Android Question Camera2 - Recording Video

biometrics

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Re: https://www.b4x.com/android/forum/threads/camera2-still-images-and-videos.83920/

1. The sample seems to set the video capture size to 1920x1080 (CaptureSize.Initialize(1920, 1080)) but my resulting file is 640x480. How do I set the video capture size? My phone is a Sony Z3 that supports that resolution.
2. How can I set the video bit rate (e.g. 1000 kbps or 500 kbps)
3. How can I set the video frame rate (e.g. 30 fps or 12 fps)
4. Is possible to add closed captioning to the recording video (subtitles) or alternatively can I overlay text?
 
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Erel

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1. The video size is set in the call to CreateMediaRecorder. In CamEx2 implementation it uses PreviewSize to set the video size.

2. You can customize the returned MediaRecorder object:
https://developer.android.com/reference/android/media/MediaRecorder#setVideoFrameRate(int)
B4X: 
Dim FrameRate As Int = 12
MediaRecorder.RunMethod("setVideoFrameRate", Array(FrameRate)) 'set to 30 by default

There is also a setVideoEncodingBitRate method (which is set to 10000000 by default).

4. It is not possible to add subtitles or text to the video itself. You can create a SRT file with the subtitles. You can play videos with subtitles with ExoPlayer.
 
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biometrics

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I'm having some trouble getting this right. I'm unsure where to put this code.

The documentation states that setVideoFrameRate "Must be called after setVideoSource()". I can't find such a call. It also says that it throws a "IllegalStateException" if "if it is called after prepare() or before setOutputFormat()".

I noticed that setOrientationHint is called in PrepareSurfaceForVideo. The documentation states that "This method should be called before prepare()."

Since setOrientationHint needs to be called before "prepare()" I assumed that would be a good place to call setVideoFrameRate. I added it after

B4X: 
MediaRecorder.RunMethod("setOrientationHint", Array(orientations.Get(Floor(rotation / 90))))

but I'm getting an IllegalStateException.

So my question is, where is the right place to call setVideoFrameRate and setVideoEncodingBitRate?
 
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biometrics

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Seems it's an issue either with Android 5 or the specific device (https://www.viatech.com/en/boards/3-5-inch-sbc/vab-630/) as it works on my Sony Z3 with Android 6.

Setting the bit rate worked fine but the frame rate remained at 25+ frames per second. I found the answer on Stackoverflow, you also need to call setCaptureRate:

B4X: 
Dim iFrameRate As Int = 15
Dim dFrameRate As Double = 15
MediaRecorder.RunMethod("setCaptureRate", Array(dFrameRate))
MediaRecorder.RunMethod("setVideoFrameRate", Array(iFrameRate))
 
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