/* Copyright (C) 1997-2022 Sam Lantinga <slouken@libsdl.org> This software is provided 'as-is', without any express or implied warranty. In no event will the authors be held liable for any damages arising from the use of this software. Permission is granted to anyone to use this software for any purpose, including commercial applications, and to alter it and redistribute it freely. */ #include "SDL.h" #include <stdlib.h> #ifdef __EMSCRIPTEN__ #include <emscripten/emscripten.h> #endif static SDL_Window *window = NULL; static SDL_Renderer *renderer = NULL; static SDL_AudioSpec spec; static SDL_AudioDeviceID devid_in = 0; static SDL_AudioDeviceID devid_out = 0; static void loop() { SDL_bool please_quit = SDL_FALSE; SDL_Event e; while (SDL_PollEvent(&e)) { if (e.type == SDL_QUIT) { please_quit = SDL_TRUE; } else if (e.type == SDL_KEYDOWN) { if (e.key.keysym.sym == SDLK_ESCAPE) { please_quit = SDL_TRUE; } } else if (e.type == SDL_MOUSEBUTTONDOWN) { if (e.button.button == 1) { SDL_PauseAudioDevice(devid_out, SDL_TRUE); SDL_PauseAudioDevice(devid_in, SDL_FALSE); } } else if (e.type == SDL_MOUSEBUTTONUP) { if (e.button.button == 1) { SDL_PauseAudioDevice(devid_in, SDL_TRUE); SDL_PauseAudioDevice(devid_out, SDL_FALSE); } } } if (SDL_GetAudioDeviceStatus(devid_in) == SDL_AUDIO_PLAYING) { SDL_SetRenderDrawColor(renderer, 0, 255, 0, 255); } else { SDL_SetRenderDrawColor(renderer, 255, 0, 0, 255); } SDL_RenderClear(renderer); SDL_RenderPresent(renderer); if (please_quit) { /* stop playing back, quit. */ SDL_Log("Shutting down.\n"); SDL_PauseAudioDevice(devid_in, 1); SDL_CloseAudioDevice(devid_in); SDL_PauseAudioDevice(devid_out, 1); SDL_CloseAudioDevice(devid_out); SDL_DestroyRenderer(renderer); SDL_DestroyWindow(window); SDL_Quit(); #ifdef __EMSCRIPTEN__ emscripten_cancel_main_loop(); #endif exit(0); } /* Note that it would be easier to just have a one-line function that calls SDL_QueueAudio() as a capture device callback, but we're trying to test the API, so we use SDL_DequeueAudio() here. */ while (SDL_TRUE) { Uint8 buf[1024]; const Uint32 br = SDL_DequeueAudio(devid_in, buf, sizeof (buf)); SDL_QueueAudio(devid_out, buf, br); if (br < sizeof (buf)) { break; } } } int main(int argc, char **argv) { /* (argv[1] == NULL means "open default device.") */ const char *devname = argv[1]; SDL_AudioSpec wanted; int devcount; int i; /* Enable standard application logging */ SDL_LogSetPriority(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO); /* Load the SDL library */ if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO) < 0) { SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't initialize SDL: %s\n", SDL_GetError()); return (1); } window = SDL_CreateWindow("testaudiocapture", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 320, 240, 0); renderer = SDL_CreateRenderer(window, -1, 0); SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255); SDL_RenderClear(renderer); SDL_RenderPresent(renderer); SDL_Log("Using audio driver: %s\n", SDL_GetCurrentAudioDriver()); devcount = SDL_GetNumAudioDevices(SDL_TRUE); for (i = 0; i < devcount; i++) { SDL_Log(" Capture device #%d: '%s'\n", i, SDL_GetAudioDeviceName(i, SDL_TRUE)); } SDL_zero(wanted); wanted.freq = 44100; wanted.format = AUDIO_F32SYS; wanted.channels = 1; wanted.samples = 4096; wanted.callback = NULL; SDL_zero(spec); /* DirectSound can fail in some instances if you open the same hardware for both capture and output and didn't open the output end first, according to the docs, so if you're doing something like this, always open your capture devices second in case you land in those bizarre circumstances. */ SDL_Log("Opening default playback device...\n"); devid_out = SDL_OpenAudioDevice(NULL, SDL_FALSE, &wanted, &spec, SDL_AUDIO_ALLOW_ANY_CHANGE); if (!devid_out) { SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't open an audio device for playback: %s!\n", SDL_GetError()); SDL_Quit(); exit(1); } SDL_Log("Opening capture device %s%s%s...\n", devname ? "'" : "", devname ? devname : "[[default]]", devname ? "'" : ""); devid_in = SDL_OpenAudioDevice(argv[1], SDL_TRUE, &spec, &spec, 0); if (!devid_in) { SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't open an audio device for capture: %s!\n", SDL_GetError()); SDL_Quit(); exit(1); } SDL_Log("Ready! Hold down mouse or finger to record!\n"); #ifdef __EMSCRIPTEN__ emscripten_set_main_loop(loop, 0, 1); #else while (1) { loop(); SDL_Delay(16); } #endif return 0; }