Merge pull request #158 from Dash-Industry-Forum/fix-mehd-removal

fix: remove mehd box from init segments
Dash-Industry-Forum · Feb 13, 2024 · 0557d4f · 0557d4f
2 parents a6fba5f + f158914
commit 0557d4f
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Showing 6 changed files with 66 additions and 19 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -17,6 +17,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Make HTTP OPTIONS method work for all URLs
 - Make --playurl work for general paths
 - Derive and insert contentType if missing
+- Remove any mehd box from init segment
 
 ## [1.1.1] - 2024-01-19
 

diff --git a/cmd/livesim2/app/asset.go b/cmd/livesim2/app/asset.go
@@ -832,7 +832,15 @@ func getInitSeg(data []byte) (*mp4.InitSegment, error) {
 	if err != nil {
 		return nil, fmt.Errorf("decode init: %w", err)
 	}
-	return initFile.Init, nil
+	initSeg := initFile.Init
+	if initSeg == nil {
+		return nil, fmt.Errorf("no init segment found")
+	}
+	err = initSeg.TweakSingleTrakLive()
+	if err != nil {
+		return nil, fmt.Errorf("tweak single trak live: %w", err)
+	}
+	return initSeg, nil
 }
 
 func getInitBytes(initSeg *mp4.InitSegment) ([]byte, error) {

diff --git a/cmd/livesim2/app/livesegment.go b/cmd/livesim2/app/livesegment.go
@@ -253,37 +253,56 @@ func findSegMetaFromNr(a *asset, rep *RepData, nr uint32, cfg *ResponseConfig, n
 	}, nil
 }
 
+type initMatch struct {
+	isInit bool
+	init   []byte
+	rep    *RepData
+}
+
 func writeInitSegment(w http.ResponseWriter, cfg *ResponseConfig, vodFS fs.FS, a *asset, segmentPart string) (isInit bool, err error) {
 	isTimeSubsInit, err := writeTimeSubsInitSegment(w, cfg, a, segmentPart)
 	if isTimeSubsInit {
 		return true, err
 	}
+	match, err := matchInit(segmentPart, cfg, a)
+	if err != nil {
+		return false, fmt.Errorf("getInitBytes: %w", err)
+	}
+	if !match.isInit {
+		return false, nil
+	}
+
+	w.Header().Set("Content-Length", strconv.Itoa(len(match.init)))
+	w.Header().Set("Content-Type", match.rep.SegmentType())
+	_, err = w.Write(match.init)
+	if err != nil {
+		slog.Error("writing response", "error", err)
+		return false, err
+	}
+	return true, nil
+}
+
+func matchInit(segmentPart string, cfg *ResponseConfig, a *asset) (initMatch, error) {
+	var im initMatch
 	for _, rep := range a.Reps {
 		if segmentPart == rep.InitURI {
-			var initBytes []byte
-			initBytes = rep.initBytes
+			im.init = rep.initBytes
 			if rep.encData != nil && cfg.DashIFECCP != "" {
 				switch cfg.DashIFECCP {
 				case "cbcs":
-					initBytes = rep.encData.cbcsInitBytes
+					im.init = rep.encData.cbcsInitBytes
 				case "cenc":
-					initBytes = rep.encData.cencInitBytes
+					im.init = rep.encData.cencInitBytes
 				default:
-					return false, fmt.Errorf("unknown DashIFECCP %s", cfg.DashIFECCP)
+					return im, fmt.Errorf("unknown DashIFECCP %s", cfg.DashIFECCP)
 				}
 			}
-			w.Header().Set("Content-Length", strconv.Itoa(len(initBytes)))
-
-			w.Header().Set("Content-Type", rep.SegmentType())
-			_, err := w.Write(initBytes)
-			if err != nil {
-				slog.Error("writing response", "error", err)
-				return false, err
-			}
-			return true, nil
+			im.rep = rep
+			im.isInit = true
+			return im, nil
 		}
 	}
-	return false, nil
+	return im, nil
 }
 
 func writeLiveSegment(w http.ResponseWriter, cfg *ResponseConfig, vodFS fs.FS, a *asset, segmentPart string, nowMS int, tt *template.Template) error {

diff --git a/cmd/livesim2/app/livesegment_test.go b/cmd/livesim2/app/livesegment_test.go
@@ -672,3 +672,22 @@ func TestSegmentStatusCodeResponse(t *testing.T) {
 		})
 	}
 }
+
+func TestMehdBoxRemovedFromInitSegment(t *testing.T) {
+	vodFS := os.DirFS("testdata/assets")
+	am := newAssetMgr(vodFS, "", false)
+	err := am.discoverAssets()
+	require.NoError(t, err)
+	asset, ok := am.findAsset("testpic_8s")
+	require.True(t, ok)
+	cfg := NewResponseConfig()
+	initV300 := "V300/init.mp4"
+	match, err := matchInit(initV300, cfg, asset)
+	require.NoError(t, err)
+	sr := bits.NewFixedSliceReader(match.init)
+	mp4File, err := mp4.DecodeFileSR(sr)
+	require.NoError(t, err)
+	initSeg := mp4File.Init
+	require.NotNil(t, initSeg)
+	require.Nil(t, initSeg.Moov.Mvex.Mehd)
+}
diff --git a/go.mod b/go.mod
@@ -7,7 +7,7 @@ toolchain go1.21.1
 require (
 	github.com/Comcast/gots v1.0.4
 	github.com/Eyevinn/dash-mpd v0.11.1
-	github.com/Eyevinn/mp4ff v0.42.0
+	github.com/Eyevinn/mp4ff v0.42.1-0.20240212112335-795b1455e438
 	github.com/caddyserver/certmagic v0.20.0
 	github.com/dusted-go/logging v1.1.3
 	github.com/go-chi/chi/v5 v5.0.11

diff --git a/go.sum b/go.sum
@@ -7,8 +7,8 @@ github.com/Comcast/gots v1.0.4 h1:OBxaTTM2kEjZZ9QTYsEVIUkaY3hAmy4spJOjpcgJk+A=
 github.com/Comcast/gots v1.0.4/go.mod h1:/EieJXsI8HTyAAGPoardzq/OY+jL+RiyG+sq0cZgkyk=
 github.com/Eyevinn/dash-mpd v0.11.1 h1:p9r31p7+YNp9E548m+sLIdohvQhQt+TmLoOxU8eGqns=
 github.com/Eyevinn/dash-mpd v0.11.1/go.mod h1:loc8wzf1XW4NIWI4M7U6TAPk+bx2H8wGpjFTvxepmcI=
-github.com/Eyevinn/mp4ff v0.42.0 h1:I85b/EDTkP77GsoBL8nRV6sfFKZhAXoP6oJHU8fv6kM=
-github.com/Eyevinn/mp4ff v0.42.0/go.mod h1:w/6GSa5ghZ1VavzJK6McQ2/flx8mKtcrKDr11SsEweA=
+github.com/Eyevinn/mp4ff v0.42.1-0.20240212112335-795b1455e438 h1:TojV4JliMS3FLLeDrcCPe+097UQ3EfyqqIPO4VAGsr4=
+github.com/Eyevinn/mp4ff v0.42.1-0.20240212112335-795b1455e438/go.mod h1:w/6GSa5ghZ1VavzJK6McQ2/flx8mKtcrKDr11SsEweA=
 github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
 github.com/alecthomas/template v0.0.0-20190718012654-fb15b899a751/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
 github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf/go.mod h1:ybxpYRFXyAe+OPACYpWeL0wqObRcbAqCMya13uyzqw0=