51 lines
1.5 KiB
Go
51 lines
1.5 KiB
Go
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// SPDX-FileCopyrightText: 2023 The Pion community <https://pion.ly>
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// SPDX-License-Identifier: MIT
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package rtp
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import (
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"encoding/binary"
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"errors"
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)
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const (
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playoutDelayExtensionSize = 3
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playoutDelayMaxValue = (1 << 12) - 1
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)
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var errPlayoutDelayInvalidValue = errors.New("invalid playout delay value")
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// PlayoutDelayExtension is a extension payload format in
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// http://www.webrtc.org/experiments/rtp-hdrext/playout-delay
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// 0 1 2 3
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// 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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// | ID | len=2 | MIN delay | MAX delay |
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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type PlayoutDelayExtension struct {
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minDelay, maxDelay uint16
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}
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// Marshal serializes the members to buffer
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func (p PlayoutDelayExtension) Marshal() ([]byte, error) {
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if p.minDelay > playoutDelayMaxValue || p.maxDelay > playoutDelayMaxValue {
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return nil, errPlayoutDelayInvalidValue
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}
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return []byte{
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byte(p.minDelay >> 4),
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byte(p.minDelay<<4) | byte(p.maxDelay>>8),
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byte(p.maxDelay),
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}, nil
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}
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// Unmarshal parses the passed byte slice and stores the result in the members
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func (p *PlayoutDelayExtension) Unmarshal(rawData []byte) error {
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if len(rawData) < playoutDelayExtensionSize {
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return errTooSmall
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}
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p.minDelay = binary.BigEndian.Uint16(rawData[0:2]) >> 4
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p.maxDelay = binary.BigEndian.Uint16(rawData[1:3]) & 0x0FFF
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return nil
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}
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