From 1e9bc1f471582c89f4aab97596246ab584cf9982 Mon Sep 17 00:00:00 2001
From: Ruben van de Ven <git@rubenvandeven.com>
Date: Wed, 22 Dec 2021 12:19:00 +0100
Subject: [PATCH] fix audio offset with negative numbers

---
 www/annotate.js | 22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/www/annotate.js b/www/annotate.js
index 19fa815..7ce4b77 100644
--- a/www/annotate.js
+++ b/www/annotate.js
@@ -380,7 +380,7 @@ class Annotator {
             start: [this.currentTime, this.duration],
             connect: true,
             range: {
-                'min': 0,
+                'min': this.audioOffset < 0 ? this.audioOffset * 1000 : 0,
                 'max': this.duration
             },
             tooltips: [
@@ -422,7 +422,8 @@ class Annotator {
         if (metadata) {
             this.annotations = metadata.annotations;
             this.audioFile = metadata.hasOwnProperty('audio') ? metadata.audio.file : null;
-            this.audioOffset = metadata.hasOwnProperty('audio') ? metadata.audio.offset : 0;
+            this.audioOffset = metadata.hasOwnProperty('audio') ? Number.parseFloat(metadata.audio.offset) : 0;
+            this.currentTime = this.audioOffset < 0 ? this.audioOffset * 1000 : 0;
             //
             // load any saved metadata
         }
@@ -449,11 +450,16 @@ class Annotator {
         this.formatter = wNumb({
             decimals: 2,
             edit: (time) => {
+                let neg = "";
+                if(time < 0) {
+                    neg = "-";
+                    time *= -1;
+                }
                 const s = Math.floor(time / 1000);
                 const minutes = Math.floor(s / 60);
                 const seconds = s - minutes * 60;
                 const ms = Math.floor((time / 1000 - s) * 1000);
-                return `${minutes}:${seconds}:${ms}`;
+                return `${neg}${minutes}:${seconds}:${ms}`;
             }
         });
 
@@ -531,9 +537,10 @@ class Annotator {
     }
 
     setAudioOffset(audioOffset) {
-        this.audioOffset = audioOffset;
+        this.audioOffset = Number.parseFloat(audioOffset);
         // TODO update playhead
         // TODO update this.duration
+        this.setUpAnnotator(); // if offset is negative, annotator starts at negative time
         this.updateState();
     }
 
@@ -542,7 +549,7 @@ class Annotator {
      * @returns float
      */
     getAudioTime(time) {
-        return Number.parseFloat(time) + (this.audioOffset * 1000 ?? 0);
+        return Number.parseFloat(time) - (this.audioOffset * 1000 ?? 0);
     }
 
     /**
@@ -558,14 +565,13 @@ class Annotator {
         const t_start = this.getAudioTime(t_in); // in ms
         const t_diff = t_out - t_in; // in ms
 
-        console.log('set time', t_in, t_start, typeof t_start, typeof t_in, t_start < 0);
         this.audioEl.pause();
 
         if (t_start < 0) {
             if (t_diff <= t_start * -1) {
-                console.log('no audio playback in segment', t_start, t_diff);
+                console.debug('no audio playback in segment', t_start, t_diff);
             } else {
-                console.log('huh?', t_start, t_diff);
+                console.debug('delay audio playback', t_start, t_diff);
                 // a negative audiooffset delays playback from the start
                 // this.audioStartTimeout = setTimeout((e) => this.audioEl.play(), t*-1000);
                 this.audioStartTimeout = setTimeout((e) => { this.audioEl.currentTime = 0 }, t_start * -1); // triggers play with "seeked" event