diff --git a/.golangci.yml b/.golangci.yml
index e00d3670..1db28d8e 100644
--- a/.golangci.yml
+++ b/.golangci.yml
@@ -1,44 +1,43 @@
 linters:
-  enable:
-    - revive
-    - errname
-    - goimports
-    - nilerr
-    - forcetypeassert
-    - asciicheck
-    - bodyclose
-    - durationcheck
-    - errorlint
-    - noctx
-    - misspell
-    - exportloopref
-    - unconvert
-    - unparam
-    - wastedassign
-    - makezero
-    - exhaustive
-    - gosec
-    - nolintlint
-    - nakedret
-    - predeclared
-    - tagliatelle
-
-run:
-  skip-dirs:
-    - dev
-    - doc
-
+    enable:
+        - asciicheck
+        - bodyclose
+        - durationcheck
+        - errname
+        - errorlint
+        - exhaustive
+        - exportloopref
+        - forcetypeassert
+        - goimports
+        - gosec
+        - makezero
+        - misspell
+        - nakedret
+        - nilerr
+        - noctx
+        - nolintlint
+        - nosprintfhostport
+        - predeclared
+        - revive
+        - tagliatelle
+        - unconvert
+        - unparam
+        - wastedassign
 linters-settings:
-  misspell:
-    ignore-words:
-      # elf RELA
-      - rela
-      - equalisation
-      - synchronisation
-  exhaustive:
-    default-signifies-exhaustive: true
-  gosec:
-    excludes:
-      # allow md5
-      - G401
-      - G501
+    exhaustive:
+        default-signifies-exhaustive: true
+    gosec:
+        excludes:
+            - G401
+            - G501
+    misspell:
+        ignore-words:
+            # elf RELA
+            - rela
+            - equalisation
+            - synchronisation
+run:
+    skip-dirs:
+        # allow md5
+        - dev
+        - doc
diff --git a/doc/presentations/bts2022/mp3.go b/doc/presentations/bts2022/mp3.go
index b4d35f43..b57e02d1 100644
--- a/doc/presentations/bts2022/mp3.go
+++ b/doc/presentations/bts2022/mp3.go
@@ -1,4 +1,4 @@
-func decode(d *decode.D, in any) any {
+func decode(d *decode.D, _ any) any {
 	d.FieldArray("headers", func(d *decode.D) {
 		for !d.End() {
 			d.TryFieldFormat("header", headerGroup)
diff --git a/format/ape/apev2.go b/format/ape/apev2.go
index 3c688f1a..4fde1414 100644
--- a/format/ape/apev2.go
+++ b/format/ape/apev2.go
@@ -21,7 +21,7 @@ func init() {
 	})
 }
 
-func apev2Decode(d *decode.D, in any) any {
+func apev2Decode(d *decode.D, _ any) any {
 	d.Endian = decode.LittleEndian
 
 	headerFooterFn := func(d *decode.D, name string) uint64 {
diff --git a/format/ar/ar.go b/format/ar/ar.go
index bf718145..9a2d085e 100644
--- a/format/ar/ar.go
+++ b/format/ar/ar.go
@@ -21,7 +21,7 @@ func init() {
 	})
 }
 
-func decodeAr(d *decode.D, in any) any {
+func decodeAr(d *decode.D, _ any) any {
 	d.FieldUTF8("signature", 8, d.AssertStr("!<arch>\n"))
 	d.FieldArray("files", func(d *decode.D) {
 		for !d.End() {
diff --git a/format/asn1/asn1_ber.go b/format/asn1/asn1_ber.go
index 7ef55876..91753f14 100644
--- a/format/asn1/asn1_ber.go
+++ b/format/asn1/asn1_ber.go
@@ -414,7 +414,7 @@ func decodeASN1BERValue(d *decode.D, bib *bitio.Buffer, sb *strings.Builder, par
 	})
 }
 
-func decodeASN1BER(d *decode.D, in any) any {
+func decodeASN1BER(d *decode.D, _ any) any {
 	decodeASN1BERValue(d, nil, nil, formConstructed, universalTypeSequence)
 	return nil
 }
diff --git a/format/av1/av1_ccr.go b/format/av1/av1_ccr.go
index 63c2c1a2..b4f82aa3 100644
--- a/format/av1/av1_ccr.go
+++ b/format/av1/av1_ccr.go
@@ -19,7 +19,7 @@ func init() {
 	})
 }
 
-func ccrDecode(d *decode.D, in any) any {
+func ccrDecode(d *decode.D, _ any) any {
 	d.FieldU1("marker")
 	d.FieldU7("version")
 	d.FieldU3("seq_profile")
diff --git a/format/av1/av1_frame.go b/format/av1/av1_frame.go
index 15dff863..635ca64d 100644
--- a/format/av1/av1_frame.go
+++ b/format/av1/av1_frame.go
@@ -25,7 +25,7 @@ func init() {
 	})
 }
 
-func frameDecode(d *decode.D, in any) any {
+func frameDecode(d *decode.D, _ any) any {
 	for d.NotEnd() {
 		d.FieldFormat("obu", obuFormat, nil)
 	}
diff --git a/format/av1/av1_obu.go b/format/av1/av1_obu.go
index 8de61356..ccada750 100644
--- a/format/av1/av1_obu.go
+++ b/format/av1/av1_obu.go
@@ -52,7 +52,7 @@ func decodeLeb128(d *decode.D) uint64 {
 	return v
 }
 
-func obuDecode(d *decode.D, in any) any {
+func obuDecode(d *decode.D, _ any) any {
 	var obuType uint64
 	var obuSize int64
 	hasExtension := false
diff --git a/format/avro/avro_ocf.go b/format/avro/avro_ocf.go
index c98e106a..25f1142d 100644
--- a/format/avro/avro_ocf.go
+++ b/format/avro/avro_ocf.go
@@ -124,7 +124,7 @@ func decodeBlockCodec(d *decode.D, dataSize int64, codec string) *bytes.Buffer {
 	return bb
 }
 
