fix Start stream 3 seconds behind edge

Jellyfin.Plugin.SRFPlay/Configuration/PluginConfiguration.cs

@@ -75,6 +75,7 @@ public class PluginConfiguration : BasePluginConfiguration
         EnableCategoryFolders = true;
         EnabledTopics = new System.Collections.Generic.List<string>();
         GenerateTitleCards = true;
+        LiveStartSegmentsBack = 3;
     }
 
     /// <summary>
@@ -162,4 +163,14 @@ public class PluginConfiguration : BasePluginConfiguration
     /// Gets or sets the output directory for sport livestream recordings.
     /// </summary>
     public string RecordingOutputPath { get; set; } = string.Empty;
+
+    /// <summary>
+    /// Gets or sets how many segments back from the live edge livestream playback should start.
+    /// Injected as <c>#EXT-X-START:TIME-OFFSET=-(N * targetDuration)</c> into the live media
+    /// playlist. This keeps the start point out of the volatile live edge, which on Android TV
+    /// (ExoPlayer) otherwise causes stalling/jumping until a manual skip. RFC 8216 requires the
+    /// offset to stay at least 3 target durations from the edge, so values below 3 are clamped.
+    /// Set to 0 to disable injection entirely.
+    /// </summary>
+    public int LiveStartSegmentsBack { get; set; }
 }

Jellyfin.Plugin.SRFPlay/Configuration/configPage.html

@@ -82,6 +82,11 @@
                         <input id="RecordingOutputPath" name="RecordingOutputPath" type="text" is="emby-input" placeholder="e.g., /media/recordings/srf" />
                         <div class="fieldDescription">Directory where sport livestream recordings will be saved (requires ffmpeg)</div>
                     </div>
+                    <div class="inputContainer">
+                        <label class="inputLabel inputLabelUnfocused" for="LiveStartSegmentsBack">Live Start Offset (segments)</label>
+                        <input id="LiveStartSegmentsBack" name="LiveStartSegmentsBack" type="number" is="emby-input" min="0" max="20" />
+                        <div class="fieldDescription">How many segments back from the live edge livestreams start playing. Fixes jumpy/stalling playback at the start on Android TV. Minimum 3 (RFC requirement); 0 disables it. Default 3.</div>
+                    </div>
                     <br />
                     <h2>Network Settings</h2>
                     <div class="inputContainer">
@@ -148,6 +153,7 @@
                         document.querySelector('#ProxyPassword').value = config.ProxyPassword || '';
                         document.querySelector('#PublicServerUrl').value = config.PublicServerUrl || '';
                         document.querySelector('#RecordingOutputPath').value = config.RecordingOutputPath || '';
+                        document.querySelector('#LiveStartSegmentsBack').value = config.LiveStartSegmentsBack != null ? config.LiveStartSegmentsBack : 3;
                         Dashboard.hideLoadingMsg();
 
                         // Load recordings UI
@@ -173,6 +179,7 @@
                     config.ProxyPassword = document.querySelector('#ProxyPassword').value;
                     config.PublicServerUrl = document.querySelector('#PublicServerUrl').value;
                     config.RecordingOutputPath = document.querySelector('#RecordingOutputPath').value;
+                    config.LiveStartSegmentsBack = parseInt(document.querySelector('#LiveStartSegmentsBack').value) || 0;
                     ApiClient.updatePluginConfiguration(SRFPlayConfig.pluginUniqueId, config).then(function (result) {
                         Dashboard.processPluginConfigurationUpdateResult(result);
                     });

Jellyfin.Plugin.SRFPlay/Controllers/StreamProxyController.cs

@@ -225,7 +225,8 @@ public class StreamProxyController : ControllerBase
                 queryParams = string.Empty;
             }
 
-            var rewrittenContent = _proxyService.RewriteVariantManifestUrls(manifestContent, baseProxyUrl, queryParams);
+            var isLiveStream = _proxyService.GetStreamMetadata(actualItemId)?.IsLiveStream ?? false;
+            var rewrittenContent = _proxyService.RewriteVariantManifestUrls(manifestContent, baseProxyUrl, queryParams, isLiveStream);
 
             // Set cache headers based on stream type (live vs VOD)
             // Variant manifests use stricter no-cache for live streams

Jellyfin.Plugin.SRFPlay/Services/Interfaces/IStreamProxyService.cs

@@ -71,8 +71,9 @@ public interface IStreamProxyService
     /// <param name="manifestContent">The variant manifest content.</param>
     /// <param name="baseProxyUrl">The base proxy URL (without query params).</param>
     /// <param name="queryParams">Query parameters to append to rewritten URLs (e.g., "?token=abc").</param>
+    /// <param name="isLiveStream">Whether this is a livestream; if so an EXT-X-START offset is injected.</param>
     /// <returns>The rewritten manifest content.</returns>
-    string RewriteVariantManifestUrls(string manifestContent, string baseProxyUrl, string queryParams);
+    string RewriteVariantManifestUrls(string manifestContent, string baseProxyUrl, string queryParams, bool isLiveStream = false);
 
     /// <summary>
     /// Cleans up old and expired stream mappings.

