S.O.N.G/flacgo
S.O.N.G/flacgo
3
0
Fork 0
Code Issues Pull requests Releases Activity

meta: Minor changes to NewSeekTable, such as error handling and comments.

Browse source
This commit is contained in:
mewmew 2012-11-04 20:49:59 +01:00
parent 3f825a3133
commit ed11fb8d6e
1 changed files with 14 additions and 14 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

28
meta/meta.go
View file

@ -12,7 +12,6 @@ const (
ErrInvalidBlockLen = "invalid block length; expected %d, got %d."
ErrInvalidMaxBlockSize = "invalid block size; expected >= 16 and <= 65535, got %d."
ErrInvalidMinBlockSize = "invalid block size; expected >= 16, got %d."
ErrInvalidNumSeekPoints = "the number of seek points must be divisible by 18: %d"
ErrInvalidNumTracksForCompact = "invalid number of tracks for a compact disc, can't be more than 100: %d"
ErrInvalidPictureType = "the picture type is invalid (must be <=20): %d"
ErrInvalidSampleRate = "invalid sample rate; expected > 0 and <= 655350, got %d."
@ -24,6 +23,7 @@ const (
// Error messages.
var (
ErrInvalidBlockType = errors.New("invalid block type.")
ErrInvalidSeekTableLen = errors.New("invalid block size; seek table not divisible by 18.")
ErrInvalidTrackNum = errors.New("invalid track number value 0 isn't allowed.")
ErrMissingLeadOutTrack = errors.New("cuesheet needs a lead out track.")
ErrReserved = errors.New("reserved value.")
@ -304,13 +304,19 @@ func NewApplication(buf []byte) (ap *Application, err error) {
// will be ignored by decoders but which can be used to reserve space for future
// seek point insertion.
type SeekTable struct {
// One or more seek points.
Points []SeekPoint
}
// A SeekPoint specifies the offset of a sample.
type SeekPoint struct {
// Sample number of first sample in the target frame, or 0xFFFFFFFFFFFFFFFF
// for a placeholder point.
SampleNumber uint64
// Offset (in bytes) from the first byte of the first frame header to the
// first byte of the target frame's header.
Offset uint64
// Number of samples in the target frame.
NumSamples uint16
}
@ -324,15 +330,8 @@ func NewSeekTable(buf []byte) (st *SeekTable, err error) {
// Seek points within a table must be unique by sample number, with the exception of placeholder points.
// The previous two notes imply that there may be any number of placeholder points, but they must all occur at the end of the table.
const (
SampleNumberLen = 64
OffsetLen = 64
NumSamplesInFrameLen = 16
)
///Error check for fractions
if len(buf)%18 != 0 {
return nil, fmt.Errorf(ErrInvalidNumSeekPoints, len(buf))
return nil, ErrInvalidSeekTableLen
}
st = new(SeekTable)
@ -340,11 +339,12 @@ func NewSeekTable(buf []byte) (st *SeekTable, err error) {
numSeekPoints := len(buf) / 18
for i := 0; i < numSeekPoints; i++ {
st.Points = append(st.Points, SeekPoint{
SampleNumber: binary.BigEndian.Uint64(b.Next(8)), //Sample Number (size: 8 bytes)
Offset: binary.BigEndian.Uint64(b.Next(8)), //Offset (in bytes) from the first byte of the first frame header to the first byte of the target frame's header. (size: 8 bytes)
NumSamples: binary.BigEndian.Uint16(b.Next(2)), //Number of samples in the target frame. (size: 2 bytes)
})
point := SeekPoint{
SampleNumber: binary.BigEndian.Uint64(b.Next(8)), // Sample number (size: 8 bytes).
Offset: binary.BigEndian.Uint64(b.Next(8)), // Offset (size: 8 bytes).
NumSamples: binary.BigEndian.Uint16(b.Next(2)), // Number of samples (size: 2 bytes).
}
st.Points = append(st.Points, point)
}
return st, nil