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Web语音对讲示例

news 2025/11/4 18:13:16

PCM文件生成
1. 在线语音合成 https://ttsmaker.cn/
2. 音频转码 ffmpeg.exe -i test.mp3 -f s16le -ar 8000 -ac 1 -vn output.pcm

RTP播放测试
新建stream.sdp文件，使用vlc打开该文件，如8kHz 单声道 16-bit:

v=0
o=- 0 0 IN IP4 127.0.0.1
s=PCM Audio Stream
c=IN IP4 127.0.0.1
t=0 0
m=audio 5004 RTP/AVP 96
a=rtpmap:96 L16/8000/1

技术实现

流媒体：SDP流媒体信息、RTP打包、RTP解包

通信层：websocket

界面层：Html获取麦克风音频数据，播放PCM音频

代码结构

media.sdp

v=0
o=- 0 0 IN IP4 127.0.0.1
s=RTP PCM Audio Stream
c=IN IP4 127.0.0.1
t=0 0
m=audio 5504 RTP/AVP 96
a=rtpmap:96 L16/8000/1

talk_G711Alaw.sdp

v=0
o=- 0 0 IN IP4 127.0.0.1
s=s=RTP G711 Audio Stream
c=IN IP4 127.0.0.1
t=0 0
m=audio 5004 RTP/AVP 8
a=rtpmap:8 PCMA/8000

talk_PCM.sdp

v=0
o=- 0 0 IN IP4 127.0.0.1
s=s=RTP G711 Audio Stream
c=IN IP4 127.0.0.1
t=0 0
m=audio 5004 RTP/AVP 96
a=rtpmap:96 L16/8000/1

using System.Net;
using System.Net.Sockets;namespace RTPService.rtp
{public class RtpStreamer{private UdpClient udpClient;private IPEndPoint remoteEndPoint;private RtpPacketizer packetizer;private int frameSize;private int sampleRate;private int channel;private int bytesPerSample;public RtpStreamer(string remoteAddress, int remotePort, uint ssrc, int sampleRate = 8000, int bitDepth = 16, int channel = 1, byte payloadType = 96, bool isBigEndian = false){udpClient = new UdpClient();remoteEndPoint = new IPEndPoint(IPAddress.Parse(remoteAddress), remotePort);this.sampleRate = sampleRate;this.channel = channel;this.bytesPerSample = bitDepth / 8;packetizer = new RtpPacketizer(ssrc, sampleRate, channel, bytesPerSample, payloadType, isBigEndian);// 计算适当的帧大小 (20ms 的数据)frameSize = (sampleRate * channel * bytesPerSample * 20) / 1000;// 确保帧大小是样本大小的倍数int sampleSize = channel * bytesPerSample;frameSize = (frameSize / sampleSize) * sampleSize;Console.WriteLine($"Streaming parameters: SSRC={ssrc},SampleRate={sampleRate}, bitDepth={bitDepth}, Channels={channel}, PayloadType={payloadType}, isBigEndian={isBigEndian}, FrameSize={frameSize}");}public void StreamPcmFile(string filePath){using (FileStream fileStream = new FileStream(filePath, FileMode.Open, FileAccess.Read)){byte[] buffer = new byte[frameSize];int bytesRead;while ((bytesRead = fileStream.Read(buffer, 0, frameSize)) > 0){SendRtp(buffer, bytesRead);// 等待适当的时间以保持正确的速率int samples = bytesRead / (channel * bytesPerSample);int delayMs = (samples * 1000) / sampleRate;Thread.Sleep(delayMs);}}}public byte[] CreateRtpPacket(byte[] buffer, int bytesRead){return packetizer.CreateRtpPacket(buffer, 0, bytesRead);}public byte[] DepacketizeRtpPacket(byte[] rtp){return packetizer.DepacketizeRtpPacket(rtp);}public void SendRtp(byte[] buffer, int bytesRead){// 创建RTP包byte[] rtpPacket = CreateRtpPacket(buffer, bytesRead);// 发送RTP包
            udpClient.Send(rtpPacket, rtpPacket.Length, remoteEndPoint);// 发送RTSP over UDP//byte[] rtspPacket = packetizer.CreateRtspPacket(rtpPacket);//udpClient.Send(rtspPacket, rtspPacket.Length, remoteEndPoint);
        }public void Close(){//udpClient?.Close();
        }}
}