From 3fde2d7b34617837c6a319e663a17d55960e7c49 Mon Sep 17 00:00:00 2001 From: dirtydishes Date: Mon, 25 May 2026 16:13:09 -0400 Subject: [PATCH] recover stalled native skips --- Dreamio/VLCNativePlaybackBackend.swift | 119 +++++++++++++++--- ...05-25-add-native-playback-seek-buffer.html | 48 +++++++ 2 files changed, 153 insertions(+), 14 deletions(-) diff --git a/Dreamio/VLCNativePlaybackBackend.swift b/Dreamio/VLCNativePlaybackBackend.swift index 09b71f9..a6cf6e4 100644 --- a/Dreamio/VLCNativePlaybackBackend.swift +++ b/Dreamio/VLCNativePlaybackBackend.swift @@ -6,6 +6,9 @@ import MobileVLCKit final class VLCNativePlaybackBackend: NSObject, NativePlaybackBackend { private static let seekBufferMilliseconds = 30_000 + private static let stalledJumpRecoveryDelay: TimeInterval = 3.0 + private static let stalledJumpProgressTolerance: TimeInterval = 0.75 + private static let stalledJumpTargetTolerance: TimeInterval = 2.0 static var isAvailable: Bool { #if canImport(MobileVLCKit) @@ -24,8 +27,11 @@ final class VLCNativePlaybackBackend: NSObject, NativePlaybackBackend { #if canImport(MobileVLCKit) private let mediaPlayer = VLCMediaPlayer() + private var currentRequest: NativePlaybackRequest? + private var recoveryGeneration = 0 #endif private var attachedSubtitleURLs = Set() + private var attachedSubtitleCandidates: [SubtitleCandidate] = [] private var didAutoSelectSubtitleTrack = false private var didUserSelectSubtitleTrack = false private var autoSelectedSubtitleTrackID: Int32? @@ -50,7 +56,10 @@ final class VLCNativePlaybackBackend: NSObject, NativePlaybackBackend { func play(request: NativePlaybackRequest) { #if canImport(MobileVLCKit) + currentRequest = request + recoveryGeneration += 1 attachedSubtitleURLs.removeAll() + attachedSubtitleCandidates.removeAll() didAutoSelectSubtitleTrack = false didUserSelectSubtitleTrack = false autoSelectedSubtitleTrackID = nil @@ -58,20 +67,7 @@ final class VLCNativePlaybackBackend: NSObject, NativePlaybackBackend { hasPendingExternalSubtitleSelection = false pendingExternalSubtitleDisplayNames.removeAll() externalSubtitleDisplayNamesByTrackID.removeAll() - let media = VLCMedia(url: request.playbackURL) - let headerValue = request.headers - .map { "\($0.key): \($0.value)" } - .joined(separator: "\r\n") - media.addOption(":http-referrer=\(request.referer)") - if let userAgent = request.userAgent { - media.addOption(":http-user-agent=\(userAgent)") - } - if !headerValue.isEmpty { - media.addOption(":http-header=\(headerValue)") - } - configureSeekBuffer(for: media) - - mediaPlayer.media = media + mediaPlayer.media = configuredMedia(for: request) #if DEBUG print("[DreamioVLC] opening url=\(URLRedactor.redactedURLString(request.playbackURL.absoluteString)) seekBufferMilliseconds=\(Self.seekBufferMilliseconds)") #endif @@ -99,6 +95,25 @@ final class VLCNativePlaybackBackend: NSObject, NativePlaybackBackend { cachingOptions.forEach { media.addOption($0) } } + + private func configuredMedia(for request: NativePlaybackRequest, startTime: TimeInterval? = nil) -> VLCMedia { + let media = VLCMedia(url: request.playbackURL) + let headerValue = request.headers + .map { "\($0.key): \($0.value)" } + .joined(separator: "\r\n") + media.addOption(":http-referrer=\(request.referer)") + if let userAgent = request.userAgent { + media.addOption(":http-user-agent=\(userAgent)") + } + if !headerValue.isEmpty { + media.addOption(":http-header=\(headerValue)") + } + if let startTime { + media.addOption(":start-time=\(Int(startTime.rounded()))") + } + configureSeekBuffer(for: media) + return media + } #endif func pause() { @@ -138,6 +153,7 @@ final class VLCNativePlaybackBackend: NSObject, NativePlaybackBackend { } mediaPlayer.position = Float(nextTime / duration) mediaPlayer.play() + scheduleStalledJumpRecovery(from: currentTime, targetTime: nextTime) #if DEBUG schedulePostSeekDiagnostics(label: "jump", expectedTime: nextTime) #endif @@ -199,6 +215,8 @@ final class VLCNativePlaybackBackend: