fixed bugs

ios/OralTrainer/Models/PlaybackModels.swift

@@ -64,7 +64,7 @@ enum BoundaryState: Equatable {
     case failed(message: String)
 }
 
-/// 云端视频必须先完成整文件下载；下载未完成前不允许创建可播放的 AVPlayerItem。
+/// 云端视频按需流式播放；若本地已有完整缓存文件则优先使用。
 enum VideoCacheState: Equatable {
     case notRequired
     case downloading
@@ -76,9 +76,9 @@ enum VideoCacheState: Equatable {
         case .notRequired, .ready:
             return nil
         case .downloading:
-            return "正在下载完整视频，下载完成后才能播放"
+            return "正在缓冲视频…"
         case .failed(let message):
-            return "视频缓存失败：\(message)"
+            return "视频加载失败：\(message)"
         }
     }
 }

ios/OralTrainer/Player/PlayerController.swift

@@ -31,8 +31,9 @@ final class PlayerController: ObservableObject {
     private var swipeBackAnchorTime: TimeInterval = 0
     private var speedBeforeLongPress: Float?
     private var transientTask: Task<Void, Never>?
-    private var cacheSwapTask: Task<Void, Never>?
+    private var cacheFallbackTask: Task<Void, Never>?
     private var activePlaybackURL: URL?
+    private var didAttemptFullFileFallback = false
     private var sentenceEndTimeObserver: Any?
     private var sentenceEndGuardToken = 0
 
@@ -91,8 +92,9 @@ final class PlayerController: ObservableObject {
     @MainActor
     func load(_ item: TrainingMediaItem) {
         cancelSentenceBoundaryGuard()
-        cacheSwapTask?.cancel()
+        cacheFallbackTask?.cancel()
-        cacheSwapTask = nil
+        cacheFallbackTask = nil
+        didAttemptFullFileFallback = false
         lastSentenceIndex = nil
         swipeBackAnchorIndex = nil
         pendingSeekPositionMs = nil
@@ -110,12 +112,8 @@ final class PlayerController: ObservableObject {
             cacheState = .ready
             preparePlaybackItem(with: cachedURL)
         } else {
-            // 关键约束：云端视频没有完整本地文件前，不把 remote URL 交给 AVPlayer。
+            cacheState = .notRequired
-            activePlaybackURL = nil
+            preparePlaybackItem(with: item.url)
-            cacheState = .downloading
-            player.replaceCurrentItem(with: nil)
-            tick()
-            scheduleFullFileDownload(for: item)
         }
     }
 
@@ -480,39 +478,8 @@ final class PlayerController: ObservableObject {
         pendingSeekPositionMs ?? currentPositionMs()
     }
 
-    @MainActor
-    private func scheduleFullFileDownload(for item: TrainingMediaItem) {
-        let remoteURL = item.url
-        cacheSwapTask = Task { [weak self] in
-            let cachedURL: URL
-            do {
-                cachedURL = try await StreamingVideoCache.shared.prefetch(remoteURL)
-            } catch is CancellationError {
-                return
-            } catch {
-                self?.cacheState = .failed(message: error.localizedDescription)
-                self?.showTransientMessage("视频缓存失败：\(error.localizedDescription)")
-                return
-            }
-            self?.prepareDownloadedFileIfNeeded(remoteURL: remoteURL, cachedURL: cachedURL)
-        }
-    }
-
-    @MainActor
-    private func prepareDownloadedFileIfNeeded(remoteURL: URL, cachedURL: URL) {
-        guard !Task.isCancelled,
-              mediaItem?.url == remoteURL,
-              activePlaybackURL == nil else {
-            return
-        }
-
-        cacheState = .ready
-        preparePlaybackItem(with: cachedURL)
-        showTransientMessage("视频已完整缓存，可以播放")
-    }
-
     private func preparePlaybackItem(with playbackURL: URL) {
-        let newItem = AVPlayerItem(url: playbackURL)
+        let newItem = makePlayerItem(url: playbackURL)
         activePlaybackURL = playbackURL
         attachItemObservers(to: newItem)
         player.replaceCurrentItem(with: newItem)
@@ -524,6 +491,19 @@ final class PlayerController: ObservableObject {
         tick()
     }
 
