fruitywav.cpp

// fruitywav.cpp - extracts ogg files from FruityLoops .wav files

#include <cstdio>
#include <cstring>
#include <iostream>
#include <memory>
#include <stdint.h>
#include <sys/fcntl.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <unistd.h>

class FileMapping {
public:
  FileMapping(const char *path) {
    if ((fd = open(path, O_RDONLY)) != -1)
      if (struct stat st; stat(path, &st) == 0)
        if ((ptr = mmap(nullptr, (len = st.st_size), PROT_READ,
                        MAP_FILE | MAP_SHARED, fd, 0)) == MAP_FAILED)
          ptr = nullptr;
  }

  ~FileMapping() { close(); }

  void close() {
    if (ptr)
      munmap(ptr, len);
    if (fd != -1)
      ::close(fd);
    fd = -1;
    len = 0;
    ptr = nullptr;
  }

  const void *data() { return ptr; }
  size_t size() { return len; }

private:
  size_t len;
  int fd;
  void *ptr{nullptr};
};

int16_t read_int16_le(const uint8_t *data) {
  return (data[0] << 0) | (data[1] << 8);
}

int32_t read_int32_le(const uint8_t *data) {
  return (data[0] << 0) | (data[1] << 8) | (data[2] << 16) | (data[3] << 24);
}

void process_file(const char *path) {
  FileMapping mapping(path);

  auto data = (const uint8_t *)mapping.data();
  if (!data)
    return (void)fprintf(stderr, "Could not open file: %s\n", path);

  if (memcmp(data, "RIFF", 4))
    return (void)fprintf(stderr, "Unsupported file type\n");

  bool isOgg = false;
  auto fileSize = read_int32_le(data + 4);
  auto end = data + fileSize - 8;
  auto chunk = data + 12;
  while (chunk < end) {
    auto chunkSize = read_int32_le(chunk + 4);
    if (!memcmp(chunk, "fmt ", 4)) {
      int16_t format = read_int16_le(chunk + 8);
      if (format == 0x674f || // WAVE_FORMAT_OGG_VORBIS_MODE_1
          format == 0x6750 || // WAVE_FORMAT_OGG_VORBIS_MODE_2
          format == 0x6751 || // WAVE_FORMAT_OGG_VORBIS_MODE_3
          format == 0x676f || // WAVE_FORMAT_OGG_VORBIS_MODE_1_PLUS
          format == 0x6770 || // WAVE_FORMAT_OGG_VORBIS_MODE_2_PLUS
          format == 0x6771)   // WAVE_FORMAT_OGG_VORBIS_MODE_3_PLUS
        isOgg = true;
    }
    if (isOgg && !memcmp(chunk, "data", 4)) {
      char *outpath = strdup(path);
      strcpy(outpath + strlen(path) - 4, ".ogg");
      printf("Extracting %s\n", outpath);
      FILE *file = fopen(outpath, "wb");
      fwrite(chunk + 8, 1, chunkSize, file);
      fclose(file);
      free(outpath);
      return;
    }
    chunk += 8 + ((chunkSize + 1) & ~1);
  }
}

int main(int argc, char **argv) {
  for (int i = 1; i < argc; i++)
    process_file(argv[i]);
  return 0;
}