decoder: use bool for return values and flags

Don't return 0/-1 on success/error, but true/false.  Instead of int,
use bool for storing flags.

18 files changed, 148 insertions, 144 deletions

diff --git a/src/decoder/aac_plugin.c b/src/decoder/aac_plugin.c
index 8ceed8b2b..8ae061667 100644
--- a/src/decoder/aac_plugin.c
+++ b/src/decoder/aac_plugin.c
@@ -34,7 +34,7 @@ typedef struct {
 	size_t bytesConsumed;
 	off_t fileOffset;
 	unsigned char *buffer;
-	int atEof;
+	bool atEof;
 } AacBuffer;
 
 static void aac_buffer_shift(AacBuffer * b, size_t length)
@@ -68,7 +68,7 @@ static void fillAacBuffer(AacBuffer * b)
 				     (void *)(b->buffer + b->bytesIntoBuffer),
 				     rest);
 		if (bread == 0 && input_stream_eof(b->inStream))
-			b->atEof = 1;
+			b->atEof = true;
 		b->bytesIntoBuffer += bread;
 	}
 
@@ -301,8 +301,8 @@ static int getAacTotalTime(char *file)
 	return file_time;
 }
 
-static int aac_stream_decode(struct decoder * mpd_decoder,
-			     struct input_stream *inStream)
+static bool
+aac_stream_decode(struct decoder *mpd_decoder, struct input_stream *inStream)
 {
 	float file_time;
 	float totalTime = 0;
@@ -318,7 +318,7 @@ static int aac_stream_decode(struct decoder * mpd_decoder,
 	size_t sampleBufferLen;
 	uint16_t bitRate = 0;
 	AacBuffer b;
-	int initialized = 0;
+	bool initialized = false;
 
 	initAacBuffer(&b, mpd_decoder, inStream);
 
@@ -354,7 +354,7 @@ static int aac_stream_decode(struct decoder * mpd_decoder,
 		faacDecClose(decoder);
 		if (b.buffer)
 			free(b.buffer);
-		return -1;
+		return false;
 	}
 
 	audio_format.bits = 16;
@@ -363,7 +363,7 @@ static int aac_stream_decode(struct decoder * mpd_decoder,
 
 	advanceAacBuffer(&b, bread);
 
-	while (1) {
+	while (true) {
 		fillAacBuffer(&b);
 		adts_find_frame(&b);
 		fillAacBuffer(&b);
@@ -392,7 +392,7 @@ static int aac_stream_decode(struct decoder * mpd_decoder,
 			audio_format.channels = frameInfo.channels;
 			audio_format.sample_rate = sample_rate;
 			decoder_initialized(mpd_decoder, &audio_format, totalTime);
-			initialized = 1;
+			initialized = true;
 		}
 
 		advanceAacBuffer(&b, frameInfo.bytesconsumed);
@@ -424,17 +424,18 @@ static int aac_stream_decode(struct decoder * mpd_decoder,
 		free(b.buffer);
 
 	if (!initialized)
-		return -1;
+		return false;
 
 	if (decoder_get_command(mpd_decoder) == DECODE_COMMAND_SEEK) {
 		decoder_seek_error(mpd_decoder);
 	}
 
-	return 0;
+	return true;
 }
 
 
-static int aac_decode(struct decoder * mpd_decoder, char *path)
+static bool
+aac_decode(struct decoder *mpd_decoder, char *path)
 {
 	float file_time;
 	float totalTime;
@@ -454,13 +455,13 @@ static int aac_decode(struct decoder * mpd_decoder, char *path)
 	uint16_t bitRate = 0;
 	AacBuffer b;
 	struct input_stream inStream;
-	int initialized = 0;
+	bool initialized = false;
 
 	if ((totalTime = getAacFloatTotalTime(path)) < 0)
-		return -1;
+		return false;
 
 	if (!input_stream_open(&inStream, path))
-		return -1;
+		return false;
 