+    private func makePlayerItem(url: URL) -> AVPlayerItem {
+        guard !url.isFileURL else {
+            return AVPlayerItem(url: url)
+        }
+        var options: [String: Any] = [:]
+        let ext = url.pathExtension.lowercased()
+        if ext.isEmpty || ["mp4", "m4v", "mov"].contains(ext) {
+            options["AVURLAssetOverrideMIMETypeKey"] = "video/mp4"
+        }
+        let asset = AVURLAsset(url: url, options: options.isEmpty ? nil : options)
+        return AVPlayerItem(asset: asset, automaticallyLoadedAssetKeys: ["playable", "tracks", "duration"])
+    }
+
     /// AVPlayer 的 seek 是异步的；所有 seek 必须统一走这里，避免播放循环、
     /// 用户手势和 seek 完成回调交错后把位置拉回旧句子。
     private func performSeek(
@@ -844,12 +824,57 @@ final class PlayerController: ObservableObject {
                 if item.status == .failed {
                     let message = item.error?.localizedDescription ?? "未知错误"
                     self.showTransientMessage("播放失败：\(message)")
+                } else if item.status == .readyToPlay {
+                    self.considerFullFileFallback(for: item)
                 }
                 self.tick()
             }
         }
     }
 
+    private func considerFullFileFallback(for item: AVPlayerItem) {
+        guard !didAttemptFullFileFallback,
+              let media = mediaItem,
+              !media.isLocalFile,
+              !(activePlaybackURL?.isFileURL ?? false) else {
+            return
+        }
+        let hasVisibleVideo = item.presentationSize.height >= 2 && item.presentationSize.width >= 2
+        if hasVisibleVideo {
+            return
+        }
+        didAttemptFullFileFallback = true
+        cacheFallbackTask?.cancel()
+        cacheFallbackTask = Task { @MainActor [weak self] in
+            try? await Task.sleep(nanoseconds: 800_000_000)
+            guard let self, !Task.isCancelled else {
+                return
+            }
+            guard self.mediaItem?.id == media.id,
+                  self.player.currentItem === item,
+                  item.presentationSize.height < 2 else {
+                return
+            }
+            do {
+                let cachedURL = try await StreamingVideoCache.shared.prefetch(media.url)
+                guard self.mediaItem?.id == media.id else {
+                    return
+                }
+                let shouldPlay = self.playbackIntent
+                let positionMs = self.pendingSeekPositionMs ?? self.currentPositionMs()
+                self.preparePlaybackItem(with: cachedURL)
+                self.cacheState = .ready
+                if positionMs > 0 {
+                    self.performSeek(to: positionMs, resumePlayback: shouldPlay)
+                }
+            } catch is CancellationError {
+                return
+            } catch {
+                self.showTransientMessage("视频画面加载失败：\(error.localizedDescription)")
+            }
+        }
+    }
+
     private func configureAudioSession() {
         let session = AVAudioSession.sharedInstance()
         try? session.setCategory(.playback, mode: .moviePlayback)

ios/OralTrainer/Player/PlayerSurfaceView.swift

@@ -13,15 +13,20 @@ struct PlayerSurfaceView: UIViewRepresentable {
 
     func makeUIView(context: Context) -> VideoSurfaceView {
         let view = VideoSurfaceView()
-        view.playerLayer.player = controller.player
         view.controller = controller
         view.onVerticalSwipe = onVerticalSwipe
+        view.attach(player: controller.player)
+        view.setContentHuggingPriority(.defaultLow, for: .vertical)
+        view.setContentHuggingPriority(.defaultLow, for: .horizontal)
+        view.setContentCompressionResistancePriority(.defaultLow, for: .vertical)
+        view.setContentCompressionResistancePriority(.defaultLow, for: .horizontal)
         return view
     }
 
     func updateUIView(_ uiView: VideoSurfaceView, context: Context) {
-        uiView.playerLayer.player = controller.player
+        uiView.controller = controller
         uiView.onVerticalSwipe = onVerticalSwipe
+        uiView.attach(player: controller.player)
     }
 }
 
@@ -29,13 +34,9 @@ final class VideoSurfaceView: UIView {
     weak var controller: PlayerController?
     var onVerticalSwipe: ((Bool) -> Void)?
 
