feat: Add audio support for videos with a sound track

Makefile

@@ -12,8 +12,8 @@ PKG_CONFIG ?= pkg-config
 
 SDL_CFLAGS := $(shell $(PKG_CONFIG) --cflags sdl2 SDL2_image)
 SDL_LIBS := $(shell $(PKG_CONFIG) --libs sdl2 SDL2_image)
-FFMPEG_CFLAGS := $(shell $(PKG_CONFIG) --cflags libavformat libavcodec libswscale libavutil)
-FFMPEG_LIBS := $(shell $(PKG_CONFIG) --libs libavformat libavcodec libswscale libavutil)
+FFMPEG_CFLAGS := $(shell $(PKG_CONFIG) --cflags libavformat libavcodec libswscale libswresample libavutil)
+FFMPEG_LIBS := $(shell $(PKG_CONFIG) --libs libavformat libavcodec libswscale libswresample libavutil)
 
 ALL_CFLAGS := $(CFLAGS) $(SDL_CFLAGS) $(FFMPEG_CFLAGS)
 ALL_LIBS := $(LIBS) $(SDL_LIBS) $(FFMPEG_LIBS) -lm
@@ -21,7 +21,7 @@ ALL_LIBS := $(LIBS) $(SDL_LIBS) $(FFMPEG_LIBS) -lm
 BUILD_DIR ?= build
 TARGET = $(BUILD_DIR)/gsplash
 DUMMY_TARGET = $(BUILD_DIR)/dummy_game
-SRC = src/gsplash.c src/video.c
+SRC = src/gsplash.c src/video.c src/audio.c
 DUMMY_SRC = src/dummy_game.c
 