Jellyfin.Plugin.SRFPlay/Services/StreamProxyService.cs

@@ -900,9 +900,15 @@ public class StreamProxyService : IStreamProxyService
     /// <param name="manifestContent">The variant manifest content.</param>
     /// <param name="baseProxyUrl">The base proxy URL (without query params).</param>
     /// <param name="queryParams">Query parameters to append to rewritten URLs (e.g., "?token=abc").</param>
+    /// <param name="isLiveStream">Whether this is a livestream; if so an EXT-X-START offset is injected.</param>
     /// <returns>The rewritten manifest content.</returns>
-    public string RewriteVariantManifestUrls(string manifestContent, string baseProxyUrl, string queryParams)
+    public string RewriteVariantManifestUrls(string manifestContent, string baseProxyUrl, string queryParams, bool isLiveStream = false)
     {
+        if (isLiveStream)
+        {
+            manifestContent = InjectLiveStartOffset(manifestContent);
+        }
+
         string RewriteUrl(string url)
         {
             if (url.Contains("://", StringComparison.Ordinal))
@@ -953,6 +959,82 @@ public class StreamProxyService : IStreamProxyService
         return result.ToString();
     }
 
+    /// <summary>
+    /// Injects an <c>#EXT-X-START:TIME-OFFSET</c> tag into a live media playlist so that players
+    /// (notably ExoPlayer on Android TV) begin a few segments back from the volatile live edge
+    /// instead of at the edge itself, which otherwise causes stalling/jumping until a manual skip.
+    /// The offset is sized relative to the playlist's own <c>EXT-X-TARGETDURATION</c> to stay
+    /// RFC 8216 compliant (≥ 3 target durations from the edge for live playlists).
+    /// </summary>
+    /// <param name="manifestContent">The media playlist content.</param>
+    /// <returns>The playlist with the tag injected, or unchanged if it is not applicable.</returns>
+    private string InjectLiveStartOffset(string manifestContent)
+    {
+        var segmentsBack = Plugin.Instance?.Configuration?.LiveStartSegmentsBack ?? 3;
+        if (segmentsBack <= 0)
+        {
+            return manifestContent; // Disabled by config.
+        }
+
+        // Only a media playlist (has segments, no variant list) should carry EXT-X-START.
+        // A master/multivariant playlist or a VOD playlist (#EXT-X-ENDLIST) is left untouched.
+        if (!manifestContent.Contains("#EXTINF", StringComparison.Ordinal)
+            || manifestContent.Contains("#EXT-X-STREAM-INF", StringComparison.Ordinal)
+            || manifestContent.Contains("#EXT-X-ENDLIST", StringComparison.Ordinal))
+        {
+            return manifestContent;
+        }
+
+        // Don't add a second tag if the source already specified a start point.
+        if (manifestContent.Contains("#EXT-X-START", StringComparison.Ordinal))
+        {
+            _logger.LogDebug("Live playlist already contains #EXT-X-START; leaving as-is");
+            return manifestContent;
+        }
+
+        var targetDurationMatch = Regex.Match(manifestContent, @"#EXT-X-TARGETDURATION:(\d+(?:\.\d+)?)");
+        if (!targetDurationMatch.Success
+            || !double.TryParse(
+                targetDurationMatch.Groups[1].Value,
+                System.Globalization.NumberStyles.Float,
+                System.Globalization.CultureInfo.InvariantCulture,
+                out var targetDuration)
+            || targetDuration <= 0)
+        {
+            _logger.LogDebug("Could not read EXT-X-TARGETDURATION; skipping EXT-X-START injection");
+            return manifestContent;
+        }
+
+        // RFC 8216: TIME-OFFSET SHOULD NOT be within 3 target durations of the live edge.
+        var clampedSegments = Math.Max(3, segmentsBack);
+        var offsetSeconds = clampedSegments * targetDuration;
+        var startTag = string.Format(
+            System.Globalization.CultureInfo.InvariantCulture,
+            "#EXT-X-START:TIME-OFFSET=-{0:0.###},PRECISE=YES",
+            offsetSeconds);
+
+        _logger.LogInformation(
+            "Injecting {StartTag} into live playlist (targetDuration={TargetDuration}s, segmentsBack={SegmentsBack})",
+            startTag,
+            targetDuration,
+            clampedSegments);
+
+        // Insert after the #EXTM3U header so it sits with the other top-level tags.
+        var headerIndex = manifestContent.IndexOf("#EXTM3U", StringComparison.Ordinal);
+        if (headerIndex < 0)
+        {
+            return startTag + "\n" + manifestContent;
+        }
+
+        var lineEnd = manifestContent.IndexOf('\n', headerIndex);
+        if (lineEnd < 0)
+        {
+            return manifestContent + "\n" + startTag;
+        }
+
+        return manifestContent[..(lineEnd + 1)] + startTag + "\n" + manifestContent[(lineEnd + 1)..];
+    }
+
     /// <summary>
     /// Cleans up old and expired stream mappings.
     /// </summary>