Live-stream starts 6 seconds from edge not at oldest segment.

2026-02-28 11:55:05 +01:00
parent 7c76402a4a
commit d75e69249b
3 changed files with 123 additions and 9 deletions
@@ -647,6 +647,21 @@ public class StreamProxyService : IStreamProxyService
            // Rewrite the manifest to replace Akamai URLs with proxy URLs
            var rewrittenContent = RewriteManifestUrls(manifestContent, authenticatedUrl, baseProxyUrl);

+            // For live streams, inject #EXT-X-START to tell the player to start near the live edge
+            // Without this, players may start at the beginning of the sliding window and stutter
+            // as old segments get rotated out by the CDN
+            if (_streamMappings.TryGetValue(itemId, out var streamInfoForManifest) && streamInfoForManifest.IsLiveStream)
+            {
+                if (!rewrittenContent.Contains("#EXT-X-START", StringComparison.Ordinal))
+                {
+                    rewrittenContent = rewrittenContent.Replace(
+                        "#EXTM3U",
+                        "#EXTM3U\n#EXT-X-START:TIME-OFFSET=-6,PRECISE=NO",
+                        StringComparison.Ordinal);
+                    _logger.LogDebug("Injected #EXT-X-START tag for live stream {ItemId}", itemId);
+                }
+            }
+
            _logger.LogDebug("Rewritten manifest for item {ItemId} ({Length} bytes):\n{Content}", itemId, rewrittenContent.Length, rewrittenContent);
            return rewrittenContent;
        }
@@ -720,6 +735,67 @@ public class StreamProxyService : IStreamProxyService
        }
    }

+    /// <summary>
+    /// Fetches a segment as a streaming response for direct forwarding to the client.
+    /// Uses HttpCompletionOption.ResponseHeadersRead to start streaming before the full
+    /// segment is downloaded, reducing time-to-first-byte for live streams.
+    /// </summary>
+    /// <param name="itemId">The item ID.</param>
+    /// <param name="segmentPath">The segment path.</param>
+    /// <param name="queryString">The original query string from the request.</param>
+    /// <param name="cancellationToken">Cancellation token.</param>
+    /// <returns>The HTTP response for streaming, or null if not found.</returns>
+    public async Task<HttpResponseMessage?> GetSegmentStreamAsync(
+        string itemId,
+        string segmentPath,
+        string? queryString = null,
+        CancellationToken cancellationToken = default)
+    {
+        var authenticatedUrl = await GetAuthenticatedUrlAsync(itemId, cancellationToken).ConfigureAwait(false);
+        if (authenticatedUrl == null)
+        {
+            return null;
+        }
+
+        try
+        {
+            var baseUri = new Uri(authenticatedUrl);
+            var baseUrl = $"{baseUri.Scheme}://{baseUri.Host}{string.Join('/', baseUri.AbsolutePath.Split('/')[..^1])}";
+
+            var queryParams = string.Empty;
+            if (!string.IsNullOrEmpty(queryString))
+            {
+                queryParams = queryString.StartsWith('?') ? queryString : $"?{queryString}";
+            }
+            else if (!segmentPath.Contains("hdntl=", StringComparison.OrdinalIgnoreCase))
+            {
+                queryParams = baseUri.Query;
+            }
+
+            var segmentUrl = $"{baseUrl}/{segmentPath}{queryParams}";
+
+            _logger.LogDebug("Streaming segment - SegmentPath: {SegmentPath}, FullUrl: {FullUrl}", segmentPath, segmentUrl);
+
+            var httpClient = _httpClientFactory.CreateClient(NamedClient.Default);
+            var request = new HttpRequestMessage(HttpMethod.Get, segmentUrl);
+            var response = await httpClient.SendAsync(request, HttpCompletionOption.ResponseHeadersRead, cancellationToken).ConfigureAwait(false);
+
+            if (!response.IsSuccessStatusCode)
+            {
+                _logger.LogWarning("Segment stream request failed with {StatusCode} for {SegmentPath}", response.StatusCode, segmentPath);
+                response.Dispose();
+                return null;
+            }
+
+            return response;
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "Failed to stream segment {SegmentPath} for item {ItemId}", segmentPath, itemId);
+            return null;
+        }
+    }
+
    /// <summary>
    /// Rewrites URLs in HLS manifest to point to proxy.
    /// </summary>