mirror of
https://github.com/hajimehoshi/ebiten.git
synced 2024-11-14 15:07:26 +01:00
267 lines
7.3 KiB
Go
267 lines
7.3 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.
|
|
|
|
// Package wav provides WAV (RIFF) decoder.
|
|
package wav
|
|
|
|
import (
|
|
"bytes"
|
|
"fmt"
|
|
"io"
|
|
|
|
"github.com/hajimehoshi/ebiten/v2/audio"
|
|
"github.com/hajimehoshi/ebiten/v2/audio/internal/convert"
|
|
)
|
|
|
|
// Stream is a decoded audio stream.
|
|
type Stream struct {
|
|
inner io.ReadSeeker
|
|
size int64
|
|
}
|
|
|
|
// Read is implementation of io.Reader's Read.
|
|
func (s *Stream) Read(p []byte) (int, error) {
|
|
return s.inner.Read(p)
|
|
}
|
|
|
|
// Seek is implementation of io.Seeker's Seek.
|
|
//
|
|
// Note that Seek can take long since decoding is a relatively heavy task.
|
|
//
|
|
// If the underlying source is not an io.Seeker, Seek panics.
|
|
func (s *Stream) Seek(offset int64, whence int) (int64, error) {
|
|
return s.inner.Seek(offset, whence)
|
|
}
|
|
|
|
// Length returns the size of decoded stream in bytes.
|
|
func (s *Stream) Length() int64 {
|
|
return s.size
|
|
}
|
|
|
|
type stream struct {
|
|
src io.Reader
|
|
headerSize int64
|
|
dataSize int64
|
|
remaining int64
|
|
}
|
|
|
|
// Read is implementation of io.Reader's Read.
|
|
func (s *stream) Read(p []byte) (int, error) {
|
|
if s.remaining <= 0 {
|
|
return 0, io.EOF
|
|
}
|
|
if s.remaining < int64(len(p)) {
|
|
p = p[0:s.remaining]
|
|
}
|
|
n, err := s.src.Read(p)
|
|
s.remaining -= int64(n)
|
|
return n, err
|
|
}
|
|
|
|
// Seek is implementation of io.Seeker's Seek.
|
|
//
|
|
// If the underlying source is not an io.Seeker, Seek panics.
|
|
func (s *stream) Seek(offset int64, whence int) (int64, error) {
|
|
seeker, ok := s.src.(io.Seeker)
|
|
if !ok {
|
|
panic("wav: s.src must be io.Seeker but not")
|
|
}
|
|
|
|
switch whence {
|
|
case io.SeekStart:
|
|
offset = offset + s.headerSize
|
|
case io.SeekCurrent:
|
|
case io.SeekEnd:
|
|
offset = s.headerSize + s.dataSize + offset
|
|
whence = io.SeekStart
|
|
}
|
|
n, err := seeker.Seek(offset, whence)
|
|
if err != nil {
|
|
return 0, err
|
|
}
|
|
if n-s.headerSize < 0 {
|
|
return 0, fmt.Errorf("wav: invalid offset")
|
|
}
|
|
s.remaining = s.dataSize - (n - s.headerSize)
|
|
// There could be a tail in wav file.
|
|
if s.remaining < 0 {
|
|
s.remaining = 0
|
|
return s.dataSize, nil
|
|
}
|
|
return n - s.headerSize, nil
|
|
}
|
|
|
|
// DecodeWithSampleRate decodes WAV (RIFF) data to playable stream.
|
|
//
|
|
// The format must be 1 or 2 channels, 8bit or 16bit little endian PCM.
|
|
// The format is converted into 2 channels and 16bit.
|
|
//
|
|
// DecodeWithSampleRate returns error when decoding fails or IO error happens.
|
|
//
|
|
// The returned Stream's Seek is available only when src is an io.Seeker.
|
|
//
|
|
// 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) {
|
|
return decode(src, nil)
|
|
}
|
|
|
|
// DecodeWithSampleRate decodes WAV (RIFF) data to playable stream.
|
|
//
|
|
// The format must be 1 or 2 channels, 8bit or 16bit little endian PCM.
|
|
// The format is converted into 2 channels and 16bit.
|
|
//
|
|
// DecodeWithSampleRate returns error when decoding fails or IO error happens.
|
|
//
|
|
// DecodeWithSampleRate automatically resamples the stream to fit with sampleRate if necessary.
|
|
//
|
|
// The returned Stream's Seek is available only when src is an io.Seeker.
|
|
//
|
|
// A Stream doesn't close src even if src implements io.Closer.
|
|
// Closing the source is src owner's responsibility.
