Audio Overload Issues with Screenflow?
I've noticed that Screenflow can show audio overs (red peaks in the waveform) even when exported out as audio, show no overages at all.
Also, to keep these overs from appearing in SF, I have to have a Brick-Wall Limiter set to -4 on the outputs of Logic Pro to keep the audio from going over in SF...
Am I missing something here? It's a direct input as Computer Audio.
A -1dB Limiter on the output (of Logic) should provide more than enough headroom going into SF to allow for errors when transcoding. Having to 'crush' it at -4 seems a bit excessive.
Any suggestions are welcome, as this is a bit of a mystery to me.
Most audio software is calibrated at digital zero- when I record from Logic or Pro Tools and have output levels set to a certain level, all other programs that that audio is imported or recorded into are identical in level and metering.
I record Screenflow from DAW's for my work (and am an Audio Engineer), and love the workflow and compatibility, but have always wondered why my SF recordings seemed slightly distorted - even with precautions taken for proper levels, processing, and limiting out of one program into SF.
I will continue to test this with output from multiple DAW's into SF, but the fact that Screenflow seems to record at a much hotter level (requiring my output from a DAW to be about 4 dB quieter) is odd - is there a way to adjust the input level of audio into Screenflow?
Thanks again for your help with this,
Hi Jon and Craig - I'm using Logic X and observing the same problem. In order to see if this is just a display issue, I captured a video of running Logic X with no clipping. Then I exported the audio as an aiff file from ScreenFlow and imported back into Logic. The difference in levels is dramatic. It also sounded distorted once played back in Logic. I'm not all that experienced in ScreenFlow yet but I don't see how this can be controlled or calibrated at record time. We may need to select the clips inside SF and reduce the levels (to what though? what should the scaling be??) but I have to wonder why isn't the captured audio exactly the same level as it is inside Logic?
I am running Logic X version 10.3 on a MacBook Pro OS X 10.11.6 My audio interface is RME UFX.
I welcome any ideas. Thanks!
As I noted in my first post, you can put a limiter on Logic's Output Channel with an output level of -4 . This will keep the levels safe when recording directly (or importing) into Screenflow.
it's a workaround, and being able to directly control the input levels into SF would be better (again, 4dB reduction is a lot), but it's usable.
It's nice to hear that someone else is seeing this happen (I know it's not just something in my setup) and maybe we can get the Techs at Telesteam to look into this.
Will be testing this week from a few other DAWs to see if it's reproducible with them as well.
Hi Jon. Putting a (-4db) limiter on the Logic output channel will crush the audio. Maybe I can lower the master level in Logic. I honestly don't know if this is directly related to Logic or in general piping audio from osx core audio to SF. Maybe more experiments are needed. I will bounce the audio from Logic and then do an import into SF to see what the levels look like that way. I can also measure file loudness with a 3rd part tool as an objective measure.
Please update with any experiments you run as well. It's possible that others don't generate audio that close to 0dbf and so maybe it's not experienced by everyone. Still - I would like to see the audio inside SF at the *exact* same level as it is inside the computer.
I will update when I have more data to share.
Craig - any thoughts?
Ok I think I figured it out at least for my own setup. Let's see if I can explain.
- My goal is to screen-cast workflows operating Logic X + doing live narration.
- I'm using an RME interface which has a poweful digital mixer built in called TotalMix.
- SF is set up to record from the RME interface "device" inside the computer. I'm not connecting audio cables. This is all routed in the audio device. I'm not recording system audio into SceenFlow
- Both Logic X and my mic are mixed inside TotalMix and fed back such that SF can read those channels. So, again - all audio is coming from the interface only
- SF captures the audio from the interface as a stereo track. It includes both the Logic sound + the microphone for narration.
- The output level from the RME interface does affect the record levels in SF as Craig implied (although he gave an example of a different output) but I set all the levels in TotalMix to unity gain so there should be no attenuation or amplification, in my opinion
- I recorded the output of (RME)TotalMix back into Logic to check the levels.