-func decodeAvroOCF(d *decode.D, in any) any {
+func decodeAvroOCF(d *decode.D, _ any) any {
 	header := decodeHeader(d)
 
 	decodeFn, err := decoders.DecodeFnForSchema(header.Schema)
diff --git a/format/bencode/bencode.go b/format/bencode/bencode.go
index 0a54b3c1..abaa4a0b 100644
--- a/format/bencode/bencode.go
+++ b/format/bencode/bencode.go
@@ -90,7 +90,7 @@ func decodeBencodeValue(d *decode.D) {
 	}
 }
 
-func decodeBencode(d *decode.D, in any) any {
+func decodeBencode(d *decode.D, _ any) any {
 	decodeBencodeValue(d)
 	return nil
 }
diff --git a/format/bson/bson.go b/format/bson/bson.go
index 18bc1ee6..246d5db2 100644
--- a/format/bson/bson.go
+++ b/format/bson/bson.go
@@ -110,7 +110,7 @@ func decodeBSONDocument(d *decode.D) {
 	})
 }
 
-func decodeBSON(d *decode.D, in any) any {
+func decodeBSON(d *decode.D, _ any) any {
 	d.Endian = decode.LittleEndian
 
 	decodeBSONDocument(d)
diff --git a/format/bzip2/bzip2.go b/format/bzip2/bzip2.go
index efb0a1be..39082e88 100644
--- a/format/bzip2/bzip2.go
+++ b/format/bzip2/bzip2.go
@@ -48,7 +48,7 @@ func (bfr bitFlipReader) Read(p []byte) (n int, err error) {
 	return n, err
 }
 
-func bzip2Decode(d *decode.D, in any) any {
+func bzip2Decode(d *decode.D, _ any) any {
 	// moreStreams := true
 
 	// d.FieldArray("streams", func(d *decode.D) {
diff --git a/format/cbor/cbor.go b/format/cbor/cbor.go
index 34e9ee3d..3502a17e 100644
--- a/format/cbor/cbor.go
+++ b/format/cbor/cbor.go
@@ -262,7 +262,7 @@ func decodeCBORValue(d *decode.D) any {
 	panic("unreachable")
 }
 
-func decodeCBOR(d *decode.D, in any) any {
+func decodeCBOR(d *decode.D, _ any) any {
 	decodeCBORValue(d)
 	return nil
 }
diff --git a/format/elf/elf.go b/format/elf/elf.go
index 4daf4217..565847dd 100644
--- a/format/elf/elf.go
+++ b/format/elf/elf.go
@@ -903,7 +903,7 @@ func elfDecodeSectionHeaders(d *decode.D, ec elfContext) {
 	}
 }
 
-func elfDecode(d *decode.D, in any) any {
+func elfDecode(d *decode.D, _ any) any {
 	var ec elfContext
 
 	d.FieldStruct("header", func(d *decode.D) { elfDecodeHeader(d, &ec) })
diff --git a/format/fairplay/fairplay.go b/format/fairplay/fairplay.go
index e728943a..13d6fce3 100644
--- a/format/fairplay/fairplay.go
+++ b/format/fairplay/fairplay.go
@@ -16,7 +16,7 @@ func init() {
 	})
 }
 
-func fairPlaySPCDecode(d *decode.D, in any) any {
+func fairPlaySPCDecode(d *decode.D, _ any) any {
 	d.FieldU32("version")
 	d.FieldRawLen("reserved", 32)
 	d.FieldRawLen("iv", 16*8)
diff --git a/format/flac/flac.go b/format/flac/flac.go
index d18a4961..cd84bb0e 100644
--- a/format/flac/flac.go
+++ b/format/flac/flac.go
@@ -35,7 +35,7 @@ func init() {
 	})
 }
 
-func flacDecode(d *decode.D, in any) any {
+func flacDecode(d *decode.D, _ any) any {
 	d.FieldUTF8("magic", 4, d.AssertStr("fLaC"))
 
 	var streamInfo format.FlacStreamInfo
diff --git a/format/flac/flac_metadatablock.go b/format/flac/flac_metadatablock.go
index e050f50c..9265df3a 100644
--- a/format/flac/flac_metadatablock.go
+++ b/format/flac/flac_metadatablock.go
@@ -49,7 +49,7 @@ var metadataBlockNames = scalar.UToSymStr{
 	MetadataBlockPicture:       "picture",
 }
 
-func metadatablockDecode(d *decode.D, in any) any {
+func metadatablockDecode(d *decode.D, _ any) any {
 	var hasStreamInfo bool
 	var streamInfo format.FlacStreamInfo
 
diff --git a/format/flac/flac_metadatablocks.go b/format/flac/flac_metadatablocks.go
index 0536f2b1..538a2dd2 100644
--- a/format/flac/flac_metadatablocks.go
+++ b/format/flac/flac_metadatablocks.go
@@ -23,7 +23,7 @@ func init() {
 	})
 }
 
-func metadatablocksDecode(d *decode.D, in any) any {
+func metadatablocksDecode(d *decode.D, _ any) any {
 	flacMetadatablocksOut := format.FlacMetadatablocksOut{}
 
 	isLastBlock := false
diff --git a/format/flac/flac_picture.go b/format/flac/flac_picture.go
index eabbd38d..9659c020 100644
--- a/format/flac/flac_picture.go
+++ b/format/flac/flac_picture.go
@@ -44,7 +44,7 @@ func init() {
 	})
 }
 
-func pictureDecode(d *decode.D, in any) any {
+func pictureDecode(d *decode.D, _ any) any {
 	lenStr := func(name string) string {
 		l := d.FieldU32(name + "_length")
 		return d.FieldUTF8(name, int(l))
diff --git a/format/flac/flac_streaminfo.go b/format/flac/flac_streaminfo.go
index 78aec834..1e353efc 100644
--- a/format/flac/flac_streaminfo.go
+++ b/format/flac/flac_streaminfo.go
@@ -15,7 +15,7 @@ func init() {
 	})
 }
 
-func streaminfoDecode(d *decode.D, in any) any {
+func streaminfoDecode(d *decode.D, _ any) any {
 	d.FieldU16("minimum_block_size")
 	d.FieldU16("maximum_block_size")
 	d.FieldU24("minimum_frame_size")
diff --git a/format/flv/flv.go b/format/flv/flv.go
index 9b0fa019..fbb77ab8 100644
--- a/format/flv/flv.go
+++ b/format/flv/flv.go
@@ -65,7 +65,7 @@ var typeNames = scalar.UToSymStr{
 	typeLongString:  "LongString",
 }
 
