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mirror of https://github.com/wader/fq.git synced 2024-12-24 13:52:02 +03:00
fq/format/vorbis/comment.go
2021-09-12 13:08:50 +02:00

54 lines
1.5 KiB
Go

package vorbis
import (
"encoding/base64"
"strings"
"github.com/wader/fq/format"
"github.com/wader/fq/format/registry"
"github.com/wader/fq/pkg/bitio"
"github.com/wader/fq/pkg/decode"
)
var flacPicture []*decode.Format
func init() {
registry.MustRegister(&decode.Format{
Name: format.VORBIS_COMMENT,
Description: "Vorbis comment",
DecodeFn: commentDecode,
Dependencies: []decode.Dependency{
{Names: []string{format.FLAC_PICTURE}, Formats: &flacPicture},
},
})
}
func commentDecode(d *decode.D, in interface{}) interface{} {
vendorLen := d.FieldU32LE("vendor_length")
d.FieldUTF8("vendor", int(vendorLen))
userCommentListLength := d.FieldU32LE("user_comment_list_length")
i := uint64(0)
d.FieldStructArrayLoopFn("user_comments", "user_comment", func() bool { return i < userCommentListLength }, func(d *decode.D) {
userCommentLength := d.FieldU32LE("length")
userComment := d.FieldUTF8("vendor", int(userCommentLength))
pairParts := strings.SplitN(userComment, "=", 2)
if len(pairParts) == 2 {
k, v := strings.ToUpper(pairParts[0]), pairParts[1]
var metadataBlockPicture = "METADATA_BLOCK_PICTURE"
if k == metadataBlockPicture {
// METADATA_BLOCK_PICTURE=<base64-flac-picture-metadatablock>
bs, err := base64.StdEncoding.DecodeString(v)
if err == nil {
bb := bitio.NewBufferFromBytes(bs, -1)
d.FieldFormatBitBuf("picture", bb, flacPicture)
} else {
panic(err)
}
}
}
i++
})
return nil
}