Audio packets not recevied by mic after sending beep sound to the another side speaker from teensy4.1

[Anushka_SS]

I am working on a project using Teensy 4.1. In this project, the Teensy is only in receiving mode. It receives audio from another device’s microphone (not a Teensy) in the form of RTP packets.


During the call, I send a beep tone from the Teensy to the speaker on the other side. The beep plays correctly, but after that, I stop receiving incoming RTP packets from the other side’s microphone.


On the other side, the microphone and speaker are connected together, and I am doing one-way communication. After the call is connected, I send a beep tone so the other user knows they can start speaking.


Below is the output I am getting.


When I initiate the call, I receive packets correctly:


RTP active: 1 packets/sec
RTP active: 47 packets/sec
RTP active: 50 packets/sec


After that, I send the beep tone to the other side’s speaker from the Teensy 4.1 code:


RTP TX seq=1709 ts=89106
RTP TX codec=0 seq=1710 ts=89266 len=160
RTP TX seq=1710 ts=89266
RTP TX codec=0 seq=1711 ts=89426 len=160
RTP TX seq=1711 ts=89426
RTP TX codec=0 seq=1712 ts=89586 len=160
RTP TX seq=1712 ts=89586
RTP TX codec=0 seq=1713 ts=89746 len=160
RTP TX seq=1713 ts=89746
RTP TX codec=0 seq=1714 ts=89906 len=160
RTP TX seq=1714 ts=89906
RTP TX codec=0 seq=1715 ts=90066 len=160
RTP TX seq=1715 ts=90066
RTP TX codec=0 seq=1716 ts=90226 len=160
RTP TX seq=1716 ts=90226
RTP TX codec=0 seq=1717 ts=90386 len=160
RTP TX seq=1717 ts=90386
RTP TX codec=0 seq=1718 ts=90546 len=160
RTP TX seq=1718 ts=90546


Beep finished
RTP active: 16 packets/sec


After this, I am not receiving any more incoming RTP packets.


Can anyone please help me understand how to resume receiving incoming RTP packets after playing the beep tone?


Thank you.

 

[kd5rxt-mark]

Sketch code ?? It is almost impossible to give any kind of meaningful advice without any clues about what code you are executing !!

Mark J Culross
KD5RXT

 

[Anushka_SS]

Thank you for the reply.

I can’t share my full code here because I’m working on a company project, but I can provide a specific function from the code where I am sending the beep sound to the speaker on the other side.

this is the function for genrate beep sound
void playBeepToIpPhone(uint16_t freqHz = 1000, uint16_t durationMs = 200) {
if (!callActive || remoteRtpPort == 0) return;
Serial.println(" Playing confirmation beep to IP phone");
ipTonePlaying = true;
CodecType toneCodec = activeCodec;
const int sampleRate =
(toneCodec == CODEC_G722) ? 16000 : 8000;
const int frameMs = 20;
const int samplesPerFrame = sampleRate * frameMs / 1000;
int totalSamples = sampleRate * durationMs / 1000;
int16_t pcm[320]; // max needed for G.722
float phase = 0.0f;
float step = 2.0f * PI * freqHz / sampleRate;
bool firstPacket = true;
while (totalSamples > 0) {
int count = min(samplesPerFrame, totalSamples);
for (int i = 0; i < count; i++) {
pcm = (int16_t)(8000.0f * sinf(phase)); // amplitude
phase += step;
if (phase > 2.0f * PI) phase -= 2.0f * PI;
}
// zero-fill if short frame
for (int i = count; i < samplesPerFrame; i++)
pcm = 0;
sendPcmToneAsRtp(
pcm,
samplesPerFrame,
toneCodec,
firstPacket);
firstPacket = false;
totalSamples -= count;
// maintain RTP timing
unsigned long t0 = millis();
while (millis() - t0 < frameMs) {
// handleSipMessages(sipUdp1, "Server1");
// handleRtpAudio();
}
}
ipTonePlaying = false;
resetAudioDecoder = true;
Serial.println(" Beep finished");
}

I am calling this function in my code, and it is working. However, after the message “ Beep finished,” no audio is coming from the phone microphone.

 

[BriComp]

When you post code can you do it between code tags using the </> button.
It preserves formatting and makes the code much more readable. I have included your code below..
I think you will agree there is a world of difference between the two.

By the way it would be SO MUCH BETTER if you could include a small program that can be run which demonstrates your program.
That would make solving your problem so much easier.

void playBeepToIpPhone(uint16_t freqHz = 1000, uint16_t durationMs = 200) {
    if (!callActive || remoteRtpPort == 0) return;
    Serial.println("🔔 Playing confirmation beep to IP phone");
    ipTonePlaying = true;
    CodecType toneCodec = activeCodec;
    const int sampleRate =
        (toneCodec == CODEC_G722) ? 16000 : 8000;
    const int frameMs = 20;
    const int samplesPerFrame = sampleRate * frameMs / 1000;
    int totalSamples = sampleRate * durationMs / 1000;
    int16_t pcm[320]; // max needed for G.722
    float phase = 0.0f;
    float step = 2.0f * PI * freqHz / sampleRate;
    bool firstPacket = true;
    while (totalSamples > 0) {
        int count = min(samplesPerFrame, totalSamples);
        for (int i = 0; i < count; i++) {
            pcm = (int16_t)(8000.0f * sinf(phase)); // amplitude
            phase += step;
            if (phase > 2.0f * PI) phase -= 2.0f * PI;
        }
        // zero-fill if short frame
        for (int i = count; i < samplesPerFrame; i++)
            pcm = 0;
        sendPcmToneAsRtp(
            pcm,
            samplesPerFrame,
            toneCodec,
            firstPacket);
        firstPacket = false;
        totalSamples -= count;
        // maintain RTP timing
        unsigned long t0 = millis();
        while (millis() - t0 < frameMs) {
            // handleSipMessages(sipUdp1, "Server1");
            // handleRtpAudio();
        }
    }
    ipTonePlaying = false;
    resetAudioDecoder = true;
    Serial.println("✅ Beep finished");
}

 

[Anushka_SS]

Okay Thankyou for the suggession I will keep this in mind.