-func flvDecode(d *decode.D, in any) any {
+func flvDecode(d *decode.D, _ any) any {
 	var fieldScriptDataObject func()
 	var fieldScriptDataVariable func(d *decode.D, name string)
 
diff --git a/format/gif/gif.go b/format/gif/gif.go
index 3d34d794..a3890cf4 100644
--- a/format/gif/gif.go
+++ b/format/gif/gif.go
@@ -51,7 +51,7 @@ func fieldColorMap(d *decode.D, name string, bitDepth int) {
 	})
 }
 
-func gifDecode(d *decode.D, in any) any {
+func gifDecode(d *decode.D, _ any) any {
 	d.Endian = decode.LittleEndian
 
 	d.FieldUTF8("header", 6, d.AssertStr("GIF87a", "GIF89a"))
diff --git a/format/gzip/gzip.go b/format/gzip/gzip.go
index eb9dd5cb..040c157c 100644
--- a/format/gzip/gzip.go
+++ b/format/gzip/gzip.go
@@ -57,7 +57,7 @@ var deflateExtraFlagsNames = scalar.UToSymStr{
 	4: "fast",
 }
 
-func gzDecode(d *decode.D, in any) any {
+func gzDecode(d *decode.D, _ any) any {
 	d.Endian = decode.LittleEndian
 
 	d.FieldRawLen("identification", 2*8, d.AssertBitBuf([]byte("\x1f\x8b")))
diff --git a/format/icc/icc_profile.go b/format/icc/icc_profile.go
index 182780a8..015cddc2 100644
--- a/format/icc/icc_profile.go
+++ b/format/icc/icc_profile.go
@@ -81,7 +81,7 @@ func decodeBCDU8(d *decode.D) uint64 {
 	return (n>>4)*10 + n&0xf
 }
 
-func iccProfileDecode(d *decode.D, in any) any {
+func iccProfileDecode(d *decode.D, _ any) any {
 	/*
 	   0..3 Profile size uInt32Number
 	   4..7 CMM Type signature see below
diff --git a/format/id3/id3v1.go b/format/id3/id3v1.go
index 47ee0149..179014e0 100644
--- a/format/id3/id3v1.go
+++ b/format/id3/id3v1.go
@@ -18,7 +18,7 @@ func init() {
 }
 
 // Decode ID3v1 tag
-func id3v1Decode(d *decode.D, in any) any {
+func id3v1Decode(d *decode.D, _ any) any {
 	d.AssertAtLeastBitsLeft(128 * 8)
 	d.FieldUTF8("magic", 3, d.AssertStr("TAG"))
 	if d.PeekBits(8) == uint64('+') {
diff --git a/format/id3/id3v11.go b/format/id3/id3v11.go
index 0a5e31a3..ac0751a4 100644
--- a/format/id3/id3v11.go
+++ b/format/id3/id3v11.go
@@ -15,7 +15,7 @@ func init() {
 	})
 }
 
-func id3v11Decode(d *decode.D, in any) any {
+func id3v11Decode(d *decode.D, _ any) any {
 	d.AssertAtLeastBitsLeft(128 * 8)
 	d.FieldUTF8("magic", 4, d.AssertStr("TAG+"))
 	d.FieldUTF8("title", 60)
diff --git a/format/id3/id3v2.go b/format/id3/id3v2.go
index 234c1f25..47de0d13 100644
--- a/format/id3/id3v2.go
+++ b/format/id3/id3v2.go
@@ -545,7 +545,7 @@ func decodeFrame(d *decode.D, version int) uint64 {
 		// TODO: DecodeFn
 		// TODO: unknown after frame decode
 		unsyncedBR := d.NewBitBufFromReader(unsyncReader{Reader: bitio.NewIOReader(d.BitBufRange(d.Pos(), int64(dataSize)*8))})
-		d.FieldFormatBitBuf("unsync", unsyncedBR, decode.FormatFn(func(d *decode.D, in any) any {
+		d.FieldFormatBitBuf("unsync", unsyncedBR, decode.FormatFn(func(d *decode.D, _ any) any {
 			if fn, ok := frames[idNormalized]; ok {
 				fn(d)
 			} else {
@@ -586,7 +586,7 @@ func decodeFrames(d *decode.D, version int, size uint64) {
 	}
 }
 
-func id3v2Decode(d *decode.D, in any) any {
+func id3v2Decode(d *decode.D, _ any) any {
 	d.AssertAtLeastBitsLeft(4 * 8)
 	d.FieldUTF8("magic", 3, d.AssertStr("ID3"))
 	version := int(d.FieldU8("version"))
diff --git a/format/jpeg/jpeg.go b/format/jpeg/jpeg.go
index dbf1dbc4..f4f65072 100644
--- a/format/jpeg/jpeg.go
+++ b/format/jpeg/jpeg.go
@@ -164,7 +164,7 @@ var markers = scalar.UToScalar{
 	TEM:   {Sym: "tem", Description: "For temporary private use in arithmetic coding"},
 }
 
-func jpegDecode(d *decode.D, in any) any {
+func jpegDecode(d *decode.D, _ any) any {
 	d.AssertLeastBytesLeft(2)
 	if !bytes.Equal(d.PeekBytes(2), []byte{0xff, SOI}) {
 		d.Errorf("no SOI marker")
diff --git a/format/json/json.go b/format/json/json.go
index 2cd3269c..deaa8e83 100644
--- a/format/json/json.go
+++ b/format/json/json.go
@@ -25,7 +25,7 @@ func init() {
 	})
 }
 
-func decodeJSON(d *decode.D, in any) any {
+func decodeJSON(d *decode.D, _ any) any {
 	br := d.RawLen(d.Len())
 	jd := stdjson.NewDecoder(bitio.NewIOReader(br))
 	var s scalar.S
diff --git a/format/macho/macho.go b/format/macho/macho.go
index e5735264..ae316463 100644
--- a/format/macho/macho.go
+++ b/format/macho/macho.go
@@ -355,7 +355,7 @@ var sectionTypes = scalar.UToSymStr{
 	0x15: "thread_local_init_function_pointers",
 }
 
