From d8f08361657dfbe04631953a8c92e6a505a180c2 Mon Sep 17 00:00:00 2001
From: xRangerDE <xRangerDE@24-music.de>
Date: Sat, 21 Mar 2026 15:47:19 +0100
Subject: [PATCH] fix: ETA calculation was using video duration instead of
 download progress

The old formula (avgSpeed * expectedDurationSeconds) simplified to just
(videoDuration - elapsedTime), showing 59min ETA for a 60min part after
1min of downloading. Now uses streamlink's actual progress percentage:
ETA = (elapsed / percent) * (100 - percent), which reflects real download
speed rather than video length.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
---
 src/main.ts | 22 +++++++++-------------
 1 file changed, 9 insertions(+), 13 deletions(-)

diff --git a/src/main.ts b/src/main.ts
index 9c66833..aa59191 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -2203,6 +2203,7 @@ function downloadVODPart(
         const args = [...streamlinkCmd.prefixArgs, url, 'best', '-o', filename, '--force'];
         let lastErrorLine = '';
         const expectedDurationSeconds = parseClockDurationSeconds(endTime);
+        let lastStreamlinkPercent = 0;
 
         if (startTime) {
             args.push('--hls-start-offset', startTime);
@@ -2250,19 +2251,13 @@ function downloadVODPart(
                     lastTime = now;
 
                     let etaStr = '';
-                    if (speed > 0 && downloadedBytes > 0) {
-                        const itemStartTime = itemTracking.startTime;
-                        const elapsedSec = (Date.now() - itemStartTime) / 1000;
-                        if (elapsedSec > 5) { // Wait at least 5 seconds before showing ETA
-                            const avgSpeed = downloadedBytes / elapsedSec;
-                            if (expectedDurationSeconds && expectedDurationSeconds > 0) {
-                                const estimatedTotalBytes = avgSpeed * expectedDurationSeconds;
-                                if (estimatedTotalBytes > downloadedBytes) {
-                                    const remainingSec = (estimatedTotalBytes - downloadedBytes) / avgSpeed;
-                                    if (remainingSec > 0 && remainingSec < 86400) { // Between 0 and 24 hours
-                                        etaStr = formatETA(remainingSec);
-                                    }
-                                }
+                    if (downloadedBytes > 0) {
+                        const elapsedSec = (Date.now() - (itemTracking?.startTime || Date.now())) / 1000;
+                        if (elapsedSec > 5 && lastStreamlinkPercent > 1) {
+                            // Use streamlink's reported progress for accurate ETA
+                            const remainingSec = (elapsedSec / lastStreamlinkPercent) * (100 - lastStreamlinkPercent);
+                            if (remainingSec > 0 && remainingSec < 86400) {
+                                etaStr = formatETA(remainingSec);
                             }
                         }
                     }
@@ -2290,6 +2285,7 @@ function downloadVODPart(
             const match = line.match(/(\d+\.\d+)%/);
             if (match) {
                 const percent = parseFloat(match[1]);
+                lastStreamlinkPercent = percent;
                 onProgress({
                     id: itemId,
                     progress: percent,