diff --git a/format/mp4/mp4io/atoms.go b/format/mp4/mp4io/atoms.go
index 901a7139..fa21d44e 100644
--- a/format/mp4/mp4io/atoms.go
+++ b/format/mp4/mp4io/atoms.go
@@ -1,7 +1,7 @@
 package mp4io
 
 import (
-	"log"
+	"errors"
 	"time"
 
 	"github.com/deepch/vdk/utils/bits/pio"
@@ -306,6 +306,10 @@ func (self *Movie) Unmarshal(b []byte, offset int) (n int, err error) {
 					err = parseErr("trak", n+offset, err)
 					return
 				}
+				if len(self.Tracks) > 100 {
+					err = errors.New("too many tracks")
+					return
+				}
 				self.Tracks = append(self.Tracks, atom)
 			}
 		default:
@@ -315,6 +319,10 @@ func (self *Movie) Unmarshal(b []byte, offset int) (n int, err error) {
 					err = parseErr("", n+offset, err)
 					return
 				}
+				if len(self.Unknowns) > 100 {
+					err = errors.New("too many unknowns")
+					return
+				}
 				self.Unknowns = append(self.Unknowns, atom)
 			}
 		}
@@ -573,11 +581,6 @@ func (self *Track) Unmarshal(b []byte, offset int) (n int, err error) {
 	for n+8 < len(b) {
 		tag := Tag(pio.U32BE(b[n+4:]))
 		size := int(pio.U32BE(b[n:]))
-		if size > 5242880 {
-			log.Println("track size", size)
-			err = parseErr("_len_Entries", 5242880, err)
-			return
-		}
 		if len(b) < n+size {
 			err = parseErr("TagSizeInvalid", n+offset, err)
 			return
@@ -608,6 +611,10 @@ func (self *Track) Unmarshal(b []byte, offset int) (n int, err error) {
 					err = parseErr("", n+offset, err)
 					return
 				}
+				if len(self.Unknowns) > 100 {
+					err = errors.New("too many unknowns")
+					return
+				}
 				self.Unknowns = append(self.Unknowns, atom)
 			}
 		}
@@ -947,6 +954,10 @@ func (self *Media) Unmarshal(b []byte, offset int) (n int, err error) {
 					err = parseErr("", n+offset, err)
 					return
 				}
+				if len(self.Unknowns) > 100 {
+					err = errors.New("too many unknowns")
+					return
+				}
 				self.Unknowns = append(self.Unknowns, atom)
 			}
 		}
@@ -1180,6 +1191,10 @@ func (self *MediaInfo) Unmarshal(b []byte, offset int) (n int, err error) {
 					err = parseErr("", n+offset, err)
 					return
 				}
+				if len(self.Unknowns) > 100 {
+					err = errors.New("too many unknowns")
+					return
+				}
 				self.Unknowns = append(self.Unknowns, atom)
 			}
 		}
@@ -1262,6 +1277,10 @@ func (self *DataInfo) Unmarshal(b []byte, offset int) (n int, err error) {
 					err = parseErr("", n+offset, err)
 					return
 				}
+				if len(self.Unknowns) > 100 {
+					err = errors.New("too many unknowns")
+					return
+				}
 				self.Unknowns = append(self.Unknowns, atom)
 			}
 		}
@@ -1824,6 +1843,10 @@ func (self *SampleDesc) Unmarshal(b []byte, offset int) (n int, err error) {
 					err = parseErr("", n+offset, err)
 					return
 				}
+				if len(self.Unknowns) > 100 {
+					err = errors.New("too many unknowns")
+					return
+				}