 	initAacBuffer(&b, mpd_decoder, &inStream);
 	aac_parse_header(&b, NULL);
@@ -490,7 +491,7 @@ static int aac_decode(struct decoder * mpd_decoder, char *path)
 		faacDecClose(decoder);
 		if (b.buffer)
 			free(b.buffer);
-		return -1;
+		return false;
 	}
 
 	audio_format.bits = 16;
@@ -499,7 +500,7 @@ static int aac_decode(struct decoder * mpd_decoder, char *path)
 
 	advanceAacBuffer(&b, bread);
 
-	while (1) {
+	while (true) {
 		fillAacBuffer(&b);
 
 		if (b.bytesIntoBuffer == 0)
@@ -527,7 +528,7 @@ static int aac_decode(struct decoder * mpd_decoder, char *path)
 			audio_format.sample_rate = sample_rate;
 			decoder_initialized(mpd_decoder, &audio_format,
 					    totalTime);
-			initialized = 1;
+			initialized = true;
 		}
 
 		advanceAacBuffer(&b, frameInfo.bytesconsumed);
@@ -559,13 +560,13 @@ static int aac_decode(struct decoder * mpd_decoder, char *path)
 		free(b.buffer);
 
 	if (!initialized)
-		return -1;
+		return false;
 
 	if (decoder_get_command(mpd_decoder) == DECODE_COMMAND_SEEK) {
 		decoder_seek_error(mpd_decoder);
 	}
 
-	return 0;
+	return true;
 }
 
 static struct tag *aacTagDup(char *file)
diff --git a/src/decoder/audiofile_plugin.c b/src/decoder/audiofile_plugin.c
index 5e5eb2cb6..5c1e0a0d0 100644
--- a/src/decoder/audiofile_plugin.c
+++ b/src/decoder/audiofile_plugin.c
@@ -41,7 +41,8 @@ static int getAudiofileTotalTime(char *file)
 	return total_time;
 }
 
-static int audiofile_decode(struct decoder * decoder, char *path)
+static bool
+audiofile_decode(struct decoder *decoder, char *path)
 {
 	int fs, frame_count;
 	AFfilehandle af_fp;
@@ -55,13 +56,13 @@ static int audiofile_decode(struct decoder * decoder, char *path)
 
 	if (stat(path, &st) < 0) {
 		ERROR("failed to stat: %s\n", path);
-		return -1;
+		return false;
 	}
 
 	af_fp = afOpenFile(path, "r", NULL);
 	if (af_fp == AF_NULL_FILEHANDLE) {
 		ERROR("failed to open: %s\n", path);
-		return -1;
+		return false;
 	}
 
 	afSetVirtualSampleFormat(af_fp, AF_DEFAULT_TRACK,
@@ -83,7 +84,7 @@ static int audiofile_decode(struct decoder * decoder, char *path)
 		ERROR("Only 8 and 16-bit files are supported. %s is %i-bit\n",
 		      path, audio_format.bits);
 		afCloseFile(af_fp);
-		return -1;
+		return false;
 	}
 
 	fs = (int)afGetVirtualFrameSize(af_fp, AF_DEFAULT_TRACK, 1);
@@ -111,7 +112,7 @@ static int audiofile_decode(struct decoder * decoder, char *path)
 	} while (decoder_get_command(decoder) != DECODE_COMMAND_STOP);
 
 	afCloseFile(af_fp);
-	return 0;
+	return true;
 }
 
 static struct tag *audiofileTagDup(char *file)
diff --git a/src/decoder/ffmpeg_plugin.c b/src/decoder/ffmpeg_plugin.c
index e8947778b..26af540b0 100644
--- a/src/decoder/ffmpeg_plugin.c
+++ b/src/decoder/ffmpeg_plugin.c
@@ -84,7 +84,7 @@ static int mpdurl_read(URLContext *h, unsigned char *buf, int size)
 {
 	int ret;
 	FopsHelper *base = (FopsHelper *) h->priv_data;
-	while (1) {
+	while (true) {
 		ret = input_stream_read(base->input, (void *)buf, size);
 		if (ret == 0) {
 			DEBUG("ret 0\n");
@@ -130,11 +130,11 @@ static URLProtocol mpdurl_fileops = {
 	.url_close = mpdurl_close,
 };
 
