revert to video bitrate and mp2 audio codec

When video bitrate is not fixed the delta delay is more unstable and can reach error threshold.
same is with audio codec pcm_bluray, maybe because it changes the format to m2ts. s302m would be best option, but is not working correctly with loudnorm filter.

lib/src/utils/config.rs

@@ -294,6 +294,11 @@ impl PlayoutConfig {
             config.processing.audio_tracks = 1
         }
 
+        let bitrate = format!(
+            "{}k",
+            config.processing.width * config.processing.height / 16
+        );
+
         config.processing.cmd = Some(vec_strings![
             "-pix_fmt",
             "yuv420p",
@@ -303,12 +308,18 @@ impl PlayoutConfig {
             "mpeg2video",
             "-g",
             "1",
-            "-qscale:v",
+            "-b:v",
-            "2",
+            &bitrate,
+            "-minrate",
+            &bitrate,
+            "-maxrate",
+            &bitrate,
+            "-bufsize",
+            &bitrate,
             "-c:a",
-            "pcm_bluray",
+            "mp2",
-            "-mpegts_m2ts_mode",
+            "-b:a",
-            "true",
+            "384k",
             "-ar",
             "48000",
             "-ac",