tag/id3v2metadata.go
2015-06-28 12:40:49 +10:00

132 lines
3.0 KiB
Go

// Copyright 2015, David Howden
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package tag
import (
"strconv"
"strings"
)
type frameNames map[string][2]string
func (f frameNames) Name(s string, fm Format) string {
l, ok := f[s]
if !ok {
return ""
}
switch fm {
case ID3v2_2:
return l[0]
case ID3v2_3, ID3v2_4:
return l[1]
}
return ""
}
var frames = frameNames(map[string][2]string{
"title": [2]string{"TT2", "TIT2"},
"artist": [2]string{"TP1", "TPE1"},
"album": [2]string{"TAL", "TALB"},
"album_artist": [2]string{"TP2", "TPE2"},
"composer": [2]string{"TCM", "TCOM"},
"year": [2]string{"TYE", "TYER"},
"track": [2]string{"TRK", "TRCK"},
"disc": [2]string{"TPA", "TPOS"},
"genre": [2]string{"TCO", "TCON"},
"picture": [2]string{"PIC", "APIC"},
"lyrics": [2]string{"", "USLT"},
})
// metadataID3v2 is the implementation of Metadata used for ID3v2 tags.
type metadataID3v2 struct {
header *id3v2Header
frames map[string]interface{}
}
func (m metadataID3v2) getString(k string) string {
v, ok := m.frames[k]
if !ok {
return ""
}
return v.(string)
}
func (m metadataID3v2) getInt(k string) int {
v, ok := m.frames[k]
if !ok {
return 0
}
return v.(int)
}
func (m metadataID3v2) Format() Format { return m.header.Version }
func (m metadataID3v2) FileType() FileType { return MP3 }
func (m metadataID3v2) Raw() map[string]interface{} { return m.frames }
func (m metadataID3v2) Title() string {
return m.getString(frames.Name("title", m.Format()))
}
func (m metadataID3v2) Artist() string {
return m.getString(frames.Name("artist", m.Format()))
}
func (m metadataID3v2) Album() string {
return m.getString(frames.Name("album", m.Format()))
}
func (m metadataID3v2) AlbumArtist() string {
return m.getString(frames.Name("album_artist", m.Format()))
}
func (m metadataID3v2) Composer() string {
return m.getString(frames.Name("composer", m.Format()))
}
func (m metadataID3v2) Genre() string {
return m.getString(frames.Name("genre", m.Format()))
}
func (m metadataID3v2) Year() int {
year, _ := strconv.Atoi(m.getString(frames.Name("year", m.Format())))
return year
}
func parseXofN(s string) (x, n int) {
xn := strings.Split(s, "/")
if len(xn) != 2 {
x, _ = strconv.Atoi(s)
return x, 0
}
x, _ = strconv.Atoi(strings.TrimSpace(xn[0]))
n, _ = strconv.Atoi(strings.TrimSpace(xn[1]))
return x, n
}
func (m metadataID3v2) Track() (int, int) {
return parseXofN(m.getString(frames.Name("track", m.Format())))
}
func (m metadataID3v2) Disc() (int, int) {
return parseXofN(m.getString(frames.Name("disc", m.Format())))
}
func (m metadataID3v2) Lyrics() string {
t, ok := m.frames[frames.Name("lyrics", m.Format())]
if !ok {
return ""
}
return t.(*Comm).Text
}
func (m metadataID3v2) Picture() *Picture {
v, ok := m.frames[frames.Name("picture", m.Format())]
if !ok {
return nil
}
return v.(*Picture)
}