which is satisfying though I have a long way to go. However I am now stymied by a problem I have encountered with ER Media Toolkit. It is a superb program and I have been using it to convert my videos to Pro Res 422 which it has done smoothly. However I was encountering frequent desynchronisation. of the video and audio. As most of my videos do not have full face shots of conversation i didn’t realise the problem. However recent clip showed that this had occurred from using the ER Media Toolkit. I have contacted them for help but just in case things do not work out, can you recommend another programme that you use for creating pro res 422 from M2T or mp4 files. This problem might just arise from my awkward M2T format.
Thanks
Terence

[George Dean]

Hi Terence,

Before this reply I ran a 6 1/2 minute m2t (the longest I have) clip through ProResER and then brought it into Resolve 16b3. The sound sync was perfect. Then I processed the m2t clip again in ProResER and this time I selected ‘Extract Audio to WAV’. I brought these two files into Resolve 16b3 and again the audio sync was perfect.

I’m thinking your m2t clips are much longer than mine, so you may want to check some of your converter ProRes 422 clips at about the 6 minute mark. If they are out of sync at that point, then it may be caused by your source. If they have not fell out of sync by the 6 minute mark, then my test results may not be of any use. At any rate you may want to try a test using the ‘Extract Audio to WAV’ option and see if that creates an audio file that will stay in sync with the video.

As far as other options to convert your m2t to ProRes 422, I know of no others, other than of course using command lines for ffmpeg, which is what ProResER is doing. ProResER, as I understand it is a front end interface for ffmpeg which is the engine used behind the scenes.

You could use Handbrake and convert to a high bit rate x.264 file. Of course MediaER will convert to mp4 and you can crank up the bit rate to preserve quality.

It’s disappointing you have gone through so much with your projects and now the audio sync issue. Wish I could offer you more, Good Luck with it.

Best Regards……George

[Terence Christopher]

George Thanks so much for responding so promptly and running that test. Yes my video is an hour long and the problem showed up in the first few minutes when I had a full face video of my 2 1/2 year old grandson having a conversation. I had requested several of the options such as deinterlacing, constraining to 1080, and anamorphic as the video otherwise comes out as a 3X4 NTSC image. I will try different combinations of these to see if they influence the outcome and then try the wav test. Does that wav output come out as two separate files or is it still synced? I have not yet learned how to handle separate audio tracks
Thanks for taking the time to help me with this. From my view point it is well worth my time to solve the problem.
Graham

[George Dean]

Hi Terence,

It will come out with 2 files, the ProRes 422 video and a matching WAV audio. Place them on the time line, audio below the video clip starting at the precise same point and they should be the same in length to fall into sync. I’m suspicious if this will work, but worth a try.

Best Regards……George

[Terence Christopher]

Thanks I will attempt that and try to find where the problem is. I have been working on restoring the synchronisation of the file in DaVinci 16 and its almost right. If I get it right could I save that back into my source? I will need to investigate the problem before charging ahead with more video and if I come up with anything I will report it back to you. Thanks indeed for all of your support. I am learning to navigate Da Vinci by bouncing off of the walls.
Terence

[George Dean]

Hi Terence, there are various formats you can use in Resolve, probably I would use DNx.

Best Regards……George

[Terence Christopher]

Hi George I have just tested another video with the same parameters, both with and without de interlacing. Unfortunately Both of these files showed a loss of sync when compared with the original. I had completely switched over to Pro Res. I don’t know what is wrong with my videos, but I think I will try your suggestion and switch to DNX
However I will sleep on it first.
Thanks for the suggestion
Terence

[Joseph Owens]

[Terence Christopher] “a loss of sync when compared with the original”

This is starting to remind me of a general problem with some consumer-level generated clips, mobile devices the leading culprit. Many of these create media with a variable frame rate as a file-size reduction strategy. These play back fine, when the Player software can deal with how the frame sequence relates to real-time synch. It would be like punching a sprocket hole only in the film strip where it would be needed to advance to the next frame. Otherewise, hold onto the frame in the gate, sort of thing. Not actually what happens.

This works great with iMovie, etc., but most NLEs, Resolve included, really want intra-frame coding and depend on a constant frame rate, and will treat every frame as sequential and will play them at the project rate until otherwise notified. I hit this for the first time dealing with some phone footage my daughter wanted me to process for her… about ten years ago… Re-encoding it is the only way to re-flag the frame rate, and it would really help if it was a true intra codec with discrete frames, not another Long-GOP.

jPO, CSI

\”I always pass on free advice — its never of any use to me\” Oscar Wilde.