mirror of
https://github.com/wader/fq.git
synced 2024-10-03 23:17:50 +03:00
b08ef00dd1
Replaces []Format with a Group type. A bit more type safe. Breaking change for RegisterFormat, now takes a first argument that is a "single" format group. Lots of naming cleanup. This is also preparation for decode group argument which will enable doing intresting probing, ex a format decoder could know it's decode as part of probe group (html could be probed possibly), or have "arg probe" group for decoder who inspect args to know if they should probe (-d /path/to/schema etc) to enable nice CLI-ergonomics.
77 lines
1.8 KiB
Go
77 lines
1.8 KiB
Go
package ape
|
|
|
|
// http://wiki.hydrogenaud.io/index.php?title=APE_Tags_Header
|
|
|
|
import (
|
|
"github.com/wader/fq/format"
|
|
"github.com/wader/fq/pkg/decode"
|
|
"github.com/wader/fq/pkg/interp"
|
|
)
|
|
|
|
var imageGroup decode.Group
|
|
|
|
func init() {
|
|
interp.RegisterFormat(
|
|
format.Apev2,
|
|
&decode.Format{
|
|
Description: "APEv2 metadata tag",
|
|
DecodeFn: apev2Decode,
|
|
Dependencies: []decode.Dependency{
|
|
{Groups: []*decode.Group{format.Image}, Out: &imageGroup},
|
|
},
|
|
})
|
|
}
|
|
|
|
func apev2Decode(d *decode.D) any {
|
|
d.Endian = decode.LittleEndian
|
|
|
|
headerFooterFn := func(d *decode.D, name string) uint64 {
|
|
var tagCount uint64
|
|
d.FieldStruct(name, func(d *decode.D) {
|
|
d.FieldUTF8("preamble", 8, d.StrAssert("APETAGEX"))
|
|
d.FieldU32("version")
|
|
d.FieldU32("tag_size")
|
|
tagCount = d.FieldU32("item_count")
|
|
d.FieldU32("flags")
|
|
d.FieldRawLen("reserved", 64, d.BitBufIsZero())
|
|
})
|
|
return tagCount
|
|
}
|
|
|
|
tagCount := headerFooterFn(d, "header")
|
|
if tagCount > 1000 {
|
|
d.Fatalf("too many tags %d", tagCount)
|
|
}
|
|
|
|
d.FieldArray("tags", func(d *decode.D) {
|
|
for i := uint64(0); i < tagCount; i++ {
|
|
d.FieldStruct("tag", func(d *decode.D) {
|
|
itemSize := d.FieldU32("item_size")
|
|
var binaryItem bool
|
|
d.FieldStruct("item_flags", func(d *decode.D) {
|
|
d.FieldU6("unused0")
|
|
binaryItem = d.FieldBool("binary")
|
|
d.FieldU25("unused1")
|
|
})
|
|
keyLen := d.PeekFindByte(0, -1)
|
|
d.FieldUTF8("key", int(keyLen))
|
|
d.FieldU8("key_terminator")
|
|
if binaryItem {
|
|
d.FramedFn(int64(itemSize)*8, func(d *decode.D) {
|
|
d.FieldUTF8Null("filename")
|
|
// assume image if binary
|
|
d.FieldFormatOrRaw("value", &imageGroup, nil)
|
|
})
|
|
} else {
|
|
d.FieldUTF8("value", int(itemSize))
|
|
}
|
|
})
|
|
}
|
|
})
|
|
|
|
// TODO: check footer flag
|
|
headerFooterFn(d, "footer")
|
|
|
|
return nil
|
|
}
|