Recently I discovered the Micro-RTSP-Audio Project from Thomas Pfitzinger which is based on Micro-RTSP from Kevin Hester.
The Real Time Streaming Protocol (RTSP) is an application-level network communication system that transfers real-time data from multimedia to an endpoint device by communicating directly with the server streaming the data.
I tried to adapt the library to make sure that it is also compiling in Arduino and converted the example to comply with the Arduino conventions. However when I started to test it, I was running into memory errors and I spent almost a full day looking at the source code trying to figure out what could be wrong and while doing this, I took the chance to perform some optimizations.
In the end it turned out that the issue was not in the library code but in the provided example: some objects where allocated on the stack and after the setup method, these objects were not valid any more!
My updated Micro-RTSP-Audio Library can be found on Github and the example is working now and I am providing an nice integration into my Audio Tools Library:
Arduino Sketch
#include "AudioTools.h"
#include "AudioLibs/RTSPStream.h"
#include "AudioStreamer.h"
#include "RTSPServer.h"
int port = 554;
int channels = 1;
int sample_rate = 16000;
int bits_per_sample = 16;
const char* wifi = "wifi";
const char* password = "password";
SineFromTable<int16_t> sineWave(32000); // subclass of SoundGenerator
GeneratedSoundStream<int16_t> sound(sineWave); // Stream generated from sine wave
RTSPSourceAudioStream source(sound); // Stream sound via RTSP
AudioStreamer streamer = AudioStreamer(&source);
RTSPServer rtsp = RTSPServer(&streamer, port);
void setup() {
Serial.begin(115200);
AudioLogger::instance().begin(Serial, AudioLogger::Info);
// Setup sine wave
auto cfgS = sineWave.defaultConfig();
cfgS.channels = channels;
cfgS.sample_rate = sample_rate;
cfgS.bits_per_sample = bits_per_sample;
sineWave.begin(cfgS, N_B4);
// Start Wifi & RTSP
rtsp.begin(wifi, password);
}
void loop() { delay(1000); }
This example can be found on Github.
To listen to the generated sound you can use the VLC Media Player. Goto -> File -> Open Network and enter the URL rtsp://server-address
Caveat: Please note that currently only the sampling rate 16000 with 1 channel is supported!
18 Comments
Jérôme · 6. April 2023 at 1:26
Do you think it is possible to combine rtsp audio and video on an esp32 cam? That will be really awesome.
pschatzmann · 14. April 2023 at 7:08
No, audio will only work with very low sampling rates.
So I don’t expect that it will work if you add video…
Jérôme · 4. April 2023 at 15:44
Hello, I have uploaded the sketch example streams-i2s-webserver_wav but the sound of the microphone through the web page only crackles. I use EPS32-WROOM-32 and INMP411 Microphone. I tried with another INMP411 freshly bought but same result. Do you have any ideas?
pschatzmann · 4. April 2023 at 15:57
Please check the discussions about the INMP411 the on Github.
Jérôme · 31. March 2023 at 12:37
Also wanted to know if it is possible to live stream audio from INMP441 microphone using rtsp or this is only possible via http (like your streams-i2s-webserver_wav exemple)
pschatzmann · 31. March 2023 at 15:24
Sure, here is an example which was using the I2S from the AudioKit: https://github.com/pschatzmann/arduino-audio-tools/blob/main/examples/examples-communication/rtsp/communication-audiokit-rtsp/communication-audiokit-rtsp.ino
Jérôme · 31. March 2023 at 15:58
Awesome! Thanks a lot!
Jérôme · 31. March 2023 at 12:15
Hello Phil, thanks a lot for your share.
How can I know the rtsp://server-address?
How the server-address is provided? Is it possible to change it?
pschatzmann · 31. March 2023 at 12:20
Of cause, it is the tcp/ip address of the ESP32! The port is specified in the sketch.
You can register your own name with mDNS but this has nothing to do with this functionality.
Jérôme · 31. March 2023 at 12:54
Thanks for your fast answer! Ok so I need to define so where that I want to use the Wifi Station mode (to get an IP address from my router). I will check in your project where to change that 🙂
Jérôme · 31. March 2023 at 21:40
I really don’t find where to configure the Wifi parameter to use the station mode :-/ Can you give me some help?
pschatzmann · 31. March 2023 at 22:03
There is nothing to configure. It is by default in station mode.
Anything else does not make a lot of sense…
Jérôme · 1. April 2023 at 9:46
Thanks! I made it works with streams-i2s-webserver_wav 🙂 next step rtsp. Have a nice day.
Mira · 30. November 2022 at 0:02
hello,
my ArduinoIDE (1.8.19) write error:
“C:\Arduino ESP32\portable\sketchbook\libraries\arduino-audio-tools-main\src/AudioLibs/AudioKit.h:4:25: fatal error: AudioKitHAL.h: No such file or directory”
I have installed both linked libraries “updated Micro-RTSP-Audio Library” and “my Audio Tools Library”.
Where can i found “AudioKitHAL.h”, please?
Thank you
pschatzmann · 30. November 2022 at 8:05
Actually, The audiokit is not necesseary and this will work on any ESP32, so I corrected the sketch.
If you still want to include the library, it can be found here https://github.com/pschatzmann/arduino-audiokit
Han · 12. October 2022 at 9:43
Hello, i enjoyed reading it! thanks for sharing.
i have question might be ridiculous, if i stopped the stream, am i be able to view the previous streams?
pschatzmann · 12. October 2022 at 11:14
I don’t know. I guess this depends on the software that you use…
Arduino Audio Tools - RTSP Revisited - Phil Schatzmann · 2. April 2023 at 18:06
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