 .PHONY: all clean install uninstall check

src/audio.c

@@ -0,0 +1,208 @@
+#include "audio.h"
+
+#include <string.h>
+#include <libavutil/opt.h>
+
+void audio_callback(void* userdata, uint8_t* stream, int len) {
+  AudioPlayer* player = (AudioPlayer*)userdata;
+  if (!player) {
+    memset(stream, 0, len);
+    return;
+  }
+
+  int bytes_written = 0;
+  while (bytes_written < len) {
+    int remaining = len - bytes_written;
+
+    if (player->audio_buffer_pos >= player->audio_buffer_filled) {
+      int bytes_decoded = decode_audio_frame(player, player->audio_buffer,
+                                             player->audio_buffer_size);
+      if (bytes_decoded <= 0) {
+        memset(stream + bytes_written, 0, remaining);
+        return;
+      }
+      player->audio_buffer_pos = 0;
+      player->audio_buffer_filled = bytes_decoded;
+    }
+
+    int available = player->audio_buffer_filled - player->audio_buffer_pos;
+    int to_copy = (remaining < available) ? remaining : available;
+
+    memcpy(stream + bytes_written,
+           player->audio_buffer + player->audio_buffer_pos, to_copy);
+    bytes_written += to_copy;
+    player->audio_buffer_pos += to_copy;
+  }
+}
+
+bool init_audio_player(AudioPlayer* player, const char* path) {
+  memset(player, 0, sizeof(*player));
+
+  if (avformat_open_input(&player->format_ctx, path, NULL, NULL) != 0) {
+    goto error;
+  }
+
+  if (avformat_find_stream_info(player->format_ctx, NULL) < 0) {
+    goto error;
+  }
+
+  player->stream_index = -1;
+  for (unsigned int i = 0; i < player->format_ctx->nb_streams; ++i) {
+    if (player->format_ctx->streams[i]->codecpar->codec_type ==
+        AVMEDIA_TYPE_AUDIO) {
+      player->stream_index = (int)i;
+      break;
+    }
+  }
+
+  if (player->stream_index < 0) {
+    goto error;
+  }
+
+  AVCodecParameters* codecpar =
+      player->format_ctx->streams[player->stream_index]->codecpar;
+  const AVCodec* decoder = avcodec_find_decoder(codecpar->codec_id);
+  if (!decoder) {
+    goto error;
+  }
+
+  player->codec_ctx = avcodec_alloc_context3(decoder);
+  if (!player->codec_ctx) {
+    goto error;
+  }
+
+  if (avcodec_parameters_to_context(player->codec_ctx, codecpar) < 0) {
+    goto error;
+  }
+
+  if (avcodec_open2(player->codec_ctx, decoder, NULL) < 0) {
+    goto error;
+  }
+
+  player->sample_rate = player->codec_ctx->sample_rate;
+  player->channels = player->codec_ctx->ch_layout.nb_channels;
+
+  player->frame = av_frame_alloc();
+  if (!player->frame) {
+    goto error;
+  }
+
+  player->swr_ctx = swr_alloc();
+  if (!player->swr_ctx) {
+    goto error;
+  }
+
+  av_opt_set_chlayout(player->swr_ctx, "in_chlayout",
+                      &player->codec_ctx->ch_layout, 0);
+  av_opt_set_chlayout(player->swr_ctx, "out_chlayout",
+                      &(AVChannelLayout)AV_CHANNEL_LAYOUT_STEREO, 0);
+  av_opt_set_int(player->swr_ctx, "in_sample_rate", player->sample_rate, 0);
+  av_opt_set_int(player->swr_ctx, "out_sample_rate", player->sample_rate, 0);
+  av_opt_set_sample_fmt(player->swr_ctx, "in_sample_fmt",
+                        player->codec_ctx->sample_fmt, 0);
+  av_opt_set_sample_fmt(player->swr_ctx, "out_sample_fmt", AV_SAMPLE_FMT_S16,
+                        0);
+
+  if (swr_init(player->swr_ctx) < 0) {
+    goto error;
+  }
+
+  player->audio_buffer_size = player->sample_rate * player->channels * 2 *
+                              2;
+  player->audio_buffer = (uint8_t*)av_malloc(player->audio_buffer_size);
+  if (!player->audio_buffer) {
+    goto error;
+  }
+
+  SDL_zero(player->desired_spec);
+  player->desired_spec.freq = player->sample_rate;
+  player->desired_spec.format = AUDIO_S16;
+  player->desired_spec.channels = 2;
+  player->desired_spec.samples = 2048;
+  player->desired_spec.callback = audio_callback;
+  player->desired_spec.userdata = player;
+
+  player->audio_device = SDL_OpenAudioDevice(NULL, 0, &player->desired_spec,
+                                             &player->obtained_spec, 0);
+  if (player->audio_device == 0) {
+    goto error;
+  }
+
+  SDL_PauseAudioDevice(player->audio_device, 0);
+  return true;
+
+error:
+  cleanup_audio_player(player);
+  return false;
+}
+
+void cleanup_audio_player(AudioPlayer* player) {
+  if (player->audio_device != 0) {
+    SDL_CloseAudioDevice(player->audio_device);
+  }
+  if (player->audio_buffer) {
+    av_free(player->audio_buffer);
+  }
+  if (player->swr_ctx) {
+    swr_free(&player->swr_ctx);
+  }
+  if (player->frame) {
+    av_frame_free(&player->frame);
+  }
+  if (player->codec_ctx) {
+    avcodec_free_context(&player->codec_ctx);
+  }
+  if (player->format_ctx) {
+    avformat_close_input(&player->format_ctx);
+  }
+  memset(player, 0, sizeof(*player));
+}
+
+int decode_audio_frame(AudioPlayer* player, uint8_t* out_buffer,
+                       int out_size) {
+  AVPacket* packet = av_packet_alloc();
+  if (!packet) {
+    return -1;
+  }
+
+  while (av_read_frame(player->format_ctx, packet) >= 0) {
+    if (packet->stream_index != player->stream_index) {
+      av_packet_unref(packet);
+      continue;
+    }
+
+    if (avcodec_send_packet(player->codec_ctx, packet) < 0) {
+      av_packet_unref(packet);
+      continue;
+    }
+    av_packet_unref(packet);
+
+    while (true) {
+      int ret = avcodec_receive_frame(player->codec_ctx, player->frame);
+      if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF) {
+        break;
+      }
+      if (ret < 0) {
+        av_packet_free(&packet);
+        return -1;
+      }
+
+      uint8_t* out[] = {out_buffer};
+      int samples = swr_convert(player->swr_ctx, out, out_size / 4,
+                                (const uint8_t**)player->frame->data,
+                                player->frame->nb_samples);
+
+      if (samples > 0) {
+        int bytes_written = samples * 4;
+        av_packet_free(&packet);
+        return bytes_written;
+      }
+    }
+  }
+
+  av_seek_frame(player->format_ctx, player->stream_index, 0,
+                AVSEEK_FLAG_BACKWARD);
+  avcodec_flush_buffers(player->codec_ctx);
+  av_packet_free(&packet);
+  return -1;
+}