-func machoDecode(d *decode.D, in any) any {
+func machoDecode(d *decode.D, _ any) any {
 	ofileDecode(d)
 	return nil
 }
diff --git a/format/matroska/matroska.go b/format/matroska/matroska.go
index 883d954c..9268d170 100644
--- a/format/matroska/matroska.go
+++ b/format/matroska/matroska.go
@@ -308,7 +308,7 @@ func decodeMaster(d *decode.D, bitsLimit int64, tag ebml.Tag, dc *decodeContext)
 
 }
 
-func matroskaDecode(d *decode.D, in any) any {
+func matroskaDecode(d *decode.D, _ any) any {
 	ebmlHeaderID := uint64(0x1a45dfa3)
 	if d.PeekBits(32) != ebmlHeaderID {
 		d.Errorf("no EBML header found")
diff --git a/format/mp3/xing.go b/format/mp3/xing.go
index 70945832..4a4cbc2c 100644
--- a/format/mp3/xing.go
+++ b/format/mp3/xing.go
@@ -16,7 +16,7 @@ func init() {
 	})
 }
 
-func xingDecode(d *decode.D, in any) any {
+func xingDecode(d *decode.D, _ any) any {
 	// TODO: info has lame extension?
 	hasLameExtension := false
 	switch d.FieldUTF8("header", 4) {
diff --git a/format/mp4/pssh_playready.go b/format/mp4/pssh_playready.go
index 966a3dde..3f5a0889 100644
--- a/format/mp4/pssh_playready.go
+++ b/format/mp4/pssh_playready.go
@@ -25,7 +25,7 @@ var recordTypeNames = scalar.UToSymStr{
 	recordTypeLicenseStore:           "License store",
 }
 
-func playreadyPsshDecode(d *decode.D, in any) any {
+func playreadyPsshDecode(d *decode.D, _ any) any {
 	d.Endian = decode.LittleEndian
 
 	d.FieldU32("size")
diff --git a/format/mpeg/adts.go b/format/mpeg/adts.go
index 444afe41..fe214027 100644
--- a/format/mpeg/adts.go
+++ b/format/mpeg/adts.go
@@ -22,7 +22,7 @@ func init() {
 	})
 }
 
-func adtsDecoder(d *decode.D, in any) any {
+func adtsDecoder(d *decode.D, _ any) any {
 	validFrames := 0
 	for !d.End() {
 		if dv, _, _ := d.TryFieldFormat("frame", adtsFrame, nil); dv == nil {
diff --git a/format/mpeg/adts_frame.go b/format/mpeg/adts_frame.go
index 77d03d66..f11292f9 100644
--- a/format/mpeg/adts_frame.go
+++ b/format/mpeg/adts_frame.go
@@ -29,7 +29,7 @@ var protectionAbsentNames = scalar.BoolToDescription{
 	false: "Has CRC",
 }
 
-func adtsFrameDecoder(d *decode.D, in any) any {
+func adtsFrameDecoder(d *decode.D, _ any) any {
 
 	/*
 	   adts_frame() {
diff --git a/format/mpeg/avc_dcr.go b/format/mpeg/avc_dcr.go
index a13ec30b..3b7e507a 100644
--- a/format/mpeg/avc_dcr.go
+++ b/format/mpeg/avc_dcr.go
@@ -116,7 +116,7 @@ func avcDcrParameterSet(d *decode.D, numParamSets uint64) {
 	}
 }
 
-func avcDcrDecode(d *decode.D, in any) any {
+func avcDcrDecode(d *decode.D, _ any) any {
 	d.FieldU8("configuration_version")
 	d.FieldU8("profile_indication", avcProfileNames)
 	d.FieldU8("profile_compatibility")
diff --git a/format/mpeg/avc_nalu.go b/format/mpeg/avc_nalu.go
index dc5eb45a..42de822d 100644
--- a/format/mpeg/avc_nalu.go
+++ b/format/mpeg/avc_nalu.go
@@ -98,7 +98,7 @@ var sliceNames = scalar.UToSymStr{
 	9: "si",
 }
 
-func avcNALUDecode(d *decode.D, in any) any {
+func avcNALUDecode(d *decode.D, _ any) any {
 	d.FieldBool("forbidden_zero_bit")
 	d.FieldU2("nal_ref_idc")
 	nalType := d.FieldU5("nal_unit_type", avcNALNames)
diff --git a/format/mpeg/avc_pps.go b/format/mpeg/avc_pps.go
index e6ad29da..45d54b21 100644
--- a/format/mpeg/avc_pps.go
+++ b/format/mpeg/avc_pps.go
@@ -20,7 +20,7 @@ func moreRBSPData(d *decode.D) bool {
 	return l >= 8 && d.PeekBits(8) != 0b1000_0000
 }
 
-func avcPPSDecode(d *decode.D, in any) any {
+func avcPPSDecode(d *decode.D, _ any) any {
 	d.FieldUFn("pic_parameter_set_id", uEV)
 	d.FieldUFn("seq_parameter_set_id", uEV)
 	d.FieldBool("entropy_coding_mode_flag")
diff --git a/format/mpeg/avc_sei.go b/format/mpeg/avc_sei.go
index b3187116..5c2e0b99 100644
--- a/format/mpeg/avc_sei.go
+++ b/format/mpeg/avc_sei.go
@@ -101,7 +101,7 @@ func ffSum(d *decode.D) uint64 {
 	return s
 }
 
-func avcSEIDecode(d *decode.D, in any) any {
+func avcSEIDecode(d *decode.D, _ any) any {
 	payloadType := d.FieldUFn("payload_type", func(d *decode.D) uint64 { return ffSum(d) }, seiNames)
 	payloadSize := d.FieldUFn("payload_size", func(d *decode.D) uint64 { return ffSum(d) })
 
diff --git a/format/mpeg/avc_sps.go b/format/mpeg/avc_sps.go
index 3d130d91..af921ee4 100644
--- a/format/mpeg/avc_sps.go
+++ b/format/mpeg/avc_sps.go
@@ -134,7 +134,7 @@ func avcHdrParameters(d *decode.D) {
 	d.FieldU5("time_offset_length")
 }
 
