mirror of
https://github.com/hajimehoshi/ebiten.git
synced 2024-11-10 13:07:26 +01:00
112 lines
2.1 KiB
Go
112 lines
2.1 KiB
Go
// Copyright 2017 The Ebiten Authors
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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// +build !js
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package mp3
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// #include "pdmp3.h"
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import "C"
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import (
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"errors"
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"io"
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"unsafe"
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)
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const (
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eof = 0xffffffff
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)
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var (
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reader io.Reader
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readerCache []uint8
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readerPos int
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readerEOF bool
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writer io.Writer
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)
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func getByte() (uint8, error) {
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for len(readerCache) == 0 && !readerEOF {
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buf := make([]uint8, 4096)
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n, err := reader.Read(buf)
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readerCache = append(readerCache, buf[:n]...)
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if err != nil {
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if err == io.EOF {
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readerEOF = true
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} else {
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return 0, err
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}
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}
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}
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if len(readerCache) == 0 {
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return 0, io.EOF
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}
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b := readerCache[0]
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readerCache = readerCache[1:]
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readerPos++
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return b, nil
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}
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func getBytes(buf []int) (int, error) {
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for i := range buf {
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v, err := getByte()
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buf[i] = int(v)
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if err == io.EOF {
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return i, io.EOF
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}
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}
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return len(buf), nil
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}
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//export Get_Filepos
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func Get_Filepos() C.unsigned {
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if len(readerCache) == 0 && readerEOF {
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return eof
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}
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return C.unsigned(readerPos)
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}
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//export writeToWriter
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func writeToWriter(data unsafe.Pointer, size C.int) C.size_t {
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buf := C.GoBytes(data, size)
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n, err := writer.Write(buf)
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if err != nil {
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panic(err)
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}
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return C.size_t(n)
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}
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var g_error error
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func decode(r io.Reader, w io.Writer) error {
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reader = r
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writer = w
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for Get_Filepos() != eof {
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err := readFrame()
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if err == nil {
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C.Decode_L3()
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continue
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}
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if Get_Filepos() == eof {
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break
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}
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if err != nil {
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return err
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}
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return errors.New("mp3: not enough maindata to decode frame")
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}
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return g_error
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}
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