src/audio.h

@@ -0,0 +1,33 @@
+#ifndef AUDIO_H
+#define AUDIO_H
+
+#include <SDL2/SDL.h>
+#include <libavcodec/avcodec.h>
+#include <libavformat/avformat.h>
+#include <libavutil/channel_layout.h>
+#include <libswresample/swresample.h>
+#include <stdbool.h>
+
+typedef struct AudioPlayer {
+  AVFormatContext* format_ctx;
+  AVCodecContext* codec_ctx;
+  SwrContext* swr_ctx;
+  AVFrame* frame;
+  int stream_index;
+  int sample_rate;
+  int channels;
+  SDL_AudioDeviceID audio_device;
+  SDL_AudioSpec desired_spec;
+  SDL_AudioSpec obtained_spec;
+  uint8_t* audio_buffer;
+  int audio_buffer_size;
+  int audio_buffer_pos;
+  int audio_buffer_filled;
+} AudioPlayer;
+
+bool init_audio_player(AudioPlayer* player, const char* path);
+void cleanup_audio_player(AudioPlayer* player);
+int decode_audio_frame(AudioPlayer* player, uint8_t* out_buffer, int out_size);
+void audio_callback(void* userdata, uint8_t* stream, int len);
+
+#endif  // AUDIO_H

src/gsplash.c

@@ -11,6 +11,7 @@
 #include <sys/wait.h>
 #include <unistd.h>
 
+#include "audio.h"
 #include "video.h"
 
 static void log_info(const char* fmt, ...) {
@@ -146,8 +147,8 @@ int main(int argc, char* argv[]) {
   log_info("Starting splash: image='%s', game='%s', mode=%d", image_path,
            game_path, render_mode);
 
-  // Initialize SDL2 Video subsystems
-  if (SDL_Init(SDL_INIT_VIDEO) < 0) {
+  // Initialize SDL2 Video and Audio subsystems
+  if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO) < 0) {
     log_error("SDL Init Failed: %s", SDL_GetError());
     return 1;
   }
@@ -176,9 +177,8 @@ int main(int argc, char* argv[]) {
   }
   log_info("Fullscreen borderless window created");
 
-  SDL_ShowCursor(SDL_DISABLE);  // Hide the mouse pointer
+  SDL_ShowCursor(SDL_DISABLE);
 
-  // Create a hardware-accelerated renderer
   SDL_Renderer* renderer =
       SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED);
   if (renderer) {
@@ -186,11 +186,22 @@ int main(int argc, char* argv[]) {
   }
   SDL_Texture* texture = NULL;
   VideoPlayer video_player;
+  AudioPlayer audio_player;
   bool video_active = false;
+  bool audio_active = false;
 
   if (has_video_extension(image_path)) {
     if (init_video_player(&video_player, renderer, image_path)) {
       video_active = true;
+      if (video_player.audio_stream_index >= 0) {
+        if (init_audio_player(&audio_player, image_path)) {
+          audio_active = true;
+          log_info("Audio stream loaded and initialized");
+        } else {
+          log_info(
+              "Video has audio stream but failed to initialize audio player");
+        }
+      }
     } else {
       log_error("Failed to open video '%s'; showing black screen", image_path);
     }
@@ -215,13 +226,18 @@ int main(int argc, char* argv[]) {
     }
     if (!texture && init_video_player(&video_player, renderer, image_path)) {
       video_active = true;
+      if (video_player.audio_stream_index >= 0) {
+        if (init_audio_player(&audio_player, image_path)) {
+          audio_active = true;
+          log_info("Audio stream loaded and initialized");
+        }
+      }
     }
   }
 
   if (!texture && !video_active) {
     log_error("Failed to load splash image '%s': %s; showing black screen",
               image_path, IMG_GetError());
-    // Fallback: Clear to solid black if image file is broken
     SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);
     SDL_RenderClear(renderer);
     SDL_RenderPresent(renderer);
@@ -263,7 +279,6 @@ int main(int argc, char* argv[]) {
   log_info("Launching game executable");
   pid_t pid = fork();
   if (pid == 0) {
-    // Inside Child Process: Hand over execution directly to the game binary
     log_info("Execing game: %s", game_path);
     execvp(game_path, &argv[arg_index + 1]);
     log_error("Failed to launch target game executable '%s': %s", game_path,
@@ -273,14 +288,12 @@ int main(int argc, char* argv[]) {
     log_error("Failed to fork process: %s", strerror(errno));
   } else {
     log_info("Game process started (pid=%d)", pid);
-    // Inside Parent Process: Manage splash screen lifecycle
     int running = 1;
     SDL_Event event;
     bool hide_scheduled = false;
     Uint32 hide_time = 0;
 