 				self.Unknowns = append(self.Unknowns, atom)
 			}
 		}
@@ -1989,6 +2012,10 @@ func (self *MP4ADesc) Unmarshal(b []byte, offset int) (n int, err error) {
 					err = parseErr("", n+offset, err)
 					return
 				}
+				if len(self.Unknowns) > 100 {
+					err = errors.New("too many unknowns")
+					return
+				}
 				self.Unknowns = append(self.Unknowns, atom)
 			}
 		}
@@ -2298,6 +2325,10 @@ func (self *AVC1Desc) Unmarshal(b []byte, offset int) (n int, err error) {
 					err = parseErr("", n+offset, err)
 					return
 				}
+				if len(self.Unknowns) > 100 {
+					err = errors.New("too many unknowns")
+					return
+				}
 				self.Unknowns = append(self.Unknowns, atom)
 			}
 		}
@@ -2418,6 +2449,10 @@ func (self *HV1Desc) Unmarshal(b []byte, offset int) (n int, err error) {
 					err = parseErr("", n+offset, err)
 					return
 				}
+				if len(self.Unknowns) > 100 {
+					err = errors.New("too many unknowns")
+					return
+				}
 				self.Unknowns = append(self.Unknowns, atom)
 			}
 		}
@@ -2559,10 +2594,6 @@ func (self *TimeToSample) Unmarshal(b []byte, offset int) (n int, err error) {
 	var _len_Entries uint32
 	_len_Entries = pio.U32BE(b[n:])
 	n += 4
-	if _len_Entries > 5242880 {
-		err = parseErr("_len_Entries", 5242880, err)
-		return
-	}
 	self.Entries = make([]TimeToSampleEntry, _len_Entries)
 	if len(b) < n+LenTimeToSampleEntry*len(self.Entries) {
 		err = parseErr("TimeToSampleEntry", n+offset, err)
@@ -2647,10 +2678,6 @@ func (self *SampleToChunk) Unmarshal(b []byte, offset int) (n int, err error) {
 	var _len_Entries uint32
 	_len_Entries = pio.U32BE(b[n:])
 	n += 4
-	if _len_Entries > 5242880 {
-		err = parseErr("_len_Entries", 5242880, err)
-		return
-	}
 	self.Entries = make([]SampleToChunkEntry, _len_Entries)
 	if len(b) < n+LenSampleToChunkEntry*len(self.Entries) {
 		err = parseErr("SampleToChunkEntry", n+offset, err)
@@ -2738,10 +2765,6 @@ func (self *CompositionOffset) Unmarshal(b []byte, offset int) (n int, err error
 	var _len_Entries uint32
 	_len_Entries = pio.U32BE(b[n:])
 	n += 4
-	if _len_Entries > 5242880 {
-		err = parseErr("_len_Entries", 5242880, err)
-		return
-	}
 	self.Entries = make([]CompositionOffsetEntry, _len_Entries)
 	if len(b) < n+LenCompositionOffsetEntry*len(self.Entries) {
 		err = parseErr("CompositionOffsetEntry", n+offset, err)
@@ -2826,10 +2849,6 @@ func (self *SyncSample) Unmarshal(b []byte, offset int) (n int, err error) {
 	var _len_Entries uint32
 	_len_Entries = pio.U32BE(b[n:])
 	n += 4
-	if _len_Entries > 5242880 {
-		err = parseErr("_len_Entries", 5242880, err)
-		return
-	}
 	self.Entries = make([]uint32, _len_Entries)
 	if len(b) < n+4*len(self.Entries) {
 		err = parseErr("uint32", n+offset, err)
@@ -2897,10 +2916,6 @@ func (self *ChunkOffset) Unmarshal(b []byte, offset int) (n int, err error) {
 	var _len_Entries uint32
 	_len_Entries = pio.U32BE(b[n:])
