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107 lines
1.9 KiB
107 lines
1.9 KiB
// Copyright 2020 Justine Alexandra Roberts Tunney
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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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// RFC2833 RTP DTMF Telephone Events
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package rtp
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import (
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"errors"
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"fmt"
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)
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// Turns telephone event into ASCII character.
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func DtmfToChar(event uint8) (byte, error) {
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switch event {
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case 0:
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return '0', nil
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case 1:
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return '1', nil
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case 2:
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return '2', nil
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case 3:
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return '3', nil
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case 4:
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return '4', nil
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case 5:
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return '5', nil
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case 6:
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return '6', nil
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case 7:
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return '7', nil
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case 8:
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return '8', nil
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case 9:
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return '9', nil
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case 10:
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return '*', nil
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case 11:
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return '#', nil
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case 12:
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return 'A', nil
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case 13:
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return 'B', nil
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case 14:
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return 'C', nil
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case 15:
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return 'D', nil
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case 16:
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return '!', nil
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default:
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return '\x00', errors.New(fmt.Sprintf("bad tel event: %v", event))
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}
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}
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// Turns ascii character into corresponding telephone event.
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func CharToDtmf(ch byte) (event uint8, err error) {
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switch ch {
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case '0':
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event = 0
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case '1':
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event = 1
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case '2':
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event = 2
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case '3':
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event = 3
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case '4':
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event = 4
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case '5':
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event = 5
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case '6':
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event = 6
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case '7':
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event = 7
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case '8':
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event = 8
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case '9':
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event = 9
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case '*':
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event = 10
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case '#':
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event = 11
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case 'a', 'A':
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event = 12
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case 'b', 'B':
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event = 13
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case 'c', 'C':
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event = 14
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case 'd', 'D':
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event = 15
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case '!':
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event = 16
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default:
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err = errors.New(fmt.Sprint("bad dtmf char:", string(ch)))
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}
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return
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}
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