-static int ffmpeg_init(void)
+static bool ffmpeg_init(void)
 {
 	av_register_all();
 	register_protocol(&mpdurl_fileops);
-	return 0;
+	return true;
 }
 
 static int
@@ -318,18 +318,18 @@ static int ffmpeg_decode_internal(BasePtrs *base)
 	return 0;
 }
 
-static int
+static bool
 ffmpeg_decode(struct decoder *decoder, struct input_stream *input)
 {
 	BasePtrs base;
-	int ret;
+	bool ret;
 
 	DEBUG("decode start\n");
 
 	base.input = input;
 	base.decoder = decoder;
 
-	ret = ffmpeg_helper(input, ffmpeg_decode_internal, &base);
+	ret = ffmpeg_helper(input, ffmpeg_decode_internal, &base) == 0;
 
 	DEBUG("decode finish\n");
 
diff --git a/src/decoder/flac_plugin.c b/src/decoder/flac_plugin.c
index dd933ce6b..a4ccd6ebb 100644
--- a/src/decoder/flac_plugin.c
+++ b/src/decoder/flac_plugin.c
@@ -219,13 +219,14 @@ static FLAC__StreamDecoderWriteStatus flacWrite(const flac_decoder *dec,
 	return flac_common_write(data, frame, buf);
 }
 
-static struct tag *flacMetadataDup(char *file, int *vorbisCommentFound)
+static struct tag *
+flacMetadataDup(char *file, bool *vorbisCommentFound)
 {
 	struct tag *ret = NULL;
 	FLAC__Metadata_SimpleIterator *it;
 	FLAC__StreamMetadata *block = NULL;
 
-	*vorbisCommentFound = 0;
+	*vorbisCommentFound = false;
 
 	it = FLAC__metadata_simple_iterator_new();
 	if (!FLAC__metadata_simple_iterator_init(it, file, 1, 0)) {
@@ -262,7 +263,7 @@ static struct tag *flacMetadataDup(char *file, int *vorbisCommentFound)
 			ret = copyVorbisCommentBlockToMpdTag(block, ret);
 
 			if (ret)
-				*vorbisCommentFound = 1;
+				*vorbisCommentFound = true;
 		} else if (block->type == FLAC__METADATA_TYPE_STREAMINFO) {
 			if (!ret)
 				ret = tag_new();
@@ -280,7 +281,7 @@ static struct tag *flacMetadataDup(char *file, int *vorbisCommentFound)
 static struct tag *flacTagDup(char *file)
 {
 	struct tag *ret = NULL;
-	int foundVorbisComment = 0;
+	bool foundVorbisComment = false;
 
 	ret = flacMetadataDup(file, &foundVorbisComment);
 	if (!ret) {
@@ -300,16 +301,16 @@ static struct tag *flacTagDup(char *file)
 	return ret;
 }
 
-static int
+static bool
 flac_decode_internal(struct decoder * decoder, struct input_stream *inStream,
-		     int is_ogg)
+		     bool is_ogg)
 {
 	flac_decoder *flacDec;
 	FlacData data;
 	const char *err = NULL;
 
 	if (!(flacDec = flac_new()))
-		return -1;
+		return false;
 	init_FlacData(&data, decoder, inStream);
 
 #if defined(FLAC_API_VERSION_CURRENT) && FLAC_API_VERSION_CURRENT > 7
@@ -342,7 +343,7 @@ flac_decode_internal(struct decoder * decoder, struct input_stream *inStream,
 
 	decoder_initialized(decoder, &data.audio_format, data.total_time);
 