 	n += 4
-	if _len_Entries > 5242880 {
-		err = parseErr("_len_Entries", 5242880, err)
-		return
-	}
 	self.Entries = make([]uint32, _len_Entries)
 	if len(b) < n+4*len(self.Entries) {
 		err = parseErr("uint32", n+offset, err)
@@ -2981,6 +2996,10 @@ func (self *MovieFrag) Unmarshal(b []byte, offset int) (n int, err error) {
 					err = parseErr("traf", n+offset, err)
 					return
 				}
+				if len(self.Tracks) > 100 {
+					err = errors.New("too many tracks")
+					return
+				}
 				self.Tracks = append(self.Tracks, atom)
 			}
 		default:
@@ -2990,6 +3009,10 @@ func (self *MovieFrag) Unmarshal(b []byte, offset int) (n int, err error) {
 					err = parseErr("", n+offset, err)
 					return
 				}
+				if len(self.Unknowns) > 100 {
+					err = errors.New("too many unknowns")
+					return
+				}
 				self.Unknowns = append(self.Unknowns, atom)
 			}
 		}
@@ -3154,6 +3177,10 @@ func (self *TrackFrag) Unmarshal(b []byte, offset int) (n int, err error) {
 					err = parseErr("", n+offset, err)
 					return
 				}
+				if len(self.Unknowns) > 100 {
+					err = errors.New("too many unknowns")
+					return
+				}
 				self.Unknowns = append(self.Unknowns, atom)
 			}
 		}
@@ -3224,6 +3251,10 @@ func (self *MovieExtend) Unmarshal(b []byte, offset int) (n int, err error) {
 					err = parseErr("trex", n+offset, err)
 					return
 				}
+				if len(self.Tracks) > 100 {
+					err = errors.New("too many tracks")
+					return
+				}
 				self.Tracks = append(self.Tracks, atom)
 			}
 		default:
@@ -3233,6 +3264,10 @@ func (self *MovieExtend) Unmarshal(b []byte, offset int) (n int, err error) {
 					err = parseErr("", n+offset, err)
 					return
 				}
+				if len(self.Unknowns) > 100 {
+					err = errors.New("too many unknowns")
+					return
+				}
 				self.Unknowns = append(self.Unknowns, atom)
 			}
 		}
@@ -3415,11 +3450,6 @@ func (self *SampleSize) Unmarshal(b []byte, offset int) (n int, err error) {
 	var _len_Entries uint32
 	_len_Entries = pio.U32BE(b[n:])
 	n += 4
-	if _len_Entries > 5242880 {
-		err = parseErr("_len_Entries", 5242880, err)
-		log.Println("_len_Entries", _len_Entries)
-		return
-	}
 	self.Entries = make([]uint32, _len_Entries)
 	if len(b) < n+4*len(self.Entries) {
 		err = parseErr("uint32", n+offset, err)
@@ -3552,10 +3582,6 @@ func (self *TrackFragRun) Unmarshal(b []byte, offset int) (n int, err error) {
 	var _len_Entries uint32
 	_len_Entries = pio.U32BE(b[n:])
 	n += 4
-	if _len_Entries > 5242880 {
-		err = parseErr("_len_Entries", 5242880, err)
-		return
-	}
 	self.Entries = make([]TrackFragRunEntry, _len_Entries)
 	if self.Flags&TRUN_DATA_OFFSET != 0 {
 		{
diff --git a/format/mp4m/mp4io/atoms.go b/format/mp4m/mp4io/atoms.go
index 3f8c584d..fa21d44e 100644
--- a/format/mp4m/mp4io/atoms.go
+++ b/format/mp4m/mp4io/atoms.go
@@ -1,6 +1,7 @@
 package mp4io
 
