Add MP3 Support

Signed-off-by: Mahyar Koshkouei <deltabeard@users.noreply.github.com>

Makefile

@@ -49,7 +49,7 @@ SOURCE_DIRS := source
 EXTRA_OUTPUT_FILES :=
 
 LIBRARY_DIRS := $(DEVKITPRO)/libctru $(DEVKITPRO)/portlibs/armv6k
-LIBRARIES := opusfile opus ogg ctru m
+LIBRARIES := mpg123 opusfile opus ogg ctru m
 
 BUILD_FLAGS :=
 RUN_FLAGS :=

source/all.h

@@ -4,7 +4,7 @@
 #define CHANNEL	0x08
 
 /* Adds extra debugging text */
-#define DEBUG	0
+#define DEBUG
 
 /* Prints more error information */
 #define err_print(err) \

source/flac.c

@@ -25,8 +25,10 @@ int playFlac(const char* in)
 		goto out;
 	}
 
+#ifdef DEBUG
 	printf("\nRate: %lu\tChan: %d\n", pFlac->sampleRate,
 			pFlac->channels);
+#endif
 
 	ndspChnReset(CHANNEL);
 	ndspChnWaveBufClear(CHANNEL);

source/main.c

@@ -18,6 +18,7 @@
 #include "all.h"
 #include "flac.h"
 #include "main.h"
+#include "mp3.h"
 #include "opus.h"
 #include "wav.h"
 
@@ -31,7 +32,8 @@ enum file_types {
 	FILE_TYPE_WAV,
 	FILE_TYPE_FLAC,
 	FILE_TYPE_OGG,
-	FILE_TYPE_OPUS
+	FILE_TYPE_OPUS,
+	FILE_TYPE_MP3
 };
 
 int main(int argc, char **argv)
@@ -85,9 +87,11 @@ int main(int argc, char **argv)
 		if(kDown & KEY_START)
 			break;
 
+#ifdef DEBUG
 		consoleSelect(&topScreen);
 		printf("\rNum: %d, Max: %d, from: %d   ", fileNum, fileMax, from);
 		consoleSelect(&bottomScreen);
+#endif
 
 		if((kHeld & KEY_UP) && fileNum > 0)
 		{
@@ -211,6 +215,10 @@ int main(int argc, char **argv)
 							playOpus(file);
 							break;
 
+						case FILE_TYPE_MP3:
+							playMp3(file);
+							break;
+
 						default:
 							consoleSelect(&bottomScreen);
 							printf("Unsupported File type.\n");
@@ -413,6 +421,20 @@ int getFileType(const char *file)
 			}
 
 			break;
+
+		default:
+			/*
+			 * MP3 without ID3 tag, ID3v1 tag is at the end of file, or MP3
+			 * with ID3 tag at the beginning  of the file.
+			 */
+			if((fileSig << 16) == 0xFBFF0000 || (fileSig << 8) == 0x33444900)
+			{
+				puts("File type is MP3.");
+				file_type = FILE_TYPE_MP3;
+				break;
+			}
+
+			printf("Unknown magic number: %#010x\n.", fileSig);
 	}
 
 	fclose(ftest);

