OpenAL how to load an Ogg Vorbis file and play it

sound.c

// Created by: http://github.com/tilkinsc


// returns ALuint* aka a single openal buffer of ready-to-play ogg vorbis sound samples
// returns 0 on error
ALuint* sound_load_ogg(const char* path) {
	ALenum error = 0;
	ALuint* sound = 0;
	FILE* fp = 0;
	OggVorbis_File vf;
	vorbis_info* vi = 0;
	ALenum format = 0;
	short* pcmout = 0;
	
  // open the file in read binary mode
	fp = fopen(path, "rb");
	if(fp == 0) {
		fprintf(stderr, "Could not open file `%s`\n", path);
		goto exit;
	}
	
  // make a handle
	sound = malloc(1 * sizeof(ALuint));
	if(sound == 0) {
		fprintf(stderr, "Out of memory.");
		goto exit;
	}
	
  // make a buffer
	alGenBuffers(1, sound);
	
  // check for errors
	if((error = alGetError()) != AL_NO_ERROR) {
		fprintf(stderr, "Failed to generate sound buffer %d\n", error);
		goto exit;
	}
	
	// open the ogg vorbis file. This is a must on windows, do not use ov_open.
  // set OV_CALLBACKS_NOCLOSE else it will close your fp when ov_close() is reached, which is fine.
	if(ov_open_callbacks(fp, &vf, NULL, 0, OV_CALLBACKS_NOCLOSE) < 0) {
		fprintf(stderr, "Stream is not a valid OggVorbis stream!\n");
		goto exit;
	}
	
	
  // fill vi with a new ogg vorbis info struct, determine audio format
  // audio format will always been a length of 16bits, vi->channels determines mono or stereo
	vi = ov_info(&vf, -1);
	format = vi->channels == 1 ? AL_FORMAT_MONO16 : AL_FORMAT_STEREO16;
	
  // data_len is the amount of data to read, allocate said data space
  // this is calculated by (samples * channels * 2 (aka 16bits))
	size_t data_len = ov_pcm_total(&vf, -1) * vi->channels * 2;
	pcmout = malloc(data_len);
	if(pcmout == 0) {
		fprintf(stderr, "Out of memory.\n");
		goto exit;
	}
	
  // fill pcmout buffer with ov_read data samples
  // you can't just slap data_len in place of 4096, it doesn't work that way
  // 0 is endianess, 0 for little, 1 for big
  // 2 is the data type short's size, mine is 2
  // 1 is the signedness you want, I want short not unsigned short (for openal) so 1
	for (size_t size = 0, offset = 0, sel = 0;
			(size = ov_read(&vf, (char*) pcmout + offset, 4096, 0, 2, 1, (int*) &sel)) != 0;
			offset += size) {
		if(size < 0)
			puts("Faulty ogg file :o"); // use https://xiph.org/vorbis/doc/vorbisfile/ov_read.html for handling enums
	}
	
  // send data to openal, vi->rate is your freq in Hz, dont assume 44100
	alBufferData(*sound, format, pcmout, data_len, vi->rate);
	if ((error = alGetError()) != AL_NO_ERROR) {
		printf("Failed to send audio information buffer to OpenAL! 0x%06x\n", error);
		goto exit;
	}
	
  // free your resources >:(
	free(pcmout);
	fclose(fp);
	ov_clear(&vf);
	return sound;
	
exit:
	free(pcmout);
	free(sound);
	fclose(fp);
	ov_clear(&vf);
	return 0;
}