-    override class var layerClass: AnyClass {
+    private let videoLayer = AVPlayerLayer()
-        AVPlayerLayer.self
-    }
 
-    var playerLayer: AVPlayerLayer {
+    var playerLayer: AVPlayerLayer { videoLayer }
-        layer as! AVPlayerLayer
-    }
 
     private let minSwipeDistance: CGFloat = 48
     private let minSwipeVelocity: CGFloat = 160
@@ -55,7 +56,11 @@ final class VideoSurfaceView: UIView {
     override init(frame: CGRect) {
         super.init(frame: frame)
         backgroundColor = .black
-        playerLayer.videoGravity = .resizeAspect
+        isOpaque = true
+        clipsToBounds = true
+        videoLayer.videoGravity = .resizeAspect
+        videoLayer.backgroundColor = UIColor.black.cgColor
+        layer.addSublayer(videoLayer)
 
         tapRecognizer = UITapGestureRecognizer(target: self, action: #selector(handleTap))
         panRecognizer = UIPanGestureRecognizer(target: self, action: #selector(handlePan))
@@ -82,6 +87,25 @@ final class VideoSurfaceView: UIView {
         fatalError("init(coder:) has not been implemented")
     }
 
+    override func layoutSubviews() {
+        super.layoutSubviews()
+        CATransaction.begin()
+        CATransaction.setDisableActions(true)
+        videoLayer.frame = bounds
+        CATransaction.commit()
+    }
+
+    func attach(player: AVPlayer) {
+        if videoLayer.player !== player {
+            videoLayer.player = player
+        }
+        if videoLayer.superlayer !== layer {
+            layer.addSublayer(videoLayer)
+        }
+        videoLayer.frame = bounds
+        videoLayer.isHidden = false
+    }
+
     @objc private func handleTap() {
         controller?.handleGesture(.singleTap)
     }
@@ -96,7 +120,6 @@ final class VideoSurfaceView: UIView {
         case .began:
             resetSwipeTracking()
         case .changed:
-            // 在滑动达到阈值时立即派发，并且同一个手势只允许派发一次。
             evaluateSwipe(dx: dx, dy: dy, velocity: velocity)
         case .ended, .cancelled, .failed:
             if !didDispatchSwipe {
@@ -112,7 +135,6 @@ final class VideoSurfaceView: UIView {
         guard !didDispatchSwipe else { return }
 
         if swipeAxis == nil {
-            // 只有方向足够明确时锁定轴向，避免轻微斜滑被误判为上下滑。
             if abs(dx) > abs(dy) * 1.2 {
                 swipeAxis = .horizontal
             } else if abs(dy) > abs(dx) * 1.2 {

ios/OralTrainer/Services/StreamingVideoCache.swift

@@ -1,11 +1,10 @@
 import CryptoKit
 import Foundation
 
-/// iOS 端的持久化整文件视频缓存。
+/// iOS 端的可选整文件视频缓存。
 ///
-/// AVFoundation 没有公开可持久化的媒体字节缓存 API。这里先把远程视频完整
+/// 播放默认走远程 URL 按需加载（AVPlayer HTTP Range）。若本地已有完整缓存文件，
-/// 下载成原子本地文件；只有文件
+/// 播放器会优先使用该文件，避免重复拉流。
-/// 完整落盘后才返回给播放器，避免用部分响应或播放列表创建可播放的 AVPlayerItem。
 @MainActor
 final class StreamingVideoCache {
     static let shared = StreamingVideoCache()

sentence_api/main.py

@@ -481,9 +481,13 @@ def create_app(
         media_path = service_settings.videos_dir / row["stored_filename"]
         if not media_path.is_file():
             raise HTTPException(status_code=404, detail="Stored video file is missing.")
+        media_type = row.get("content_type") or "video/mp4"
+        if not str(media_type).lower().startswith("video/"):
+            guessed = mimetypes.guess_type(str(row.get("stored_filename") or ""))[0]
+            media_type = guessed if guessed and guessed.lower().startswith("video/") else "video/mp4"
         return FileResponse(
             media_path,
-            media_type=row["content_type"],
+            media_type=media_type,
             headers={"Accept-Ranges": "bytes", "Cache-Control": "public, max-age=3600"},
         )
 

sentence_api/processing.py

@@ -1,10 +1,11 @@
+import json
 import logging
 import shutil
 import subprocess
 import tempfile
 import uuid
 from pathlib import Path
-from typing import Any, Dict, List, Optional
+from typing import Any, Dict, List, Optional, Tuple
 
 from .audio_metrics import (
     AudioAnalysisError,
@@ -85,6 +86,126 @@ def _ensure_webm_cues_front(filepath: Path) -> None:
         tmp.unlink(missing_ok=True)
 