NSObject, NativePlaybackBackend { mediaPlayer.stop() mediaPlayer.drawable = nil mediaPlayer.media = nil + currentRequest = nil + recoveryGeneration += 1 #endif } @@ -310,6 +328,7 @@ final class VLCNativePlaybackBackend: NSObject, NativePlaybackBackend { return } attachedSubtitleURLs.insert(candidate.url) + attachedSubtitleCandidates.append(candidate) externalSubtitleBaselineTrackIDs.formUnion(baselineTrackIDs) hasPendingExternalSubtitleSelection = true pendingExternalSubtitleDisplayNames.append(SubtitleDisplayName.displayName(for: candidate)) @@ -370,6 +389,78 @@ final class VLCNativePlaybackBackend: NSObject, NativePlaybackBackend { } } + private func scheduleStalledJumpRecovery(from originalTime: TimeInterval, targetTime: TimeInterval) { + recoveryGeneration += 1 + let generation = recoveryGeneration + DispatchQueue.main.asyncAfter(deadline: .now() + Self.stalledJumpRecoveryDelay) { [weak self] in + self?.recoverStalledJumpIfNeeded( + generation: generation, + originalTime: originalTime, + targetTime: targetTime + ) + } + } + + private func recoverStalledJumpIfNeeded( + generation: Int, + originalTime: TimeInterval, + targetTime: TimeInterval + ) { + guard generation == recoveryGeneration, + let request = currentRequest, + mediaPlayer.state == .buffering else { + return + } + + let hasMadeProgress = abs(currentTime - originalTime) > Self.stalledJumpProgressTolerance + let hasReachedTarget = abs(currentTime - targetTime) <= Self.stalledJumpTargetTolerance + guard !hasMadeProgress && !hasReachedTarget else { + return + } + + let subtitleCandidates = attachedSubtitleCandidates + let selectedAudioTrackID = mediaPlayer.currentAudioTrackIndex + let selectedSubtitleTrackID = mediaPlayer.currentVideoSubTitleIndex + let wasUserSubtitleSelection = didUserSelectSubtitleTrack +#if DEBUG + print("[DreamioVLC] stalled jump recovery target=\(targetTime) original=\(originalTime) current=\(currentTime) position=\(mediaPlayer.position)") +#endif + recoveryGeneration += 1 + attachedSubtitleURLs.removeAll() + attachedSubtitleCandidates.removeAll() + externalSubtitleBaselineTrackIDs.removeAll() + hasPendingExternalSubtitleSelection = false + pendingExternalSubtitleDisplayNames.removeAll() + externalSubtitleDisplayNamesByTrackID.removeAll() + didUserSelectSubtitleTrack = wasUserSubtitleSelection + + mediaPlayer.stop() + mediaPlayer.media = configuredMedia(for: request, startTime: targetTime) + mediaPlayer.play() + _ = attachSubtitles(subtitleCandidates) + scheduleTrackRecovery(audioTrackID: selectedAudioTrackID, subtitleTrackID: selectedSubtitleTrackID) + } + + private func scheduleTrackRecovery(audioTrackID: Int32, subtitleTrackID: Int32) { + [0.4, 1.2, 2.5].forEach { delay in + DispatchQueue.main.asyncAfter(deadline: .now() + delay) { [weak self] in + guard let self else { + return + } + if audioTrackID >= 0, + self.audioTracks.contains(where: { $0.id == audioTrackID }) { + self.mediaPlayer.currentAudioTrackIndex = audioTrackID + } + if subtitleTrackID >= 0, + self.subtitleTracks.contains(where: { $0.id == subtitleTrackID }) { + self.mediaPlayer.currentVideoSubTitleIndex = subtitleTrackID + } + self.onAudioTracksChange?() + self.onSubtitleTracksChange?() + } + } + } + #if DEBUG private func logPlaybackSnapshot(reason: String) { print("[DreamioVLC] snapshot reason=\(reason) state=\(stateName(mediaPlayer.state)) isPlaying=\(mediaPlayer.isPlaying) isSeekable=\(mediaPlayer.isSeekable) time=\(currentTime) duration=\(duration) position=\(mediaPlayer.position) selectedAudio=\(mediaPlayer.currentAudioTrackIndex) selectedSubtitle=\(mediaPlayer.currentVideoSubTitleIndex)") diff --git a/docs/turns/2026-05-25-add-native-playback-seek-buffer.html b/docs/turns/2026-05-25-add-native-playback-seek-buffer.html index 82ecef3..b8632eb 100644 --- a/docs/turns/2026-05-25-add-native-playback-seek-buffer.html +++ b/docs/turns/2026-05-25-add-native-playback-seek-buffer.html @@ -385,6 +385,54 @@ index c3c2318..0fa779a 100644

