HALF FRAME MUTE /DELAY AUDIO H264 H265 IN PREMIERE PRO

[Odobe]

We are working with an audio partner who has noticed that our mp4s made in h264 (and sometimes h265) are mute for approx half a frame. The same is true of Media Encoder and Premiere pro.

When we import these into Premiere Pro the Waveform aligns with the WAV supplied by the partner.
But in Davinci you can see there is a muted and delayed half frame.

Exporting the same audio clip from Davinci to mp4 we aren't seeing the same delay/muting.

The Quicktime is fine.

I would love to have a workaround for this so that we can continue to deliver Mp4s from Premiere or Media Encoder.

[Dani_V.]

Hi @Odobe,

Thank you for submitting a bug report. A few questions so we can look further into this: What version of Premiere Pro are you working with? Do you know what software the audio partner is picking up on the discrepancy with, is it in DaVinci Resolve as well? Is the WAV sample rate the same as the export sequence sample rate?

Just to clarify, your .mp4 files are audio only with no video at all, and that half-frame of no sound/mute is actually off-setting the entire track by that same half-frame within DaVinci Resolve, correct?

Sorry for the frustration,
Dani

[Odobe]

@Dani_V.  We are using Version 25.2.1 Build2 - across ten computers currently - the problem occurs across the computers.

Our audio partner is using Protools.

The sample rate in both the original wav and the sequence is 48khz.

I removed video as it is just an audio issue.

[Rach McIntire]

Hi @Odobe, 

Please give me more details about your workflow for context and so I can try to reproduce it better.

Am I correct that you are sending a ref QT to an audio facility, and the audio in the ref QT is off by half a frame?  Or is this a file you are receiving that is off?  

I'm glad to hear the sample rates match. What frame rate are you working with/ exporting to so I can match it?  Also, just double-check: When you say the project occurs across all the systems, are you using the same project to test it across systems or creating a new one each time?

I hope we can help you soon.

[Odobe]

Hi Rach, 

I started the process again - this time taking a wav from the free Audtion sfx packs.

I created a new timeline based on the wav and exported as both Quicktime, h264 in a quicktime wrapper, h264 in an mp4 wrapper etc. 

You can see that there is a delay to the audio in the mp4 which doesnt occur in the quicktime.

When the same process happens in Davinci the h264 in mp4 wrapper doesnt have the same amount of delay (if any visible).

Image attached below showing the delay.

[Rach McIntire]

Hi @Odobe,
 Can you tell me more about your export settings? Are you exporting out of Premiere or sending it to Media Encoder? Could you let me know if you are getting this menu, and if so, which option are you selecting?  If not, what are your settings?

 

[Odobe]

Hi @Rach McIntire 

If you look at the screenshot from June 9th you can see that I exported a bunch of different ways.

Our most common workflow would be to use an H264 VBR 2Pass at something like 50 or higher

Can you let me know if you think altering that would change the outcome - and please let me know if you can export a WAV from Premiere without any delay and with which settings?

[Odobe]

@Rach McIntire @Dani_V. 

I'm at the point where my company is delivering 300+ assets a week in mp4 and we'd love a fix for this before we move into just delivering from Davinci - I'd love to stay in Premiere if possible.

Can you let me know asap if you can find a workaround?

[Rach McIntire]

HI @Odobe, 
I haven't been able to get a good repro on this, but based on the information you've provided, I think Premiere is somehow interpreting the VBR differently than other programs, but this is just a guess at this stage. If you use a non-VBR codec, does the audio align? That might be a workaround for now.

[Odobe]

@Rach McIntire Thank you - ill try using a non vbr export and see if that remedies it - and i think it could be about the interpretation too, cheers

[Odobe]

@Rach McIntire @Dani_V.  Hmm... I'm still getting this delay when the mp4 made in CBR is viewed in Davinci vs when viewed in Premiere - I'd love to be able to reassure our clients and audio partners. If our audio partners view the CBR in Protools and see the same delay we can't deliver from Media Encoder or Premiere - any ideas?

[FlyingFourFun]

Is there any chance that delay is related to the preferance setting for audio hardware;  I think the default is 200ms but there are other options...  I cant test it properly to know for sure, but its an easy change for you to make/test if your interested.

[Rach McIntire]

@Odobe  Interesting.  There goes that theory.  Did @FlyingFourFun's suggestion make a difference?   

[Odobe]

@FlyingFourFun @Rach McIntire 

I will test this today.
But also if you can export an mp4 without this delay please can you share you settings?

[Odobe]

@Rach McIntire @Dani_V. 

Hello - I realise the latency was about playback.
This is about guaranteeing an encode doesn't have a delay when an h264 is in an mp4 wrapper.
We're about to be pushed to move away from encoding any more mp4 from Premiere or Media Encoder as we can't seem to export an Mp4 without this visible in the waveform in Protools or Davinci which is how our audio partner is viewing the waveforms.

Please as a matter of urgency can you test a WAV audio into an Mp4 and look at it at the audio units level but outside of Premiere pro and let me know if you can successfully export?

Thank you.

[Rach McIntire]

Hi @Odobe,

I've filed a bug report with the team. Hopefully, we can find a solution soon. 

[Odobe]

@Rach McIntire Thank you

[Odobe]

@Rach McIntire I wondered if there was any update on this?

[Rach McIntire]

Hi @Odobe, 
 We have reliably reproduced the issue internally, and the bug is still being worked on.