source/mp3.c

@@ -0,0 +1,159 @@
+#include <3ds.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "all.h"
+#include "mp3.h"
+
+int playMp3(const char* in)
+{
+	int				err = 0;
+	mpg123_handle	*mh = NULL;
+	size_t			buffer_size = 0;
+	size_t			done = 0;
+	long			rate = 0;
+	int				channels = 0;
+	int				encoding = 0;
+	unsigned char*	buffer1 = NULL;
+	unsigned char*	buffer2 = NULL;
+	int				ret = 0;
+	ndspWaveBuf		waveBuf[2];
+	bool			playing = true;
+	bool			lastbuf = false;
+
+	if(R_FAILED(ndspInit()))
+	{
+		printf("Initialising ndsp failed.");
+		goto out;
+	}
+
+	if((err = mpg123_init()) != MPG123_OK)
+		return err;
+
+	if((mh = mpg123_new(NULL, &err)) == NULL)
+	{
+		printf("Error: %s\n", mpg123_plain_strerror(err));
+		goto err;
+	}
+
+	if(mpg123_open(mh, in) != MPG123_OK ||
+			mpg123_getformat(mh, &rate, &channels, &encoding) != MPG123_OK)
+	{
+		printf("Trouble with mpg123: %s\n", mpg123_strerror(mh));
+		goto err;
+	}
+
+	/* Ensure that this output format will not change
+	   (it might, when we allow it). */
+	mpg123_format_none(mh);
+	mpg123_format(mh, rate, channels, encoding);
+
+	/* Buffer could be almost any size here, mpg123_outblock() is just some
+	   recommendation. The size should be a multiple of the PCM frame size. */
+	buffer_size = mpg123_outblock(mh) * 16;
+	buffer1 = linearAlloc(buffer_size);
+	buffer2 = linearAlloc(buffer_size);
+
+	/* I'm not sure if this error will ever occur. */
+	if(channels > 2)
+	{
+		printf("Invalid number of channels %d\n", channels);
+		goto err;
+	}
+
+	ndspChnReset(CHANNEL);
+	ndspChnWaveBufClear(CHANNEL);
+	ndspSetOutputMode(NDSP_OUTPUT_STEREO);
+	ndspChnSetInterp(CHANNEL, NDSP_INTERP_POLYPHASE);
+	ndspChnSetRate(CHANNEL, rate);
+	ndspChnSetFormat(CHANNEL,
+			channels == 2 ? NDSP_FORMAT_STEREO_PCM16 : NDSP_FORMAT_MONO_PCM16);
+
+	memset(waveBuf, 0, sizeof(waveBuf));
+
+	mpg123_read(mh, buffer1, buffer_size, &done);
+	waveBuf[0].nsamples = done / (sizeof(s16) * channels);
+	waveBuf[0].data_vaddr = &buffer1[0];
+	ndspChnWaveBufAdd(CHANNEL, &waveBuf[0]);
+
+	mpg123_read(mh, buffer2, buffer_size, &done);
+	waveBuf[1].nsamples = done / (sizeof(s16) * channels);
+	waveBuf[1].data_vaddr = &buffer2[0];
+	ndspChnWaveBufAdd(CHANNEL, &waveBuf[1]);
+
+	printf("Playing %s\n", in);
+	/**
+	 * There may be a chance that the music has not started by the time we get
+	 * to the while loop. So we ensure that music has started here.
+	 */
+	while(ndspChnIsPlaying(CHANNEL) == false);
+
+	while(playing == false || ndspChnIsPlaying(CHANNEL) == true)
+	{
+		u32 kDown;
+
+		gfxSwapBuffers();
+		gfxFlushBuffers();
+		gspWaitForVBlank();
+
+		hidScanInput();
+		kDown = hidKeysDown();
+
+		if(kDown & KEY_B)
+			break;
+
+		if(kDown & (KEY_A | KEY_R))
+		{
+			playing = !playing;
+			printf("\33[2K\r%s", playing == false ? "Paused" : "");
+		}
+
+		if(playing == false || lastbuf == true)
+			continue;
+
+		if(waveBuf[0].status == NDSP_WBUF_DONE)
+		{
+			err = mpg123_read(mh, buffer1, buffer_size, &done);
+
+			if(err != MPG123_OK)
+			{
+				lastbuf = true;
+				continue;
+			}
+
+			ndspChnWaveBufAdd(CHANNEL, &waveBuf[0]);
+		}
+
+		if(waveBuf[1].status == NDSP_WBUF_DONE)
+		{
+			err = mpg123_read(mh, buffer2, buffer_size, &done);
+
+			if(err != MPG123_OK)
+			{
+				lastbuf = true;
+				continue;
+			}
+
+			ndspChnWaveBufAdd(CHANNEL, &waveBuf[1]);
+		}
+
+		DSP_FlushDataCache(buffer1, buffer_size);
+		DSP_FlushDataCache(buffer2, buffer_size);
+	}
+
+out:
+	linearFree(buffer1);
+	linearFree(buffer2);
+	ndspChnWaveBufClear(CHANNEL);
+	ndspExit();
+	mpg123_close(mh);
+	mpg123_delete(mh);
+	mpg123_exit();
+	printf("\nStopping MP3 playback.\n");
+	return ret;
+
+err:
+	ret = -1;
+	goto out;
+}

source/mp3.h

@@ -0,0 +1,3 @@
+#include <mpg123.h>
+
+int playMp3(const char* in);

source/opus.c

@@ -38,8 +38,10 @@ int playOpus(const char* in)
 	}
 
 	opusHead = op_head(opusFile, link);
+#ifdef DEBUG
 	printf("\nRate: %lu\tChan: %d\n", opusHead->input_sample_rate,
 			opusHead->channel_count);
+#endif
 
 	ndspChnReset(CHANNEL);
 	ndspChnWaveBufClear(CHANNEL);