lichen-community-systemsGH-5: Tidied up smpte offset and quarter fram…

…e handling.
duhrer · Feb 13, 2023 · 2f7e77a · 2f7e77a
1 parent 72ba1a1
commit 2f7e77a
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Showing 3 changed files with 6 additions and 5 deletions.
diff --git a/src/js/core.js b/src/js/core.js
@@ -382,7 +382,7 @@
                 break;
             // Rate and hour most significant bits.
             case 7:
-                quarterFrameObject.rate = (dataBits & 6) >> 1;
+                quarterFrameObject.rate = (dataBits & 6) >>> 1;
                 quarterFrameObject.hour = (dataBits & 1) << 4;
                 break;
             default:

diff --git a/src/js/smf.js b/src/js/smf.js
@@ -159,13 +159,14 @@
             // https://www.mobilefish.com/tutorials/midi/midi_quickguide_specification.html
             divisionObject.fps = (((~rawDivision) >>> 8) & 127) + 1;
 
-            divisionObject.unitsPerFrame = rawDivision & 127;
+            // Bits 7 through 0 represent the ticks per frame.
+            divisionObject.ticksPerFrame = rawDivision & 127;
         }
         // Ticks Per Quarter Note
         else {
             divisionObject.type = "ticksPerQuarterNote";
             // Bits 14 through 0 represent the number of ticks for each quarter note.
-            divisionObject.resolution = rawDivision & 16383;
+            divisionObject.resolution = rawDivision & 8191;
         }
 
         return divisionObject;

diff --git a/tests/js/smf-unit-tests.js b/tests/js/smf-unit-tests.js
@@ -96,8 +96,8 @@
         },
         // FF 54 05 hr mn se fr ff SMPTE Offset
         "SMPTE offset": {
-            bytes: [0x54, 0x05, 0x0B, 0x13, 0x19, 0x05, 0x32],
-            object: { type: "smpteOffset", hour: 11, minute: 19, second: 25, frame: 5, fractionalFrame: 50 }
+            bytes: [0x54, 0x05, 0x6B, 0x13, 0x19, 0x05, 0x32],
+            object: { type: "smpteOffset", rate: 3, hour: 11, minute: 19, second: 25, frame: 5, fractionalFrame: 50 }
         },
         // FF 58 04 nn dd cc bb Time Signature
         "time signature": {