-func avcSPSDecode(d *decode.D, in any) any {
+func avcSPSDecode(d *decode.D, _ any) any {
 	profileIdc := d.FieldU8("profile_idc", avcProfileNames)
 	d.FieldBool("constraint_set0_flag")
 	d.FieldBool("constraint_set1_flag")
diff --git a/format/mpeg/hevc_dcr.go b/format/mpeg/hevc_dcr.go
index 2a11d921..f080b24b 100644
--- a/format/mpeg/hevc_dcr.go
+++ b/format/mpeg/hevc_dcr.go
@@ -20,7 +20,7 @@ func init() {
 	})
 }
 
-func hevcDcrDecode(d *decode.D, in any) any {
+func hevcDcrDecode(d *decode.D, _ any) any {
 	d.FieldU8("configuration_version")
 	d.FieldU2("general_profile_space")
 	d.FieldU1("general_tier_flag")
diff --git a/format/mpeg/hevc_nalu.go b/format/mpeg/hevc_nalu.go
index cbf3ae67..86dff61a 100644
--- a/format/mpeg/hevc_nalu.go
+++ b/format/mpeg/hevc_nalu.go
@@ -82,7 +82,7 @@ var hevcNALNames = scalar.UToSymStr{
 	47:            "RSV_NVCL47",
 }
 
-func hevcNALUDecode(d *decode.D, in any) any {
+func hevcNALUDecode(d *decode.D, _ any) any {
 	d.FieldBool("forbidden_zero_bit")
 	nalType := d.FieldU6("nal_unit_type", hevcNALNames)
 	d.FieldU6("nuh_layer_id")
diff --git a/format/mpeg/hevc_pps.go b/format/mpeg/hevc_pps.go
index 239a667c..1184f83f 100644
--- a/format/mpeg/hevc_pps.go
+++ b/format/mpeg/hevc_pps.go
@@ -17,7 +17,7 @@ func init() {
 }
 
 // H.265 page 36
-func hevcPPSDecode(d *decode.D, in any) any {
+func hevcPPSDecode(d *decode.D, _ any) any {
 	d.FieldUFn("pps_pic_parameter_set_id", uEV)
 	d.FieldUFn("pps_seq_parameter_set_id", uEV)
 	d.FieldBool("dependent_slice_segments_enabled_flag")
diff --git a/format/mpeg/hevc_sps.go b/format/mpeg/hevc_sps.go
index 5a8e4895..7c5d587a 100644
--- a/format/mpeg/hevc_sps.go
+++ b/format/mpeg/hevc_sps.go
@@ -241,7 +241,7 @@ func hevcVuiParameters(d *decode.D, spsMaxSubLayersMinus1 uint64) {
 }
 
 // H.265 page 34
-func hevcSPSDecode(d *decode.D, in any) any {
+func hevcSPSDecode(d *decode.D, _ any) any {
 	d.FieldU4("sps_video_parameter_set_id")
 	spsMaxSubLayersMinus1 := d.FieldU3("sps_max_sub_layers_minus1")
 	d.FieldBool("sps_temporal_id_nesting_flag")
diff --git a/format/mpeg/hevc_vps.go b/format/mpeg/hevc_vps.go
index e2a13e6f..5176e8b8 100644
--- a/format/mpeg/hevc_vps.go
+++ b/format/mpeg/hevc_vps.go
@@ -17,7 +17,7 @@ func init() {
 }
 
 // H.265 page 33
-func hevcVPSDecode(d *decode.D, in any) any {
+func hevcVPSDecode(d *decode.D, _ any) any {
 	d.FieldU4("vps_video_parameter_set_id")
 	d.FieldBool("vps_base_layer_internal_flag")
 	d.FieldBool("vps_base_layer_available_flag")
diff --git a/format/mpeg/mp3_frame.go b/format/mpeg/mp3_frame.go
index 3e2d590a..a2eba631 100644
--- a/format/mpeg/mp3_frame.go
+++ b/format/mpeg/mp3_frame.go
@@ -140,7 +140,7 @@ var protectionNames = scalar.BoolToDescription{
 	false: "Has CRC",
 }
 
-func frameDecode(d *decode.D, in any) any {
+func frameDecode(d *decode.D, _ any) any {
 	const headerBytes = 4
 	var sideInfoBytes int64
 	var isStereo bool
diff --git a/format/mpeg/mpeg_asc.go b/format/mpeg/mpeg_asc.go
index f9adedeb..d2bb576e 100644
--- a/format/mpeg/mpeg_asc.go
+++ b/format/mpeg/mpeg_asc.go
@@ -44,7 +44,7 @@ var channelConfigurationNames = scalar.UToDescription{
 	7: "front-center, front-left, front-right, side-left, side-right, back-left, back-right, LFE-channel",
 }
 
-func ascDecoder(d *decode.D, in any) any {
+func ascDecoder(d *decode.D, _ any) any {
 	objectType := d.FieldUFn("object_type", decodeEscapeValueCarryFn(5, 6, 0), format.MPEGAudioObjectTypeNames)
 	d.FieldUFn("sampling_frequency", decodeEscapeValueAbsFn(4, 24, 0), frequencyIndexHzMap)
 	d.FieldU4("channel_configuration", channelConfigurationNames)
diff --git a/format/mpeg/mpeg_es.go b/format/mpeg/mpeg_es.go
index cef1242e..2092f9f1 100644
--- a/format/mpeg/mpeg_es.go
+++ b/format/mpeg/mpeg_es.go
@@ -172,7 +172,7 @@ type esDecodeContext struct {
 	decoderConfigs       []format.MpegDecoderConfig
 }
 
-func odDecodeTag(d *decode.D, edc *esDecodeContext, expectedTagID int, fn func(d *decode.D)) {
+func odDecodeTag(d *decode.D, edc *esDecodeContext, _ int, fn func(d *decode.D)) {
 	odDecoders := map[uint64]func(d *decode.D){
 		ES_DescrTag: func(d *decode.D) {
 			d.FieldU16("es_id")
@@ -276,7 +276,7 @@ func odDecodeTag(d *decode.D, edc *esDecodeContext, expectedTagID int, fn func(d
 	}
 }
 
