mirror of
https://github.com/hajimehoshi/ebiten.git
synced 2024-12-26 11:48:55 +01:00
audio/vorbis: refactoring
This commit is contained in:
Hajime Hoshi
parent
b0a4b6ebbf
commit
5942192b66
@ -27,28 +27,28 @@ import (
|
||||
|
||||
// Stream is a decoded audio stream.
|
||||
type Stream struct {
|
||||
decoded io.ReadSeeker
|
||||
size int64
|
||||
readSeeker io.ReadSeeker
|
||||
length int64
|
||||
sampleRate int
|
||||
}
|
||||
|
||||
// Read is implementation of io.Reader's Read.
|
||||
func (s *Stream) Read(p []byte) (int, error) {
|
||||
return s.decoded.Read(p)
|
||||
return s.readSeeker.Read(p)
|
||||
}
|
||||
|
||||
// Seek is implementation of io.Seeker's Seek.
|
||||
//
|
||||
// Note that Seek can take long since decoding is a relatively heavy task.
|
||||
func (s *Stream) Seek(offset int64, whence int) (int64, error) {
|
||||
return s.decoded.Seek(offset, whence)
|
||||
return s.readSeeker.Seek(offset, whence)
|
||||
}
|
||||
|
||||
// Length returns the size of decoded stream in bytes.
|
||||
//
|
||||
// If the source is not io.Seeker, Length returns 0.
|
||||
func (s *Stream) Length() int64 {
|
||||
return s.size
|
||||
return s.length
|
||||
}
|
||||
|
||||
// SampleRate returns the sample rate of the decoded stream.
|
||||
@ -56,27 +56,19 @@ func (s *Stream) SampleRate() int {
|
||||
return s.sampleRate
|
||||
}
|
||||
|
||||
type decoder interface {
|
||||
Read([]float32) (int, error)
|
||||
SetPosition(int64) error
|
||||
Length() int64
|
||||
Channels() int
|
||||
SampleRate() int
|
||||
type i16Stream struct {
|
||||
totalBytes int
|
||||
posInBytes int
|
||||
vorbisReader *oggvorbis.Reader
|
||||
i16Reader io.Reader
|
||||
}
|
||||
|
||||
type decoded struct {
|
||||
totalBytes int
|
||||
posInBytes int
|
||||
decoder decoder
|
||||
decoderr io.Reader
|
||||
}
|
||||
|
||||
func (d *decoded) Read(b []byte) (int, error) {
|
||||
if d.decoderr == nil {
|
||||
d.decoderr = convert.NewReaderFromFloat32Reader(d.decoder)
|
||||
func (s *i16Stream) Read(b []byte) (int, error) {
|
||||
if s.i16Reader == nil {
|
||||
s.i16Reader = convert.NewReaderFromFloat32Reader(s.vorbisReader)
|
||||
}
|
||||
|
||||
l := d.totalBytes - d.posInBytes
|
||||
l := s.totalBytes - s.posInBytes
|
||||
if l > len(b) {
|
||||
l = len(b)
|
||||
}
|
||||
@ -85,7 +77,7 @@ func (d *decoded) Read(b []byte) (int, error) {
|
||||
}
|
||||
|
||||
retry:
|
||||
n, err := d.decoderr.Read(b[:l])
|
||||
n, err := s.i16Reader.Read(b[:l])
|
||||
if err != nil && err != io.EOF {
|
||||
return 0, err
|
||||
}
|
||||
@ -94,59 +86,63 @@ retry:
|
||||
goto retry
|
||||
}
|
||||
|
||||
d.posInBytes += n
|
||||
if d.posInBytes == d.totalBytes || err == io.EOF {
|
||||
s.posInBytes += n
|
||||
if s.posInBytes == s.totalBytes || err == io.EOF {
|
||||
return n, io.EOF
|
||||
}
|
||||
return n, nil
|
||||
}
|
||||
|
||||
func (d *decoded) Seek(offset int64, whence int) (int64, error) {
|
||||
func (s *i16Stream) Seek(offset int64, whence int) (int64, error) {
|
||||
next := int64(0)
|
||||
switch whence {
|
||||
case io.SeekStart:
|
||||
next = offset
|
||||
case io.SeekCurrent:
|
||||
next = int64(d.posInBytes) + offset
|
||||
next = int64(s.posInBytes) + offset
|
||||
case io.SeekEnd:
|
||||
next = int64(d.totalBytes) + offset
|
||||
next = int64(s.totalBytes) + offset
|
||||
}
|
||||
// pos should be always even
|
||||
next = next / 2 * 2
|
||||
d.posInBytes = int(next)
|
||||
if err := d.decoder.SetPosition(next / int64(d.decoder.Channels()) / 2); err != nil {
|
||||
s.posInBytes = int(next)
|
||||
if err := s.vorbisReader.SetPosition(next / int64(s.vorbisReader.Channels()) / 2); err != nil {
|
||||
return 0, err
|
||||
}
|
||||
d.decoderr = nil
|
||||
s.i16Reader = nil
|
||||
return next, nil
|
||||
}
|
||||
|
||||
func (d *decoded) Length() int64 {
|
||||
return int64(d.totalBytes)
|
||||
func (s *i16Stream) Length() int64 {
|
||||
return int64(s.totalBytes)
|
||||
}
|
||||
|
||||
// decode accepts an ogg stream and returns a decorded stream.
