From 4bf04cf93c08813fa91f8a1fe23bb7f0dccd4c25 Mon Sep 17 00:00:00 2001
From: Victor Giers <mail@victorgiers.com>
Date: Tue, 14 Jul 2026 09:41:06 +0200
Subject: [PATCH] Implement time signature handling and build arrangement
 events for Ableton export

---
 src/lib/exporters/ableton/builders.ts | 91 +++++++++++++++++----------
 1 file changed, 59 insertions(+), 32 deletions(-)

diff --git a/src/lib/exporters/ableton/builders.ts b/src/lib/exporters/ableton/builders.ts
index aa98a40..8f6a399 100644
--- a/src/lib/exporters/ableton/builders.ts
+++ b/src/lib/exporters/ableton/builders.ts
@@ -280,18 +280,6 @@ function trackAutomationTargets(
   return targets;
 }
 
-function groupAutomationTargets(groupTrack: any) {
-  const targets: AbletonAutomationTargets = {};
-  const mixer = groupTrack.DeviceChain.Mixer;
-  addTarget(targets, FaderParam.LVL, targetFor(mixer.Volume));
-  addTarget(targets, FaderParam.PAN, targetFor(mixer.Pan));
-  const send = mixer.Sends?.TrackSendHolder?.Send;
-  if (send) {
-    addTarget(targets, FaderParam.FX, targetFor(send));
-  }
-  return targets;
-}
-
 async function buildMidiClip(
   koClip: AblClip,
   clipIdx: number,
@@ -1107,6 +1095,44 @@ async function buildReturnTrack(
   return { ReturnTrack: returnTrack };
 }
 
+function getTimeSignatureId(timeSignature: { numerator: number; denominator: number }) {
+  return (
+    TIME_SIGNATURES[`${timeSignature.numerator}/${timeSignature.denominator}`] ||
+    TIME_SIGNATURES['4/4']
+  );
+}
+
+function buildArrangementTimeSignatureEvents(
+  sections: AblArrangementSection[],
+  fallbackTimeSignature: { numerator: number; denominator: number },
+) {
+  const initialTimeSignature = sections[0]?.timeSignature || fallbackTimeSignature;
+  const events = [
+    {
+      '@Id': 0,
+      '@Time': -63072000,
+      '@Value': getTimeSignatureId(initialTimeSignature),
+    },
+  ];
+  let previousTimeSignatureId = getTimeSignatureId(initialTimeSignature);
+
+  sections.forEach((section, index) => {
+    const timeSignatureId = getTimeSignatureId(section.timeSignature);
+    if (index === 0 || timeSignatureId === previousTimeSignatureId) {
+      previousTimeSignatureId = timeSignatureId;
+      return;
+    }
+    events.push({
+      '@Id': events.length,
+      '@Time': section.offset,
+      '@Value': timeSignatureId,
+    });
+    previousTimeSignatureId = timeSignatureId;
+  });
+
+  return events;
+}
+
 export async function buildProject(projectData: ProjectRawData, exporterParams: ExporterParams) {
   resetIds();
   const abletonVersion = getAbletonVersion(exporterParams);
@@ -1132,18 +1158,21 @@ export async function buildProject(projectData: ProjectRawData, exporterParams:
   project.Ableton.LiveSet.MasterTrack.AutomationEnvelopes.Envelopes.AutomationEnvelope[1].Automation.Events.FloatEvent[
     '@Value'
   ] = projectData.settings.bpm;
-  // setting up time signature
-  project.Ableton.LiveSet.MasterTrack.AutomationEnvelopes.Envelopes.AutomationEnvelope[0].Automation.Events.EnumEvent[
-    '@Value'
-  ] =
-    TIME_SIGNATURES[
-      `${projectData.scenesSettings.timeSignature.numerator}/${projectData.scenesSettings.timeSignature.denominator}`
-    ] || TIME_SIGNATURES['4/4'];
+  const initialTimeSignature =
+    transformedData.arrangementSections[0]?.timeSignature ||
+    projectData.scenesSettings.timeSignature;
+  project.Ableton.LiveSet.MasterTrack.DeviceChain.Mixer.TimeSignature.Manual['@Value'] =
+    getTimeSignatureId(initialTimeSignature);
+  project.Ableton.LiveSet.MasterTrack.AutomationEnvelopes.Envelopes.AutomationEnvelope[0].Automation.Events.EnumEvent =
+    buildArrangementTimeSignatureEvents(
+      transformedData.arrangementSections,
+      projectData.scenesSettings.timeSignature,
+    ) as any;
 
   const tracks = await buildTracks(
     transformedData.tracks,
     transformedData.groupLanes,
-    transformedData.scenes.length,
+    transformedData.scenes,
     exporterParams,
   );
   project.Ableton.LiveSet.Tracks = { '#': tracks } as any;
@@ -1158,18 +1187,16 @@ export async function buildProject(projectData: ProjectRawData, exporterParams:
     project.Ableton.LiveSet.Tracks['#'].push(returnTrack);
   }
 
-  if (exporterParams.clips) {
-    const scenes = await buildScenes(
-      transformedData.scenes,
-      projectData.settings,
-      transformedData.scenes.length,
-      abletonVersion,
-    );
-    if (abletonVersion === '10') {
-      (project.Ableton.LiveSet as any).SceneNames.Scene = scenes;
-    } else {
-      project.Ableton.LiveSet.Scenes.Scene = scenes;
-    }
+  const scenes = await buildScenes(
+    transformedData.scenes,
+    projectData.settings,
+    transformedData.scenes.length,
+    abletonVersion,
+  );
+  if (abletonVersion === '10') {
+    (project.Ableton.LiveSet as any).SceneNames.Scene = scenes;
+  } else {
+    project.Ableton.LiveSet.Scenes.Scene = scenes;
   }
 
   if (exporterParams.sendEffects) {