-func esDecode(d *decode.D, in any) any {
+func esDecode(d *decode.D, _ any) any {
 	var edc esDecodeContext
 	odDecodeTag(d, &edc, -1, nil)
 	return format.MpegEsOut{DecoderConfigs: edc.decoderConfigs}
diff --git a/format/mpeg/mpeg_pes.go b/format/mpeg/mpeg_pes.go
index a6afdb07..6554aae8 100644
--- a/format/mpeg/mpeg_pes.go
+++ b/format/mpeg/mpeg_pes.go
@@ -33,7 +33,7 @@ type subStream struct {
 	l int
 }
 
-func pesDecode(d *decode.D, in any) any {
+func pesDecode(d *decode.D, _ any) any {
 	substreams := map[int]*subStream{}
 
 	prefix := d.PeekBits(24)
diff --git a/format/mpeg/mpeg_pes_packet.go b/format/mpeg/mpeg_pes_packet.go
index 1b4c8df9..5a3c500f 100644
--- a/format/mpeg/mpeg_pes_packet.go
+++ b/format/mpeg/mpeg_pes_packet.go
@@ -69,7 +69,7 @@ var mpegVersion = scalar.UToDescription{
 	0b10: "MPEG1",
 }
 
-func pesPacketDecode(d *decode.D, in any) any {
+func pesPacketDecode(d *decode.D, _ any) any {
 	var v any
 
 	d.FieldU24("prefix", d.AssertU(0b0000_0000_0000_0000_0000_0001), scalar.ActualBin)
diff --git a/format/mpeg/mpeg_spu.go b/format/mpeg/mpeg_spu.go
index dbd62852..8ef82253 100644
--- a/format/mpeg/mpeg_spu.go
+++ b/format/mpeg/mpeg_spu.go
@@ -99,7 +99,7 @@ func decodeLines(d *decode.D, lines int, width int) []string {
 	return ls
 }
 
-func spuDecode(d *decode.D, in any) any {
+func spuDecode(d *decode.D, _ any) any {
 	d.FieldU16("size")
 	dcsqtOffset := d.FieldU16("dcsqt_offset")
 
diff --git a/format/mpeg/mpeg_ts.go b/format/mpeg/mpeg_ts.go
index 19541a1d..69575da3 100644
--- a/format/mpeg/mpeg_ts.go
+++ b/format/mpeg/mpeg_ts.go
@@ -19,7 +19,7 @@ func init() {
 
 // TODO: ts_packet
 
-func tsDecode(d *decode.D, in any) any {
+func tsDecode(d *decode.D, _ any) any {
 	d.FieldU8("sync", d.AssertU(0x47), scalar.ActualHex)
 	d.FieldBool("transport_error_indicator")
 	d.FieldBool("payload_unit_start")
diff --git a/format/mpeg/shared.go b/format/mpeg/shared.go
index f7a02372..4f6185f1 100644
--- a/format/mpeg/shared.go
+++ b/format/mpeg/shared.go
@@ -17,7 +17,7 @@ func init() {
 
 // transform to binary using fn
 func makeBinaryTransformFn(fn func(r io.Reader) (io.Reader, error)) func(i *interp.Interp, c any) any {
-	return func(i *interp.Interp, c any) any {
+	return func(_ *interp.Interp, c any) any {
 		inBR, err := interp.ToBitReader(c)
 		if err != nil {
 			return err
diff --git a/format/msgpack/msgpack.go b/format/msgpack/msgpack.go
index 0dbf14f4..917f0cdd 100644
--- a/format/msgpack/msgpack.go
+++ b/format/msgpack/msgpack.go
@@ -153,7 +153,7 @@ func decodeMsgPackValue(d *decode.D) {
 	}
 }
 
-func decodeMsgPack(d *decode.D, in any) any {
+func decodeMsgPack(d *decode.D, _ any) any {
 	decodeMsgPackValue(d)
 	return nil
 }
diff --git a/format/ogg/ogg.go b/format/ogg/ogg.go
index f6073786..5e5752ff 100644
--- a/format/ogg/ogg.go
+++ b/format/ogg/ogg.go
@@ -57,7 +57,7 @@ type stream struct {
 	flacStreamInfo format.FlacStreamInfo
 }
 
-func decodeOgg(d *decode.D, in any) any {
+func decodeOgg(d *decode.D, _ any) any {
 	validPages := 0
 	streams := map[uint32]*stream{}
 	streamsD := d.FieldArrayValue("streams")
diff --git a/format/ogg/ogg_page.go b/format/ogg/ogg_page.go
index 4e83eaab..61048585 100644
--- a/format/ogg/ogg_page.go
+++ b/format/ogg/ogg_page.go
@@ -19,7 +19,7 @@ func init() {
 	})
 }
 
-func pageDecode(d *decode.D, in any) any {
+func pageDecode(d *decode.D, _ any) any {
 	p := format.OggPageOut{}
 	startPos := d.Pos()
 
diff --git a/format/opus/opus_packet.go b/format/opus/opus_packet.go
index b3bc836a..92aa234e 100644
--- a/format/opus/opus_packet.go
+++ b/format/opus/opus_packet.go
@@ -23,7 +23,7 @@ func init() {
 	})
 }
 
-func opusDecode(d *decode.D, in any) any {
+func opusDecode(d *decode.D, _ any) any {
 	d.Endian = decode.LittleEndian
 
 	var prefix []byte
diff --git a/format/pcap/pcap.go b/format/pcap/pcap.go
index 2ca0452d..ca65aca7 100644
--- a/format/pcap/pcap.go
+++ b/format/pcap/pcap.go
@@ -39,7 +39,7 @@ func init() {
 	})
 }
 
-func decodePcap(d *decode.D, in any) any {
+func decodePcap(d *decode.D, _ any) any {
 	endian := d.FieldU32("magic", d.AssertU(bigEndian, littleEndian), endianMap, scalar.ActualHex)
 	switch endian {
 	case bigEndian:
diff --git a/format/pcap/pcapng.go b/format/pcap/pcapng.go
index 2e9f2720..646e31fa 100644
--- a/format/pcap/pcapng.go
+++ b/format/pcap/pcapng.go
@@ -361,7 +361,7 @@ type decodeContext struct {
 	flowDecoder        *flowsdecoder.Decoder
 }
 