     while (running) {
-      // Non-blocking check: Has the game quit?
       int status;
       pid_t result = waitpid(pid, &status, WNOHANG);
       if (result > 0) {
@@ -291,15 +304,14 @@ int main(int argc, char* argv[]) {
         } else {
           log_info("Game exited");
         }
-        break;  // Game closed, break the loop and close the script
+        break;
       } else if (result < 0) {
         log_error("waitpid failed: %s", strerror(errno));
-        break;  // Process error safetynet
+        break;
       }
 
       if (video_active && SDL_GetTicks() >= video_player.next_frame_tick) {
         if (!decode_next_frame(&video_player)) {
-          // If decoding fails or loops, try again on next tick
         }
         video_player.next_frame_tick += (Uint32)video_player.frame_delay_ms;
         Uint32 now = SDL_GetTicks();
@@ -318,22 +330,18 @@ int main(int argc, char* argv[]) {
         SDL_RenderPresent(renderer);
       }
 
-      // Check desktop server window events
       while (SDL_PollEvent(&event)) {
         if (event.type == SDL_QUIT) {
           log_info("Splash dismissed via window close");
           running = 0;
         }
         if (event.type == SDL_WINDOWEVENT) {
-          // THE MOMENT THE GAME WINDOW STEALS FOCUS:
           if (event.window.event == SDL_WINDOWEVENT_FOCUS_LOST &&
               !hide_scheduled) {
             log_info("Splash window hidden (focus lost), scheduling hide");
             hide_scheduled = true;
-            hide_time =
-                SDL_GetTicks() + 100;  // 100ms delay to prevent desktop flash
+            hide_time = SDL_GetTicks() + 100;
           }
-          // Re-render static image when compositor requests a redraw
           if (event.window.event == SDL_WINDOWEVENT_EXPOSED && texture &&
               !video_active) {
             int out_w = 0, out_h = 0;
@@ -354,7 +362,7 @@ int main(int argc, char* argv[]) {
         if (event.type == SDL_KEYDOWN) {
           if (event.key.keysym.sym == SDLK_ESCAPE) {
             log_info("Splash dismissed via escape key");
-            running = 0;  // Emergency escape key loop override
+            running = 0;
           }
         }
       }
@@ -372,7 +380,7 @@ int main(int argc, char* argv[]) {
           SDL_Delay(delay > 33 ? 33 : delay);
         }
       } else {
-        SDL_Delay(33);  // ~30 FPS polling loop to ensure near-zero CPU usage
+        SDL_Delay(33);
       }
     }
   }
@@ -380,6 +388,7 @@ int main(int argc, char* argv[]) {
   // Clean up memory space
   if (texture) SDL_DestroyTexture(texture);
   if (video_active) cleanup_video_player(&video_player);
+  if (audio_active) cleanup_audio_player(&audio_player);
   SDL_DestroyRenderer(renderer);
   SDL_DestroyWindow(window);
   IMG_Quit();

src/video.c

@@ -44,11 +44,15 @@ bool init_video_player(VideoPlayer* player, SDL_Renderer* renderer,
   }
 
   player->stream_index = -1;
+  player->audio_stream_index = -1;
+
   for (unsigned int i = 0; i < player->format_ctx->nb_streams; ++i) {
     if (player->format_ctx->streams[i]->codecpar->codec_type ==
-        AVMEDIA_TYPE_VIDEO) {
+        AVMEDIA_TYPE_VIDEO && player->stream_index < 0) {
       player->stream_index = (int)i;
-      break;
+    } else if (player->format_ctx->streams[i]->codecpar->codec_type ==
+                   AVMEDIA_TYPE_AUDIO && player->audio_stream_index < 0) {
+      player->audio_stream_index = (int)i;
     }
   }
 

src/video.h

@@ -17,6 +17,7 @@ typedef struct VideoPlayer {
   uint8_t* rgba_buffer;
   int rgba_buffer_size;
   int stream_index;
+  int audio_stream_index;
   int width;
   int height;
   int frame_delay_ms;