add source code

CMakeLists.txt

@@ -0,0 +1,8 @@
+cmake_minimum_required(3.10)
+project(sdl-pcm LANGUAGE C)
+
+find_package(SDL2 REQUIRED)
+
+add_executable(${PROJECT_NAME} main.c)
+
+target_link_libraries(${PROJECT_NAME} PRIVATE SDL2::SDL2)

main.c

@@ -0,0 +1,45 @@
+#include <SDL2/SDL.h>
+#include <SDL2/SDL_audio.h>
+#include <SDL2/SDL_error.h>
+#include <stddef.h>
+#include <stdio.h>
+
+#define PCM_BUF_SIZE (1024*2*2*2)
+
+static Uint8 *s_audio_buf = NULL;
+static Uint8 *s_audio_pos = NULL;
+static Uint8 *s_audio_end = NULL;
+
+void audo_pcm_callback(void *data, Uint8 *stream, int len) {
+    SDL_memset(stream, 0, len);
+
+    if (s_audio_pos >= s_audio_end) {
+        return;
+    }
+
+    int remain_buffer_len = s_audio_end - s_audio_pos;
+    len = (len < remain_buffer_len) ? len : remain_buffer_len;
+
+    SDL_MixAudio(stream, s_audio_pos, len, SDL_MIX_MAXVOLUME/8);
+    s_audio_pos += len;
+}
+
+#undef main
+int main(int argc, char* argv[]) {
+    int ret = -1;
+    FILE *audio_fd = NULL;
+    SDL_AudioSpec spec;
+    const char *path = "44100_16bit_2ch.pcm";
+    size_t read_buffer_len = 0;
+
+    if (SDL_Init(SDL_INIT_AUDIO)) {
+        fprintf(stderr, "SDL_Init(SDL_INIT_AUDIO) failed: %s\n", SDL_GetError());
+        return ret;
+    }
+
+    audio_fd = fopen(path, "rb");
+    if (!audio_fd) {
+        fprintf(stderr, "fopen(path, \"rb\")\n");
+        goto fail;
+    }
+}