-func decodePcapng(d *decode.D, in any) any {
+func decodePcapng(d *decode.D, _ any) any {
 	sectionHeaders := 0
 	for !d.End() {
 		fd := flowsdecoder.New()
diff --git a/format/png/png.go b/format/png/png.go
index ba022bc4..28e7928e 100644
--- a/format/png/png.go
+++ b/format/png/png.go
@@ -77,7 +77,7 @@ var colorTypeMap = scalar.UToSymStr{
 	colorTypeRGBA:               "rgba",
 }
 
-func pngDecode(d *decode.D, in any) any {
+func pngDecode(d *decode.D, _ any) any {
 	iEndFound := false
 	var colorType uint64
 
@@ -127,7 +127,7 @@ func pngDecode(d *decode.D, in any) any {
 
 				switch compressionMethod {
 				case compressionDeflate:
-					d.FieldFormatReaderLen("uncompressed", dataLen, zlib.NewReader, decode.FormatFn(func(d *decode.D, in any) any {
+					d.FieldFormatReaderLen("uncompressed", dataLen, zlib.NewReader, decode.FormatFn(func(d *decode.D, _ any) any {
 						d.FieldUTF8("text", int(d.BitsLeft()/8))
 						return nil
 					}))
diff --git a/format/protobuf/protobuf_widevine.go b/format/protobuf/protobuf_widevine.go
index 14aae4e5..968fd20f 100644
--- a/format/protobuf/protobuf_widevine.go
+++ b/format/protobuf/protobuf_widevine.go
@@ -22,7 +22,7 @@ func init() {
 	})
 }
 
-func widevineDecode(d *decode.D, in any) any {
+func widevineDecode(d *decode.D, _ any) any {
 	widewinePb := format.ProtoBufMessage{
 		1: {Type: format.ProtoBufTypeEnum, Name: "algorithm", Enums: scalar.UToSymStr{
 			0: "unencrypted",
diff --git a/format/raw/raw.go b/format/raw/raw.go
index d6e254b5..bb07e860 100644
--- a/format/raw/raw.go
+++ b/format/raw/raw.go
@@ -10,6 +10,6 @@ func init() {
 	interp.RegisterFormat(decode.Format{
 		Name:        format.RAW,
 		Description: "Raw bits",
-		DecodeFn:    func(d *decode.D, in any) any { return nil },
+		DecodeFn:    func(d *decode.D, _ any) any { return nil },
 	})
 }
diff --git a/format/rtmp/amf0.go b/format/rtmp/amf0.go
index 4b4e94b3..896b3baf 100644
--- a/format/rtmp/amf0.go
+++ b/format/rtmp/amf0.go
@@ -144,7 +144,7 @@ func amf0DecodeValue(d *decode.D) {
 	}
 }
 
-func amf0Decode(d *decode.D, in any) any {
+func amf0Decode(d *decode.D, _ any) any {
 	amf0DecodeValue(d)
 	return nil
 }
diff --git a/format/tar/tar.go b/format/tar/tar.go
index f0f28cf0..e6ed845b 100644
--- a/format/tar/tar.go
+++ b/format/tar/tar.go
@@ -26,7 +26,7 @@ func init() {
 	})
 }
 
-func tarDecode(d *decode.D, in any) any {
+func tarDecode(d *decode.D, _ any) any {
 	const blockBytes = 512
 	const blockBits = blockBytes * 8
 
diff --git a/format/tiff/tiff.go b/format/tiff/tiff.go
index bfb09f39..70b7e01f 100644
--- a/format/tiff/tiff.go
+++ b/format/tiff/tiff.go
@@ -201,7 +201,7 @@ func decodeIfd(d *decode.D, s *strips, tagNames scalar.UToSymStr) int64 {
 	return nextIfdOffset
 }
 
-func tiffDecode(d *decode.D, in any) any {
+func tiffDecode(d *decode.D, _ any) any {
 	endian := d.FieldU32("endian", endianNames, scalar.ActualHex)
 
 	switch endian {
diff --git a/format/vorbis/vorbis_comment.go b/format/vorbis/vorbis_comment.go
index e55d3a0b..0cb6b889 100644
--- a/format/vorbis/vorbis_comment.go
+++ b/format/vorbis/vorbis_comment.go
@@ -23,7 +23,7 @@ func init() {
 	})
 }
 
-func commentDecode(d *decode.D, in any) any {
+func commentDecode(d *decode.D, _ any) any {
 	d.Endian = decode.LittleEndian
 
 	vendorLen := d.FieldU32("vendor_length")
diff --git a/format/vorbis/vorbis_packet.go b/format/vorbis/vorbis_packet.go
index a6dc9b3f..2e7102a4 100644
--- a/format/vorbis/vorbis_packet.go
+++ b/format/vorbis/vorbis_packet.go
@@ -38,7 +38,7 @@ var packetTypeNames = map[uint]string{
 	packetTypeSetup:          "Setup",
 }
 
-func vorbisDecode(d *decode.D, in any) any {
+func vorbisDecode(d *decode.D, _ any) any {
 	d.Endian = decode.LittleEndian
 
 	packetType := d.FieldUScalarFn("packet_type", func(d *decode.D) scalar.S {
diff --git a/format/vpx/vp8_frame.go b/format/vpx/vp8_frame.go
index cf075ed9..a9cc954d 100644
--- a/format/vpx/vp8_frame.go
+++ b/format/vpx/vp8_frame.go
@@ -19,7 +19,7 @@ func init() {
 	})
 }
 
-func vp8Decode(d *decode.D, in any) any {
+func vp8Decode(d *decode.D, _ any) any {
 	var isKeyFrame bool
 
 	versions := map[uint64]struct {
diff --git a/format/vpx/vp9_cfm.go b/format/vpx/vp9_cfm.go
index 802c36f1..78a492ac 100644
--- a/format/vpx/vp9_cfm.go
+++ b/format/vpx/vp9_cfm.go
@@ -18,7 +18,7 @@ func init() {
 	})
 }
 