Related issues or PRs

Related Beads issue: dreamio-3yb. This is a diagnostic update to the same native seek-buffer investigation. The diff is shown as a plain fallback because @pierre/diffs/ssr is not installed in this workspace.

+ +
+

New Changes as of 2026-05-25 16:13 EDT

+

Summary of changes

+

Device logs showed VLC accepted the jump request but kept reporting the old timestamp and position while buffering. The backend now detects that stalled jump pattern and performs a native-only recovery by reopening the same media with VLC's :start-time option set to the requested target timestamp.

+ +

Why this change was made

+

The seek buffer and alternate seek APIs did not make libVLC apply the seek on this direct stream. Reopening the same media at the target time gives VLC a fresh input pipeline while keeping the behavior inside VLCNativePlaybackBackend and without adding player UI or protocol settings.

+ +

Code diffs

+ 
diff --git a/Dreamio/VLCNativePlaybackBackend.swift b/Dreamio/VLCNativePlaybackBackend.swift
+@@
++    private static let stalledJumpRecoveryDelay: TimeInterval = 3.0
++    private static let stalledJumpProgressTolerance: TimeInterval = 0.75
++    private static let stalledJumpTargetTolerance: TimeInterval = 2.0
+@@
++    private var currentRequest: NativePlaybackRequest?
++    private var recoveryGeneration = 0
+@@
++        if let startTime {
++            media.addOption(":start-time=\(Int(startTime.rounded()))")
++        }
+@@
+         mediaPlayer.position = Float(nextTime / duration)
+         mediaPlayer.play()
++        scheduleStalledJumpRecovery(from: currentTime, targetTime: nextTime)
+@@
++        guard generation == recoveryGeneration,
++              let request = currentRequest,
++              mediaPlayer.state == .buffering else {
++            return
++        }
++
++        let hasMadeProgress = abs(currentTime - originalTime) > Self.stalledJumpProgressTolerance
++        let hasReachedTarget = abs(currentTime - targetTime) <= Self.stalledJumpTargetTolerance
++        guard !hasMadeProgress && !hasReachedTarget else {
++            return
++        }
++
++        mediaPlayer.stop()
++        mediaPlayer.media = configuredMedia(for: request, startTime: targetTime)
++        mediaPlayer.play()
++        _ = attachSubtitles(subtitleCandidates)
++        scheduleTrackRecovery(audioTrackID: selectedAudioTrackID, subtitleTrackID: selectedSubtitleTrackID)
+ +

Related issues or PRs

+

Related Beads issue: dreamio-3yb. This remains part of the same native playback seek-buffer branch. The branch now includes a fallback for streams where VLC's in-place seek does not take effect.

+