com.github.xingshuangs.iot.protocol.rtp.model.payload.H264NaluHeader Maven / Gradle / Ivy
/*
* MIT License
*
* Copyright (c) 2021-2099 Oscura (xingshuang)
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
package com.github.xingshuangs.iot.protocol.rtp.model.payload;
import com.github.xingshuangs.iot.common.IObjectByteArray;
import com.github.xingshuangs.iot.common.buff.ByteReadBuff;
import com.github.xingshuangs.iot.protocol.rtp.enums.EH264NaluType;
import com.github.xingshuangs.iot.utils.BooleanUtil;
import lombok.Data;
/**
* Nalu的头
* +---------------+
* |0|1|2|3|4|5|6|7|
* +-+-+-+-+-+-+-+-+
* |F|NRI| Type |
* +---------------+
*
* @author xingshuang
*/
@Data
public class H264NaluHeader implements IObjectByteArray {
/**
* H264 规范要求该位为 0
*/
private boolean forbiddenZeroBit;
/**
* 取值 0~3，指示该 NALU 重要性，对于 NRI=0 的 NALU 解码器可以丢弃它而不影响图像的回放，该值越大说明该 NALU 越重要，
* 需要受到保护。如果当前 NALU 属于参考帧的数据，或者是序列参数集，图像参数集等重要信息，则该值必须大于 0
*/
private int nri;
/**
* 表示 NALU 数据类型，该字段占 5 位，取值 0 ~ 31
*/
private EH264NaluType type;
@Override
public int byteArrayLength() {
return 1;
}
@Override
public byte[] toByteArray() {
byte res = (byte) (BooleanUtil.setBit(7, this.forbiddenZeroBit)
| ((this.nri << 5) & 0x60)
| (this.type.getCode() & 0x1F));
return new byte[]{res};
}
/**
* 字节数组数据解析
*
* @param data 字节数组数据
* @return RtcpHeader
*/
public static H264NaluHeader fromBytes(final byte[] data) {
return fromBytes(data, 0);
}
/**
* 字节数组数据解析
*
* @param data 字节数组数据
* @param offset 偏移量
* @return RtcpHeader
*/
public static H264NaluHeader fromBytes(final byte[] data, final int offset) {
if (data.length < 1) {
throw new IndexOutOfBoundsException("header, data length < 1");
}
ByteReadBuff buff = new ByteReadBuff(data, offset);
H264NaluHeader res = new H264NaluHeader();
byte aByte = buff.getByte();
res.forbiddenZeroBit = BooleanUtil.getValue(aByte, 7);
res.nri = (aByte >> 5) & 0x03;
res.type = EH264NaluType.from(aByte & 0x1F);
return res;
}
}