-func vp9CFMDecode(d *decode.D, in any) any {
+func vp9CFMDecode(d *decode.D, _ any) any {
 	for d.NotEnd() {
 		d.FieldStruct("feature", func(d *decode.D) {
 			id := d.FieldU8("id", vp9FeatureIDNames)
diff --git a/format/vpx/vp9_frame.go b/format/vpx/vp9_frame.go
index 3ec29609..cb54753d 100644
--- a/format/vpx/vp9_frame.go
+++ b/format/vpx/vp9_frame.go
@@ -107,7 +107,7 @@ func vp9DecodeFrameSize(d *decode.D) {
 	d.FieldUFn("frame_height", func(d *decode.D) uint64 { return d.U16() + 1 })
 }
 
-func vp9Decode(d *decode.D, in any) any {
+func vp9Decode(d *decode.D, _ any) any {
 
 	// TODO: header_size at end? even for show_existing_frame?
 
diff --git a/format/vpx/vpx_ccr.go b/format/vpx/vpx_ccr.go
index 0d9be10c..e51a1f27 100644
--- a/format/vpx/vpx_ccr.go
+++ b/format/vpx/vpx_ccr.go
@@ -16,7 +16,7 @@ func init() {
 	})
 }
 
-func vpxCCRDecode(d *decode.D, in any) any {
+func vpxCCRDecode(d *decode.D, _ any) any {
 	d.FieldU8("profile")
 	d.FieldU8("level", vpxLevelNames)
 	d.FieldU4("bit_depth")
diff --git a/format/wav/wav.go b/format/wav/wav.go
index a3590eae..1f9bffdf 100644
--- a/format/wav/wav.go
+++ b/format/wav/wav.go
@@ -201,7 +201,7 @@ func decodeChunks(d *decode.D, stringData bool) {
 	})
 }
 
-func wavDecode(d *decode.D, in any) any {
+func wavDecode(d *decode.D, _ any) any {
 	// there are wav files in the wild with id3v2 header id3v1 footer
 	_, _, _ = d.TryFieldFormat("header", headerFormat, nil)
 
diff --git a/format/webp/webp.go b/format/webp/webp.go
index 32bb02bc..f469e8e0 100644
--- a/format/webp/webp.go
+++ b/format/webp/webp.go
@@ -41,7 +41,7 @@ func decodeChunk(d *decode.D, expectedChunkID string, fn func(d *decode.D)) bool
 	return true
 }
 
-func webpDecode(d *decode.D, in any) any {
+func webpDecode(d *decode.D, _ any) any {
 	d.Endian = decode.LittleEndian
 
 	d.FieldUTF8("riff_id", 4, d.AssertStr("RIFF"))
diff --git a/pkg/decode/decode.go b/pkg/decode/decode.go
index 80bd02ec..33f873a3 100644
--- a/pkg/decode/decode.go
+++ b/pkg/decode/decode.go
@@ -122,7 +122,7 @@ func decode(ctx context.Context, br bitio.ReaderAtSeeker, group Group, opts Opti
 		}
 
 		var minMaxRange ranges.Range
-		if err := d.Value.WalkRootPreOrder(func(v *Value, rootV *Value, depth int, rootDepth int) error {
+		if err := d.Value.WalkRootPreOrder(func(v *Value, _ *Value, _ int, _ int) error {
 			minMaxRange = ranges.MinMax(minMaxRange, v.Range)
 			v.Range.Start += decodeRange.Start
 			v.RootReader = br
@@ -281,7 +281,7 @@ func (d *D) SharedReadBuf(n int) []byte {
 
 func (d *D) FillGaps(r ranges.Range, namePrefix string) {
 	makeWalkFn := func(fn func(iv *Value)) func(iv *Value, rootV *Value, depth int, rootDepth int) error {
-		return func(iv *Value, rootV *Value, depth int, rootDepth int) error {
+		return func(iv *Value, _ *Value, _ int, _ int) error {
 			switch iv.V.(type) {
 			case *Compound:
 			default:
@@ -294,7 +294,7 @@ func (d *D) FillGaps(r ranges.Range, namePrefix string) {
 	// TODO: redo this, tries to get rid of slice grow
 	// TODO: pre-sorted somehow?
 	n := 0
-	_ = d.Value.WalkRootPreOrder(makeWalkFn(func(iv *Value) { n++ }))
+	_ = d.Value.WalkRootPreOrder(makeWalkFn(func(_ *Value) { n++ }))
 	valueRanges := make([]ranges.Range, n)
 	i := 0
 	_ = d.Value.WalkRootPreOrder(makeWalkFn(func(iv *Value) {
diff --git a/pkg/decode/format.go b/pkg/decode/format.go
index 534b4c24..ca0cfada 100644
--- a/pkg/decode/format.go
+++ b/pkg/decode/format.go
@@ -14,7 +14,7 @@ type Format struct {
 	ProbeOrder    int // probe order is from low to hi value then by name
 	Description   string
 	Groups        []string
-	DecodeFn      func(d *D, in any) any
+	DecodeFn      func(d *D, _ any) any
 	DecodeInArg   any
 	DecodeOutType any
 	RootArray     bool
@@ -46,7 +46,7 @@ type FormatHelp struct {
 	References []HelpReference
 }
 
-func FormatFn(d func(d *D, in any) any) Group {
+func FormatFn(d func(d *D, _ any) any) Group {
 	return Group{{
 		DecodeFn: d,
 	}}
diff --git a/pkg/interp/interp.go b/pkg/interp/interp.go
index 6181c451..73052497 100644
--- a/pkg/interp/interp.go
+++ b/pkg/interp/interp.go
@@ -68,7 +68,7 @@ func init() {
 	RegisterFunc0("_exttype", (*Interp)._extType)
 
 	RegisterFunc0("_global_state", func(i *Interp, c any) any { return *i.state })
-	RegisterFunc1("_global_state", func(i *Interp, c any, v any) any { *i.state = v; return v })
+	RegisterFunc1("_global_state", func(i *Interp, _ any, v any) any { *i.state = v; return v })
 
 	RegisterFunc0("history", (*Interp).history)
 	RegisterIter1("_display", (*Interp)._display)