Update video template to support transparent videos

Tools/ModelUtilities/Video/VideoLookAtCamera.any

@@ -61,25 +61,35 @@ To use the class template.
 #class_template VideoLookAtCamera (
   UP_DIRECTION = y, 
   CREATE_GIF = 0,
+  TRANSPARENT_BACKGROUND=0,
   _AUTO_PLAY_VIDEOS = 1,
   _OVER_WRITE = 1,
   _DEBUG = 0,
   _CLEAN_UP_IMAGES = 1,
   _AUTO_OPEN_PREVIEW_ = 1,
   ENABLE_SAVE_SETTINGS=0,
-  ENABLE_OVERLAY= 1
+  ENABLE_OVERLAY= 1,
+  VIDEO_ENCODER="vp9"
   ) 
 {
   // Arguments:
   // ---------------
   //VideoLookAtCamera#UP_DIRECTION
   // The direction of the up vector of the camera.
   //
+  //VideoLookAtCamera#TRANSPARENT_BACKGROUND
+  // Create images and videos with transparent background.
+  //
   //VideoLookAtCamera#CREATE_GIF
   // If set to 1, a gif will be created in addition to the video. 
   //
   //VideoLookAtCamera#ENABLE_OVERLAY
   // If set to 1, the settings used to create the video will be saved in a file.
+  //
+  //VideoLookAtCamera#VIDEO_ENCODER
+  // Sets the codec used for encoding the video in FFMPEG. A few options have been 
+  // preconfigured. "xvid" gives mp4 videos encoded with xvid which are highly compatible. 
+  // "vp9" gives "*.webm" videos which have better quality for the size and support transparency.
 
 
   //VideoLookAtCamera
@@ -108,7 +118,7 @@ To use the class template.
   /// The video codec ffmepg will use to create the video. 
   /// Choose "libxvid" for best for compatibility (eg. with PowerPoint)
   /// or "libvpx-vp9" for best performance
-  #var AnyString VideoCodec = "libvpx-vp9";
+  #var AnyString VideoCodec = "";
 
   //VideoLookAtCamera
   /// This is the start frame used when creating Videos. This can be used to 
@@ -189,7 +199,11 @@ To use the class template.
 
   AnyFolder CheckInputs = {
     AnyInt VideoInputFrameRate = assert(gtfun(.VideoInputFrameRate,0), "Video Input frame rate should larger than 0");
+    AnyInt deprecated_codec = warn(not(.VideoCodec), strformat("\n") +"Deprecated: The member VideoCodec is deprecated. Use class argument VIDEO_ENCODER instead");
 
+    #if VIDEO_ENCODER == "xvid" & TRANSPARENT_BACKGROUND
+    AnyInt warn_transparent = warn(0, strformat("\nPlease use argument VIDEO_ENCODER=" + strquote("vp9") + " to create videos that support transparency."));
+    #endif
   };
 
 
@@ -219,7 +233,7 @@ To use the class template.
     #endif
     AnyOperationMacro ResetFilename = 
     {
-      MacroStr = {"classoperation "+CompleteNameOf(..Camera.Recorder.F)+"ileName "+strquote("Reset Value")};
+      MacroStr = {"classoperation "+CompleteNameOf(..Camera.Recorder.F) + "ileName " + strquote("Reset Value")};
     };
   };
 
@@ -294,6 +308,10 @@ To use the class template.
       #var ResetTrig = DesignVar(Off);
       #var AntiAlias = 16;
 
+      #if TRANSPARENT_BACKGROUND
+      #var TransparentBackgroundOnOff = On;
+      #endif
+
       FileName = ..VideoOutputPath+ "/"+ ..VideoName + "_" + strval(..Counter , CounterFormat)+ ".png";
 
 
@@ -451,9 +469,15 @@ To use the class template.
       #var FileName = "cmd.exe";
       #var AnyStringVar inputfile = ..VideoName + "_" + ..Camera.Recorder.CounterFormat +".png";
 
