example of playing audio in chunk

CMakeLists.txt

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+cmake_minimum_required(VERSION 3.28)
+project(M2-PT-DRP LANGUAGES CXX)
+
+
+set(CMAKE_CXX_STANDARD 20)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+
+
+find_package(PkgConfig REQUIRED)
+pkg_check_modules(MPG123 REQUIRED libmpg123)
+pkg_check_modules(PORTAUDIO REQUIRED portaudio-2.0)
+
+
+add_executable(M2-PT-DRP
+        source/connection.cpp
+        source/stream.cpp
+        source/stream.hpp
+)
+target_include_directories(M2-PT-DRP PRIVATE
+        ${MPG123_INCLUDE_DIRS}
+        ${PORTAUDIO_INCLUDE_DIRS}
+)
+target_link_libraries(M2-PT-DRP PRIVATE
+        ${MPG123_LIBRARIES}
+        ${PORTAUDIO_LIBRARIES}
+)

source/connection.cpp

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+#include "connection.hpp"
+
+
+#include <chrono>
+#include <stdexcept>
+#include <string>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netdb.h>
+
+
+/*
+int main(int argc, char* argv[]) {
+    // create an IPv6 socket based on datagram (UDP)
+    const int serverSocket = socket(
+        AF_INET6,
+        SOCK_DGRAM,
+        0
+    );
+
+    // get the broadcast address
+    addrinfo broadcastAddressConfig = {};
+    broadcastAddressConfig.ai_family = AF_INET6;
+    broadcastAddressConfig.ai_socktype = SOCK_DGRAM;
+    broadcastAddressConfig.ai_protocol = IPPROTO_UDP;
+
+    addrinfo *broadcastAddress;
+    if(!getaddrinfo(
+        "ff02::1",  // multicast address
+        "5650",  // our port
+        &broadcastAddressConfig,
+        &broadcastAddress
+    ))
+        throw std::runtime_error("Could not get the address.");
+
+    const std::string message = "Salut !";
+
+    // broadcast the message
+    if (sendto(
+        serverSocket,
+        message.c_str(),
+        message.size(),
+        0,
+        broadcastAddress->ai_addr,
+        broadcastAddress->ai_addrlen
+    ) == -1)
+        throw std::runtime_error("Could not broadcast the message.");
+
+    return 0;
+}
+*/

source/connection.hpp

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+#pragma once

source/stream.cpp

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+#include "stream.hpp"
+
+#include <algorithm>
+#include <chrono>
+#include <cstdint>
+#include <iostream>
+#include <stdexcept>
+#include <vector>
+
+#include <openssl/aes.h>
+#include <mpg123.h>
+#include <portaudio.h>
+
+
+int main(int argc, char* argv[]) {
+    // initialize the mpg123 library
+    if (mpg123_init() != MPG123_OK)
+        throw std::runtime_error("Error while initializing mpg123.");
+
+    // create a new mpg123 handle
+    int error;
+    mpg123_handle* mpgHandle = mpg123_new(nullptr, &error);
+
+    // open the mp3 file
+    if (mpg123_open(mpgHandle, "./assets/Caravan Palace - Wonderland.mp3"))
+        throw std::runtime_error("Could not open file.");
+
+    // get the format of the file
+    long rate;
+    int channels;
+    int encoding;
+    mpg123_getformat(mpgHandle, &rate, &channels, &encoding);
+    printf("rate: %ld, channels: %d, encoding: %d\n", rate, channels, encoding);
+
+    // ---
+
+    // initialize the PortAudio library
+    if (Pa_Initialize() != paNoError)
+        throw std::runtime_error("Could not initialize PortAudio.");
+
+    // open the PortAudio stream
+    PaStream* stream;
+    if (Pa_OpenDefaultStream(
+        &stream,
+        0,
+        channels,
+        paInt16,
+        static_cast<double>(rate),
+        512,
+        nullptr,
+        nullptr
+    ) != paNoError)
+        throw std::runtime_error("Could not open PortAudio stream.");
+
+    // start the PortAudio stream
+    if (Pa_StartStream(stream) != paNoError)
+        throw std::runtime_error("Could not start the PortAudio stream.");
+
+    // ---
+
+    // read the file
+    std::vector<std::uint8_t> buffer(4096);
+    std::size_t done;
+    std::size_t i = 0;
+
+    while ((error = mpg123_read(mpgHandle, buffer.data(), buffer.size(), &done)) == MPG123_OK) {
+        // write the audio data to the PortAudio stream
+        if ((error = Pa_WriteStream(stream, buffer.data(), done / 2 / channels)) != paNoError)
+            throw std::runtime_error(
+                "Could not write audio data in the PortAudio stream.\n" +
+                std::string(Pa_GetErrorText(error))
+            );
+
+        printf("write (%04lu)\n", i++);
+    }
+
+    // display the error message
+    std::printf(mpg123_plain_strerror(error));
+
+    // Stop the audio stream
+    Pa_StopStream(stream);
+    Pa_CloseStream(stream);
+
+    // delete the mpg123 handle
+    mpg123_close(mpgHandle);
+    mpg123_delete(mpgHandle);
+
+    // free the libraries
+    Pa_Terminate();
+    mpg123_exit();
+
+    return error;
+}

source/stream.hpp

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+#pragma once