Set FFmpeg maximum stream analyze duration to 10ms

This decreases the startup delay for streams processed by FFmpeg,
such as H263 and rotated streams.

bbb-video/src/main/java/org/bigbluebutton/app/video/converter/H263Converter.java

@@ -51,6 +51,7 @@ public class H263Converter {
 		ffmpeg.setFormat("flv");
 		ffmpeg.setOutput(output);
 		ffmpeg.setLoglevel("warning");
+		ffmpeg.setAnalyzeDuration("10000"); // 10ms
 
 		this.addListener();
 	}

bbb-video/src/main/java/org/bigbluebutton/app/video/converter/VideoRotator.java

@@ -51,6 +51,7 @@ public class VideoRotator {
 		ffmpeg.setOutput(output);
 		ffmpeg.setLoglevel("warning");
 		ffmpeg.setRotation(direction);
+		ffmpeg.setAnalyzeDuration("10000"); // 10ms
 
 		start();
 	}

bbb-video/src/main/java/org/bigbluebutton/app/video/ffmpeg/FFmpegCommand.java

@@ -22,6 +22,9 @@ public class FFmpegCommand {
     private String input;
     private String output;
 
+    /* Analyze duration is a special parameter that MUST come before the input */
+    private String analyzeDuration;
+
     public FFmpegCommand() {
         this.args = new HashMap();
         this.x264Params = new HashMap();
@@ -44,6 +47,12 @@ public class FFmpegCommand {
 
         comm.add(this.ffmpegPath);
 
+        /* Analyze duration MUST come before the input */
+        if(analyzeDuration != null && !analyzeDuration.isEmpty()) {
+            comm.add("-analyzeduration");
+            comm.add(analyzeDuration);
+        }
+
         comm.add("-i");
         comm.add(input);
 
@@ -142,4 +151,15 @@ public class FFmpegCommand {
                 break;
         }
     }
+
+    /**
+     * Set how much time FFmpeg should  analyze stream
+     * data to get stream information. Note that this
+     * affects directly the delay to start the stream.
+     *
+     * @param duration Rotate direction
+     */
+    public void setAnalyzeDuration(String duration) {
+        this.analyzeDuration = duration;
+    }
 }