Low Quality Video Capture

[otymartin]

@piemonte
Hey the previous issue #34 was closed so I thought it necessary to bring this up again since i failed to fix it.

For whatever reason despite setting videoConfigured to high quality, I still get lowQuality output video when I play back using your other library Player.

I have these settings in my viewDidLoad so would appreciate further hints as to what could possible cause the bad video. Im using the latest version of this library.

self.nextLevel.delegate = self
        self.nextLevel.videoDelegate = self
        self.nextLevel.photoDelegate = self
        self.nextLevel.deviceDelegate = self
        self.nextLevel.captureMode = .video
        self.nextLevel.focusMode = .autoFocus
        self.nextLevel.devicePosition = .front
        self.nextLevel.deviceOrientation = .portrait
        self.nextLevel.videoStabilizationMode = .auto
        self.nextLevel.videoConfiguration.bitRate = 2000000
        self.nextLevel.videoConfiguration.preset = AVCaptureSessionPresetHigh
        self.nextLevel.videoConfiguration.transform = CGAffineTransform(scaleX: -1, y: 1)```

[piemonte]

hey @otymartin thanks, will check this out when i get a chance

[yazeedabalkhail]

Hello there!

Was wondering if any update has happened on this, or if you found a workaround? Experiencing the same issue.

@otymartin @piemonte

[yazeedabalkhail]

If it is any help with helping debugging the problem, here are a couple of tests i did on different presets:

1- When using presets low or medium --> You get the same results as expected (no pixelation)
2- When using presets high or hd etc --> You get pixelated, however the first second of displaying the video will not be pixelated
3- When using preset hd4K3840x2160 --> You get pixelated, however it is the lesser of all high preset options such as hd720, etc. Although still noticable
4- When using preset iFrame960x540 --> You get a video better then medium quality, without the pixelation happening

Hope this can help, thank you.

[otymartin]

@yazeedabalkhail no had to use another lib. Would love to use this lib though so will come back to it and take on this issue again and see if i can figure it out.

[BrikerMan]

I have the similar issue, is there any ways to improve video quality.

[klpl]

I had the same issue. I resolved it by increasing the bitRate.

[otymartin]

@klpl what did you increase it to?

[klpl]

the value I used was based on Apple's sample code: https://developer.apple.com/library/content/samplecode/RosyWriter/Listings/Classes_Utilities_MovieRecorder_m.html#//apple_ref/doc/uid/DTS40011110-Classes_Utilities_MovieRecorder_m-DontLinkElementID_23

bitsPerSecond = numPixels * bitsPerPixel;

[otymartin]

@klpl cool man, will try it out and see if this finally solves it.

[tungfam]

@klpl hi, could you please kindly share the code how you calculate bitsPerSecond?
from apple's docs it seems we need this:
CMVideoDimensions dimensions = CMVideoFormatDescriptionGetDimensions( videoFormatDescription )
in order to calculate it. But where can we get it from ? 😅

Will appreciate any help!

[klpl]

@tungfam
In NextLevelConfiguration.swift > avcaptureSettingsDictionary method:
let numPixels = (config[AVVideoWidthKey] as! Int) * (config[AVVideoHeightKey] as! Int)
let bitsPerPixel = 10.1
let bitsPerSecond = Int(Double(numPixels) * bitsPerPixel)
[...]
compressionDict[AVVideoAverageBitRateKey] = NSNumber(integerLiteral: bitsPerSecond)

[tungfam]

many thanks to @klpl I found out what fixes the issue and created a PR.

More details:

after few hours of testing and going around the code, I found out that no matter what value you set to NextLevel.shared.videoConfiguration.bitRate either 1 or 999999999 it will not affect the video quality.

then I applied the code that @klpl suggested. And checked again that changing NextLevel.shared.videoConfiguration.bitRate doesn't affect anything. But the video quality did become better.

Then I changed videoConfiguration.preset to .high or to .hd4K3840x2160 and the quality was just amazing 👌 .

@yazeedabalkhail thank you too!:) I was trying to use iFrame960x540 which was actually good (before I applied changes from PR). But then after fixing the issue the .high was better than iFrame960x540.

@piemonte first of all thanks a lot for a such cool lib!
please take a chance to review the PR.
Try testing it and you will see how better the video quality became. Please let me know if you have questions.

[piemonte]

i added a better configuration to the sample project, hope that helps everyone.

050ba1b