+
+      #var AnyStringVar video_extension = 
+      #if VIDEO_ENCODER == "vp9" 
+         ".webm";
+      #else
+        ".mp4";
+      #endif
 
-      #var AnyFileVar out_file = ..VideoOutputPath+ "/"+ ..VideoName + ".mp4";
-
+      #var AnyFileVar out_file = ..VideoOutputPath+ "/"+ ..VideoName + video_extension;
 
       #if ENABLE_OVERLAY
       #var AnyString OverLayFilter = "[bg];[1:v]scale=-2:2*trunc("+strval(..VideoResolution[1])+"*"+strval(..OverlayImageScale)+"/2)[overlay];[bg][overlay]overlay=W-w:H-h";
@@ -472,23 +496,30 @@ To use the class template.
       " -r " + strval(..VideoInputFrameRate) +
       " -start_number " + strval(..VideoStartFrame,..Camera.Recorder.CounterFormat) + 
       " -i "+strquote(inputfile) +
+      #if ENABLE_OVERLAY
       " -i " + strquote(..OverlayImage) + 
+      #endif
       " -filter_complex " + strquote("[0:v]fps="+strval(..VideoOutputFrameRate)+ ",scale=trunc(iw/(2*"+strval(InputOutputScale,"%g" )+"))*2:trunc(ih/(2*"+strval(InputOutputScale,"%g" )+"))*2" + OverLayFilter + "[outv]") +
       " -map [outv]" +
       " -an" +
       " -metadata comment=" + strquote("Created with the AnyBody Modeling System.") 
       ;
 
-      #var AnyStringVar CodecArgs = "  -c:v " + ..VideoCodec + " -crf " + strval(..ConstantRateFactor)+" -level 3.0 -pix_fmt yuv420p -strict experimental -movflags +faststart ";
-      #var AnyStringVar CodecArgs_VP9 = " -c:v libvpx-vp9" + " -crf " + strval(..ConstantRateFactor)+" -pix_fmt yuv420p -row-mt 1 ";
+      #var AnyStringVar CodecArgs_default = "  -c:v libxvid -crf " + strval(..ConstantRateFactor)+" -level 3.0 -pix_fmt yuv420p -strict experimental -movflags +faststart ";
+      #var AnyStringVar CodecArgs_vp9 = " -c:v libvpx-vp9 -an -crf " + strval(..ConstantRateFactor)+" -pix_fmt yuva420p  -row-mt 1 "; //-metadata:s:v:0 alpha_mode=" + strquote("1")
+//      #var AnyStringVar CodecArgs_VP9 = " -c:v apng" + " -crf " + strval(..ConstantRateFactor)+" -pix_fmt rgba  -row-mt 1 ";
 
 
       #var AnyStringVar OutputArg = strquote(FilePathCompleteOf(out_file));
 
-      #var Arguments =  iffun(_DEBUG , "/K","/C") + " TITLE Creating Video && "+iffun(neqfun(..VideoCodec,"libvpx-vp9"),
-                 ffmpegBaseArg + CodecArgs + OutputArg,
-                 ffmpegBaseArg + CodecArgs_VP9 +" -pass 1 -f null NUL && " + ffmpegBaseArg + CodecArgs_VP9 + " -pass 2 " + OutputArg
-      ) ;
+      #var Arguments =  iffun(_DEBUG , "/K","/C") + " TITLE Creating Video && " + ffmpegBaseArg 
+      #if VIDEO_ENCODER == "vp9" 
+      + CodecArgs_vp9 +" -pass 1 -f null NUL && " + ffmpegBaseArg + CodecArgs_vp9 + " -pass 2 -auto-alt-ref 0 "
+      #else
+      + CodecArgs_default
+      #endif
+      + OutputArg;
+
       #var WorkDir = ..VideoOutputPath;
       #var Show = DesignVar(_DEBUG);
     };