diff --git a/.github/workflows/playback.yml b/.github/workflows/playback.yml
new file mode 100644
index 0000000..24dd7d0
--- /dev/null
+++ b/.github/workflows/playback.yml
@@ -0,0 +1,43 @@
+name: Playback core regression
+
+on:
+  push:
+    branches: [main, master, 'fix/**']
+  pull_request:
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+concurrency:
+  group: playback-${{ github.ref }}
+  cancel-in-progress: true
+
+env:
+  GOPROXY: https://proxy.golang.org,direct
+  GOSUMDB: sum.golang.org
+
+jobs:
+  playback-core:
+    runs-on: ubuntu-latest
+    timeout-minutes: 15
+    strategy:
+      fail-fast: false
+      matrix:
+        all-sources: ['false', 'true']
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-go@v5
+        with:
+          go-version-file: native/go.mod
+          cache-dependency-path: native/go.sum
+      - name: 播放与下载核心回归
+        working-directory: native
+        env:
+          ALL_SOURCES: ${{ matrix.all-sources }}
+        run: >-
+          go test -count=1 -race -timeout=5m
+          -ldflags="-X duanjuapp/native/core.buildAllSources=$ALL_SOURCES"
+          ./core
+          -run 'TestNative(Playback|Download|Downloaded|HLS|Danmaku)|TestDownloadMigration|TestLegacyPlayback'
+
diff --git a/native/core/app_stream.go b/native/core/app_stream.go
index f58a21c..e55aa96 100644
--- a/native/core/app_stream.go
+++ b/native/core/app_stream.go
@@ -95,7 +95,7 @@ func (stream *nativeStreamServer) nativeOpen(media providerMedia) (string, strin
 	stream.sessions[token] = session
 	stream.mu.Unlock()
 	entry := nativeStreamAsset{address: media.URL, contentType: "video/mp4"}
-	isHLS := media.Playlist != "" || len(media.HLSKey) > 0 || strings.Contains(strings.ToLower(media.URL), "m3u8") || strings.Contains(strings.ToLower(media.URL), "hls")
+	isHLS := media.Playlist != "" || len(media.HLSKey) > 0
 	if isHLS {
 		entry.contentType = "application/vnd.apple.mpegurl"
 	}
@@ -301,7 +301,7 @@ func (stream *nativeStreamServer) nativeServe(writer http.ResponseWriter, reques
 	if response.Request != nil && response.Request.URL != nil {
 		finalURL = response.Request.URL
 	}
-	playlist := strings.Contains(asset.contentType, "mpegurl") || strings.Contains(contentType, "mpegurl") || strings.HasSuffix(strings.ToLower(finalURL.Path), ".m3u8") || strings.Contains(strings.ToLower(finalURL.String()), "m3u8") || len(session.key) > 0
+	playlist := strings.Contains(asset.contentType, "mpegurl") || strings.Contains(contentType, "mpegurl") || strings.HasSuffix(strings.ToLower(finalURL.Path), ".m3u8")
 	reader := bufio.NewReader(response.Body)
 	if !playlist && request.Method == http.MethodGet {
 		peek, _ := reader.Peek(512)
diff --git a/native/core/app_stream_format_test.go b/native/core/app_stream_format_test.go
new file mode 100644
index 0000000..80ac5bf
--- /dev/null
+++ b/native/core/app_stream_format_test.go
@@ -0,0 +1,49 @@
+package core
+
+import (
+	"bytes"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+)
+
+func TestNativePlaybackMP4IgnoresPlaylistWordsInSignedURL(t *testing.T) {
+	body := append([]byte("\x00\x00\x00\x1cftypisom"), bytes.Repeat([]byte{0x42}, 4<<20)...)
+	upstream := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "video/mp4")
+		_, _ = w.Write(body)
+	}))
+	defer upstream.Close()
+	engine, err := newNativeEngine(t.TempDir())
+	if err != nil {
+		t.Fatal(err)
+	}
+	stream, err := newNativeStreamServer(engine.downloader)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer stream.server.Close()
+	for _, suffix := range []string{"/video/?rc=signaturehLSvalue", "/video/?hint=m3u8", "/hls-cache/video.mp4"} {
+		t.Run(suffix, func(t *testing.T) {
+			address, token := stream.nativeOpen(providerMedia{URL: upstream.URL + suffix, CENCKey: bytes.Repeat([]byte{1}, 16)})
+			defer stream.nativeRelease(token)
+			if !strings.HasSuffix(address, ".mp4") {
+				t.Errorf("MP4 classified as a playlist: %s", address)
+			}
+			response, err := http.Get(address)
+			if err != nil {
+				t.Fatal(err)
+			}
+			defer response.Body.Close()
+			actual, err := io.ReadAll(response.Body)
+			if err != nil {
+				t.Fatal(err)
+			}
+			if response.StatusCode != http.StatusOK || !bytes.Equal(actual, body) {
+				t.Fatalf("MP4 was not streamed intact: status=%d, bytes=%d", response.StatusCode, len(actual))
+			}
+		})
+	}
+}