|
|
func DecodeWithSampleRate(sampleRate int, src io.Reader) (*Stream, error) {
|
|
return decode(src, &sampleRate)
|
|
}
|
|
|
|
func decode(src io.Reader, sampleRate *int) (*Stream, error) {
|
|
buf := make([]byte, 12)
|
|
n, err := io.ReadFull(src, buf)
|
|
if n != len(buf) {
|
|
return nil, fmt.Errorf("wav: invalid header")
|
|
}
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
if !bytes.Equal(buf[0:4], []byte("RIFF")) {
|
|
return nil, fmt.Errorf("wav: invalid header: 'RIFF' not found")
|
|
}
|
|
if !bytes.Equal(buf[8:12], []byte("WAVE")) {
|
|
return nil, fmt.Errorf("wav: invalid header: 'WAVE' not found")
|
|
}
|
|
|
|
// Read chunks
|
|
dataSize := int64(0)
|
|
headerSize := int64(len(buf))
|
|
sampleRateFrom := 0
|
|
sampleRateTo := 0
|
|
mono := false
|
|
bitsPerSample := 0
|
|
chunks:
|
|
for {
|
|
buf := make([]byte, 8)
|
|
n, err := io.ReadFull(src, buf)
|
|
if n != len(buf) {
|
|
return nil, fmt.Errorf("wav: invalid header")
|
|
}
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
headerSize += 8
|
|
size := int64(buf[4]) | int64(buf[5])<<8 | int64(buf[6])<<16 | int64(buf[7])<<24
|
|
switch {
|
|
case bytes.Equal(buf[0:4], []byte("fmt ")):
|
|
// Size of 'fmt' header is usually 16, but can be more than 16.
|
|
if size < 16 {
|
|
return nil, fmt.Errorf("wav: invalid header: maybe non-PCM file?")
|
|
}
|
|
buf := make([]byte, size)
|
|
n, err := io.ReadFull(src, buf)
|
|
if n != len(buf) {
|
|
return nil, fmt.Errorf("wav: invalid header")
|
|
}
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
format := int(buf[0]) | int(buf[1])<<8
|
|
if format != 1 {
|
|
return nil, fmt.Errorf("wav: format must be linear PCM")
|
|
}
|
|
channelNum := int(buf[2]) | int(buf[3])<<8
|
|
switch channelNum {
|
|
case 1:
|
|
mono = true
|
|
case 2:
|
|
mono = false
|
|
default:
|
|
return nil, fmt.Errorf("wav: channel num must be 1 or 2 but was %d", channelNum)
|
|
}
|
|
bitsPerSample = int(buf[14]) | int(buf[15])<<8
|
|
if bitsPerSample != 8 && bitsPerSample != 16 {
|
|
return nil, fmt.Errorf("wav: bits per sample must be 8 or 16 but was %d", bitsPerSample)
|
|
}
|
|
origSampleRate := int64(buf[4]) | int64(buf[5])<<8 | int64(buf[6])<<16 | int64(buf[7])<<24
|
|
if sampleRate != nil && int64(*sampleRate) != origSampleRate {
|
|
sampleRateFrom = int(origSampleRate)
|
|
sampleRateTo = *sampleRate
|
|
}
|
|
headerSize += size
|
|
case bytes.Equal(buf[0:4], []byte("data")):
|
|
dataSize = size
|
|
break chunks
|
|
default:
|
|
buf := make([]byte, size)
|
|
n, err := io.ReadFull(src, buf)
|
|
if n != len(buf) {
|
|
return nil, fmt.Errorf("wav: invalid header")
|
|
}
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
headerSize += size
|
|
}
|
|
}
|
|
var s io.ReadSeeker = &stream{
|
|
src: src,
|
|
headerSize: headerSize,
|
|
dataSize: dataSize,
|
|
remaining: dataSize,
|
|
}
|
|
|
|
if mono || bitsPerSample != 16 {
|
|
s = convert.NewStereo16(s, mono, bitsPerSample != 16)
|
|
if mono {
|
|
dataSize *= 2
|
|
}
|
|
if bitsPerSample != 16 {
|
|
dataSize *= 2
|
|
}
|
|
}
|
|
if sampleRateFrom != sampleRateTo {
|
|
r := convert.NewResampling(s, dataSize, sampleRateFrom, sampleRateTo)
|
|
s = r
|
|
dataSize = r.Length()
|
|
}
|
|
ss := &Stream{inner: s, size: dataSize}
|
|
return ss, nil
|
|
}
|
|
|
|
// Decode decodes WAV (RIFF) data to playable stream.
|
|
//
|
|
// The format must be 1 or 2 channels, 8bit or 16bit little endian PCM.
|
|
// The format is converted into 2 channels and 16bit.
|
|
//
|
|
// Decode returns error when decoding fails or IO error happens.
|
|
//
|
|
// Decode automatically resamples the stream to fit with the audio context if necessary.
|
|
//
|
|
// The returned Stream's Seek is available only when src is an io.Seeker.
|
|
//
|
|
// A Stream doesn't close src even if src implements io.Closer.
|
|
// Closing the source is src owner's responsibility.
|
|
//
|
|
// Deprecated: as of v2.1. Use DecodeWithSampleRate instead.
|
|
func Decode(context *audio.Context, src io.Reader) (*Stream, error) {
|
|
return DecodeWithSampleRate(context.SampleRate(), src)
|
|
}
|