 
+_IOS_VIDEO_CODECS = {"h264", "hevc"}
+_IOS_AUDIO_CODECS = {"aac", "mp3", "ac3", "eac3", "alac"}
+
+
+def _probe_stream_codecs(filepath: Path) -> Tuple[Optional[str], Optional[str]]:
+    ffprobe = shutil.which("ffprobe")
+    if ffprobe is None:
+        return None, None
+    completed = subprocess.run(
+        [
+            ffprobe,
+            "-hide_banner",
+            "-loglevel",
+            "error",
+            "-show_streams",
+            "-of",
+            "json",
+            str(filepath),
+        ],
+        capture_output=True,
+        text=True,
+        timeout=60,
+    )
+    if completed.returncode != 0:
+        return None, None
+    try:
+        payload = json.loads(completed.stdout or "{}")
+    except json.JSONDecodeError:
+        return None, None
+    video_codec = None
+    audio_codec = None
+    for stream in payload.get("streams") or []:
+        codec_type = stream.get("codec_type")
+        codec_name = stream.get("codec_name")
+        if codec_type == "video" and video_codec is None and codec_name not in {"mjpeg", "png"}:
+            video_codec = codec_name
+        elif codec_type == "audio" and audio_codec is None:
+            audio_codec = codec_name
+    return video_codec, audio_codec
+
+
+def _needs_ios_compatible_transcode(video_codec: Optional[str], audio_codec: Optional[str]) -> bool:
+    if video_codec is None and audio_codec is None:
+        return False
+    video_ok = video_codec is None or video_codec in _IOS_VIDEO_CODECS
+    audio_ok = audio_codec is None or audio_codec in _IOS_AUDIO_CODECS
+    return not (video_ok and audio_ok)
+
+
+def _ensure_ios_compatible_media(filepath: Path) -> None:
+    """Transcode AV1/VP9/Opus etc. to H.264/AAC so iOS AVPlayer can show video."""
+    video_codec, audio_codec = _probe_stream_codecs(filepath)
+    if not _needs_ios_compatible_transcode(video_codec, audio_codec):
+        return
+    ffmpeg = shutil.which("ffmpeg")
+    if ffmpeg is None:
+        logger.warning(
+            "ffmpeg not found; skipping iOS-compatible transcode for %s (%s/%s)",
+            filepath.name,
+            video_codec,
+            audio_codec,
+        )
+        return
+    tmp = filepath.with_suffix(".ios_tmp.mp4")
+    command = [
+        ffmpeg,
+        "-hide_banner",
+        "-loglevel",
+        "error",
+        "-y",
+        "-i",
+        str(filepath),
+        "-map",
+        "0:v:0",
+        "-map",
+        "0:a:0?",
+        "-vf",
+        "scale='min(1920,iw)':-2",
+        "-c:v",
+        "libx264",
+        "-preset",
+        "veryfast",
+        "-crf",
+        "23",
+        "-pix_fmt",
+        "yuv420p",
+        "-c:a",
+        "aac",
+        "-b:a",
+        "128k",
+        "-ac",
+        "2",
+        "-movflags",
+        "+faststart",
+        str(tmp),
+    ]
+    logger.info(
+        "Transcoding %s for iOS playback (%s/%s -> h264/aac)",
+        filepath.name,
+        video_codec,
+        audio_codec,
+    )
+    try:
+        completed = subprocess.run(command, capture_output=True, text=True, timeout=7200)
+        if completed.returncode == 0 and tmp.is_file() and tmp.stat().st_size > 0:
+            tmp.replace(filepath)
+            logger.info("iOS-compatible transcode finished: %s", filepath.name)
+            return
+        logger.warning(
+            "iOS-compatible transcode failed for %s: rc=%d stderr=%s",
+            filepath.name,
+            completed.returncode,
+            (completed.stderr or "")[-400:],
+        )
+    except (subprocess.TimeoutExpired, OSError) as exc:
+        logger.warning("iOS-compatible transcode error for %s: %s", filepath.name, exc)
+    finally:
+        tmp.unlink(missing_ok=True)
+
+
 class VideoProcessor:
     def __init__(
         self,
@@ -110,6 +231,7 @@ class VideoProcessor:
         work_path: Optional[Path] = None
         try:
             _ensure_webm_cues_front(media_path)
+            _ensure_ios_compatible_media(media_path)
             if self.transcriber.available:
                 work_path = self.settings.work_dir / f"{video_hash}-{uuid.uuid4().hex}.wav"
                 extract_audio(media_path, work_path)