|
||||
func decode(in io.Reader) (*decoded, int, int, error) {
|
||||
func decode(in io.Reader) (*i16Stream, int, int, error) {
|
||||
r, err := oggvorbis.NewReader(in)
|
||||
if err != nil {
|
||||
return nil, 0, 0, err
|
||||
}
|
||||
d := &decoded{
|
||||
if r.Channels() != 1 && r.Channels() != 2 {
|
||||
return nil, 0, 0, fmt.Errorf("vorbis: number of channels must be 1 or 2 but was %d", r.Channels())
|
||||
}
|
||||
|
||||
s := &i16Stream{
|
||||
// TODO: r.Length() returns 0 when the format is unknown.
|
||||
// Should we check that?
|
||||
totalBytes: int(r.Length()) * r.Channels() * 2, // 2 means 16bit per sample.
|
||||
posInBytes: 0,
|
||||
decoder: r,
|
||||
totalBytes: int(r.Length()) * r.Channels() * 2, // 2 means 16bit per sample.
|
||||
posInBytes: 0,
|
||||
vorbisReader: r,
|
||||
}
|
||||
if _, ok := in.(io.Seeker); ok {
|
||||
if _, err := d.Read(make([]byte, 65536)); err != nil && err != io.EOF {
|
||||
if _, err := s.Read(make([]byte, 65536)); err != nil && err != io.EOF {
|
||||
return nil, 0, 0, err
|
||||
}
|
||||
if _, err := d.Seek(0, io.SeekStart); err != nil {
|
||||
if _, err := s.Seek(0, io.SeekStart); err != nil {
|
||||
return nil, 0, 0, err
|
||||
}
|
||||
}
|
||||
return d, r.Channels(), r.SampleRate(), nil
|
||||
return s, r.Channels(), r.SampleRate(), nil
|
||||
}
|
||||
|
||||
// DecodeWithoutResampling decodes Ogg/Vorbis data to playable stream.
|
||||
@ -158,22 +154,21 @@ func decode(in io.Reader) (*decoded, int, int, error) {
|
||||
// A Stream doesn't close src even if src implements io.Closer.
|
||||
// Closing the source is src owner's responsibility.
|
||||
func DecodeWithoutResampling(src io.Reader) (*Stream, error) {
|
||||
decoded, channelCount, sampleRate, err := decode(src)
|
||||
i16Stream, channelCount, sampleRate, err := decode(src)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
if channelCount != 1 && channelCount != 2 {
|
||||
return nil, fmt.Errorf("vorbis: number of channels must be 1 or 2 but was %d", channelCount)
|
||||
}
|
||||
var s io.ReadSeeker = decoded
|
||||
size := decoded.Length()
|
||||
|
||||
var s io.ReadSeeker = i16Stream
|
||||
length := i16Stream.Length()
|
||||
if channelCount == 1 {
|
||||
s = convert.NewStereo16(s, true, false)
|
||||
size *= 2
|
||||
length *= 2
|
||||
}
|
||||
|
||||
stream := &Stream{
|
||||
decoded: s,
|
||||
size: size,
|
||||
readSeeker: s,
|
||||
length: length,
|
||||
sampleRate: sampleRate,
|
||||
}
|
||||
return stream, nil
|
||||
@ -193,27 +188,25 @@ func DecodeWithoutResampling(src io.Reader) (*Stream, error) {
|
||||
// Resampling can be a very heavy task. Stream has a cache for resampling, but the size is limited.
|
||||
// Do not expect that Stream has a resampling cache even after whole data is played.
|
||||
func DecodeWithSampleRate(sampleRate int, src io.Reader) (*Stream, error) {
|
||||
decoded, channelCount, origSampleRate, err := decode(src)
|
||||
i16Stream, channelCount, origSampleRate, err := decode(src)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
if channelCount != 1 && channelCount != 2 {
|
||||
return nil, fmt.Errorf("vorbis: number of channels must be 1 or 2 but was %d", channelCount)
|
||||
}
|
||||
var s io.ReadSeeker = decoded
|
||||
size := decoded.Length()
|
||||
|
||||
var s io.ReadSeeker = i16Stream
|
||||
length := i16Stream.Length()
|
||||
if channelCount == 1 {
|
||||
s = convert.NewStereo16(s, true, false)
|
||||
size *= 2
|
||||
length *= 2
|
||||
}
|
||||
if origSampleRate != sampleRate {
|
||||
r := convert.NewResampling(s, size, origSampleRate, sampleRate)
|
||||
r := convert.NewResampling(s, length, origSampleRate, sampleRate)
|
||||
s = r
|
||||
size = r.Length()
|
||||
length = r.Length()
|
||||
}
|
||||
stream := &Stream{
|
||||
decoded: s,
|
||||
size: size,
|
||||
readSeeker: s,
|
||||
length: length,
|
||||
sampleRate: sampleRate,
|
||||
}
|
||||
return stream, nil
|
||||
|
||||
Loading…
Reference in New Issue
Block a user