- I then recorded via SF and exported as Lossless audio and then imported into Logic to compare all these audio files.
- The SF audio was distinctly louder than both the original audio in Logic and the output of TotalMix which was recorded back into Logic. This is the problem I've reported.
- I finally went into the audio tab in SF and noticed that the two tracks that were coming in from the RME interface were set by default to....mono... I selected and panned one left and one right. I immediately noticed that the waveforms inside the stereo audio track shrunk back to what they originally looked in Logic and no longer clipped!
- I then exported the audio from SF and imported into Logic and the levels matched my own recording.
I think this is the problem. The question then is - why are the tracks set to mono and end up at such a high level? It's obvious to me that the panning fixes the problem.
I'm relieved and confused at the same time.
CraigS - can you follow what I described?
At the end of the day my whole procedure is less important than the fact that the captured stereo track ends up with higher levels because the tracks are not panned.
Avi Ziv Yes, -4dB is a lot, but never lower the Master Fader in Logic - always lower the individual Channels,
I tested different Limiting levels (at half dB increments) and found that -4 was the one that worked.
Edit - I agree that panning stereo channels will lower levels, but this has to be done in SF's Audio Mixer before editing. I wish there was a Template that allowed this from the start of a session.
I do very similar sessions to what you are doing (LPX videos for education), and having SF start in stereo mode would eliminate what is (almost always for me) a forgotten step because I want to get into editing and annotation...
Jon Curtis said "Edit - I agree that panning stereo channels will lower levels, but this has to be done in SF's Audio Mixer before editing. I wish there was a Template that allowed this from the start of a session."
I fully agree. So far my observation is that panning fixes the levels issue and there needs to be a way to configure SF so that this persists as either a template or a project preference. I'm new to SF and I don't know how long it would take others to find the relationship of the panning to the levels as we have. Like I said, after panning, if I export the audio and bring it back into LPX, the levels are good.
Out of curiosity, I fired up SF 5.0.7 on my secondary MacBook Pro here at the office, and did the same Sine wave test as above (generated Mono 1kHz Sine, 0dBFS) and recorded into Screenflow. Mac set to Internal Speakers with level set to 0 (lowest setting) - still overloads:
Here is the WAV file of the Sine if anyone wants to test it themselves:
More testing to come...
However - when recording those session into Screenflow, PT will show over for the 0dB Wav, but not the -3 one. Logic shows overs for *both* the 0dB and -3dB files.
This would explain why -4 seems to be the right level out of LPX into SF, but I don't know why they are so different on output...
The recording path into SF was monitor screen and computer audio only for both examples. Audio monitoring was done on headphones.
Jon Curtis Are we in agreement that the issue is with the channel panning inside SF? This is my conclusion for my case at least. My guess is that SF sees two channels coming in and doesn't know if they are two mono channels or a stereo pair and we need some way to define our setup for SF and have it stick. Once I pan the channels in SF, the levels are ok as measured when I import back into LPX.
Thanks for running your tests!
Avi Ziv My guess is that SF sees two channels coming in and doesn't know if they are two mono channels or a stereo pair and we need some way to define our setup for SF and have it stick.
If you're coming from an external device, ScreenFlow probably wouldn't know if the source is dual mono or stereo. Certainly report that. Include your workflow in the report. After you get the case number, include relevant screen shots.
ScreenFlow Support Form
Jon Curtis I imported your wav file test tone into ScreenFlow.
I also imported it into FCPX 10.3.2 which should handle it the way Logic Pro handles it.
FCPX shows it as -6db which would be "0" so that is correct based on how those meters are calibrated.
I checked to see how far I needed to bring down the levels in ScreenFlow to for the red to disappear and it was only 1% so they actually do match almost exactly.
So esentially using your test wav file ScreenFlow matches FCPX. This isn't an issue.