Add Vorbis decoder

Additionally implemented better handling of the playback stopping
procedure.

Signed-off-by: Mahyar Koshkouei <mk@deltabeard.com>

source/vorbis.c

@@ -0,0 +1,151 @@
+#include <3ds.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "vorbis.h"
+#include "playback.h"
+
+static OggVorbis_File	vorbisFile;
+static vorbis_info		*vi;
+static int				current_section;
+static FILE				*f;
+static const size_t		buffSize = 8 * 4096;
+
+/**
+ * Set decoder parameters for Vorbis.
+ *
+ * \param	decoder	Structure to store parameters.
+ */
+void setVorbis(struct decoder_fn* decoder)
+{
+	decoder->init = &initVorbis;
+	decoder->rate = &rateVorbis;
+	decoder->channels = &channelVorbis;
+	decoder->buffSize = buffSize;
+	decoder->decode = &decodeVorbis;
+	decoder->exit = &exitVorbis;
+}
+
+/**
+ * Initialise Vorbis decoder.
+ *
+ * \param	file	Location of vorbis file to play.
+ * \return			0 on success, else failure.
+ */
+int initVorbis(const char* file)
+{
+	int err = -1;
+	f = fopen(file, "r");
+
+	if(ov_open(f, &vorbisFile, NULL, 0) < 0)
+		goto out;
+
+	if((vi = ov_info(&vorbisFile, -1)) == NULL)
+		goto out;
+
+	current_section = 0;
+	err = 0;
+
+out:
+	return err;
+}
+
+/**
+ * Get sampling rate of Vorbis file.
+ *
+ * \return	Sampling rate.
+ */
+uint32_t rateVorbis(void)
+{
+	printf("Rate: %ld\n", vi->rate);
+	return vi->rate;
+}
+
+/**
+ * Get number of channels of Vorbis file.
+ *
+ * \return	Number of channels for opened file.
+ */
+uint8_t channelVorbis(void)
+{
+	printf("Rate: %d\n", vi->channels);
+	return vi->channels;
+}
+
+/**
+ * Decode part of open Vorbis file.
+ *
+ * \param buffer	Decoded output.
+ * \return			Samples read for each channel. 0 for end of file, negative
+ *					for error.
+ */
+uint64_t decodeVorbis(void* buffer)
+{
+	return fillVorbisBuffer(buffer);
+}
+
+/**
+ * Free Vorbis decoder.
+ */
+void exitVorbis(void)
+{
+	fclose(f);
+	ov_clear(&vorbisFile);
+}
+
+/**
+ * Decode Vorbis file to fill buffer.
+ *
+ * \param opusFile		File to decode.
+ * \param bufferOut		Pointer to buffer.
+ * \return				Samples read per channel.
+ */
+uint64_t fillVorbisBuffer(char* bufferOut)
+{
+	uint64_t samplesRead = 0;
+	int samplesToRead = buffSize;
+
+	while(samplesToRead > 0)
+	{
+		int samplesJustRead =
+			ov_read(&vorbisFile, bufferOut, samplesToRead, &current_section);
+
+		if(samplesJustRead < 0)
+			return samplesJustRead;
+		else if(samplesJustRead == 0)
+		{
+			/* End of file reached. */
+			break;
+		}
+
+		samplesRead += samplesJustRead * 2;
+		samplesToRead -= samplesJustRead * 2;
+		bufferOut += samplesJustRead * 2;
+	}
+
+	return samplesRead;
+}
+
+/**
+ * Checks if the input file is Vorbis.
+ *
+ * \param in	Input file.
+ * \return		0 if Vorbis file, else not or failure.
+ */
+int isVorbis(const char *in)
+{
+	// TODO: Only free if a new file is selected to play.
+	FILE *ft = fopen(in, "r");
+	OggVorbis_File testvf;
+	int err;
+
+	if(ft == NULL)
+		return -1;
+
+	err = ov_test(ft, &testvf, NULL, 0);
+
+	fclose(ft);
+	ov_clear(&testvf);
+	return err;
+}