 import (
+	"errors"
 	"time"
 
 	"github.com/deepch/vdk/utils/bits/pio"
@@ -24,17 +25,18 @@ func (self AVC1Desc) Tag() Tag {
 	return AVC1
 }
 
-//0x31766568
+// 0x31766568
 const HEV1 = Tag(0x68766331)
 
 func (self HV1Desc) Tag() Tag {
 	return HEV1
 }
 
-//const HVC1 = Tag(0x68766331)
-//func (self HVC1Desc) Tag() Tag {
-//	return HVC1
-//}
+// const HVC1 = Tag(0x68766331)
+//
+//	func (self HVC1Desc) Tag() Tag {
+//		return HVC1
+//	}
 const URL = Tag(0x75726c20)
 
 func (self DataReferUrl) Tag() Tag {
@@ -304,6 +306,10 @@ func (self *Movie) Unmarshal(b []byte, offset int) (n int, err error) {
 					err = parseErr("trak", n+offset, err)
 					return
 				}
+				if len(self.Tracks) > 100 {
+					err = errors.New("too many tracks")
+					return
+				}
 				self.Tracks = append(self.Tracks, atom)
 			}
 		default:
@@ -313,6 +319,10 @@ func (self *Movie) Unmarshal(b []byte, offset int) (n int, err error) {
 					err = parseErr("", n+offset, err)
 					return
 				}
+				if len(self.Unknowns) > 100 {
+					err = errors.New("too many unknowns")
+					return
+				}
 				self.Unknowns = append(self.Unknowns, atom)
 			}
 		}
@@ -601,6 +611,10 @@ func (self *Track) Unmarshal(b []byte, offset int) (n int, err error) {
 					err = parseErr("", n+offset, err)
 					return
 				}
+				if len(self.Unknowns) > 100 {
+					err = errors.New("too many unknowns")
+					return
+				}
 				self.Unknowns = append(self.Unknowns, atom)
 			}
 		}
@@ -940,6 +954,10 @@ func (self *Media) Unmarshal(b []byte, offset int) (n int, err error) {
 					err = parseErr("", n+offset, err)
 					return
 				}
+				if len(self.Unknowns) > 100 {
+					err = errors.New("too many unknowns")
+					return
+				}
 				self.Unknowns = append(self.Unknowns, atom)
 			}
 		}
@@ -1173,6 +1191,10 @@ func (self *MediaInfo) Unmarshal(b []byte, offset int) (n int, err error) {
 					err = parseErr("", n+offset, err)
 					return
 				}
+				if len(self.Unknowns) > 100 {
+					err = errors.New("too many unknowns")
+					return
+				}
 				self.Unknowns = append(self.Unknowns, atom)
 			}
 		}
@@ -1255,6 +1277,10 @@ func (self *DataInfo) Unmarshal(b []byte, offset int) (n int, err error) {
 					err = parseErr("", n+offset, err)
 					return
 				}
+				if len(self.Unknowns) > 100 {
+					err = errors.New("too many unknowns")
+					return
+				}
 				self.Unknowns = append(self.Unknowns, atom)
 			}
 		}
@@ -1817,6 +1843,10 @@ func (self *SampleDesc) Unmarshal(b []byte, offset int) (n int, err error) {
 					err = parseErr("", n+offset, err)
 					return
 				}
+				if len(self.Unknowns) > 100 {
+					err = errors.New("too many unknowns")
+					return
+				}
 				self.Unknowns = append(self.Unknowns, atom)
 			}
 		}
@@ -1982,6 +2012,10 @@ func (self *MP4ADesc) Unmarshal(b []byte, offset int) (n int, err error) {
 					err = parseErr("", n+offset, err)
 					return
 				}
+				if len(self.Unknowns) > 100 {
+					err = errors.New("too many unknowns")
+					return
+				}
 				self.Unknowns = append(self.Unknowns, atom)
 			}
 		}
@@ -2291,6 +2325,10 @@ func (self *AVC1Desc) Unmarshal(b []byte, offset int) (n int, err error) {
 					err = parseErr("", n+offset, err)
 					return
 				}
+				if len(self.Unknowns) > 100 {
+					err = errors.New("too many unknowns")
+					return
+				}
 				self.Unknowns = append(self.Unknowns, atom)
 			}
 		}
@@ -2411,6 +2449,10 @@ func (self *HV1Desc) Unmarshal(b []byte, offset int) (n int, err error) {
 					err = parseErr("", n+offset, err)
 					return
 				}
+				if len(self.Unknowns) > 100 {
+					err = errors.New("too many unknowns")
+					return
+				}
 				self.Unknowns = append(self.Unknowns, atom)
 			}
 		}
@@ -2954,6 +2996,10 @@ func (self *MovieFrag) Unmarshal(b []byte, offset int) (n int, err error) {
 					err = parseErr("traf", n+offset, err)
 					return
 				}
+				if len(self.Tracks) > 100 {
+					err = errors.New("too many tracks")
+					return
+				}
 				self.Tracks = append(self.Tracks, atom)
 			}
 		default:
@@ -2963,6 +3009,10 @@ func (self *MovieFrag) Unmarshal(b []byte, offset int) (n int, err error) {
 					err = parseErr("", n+offset, err)
 					return
 				}
+				if len(self.Unknowns) > 100 {
+					err = errors.New("too many unknowns")
+					return
+				}
 				self.Unknowns = append(self.Unknowns, atom)
 			}
 		}
@@ -3127,6 +3177,10 @@ func (self *TrackFrag) Unmarshal(b []byte, offset int) (n int, err error) {
 					err = parseErr("", n+offset, err)
 					return
 				}
+				if len(self.Unknowns) > 100 {
+					err = errors.New("too many unknowns")
+					return
+				}
 				self.Unknowns = append(self.Unknowns, atom)
 			}
 		}
@@ -3197,6 +3251,10 @@ func (self *MovieExtend) Unmarshal(b []byte, offset int) (n int, err error) {
 					err = parseErr("trex", n+offset, err)
 					return
 				}
+				if len(self.Tracks) > 100 {
+					err = errors.New("too many tracks")
+					return
+				}
 				self.Tracks = append(self.Tracks, atom)
 			}
 		default:
@@ -3206,6 +3264,10 @@ func (self *MovieExtend) Unmarshal(b []byte, offset int) (n int, err error) {
 					err = parseErr("", n+offset, err)
 					return
 				}
+				if len(self.Unknowns) > 100 {
+					err = errors.New("too many unknowns")
+					return
+				}
 				self.Unknowns = append(self.Unknowns, atom)
 			}
 		}