mirror of
https://github.com/hajimehoshi/ebiten.git
synced 2024-11-10 13:07:26 +01:00
102 lines
2.3 KiB
Go
102 lines
2.3 KiB
Go
// Copyright 2016 Hajime Hoshi
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
// +build !js
|
|
|
|
package vorbis
|
|
|
|
import (
|
|
"bytes"
|
|
"errors"
|
|
"fmt"
|
|
"io"
|
|
"math"
|
|
|
|
"github.com/hajimehoshi/ebiten/audio"
|
|
"github.com/jfreymuth/go-vorbis/ogg/vorbis"
|
|
)
|
|
|
|
type Stream struct {
|
|
buf *bytes.Reader
|
|
}
|
|
|
|
func newStream(v *vorbis.Vorbis) (*Stream, error) {
|
|
data := []byte{}
|
|
// TODO: We can delay decoding.
|
|
for {
|
|
out, err := v.DecodePacket()
|
|
if err == io.EOF {
|
|
break
|
|
}
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
const channelNum = 2
|
|
b := make([]byte, len(out[0])*2*channelNum)
|
|
for i := 0; i < len(out[0]); i++ {
|
|
vv := int16(out[0][i] * math.MaxInt16)
|
|
b[4*i] = byte(vv)
|
|
b[4*i+1] = byte(vv >> 8)
|
|
vv = int16(out[1][i] * math.MaxInt16)
|
|
b[4*i+2] = byte(vv)
|
|
b[4*i+3] = byte(vv >> 8)
|
|
}
|
|
data = append(data, b...)
|
|
}
|
|
s := &Stream{
|
|
buf: bytes.NewReader(data),
|
|
}
|
|
return s, nil
|
|
}
|
|
|
|
func (s *Stream) Read(p []byte) (int, error) {
|
|
return s.buf.Read(p)
|
|
}
|
|
|
|
func (s *Stream) Seek(offset int64, whence int) (int64, error) {
|
|
return s.buf.Seek(offset, whence)
|
|
}
|
|
|
|
func (s *Stream) Close() error {
|
|
s.buf = nil
|
|
return nil
|
|
}
|
|
|
|
// Size returns the size of decoded stream in bytes.
|
|
func (s *Stream) Size() int64 {
|
|
return s.buf.Size()
|
|
}
|
|
|
|
// Decode decodes Ogg/Vorbis data to playable stream.
|
|
//
|
|
// The sample rate must be same as that of audio context.
|
|
func Decode(context *audio.Context, src audio.ReadSeekCloser) (*Stream, error) {
|
|
v, err := vorbis.Open(src)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
// TODO: Remove this magic number
|
|
if v.Channels() != 2 {
|
|
return nil, errors.New("vorbis: number of channels must be 2")
|
|
}
|
|
if v.SampleRate() != context.SampleRate() {
|
|
return nil, fmt.Errorf("vorbis: sample rate must be %d but %d", context.SampleRate(), v.SampleRate())
|
|
}
|
|
s, err := newStream(v)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
return s, nil
|
|
}
|