Make video codec and scale configurable (appium#833)

lib/commands/recordscreen.js

@@ -12,6 +12,7 @@ const DEFAULT_RECORDING_TIME_SEC = 60 * 3;
 const DEFAULT_MJPEG_SERVER_PORT = 9100;
 const DEFAULT_FPS = 10;
 const DEFAULT_QUALITY = 'medium';
+const DEFAULT_VCODEC = 'mjpeg';
 const MP4_EXT = '.mp4';
 const FFMPEG_BINARY = 'ffmpeg';
 const ffmpegLogger = logger.getLogger(FFMPEG_BINARY);
@@ -49,9 +50,14 @@ class ScreenRecorder {
     const args = [
       '-f', 'mjpeg',
       '-i', `http://localhost:${localPort}`,
-      '-vcodec', 'mjpeg',
-      '-y', this.videoPath,
     ];
+    if (this.opts.videoScale) {
+      args.push('-vf', `scale=${this.opts.videoScale}`);
+    }
+    args.push(
+      '-vcodec', this.opts.videoType,
+      '-y', this.videoPath
+    );
     this.mainProcess = new SubProcess(FFMPEG_BINARY, args);
     this.mainProcess.on('output', (stdout, stderr) => {
       if (stderr && !stderr.includes('frame=')) {
@@ -142,20 +148,23 @@ class ScreenRecorder {
  * @property {?string} remotePath - The path to the remote location, where the resulting video should be uploaded.
  *                                  The following protocols are supported: http/https, ftp.
  *                                  Null or empty string value (the default setting) means the content of resulting
- *                                  file should be encoded as Base64 and passed as the endpount response value.
+ *                                  file should be encoded as Base64 and passed as the endpoint response value.
  *                                  An exception will be thrown if the generated media file is too big to
  *                                  fit into the available process memory.
- *                                  This option only has an effect if there is screen recording process in progreess
+ *                                  This option only has an effect if there is screen recording process in progress
  *                                  and `forceRestart` parameter is not set to `true`.
  * @property {?string} user - The name of the user for the remote authentication. Only works if `remotePath` is provided.
  * @property {?string} pass - The password for the remote authentication. Only works if `remotePath` is provided.
  * @property {?string} method - The http multipart upload method name. The 'PUT' one is used by default.
  *                              Only works if `remotePath` is provided.
- * @property {?string} videoType - The format of the screen capture to be recorded.
- *                                 Available formats: "h264", "mp4" or "fmp4". Default is "mp4".
+ * @property {?string} videoType - The video codec type used for encoding of the be recorded screen capture.
+ *                                 Execute `ffmpeg -codecs` in the terminal to see the list of supported video codecs.
+ *                                 'mjpeg' by default.
  * @property {?string|number} videoQuality - The video encoding quality (low, medium, high, photo - defaults to medium).
  * @property {?string|number} videoFps - The Frames Per Second rate of the recorded video. Change this value if the resulting video
  *                                is too slow or too fast. Defaults to 10.
+ * @property {?string} videoScale - The scaling value to apply. Read https://trac.ffmpeg.org/wiki/Scaling for possible values.
+ *                                  No scale is applied by default.
  * @property {?boolean} forceRestart - Whether to try to catch and upload/return the currently running screen recording
  *                                     (`false`, the default setting) or ignore the result of it and start a new recording
  *                                     immediately.
@@ -164,8 +173,8 @@ class ScreenRecorder {
  */
 
 /**
- * Record the display of devices running iOS Simulator since Xcode 8.3 or real devices since iOS 8
- * (ios-minicap utility is required: https://github.com/openstf/ios-minicap).
+ * Record the display of devices running iOS Simulator since Xcode 9 or real devices since iOS 11
+ * (ffmpeg utility is required: 'brew install ffmpeg').
  * It records screen activity to a MPEG-4 file. Audio is not recorded with the video file.
  * If screen recording has been already started then the command will stop it forcefully and start a new one.
  * The previously recorded video file will be deleted.
@@ -177,11 +186,11 @@ class ScreenRecorder {
  */
 commands.startRecordingScreen = async function (options = {}) {
   const {
-    // TODO: Apply video type to ffmpeg command line
-    // videoType,
+    videoType = DEFAULT_VCODEC,
     timeLimit = DEFAULT_RECORDING_TIME_SEC,
     videoQuality = DEFAULT_QUALITY,
     videoFps = DEFAULT_FPS,
+    videoScale,
     forceRestart,
   } = options;
 
@@ -200,6 +209,8 @@ commands.startRecordingScreen = async function (options = {}) {
   const screenRecorder = new ScreenRecorder(this.opts.device.udid, videoPath, {
     remotePort: this.opts.mjpegServerPort || DEFAULT_MJPEG_SERVER_PORT,
     usePortForwarding: this.isRealDevice(),
+    videoType,
+    videoScale,
   });
   if (!await screenRecorder.interrupt(true)) {
     log.errorAndThrow('Unable to stop screen recording process');
@@ -264,7 +275,7 @@ commands.startRecordingScreen = async function (options = {}) {
  * @property {?string} remotePath - The path to the remote location, where the resulting video should be uploaded.
  *                                  The following protocols are supported: http/https, ftp.
  *                                  Null or empty string value (the default setting) means the content of resulting
- *                                  file should be encoded as Base64 and passed as the endpount response value.
+ *                                  file should be encoded as Base64 and passed as the endpoint response value.
  *                                  An exception will be thrown if the generated media file is too big to
  *                                  fit into the available process memory.
  * @property {?string} user - The name of the user for the remote authentication. Only works if `remotePath` is provided.