Using "Vine-like" mode, each clip is missing the front ~0.25s of audio

[nickkruge]

swift4.2 branch, latest
devices tried: iphone x, xs, xs+ running 12.1

When recording using the default settings two issues happen. The video starts out sharp, then turns pixelated at around 0.2s, then the audio pops in at about 0.25s. It is silent before it pops in.

I've looked inside the temp directory and the problem is happening at the individual clip level.
I've checked similar issues here on github and none seem to match exactly.

Here is a clip showing the issue: https://youtu.be/gDTwWR2Z4mU
I am making a sound the entire time, and you can hear how it cuts in and out. The pixelated problem may not come across as well since it is being re-encoded but you can clearly see that there is a snapped difference between the very start of a clip and short while later.

Initializing:

camera.videoDelegate = self
camera.videoConfiguration.maximumCaptureDuration = Helpers.cmTime(seconds: maxRecordingTime)
camera.captureMode = .video

do {
        try camera.start()
} catch {
        showPassiveError(message: "Unable to start camera \(error.localizedDescription)")
}

Starting and stopping:

camera.record()
camera.pause()

Exporting:

session.mergeClips(usingPreset: AVAssetExportPresetHighestQuality) { (url, error) in
                if let url = url {
                    // Do stuff
                } else if let error = error {
                    self.showPassiveError(message: "Error exporting \(error.localizedDescription)")
                }
            }

[pribeh]

Experiencing the audio issue as well. 0.15.2, Swift 5, on iPhone 6s running 12.2.

[UlanNurmatov]

Hi nickkruge,

Did you find any solution?

[nickkruge]

Unfortunately, no. I ended up implementing a camera from scratch.

On Mon, Jul 1, 2019 at 3:40 PM UlanNurmatov ***@***.***> wrote: Hi nickkruge, Did you find any solution? — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#171?email_source=notifications&email_token=AAHAGK3LER6HFXLEJKIQJN3P5KBVVA5CNFSM4HEONMKKYY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGODY7RLKI#issuecomment-507450793>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAHAGKZ73FAN25JFF6DHH6LP5KBVVANCNFSM4HEONMKA> .

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[CameraPost]

@nickkruge would you be open to sharing the code for making a camera from scratch that allows for merging clips? also experiencing the pixelation and sound delay -- plus an issue maybe not directly related where some portion at the end of what is supposed to be recording is not actually recorded when pressing to stop recording. thanks!!

[piemonte]

please verify with 0.16.1

[naturalui]

@piemonte I have tested this on 0.16.3 and still having issues with audio. It seems like the first part of audio is always missing. Maybe this has to do with when the audio is getting initialized when recordings start.

@tkohout Did your fix help with this? maybe good place to start looking for the bug.

Here are two sample clips (the sine tone is playing the whole time).
samples_audio_bug.zip

Ref: #216
Ref: #116

[naturalui]

Code: master (0.16.3)
Devices tried: iPhoneX and iPhone11ProMax

Small update that may help root cause:

I noticed when you toggle between the front and rear cameras once, the audio lag seems to get better. Not sure exactly what this means but maybe a hint towards the issue.

audio_bug_2.zip

Attached is zip with 4 samples, 0/1.mp4 are captured from fresh session start and 2/3.mp4 are captured after toggling the camera (.back to .front > .front to .back) using NextLevel.shared.flipCaptureDevicePosition()

As we can see in waveforms below it is consistently better after toggling the DevicePosition.

From Clean Session Start:

After Flipping to front camera and then back to the rear camera:

Notice the gap from the starting point to when audio comes in is much smaller.

[piemonte]

@naturalui thanks so much 🙌

[dstuecken]

Did you guys find any solution to this issue? I am experiencing the same issue.

Flipping the camera back and forth does not sound like an ideal solution. :)