feat: Add customizable Video Bit Rate (videoBitRate) (#1882)

* feat: Add `videoBitRate` option to `RecordVideoOptions`

* feat: Implement `videoBitRate` on iOS

* feat: Implement `videoBitRate` on Android

* chore: Format

* docs: Separate recording and photo docs

* docs: Fix links

* docs: Add docs about bitrate and quality

* docs: Add blob

* fix: Don't use inline style for CI

* fix: Correctly log default bitRate

* fix: Fix typo

* fix: Calculate default bit-rate on Android depending on resolution

* Update RecordingSession.kt

package/android/src/main/java/com/mrousavy/camera/CameraView+RecordVideo.kt

@@ -33,6 +33,10 @@ suspend fun CameraView.startRecording(options: ReadableMap, onRecordCallback: Ca
   if (options.hasKey("fileType")) {
     fileType = VideoFileType.fromUnionValue(options.getString("fileType"))
   }
+  var bitRate: Double? = null
+  if (options.hasKey("videoBitRate")) {
+    bitRate = options.getDouble("videoBitRate")
+  }
 
   val callback = { video: RecordingSession.Video ->
     val map = Arguments.createMap()
@@ -44,7 +48,7 @@ suspend fun CameraView.startRecording(options: ReadableMap, onRecordCallback: Ca
     val errorMap = makeErrorMap(error.code, error.message)
     onRecordCallback(null, errorMap)
   }
-  cameraSession.startRecording(audio == true, codec, fileType, callback, onError)
+  cameraSession.startRecording(audio == true, codec, fileType, bitRate, callback, onError)
 }
 
 @SuppressLint("RestrictedApi")

package/android/src/main/java/com/mrousavy/camera/core/CameraSession.kt

@@ -279,6 +279,7 @@ class CameraSession(
     enableAudio: Boolean,
     codec: VideoCodec,
     fileType: VideoFileType,
+    bitRate: Double?,
     callback: (video: RecordingSession.Video) -> Unit,
     onError: (error: RecorderError) -> Unit
   ) {
@@ -287,7 +288,8 @@ class CameraSession(
       val outputs = outputs ?: throw CameraNotReadyError()
       val videoOutput = outputs.videoOutput ?: throw VideoNotEnabledError()
 
-      val recording = RecordingSession(context, videoOutput.size, enableAudio, fps, codec, orientation, fileType, callback, onError)
+      val recording =
+        RecordingSession(context, videoOutput.size, enableAudio, fps, codec, orientation, fileType, bitRate, callback, onError)
       recording.start()
       this.recording = recording
     }

package/android/src/main/java/com/mrousavy/camera/core/RecordingSession.kt

@@ -22,14 +22,13 @@ class RecordingSession(
   private val codec: VideoCodec = VideoCodec.H264,
   private val orientation: Orientation,
   private val fileType: VideoFileType = VideoFileType.MP4,
+  videoBitRate: Double? = null,
   private val callback: (video: Video) -> Unit,
   private val onError: (error: RecorderError) -> Unit
 ) {
   companion object {
     private const val TAG = "RecordingSession"
 
-    // bits per second
-    private const val VIDEO_BIT_RATE = 10_000_000
     private const val AUDIO_SAMPLING_RATE = 44_100
     private const val AUDIO_BIT_RATE = 16 * AUDIO_SAMPLING_RATE
     private const val AUDIO_CHANNELS = 1
@@ -37,6 +36,7 @@ class RecordingSession(
 
   data class Video(val path: String, val durationMs: Long)
 
+  private val bitRate = videoBitRate ?: getDefaultBitRate()
   private val recorder: MediaRecorder
   private val outputFile: File
   private var startTime: Long? = null
@@ -44,7 +44,6 @@ class RecordingSession(
   val surface: Surface = MediaCodec.createPersistentInputSurface()
 
   init {
-
     outputFile = File.createTempFile("mrousavy", fileType.toExtension(), context.cacheDir)
 
     Log.i(TAG, "Creating RecordingSession for ${outputFile.absolutePath}")
@@ -56,11 +55,11 @@ class RecordingSession(
 
     recorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4)
     recorder.setOutputFile(outputFile.absolutePath)
-    recorder.setVideoEncodingBitRate(VIDEO_BIT_RATE)
+    recorder.setVideoEncodingBitRate((bitRate * 1_000_000).toInt())
     recorder.setVideoSize(size.height, size.width)
     if (fps != null) recorder.setVideoFrameRate(fps)
 
-    Log.i(TAG, "Using $codec Video Codec..")
+    Log.i(TAG, "Using $codec Video Codec at $bitRate Mbps..")
     recorder.setVideoEncoder(codec.toVideoCodec())
     if (enableAudio) {
       Log.i(TAG, "Adding Audio Channel..")
@@ -131,8 +130,22 @@ class RecordingSession(
     }
   }
 
+  private fun getDefaultBitRate(): Double {
+    var baseBitRate = when (size.width * size.height) {
+      in 0..640 * 480 -> 2.0
+      in 640 * 480..1280 * 720 -> 5.0
+      in 1280 * 720..1920 * 1080 -> 10.0
+      in 1920 * 1080..3840 * 2160 -> 30.0
+      in 3840 * 2160..7680 * 4320 -> 100.0
+      else -> 100.0
+    }
+    baseBitRate = baseBitRate / 30.0 * (fps ?: 30).toDouble()
+    if (this.codec == VideoCodec.H265) baseBitRate *= 0.8
+    return baseBitRate
+  }
+
   override fun toString(): String {
     val audio = if (enableAudio) "with audio" else "without audio"
-    return "${size.width} x ${size.height} @ $fps FPS $codec $fileType $orientation RecordingSession ($audio)"
+    return "${size.width} x ${size.height} @ $fps FPS $codec $fileType $orientation $bitRate Mbps RecordingSession ($audio)"
   }
 }