-	while (1) {
+	while (true) {
 		if (!flac_process_single(flacDec))
 			break;
 		if (decoder_get_command(decoder) == DECODE_COMMAND_SEEK) {
@@ -372,15 +373,15 @@ fail:
 
 	if (err) {
 		ERROR("flac %s\n", err);
-		return -1;
+		return false;
 	}
-	return 0;
+	return true;
 }
 
-static int
+static bool
 flac_decode(struct decoder * decoder, struct input_stream *inStream)
 {
-	return flac_decode_internal(decoder, inStream, 0);
+	return flac_decode_internal(decoder, inStream, false);
 }
 
 #if defined(FLAC_API_VERSION_CURRENT) && FLAC_API_VERSION_CURRENT > 7 && \
@@ -415,10 +416,10 @@ out:
 	return ret;
 }
 
-static int
+static bool
 oggflac_decode(struct decoder *decoder, struct input_stream *inStream)
 {
-	return flac_decode_internal(decoder, inStream, 1);
+	return flac_decode_internal(decoder, inStream, true);
 }
 
 static bool
diff --git a/src/decoder/mod_plugin.c b/src/decoder/mod_plugin.c
index bdf71ec37..3f120abf4 100644
--- a/src/decoder/mod_plugin.c
+++ b/src/decoder/mod_plugin.c
@@ -91,18 +91,18 @@ static MDRIVER drv_mpd = {
 	VC_VoiceRealVolume
 };
 
-static int mod_mikModInitiated;
-static int mod_mikModInitError;
+static bool mod_mikModInitiated;
+static bool mod_mikModInitError;
 
-static int mod_initMikMod(void)
+static bool mod_initMikMod(void)
 {
 	static char params[] = "";
 
 	if (mod_mikModInitError)
-		return -1;
+		return false;
 
 	if (!mod_mikModInitiated) {
-		mod_mikModInitiated = 1;
+		mod_mikModInitiated = true;
 
 		md_device = 0;
 		md_reverb = 0;
@@ -119,11 +119,11 @@ static int mod_initMikMod(void)
 	if (MikMod_Init(params)) {
 		ERROR("Could not init MikMod: %s\n",
 		      MikMod_strerror(MikMod_errno));
-		mod_mikModInitError = 1;
-		return -1;
+		mod_mikModInitError = true;
+		return false;
 	}
 
-	return 0;
+	return true;
 }
 
 static void mod_finishMikMod(void)
@@ -165,7 +165,8 @@ static void mod_close(mod_Data * data)
 	free(data);
 }
 
-static int mod_decode(struct decoder * decoder, char *path)
+static bool
+mod_decode(struct decoder *decoder, char *path)
 {
 	mod_Data *data;
 	struct audio_format audio_format;
@@ -173,13 +174,13 @@ static int mod_decode(struct decoder * decoder, char *path)
 	int ret;
 	float secPerByte;
 
-	if (mod_initMikMod() < 0)
-		return -1;
+	if (!mod_initMikMod())
+		return false;
 
 	if (!(data = mod_open(path))) {
 		ERROR("failed to open mod: %s\n", path);
 		MikMod_Exit();
-		return -1;
+		return false;
 	}
 
 	audio_format.bits = 16;
@@ -192,7 +193,7 @@ static int mod_decode(struct decoder * decoder, char *path)
 
 	decoder_initialized(decoder, &audio_format, 0);
 
-	while (1) {
+	while (true) {
 		if (decoder_get_command(decoder) == DECODE_COMMAND_SEEK) {
 			decoder_seek_error(decoder);
 		}
@@ -214,7 +215,7 @@ static int mod_decode(struct decoder * decoder, char *path)
 
 	MikMod_Exit();
 
-	return 0;
+	return true;
 }
 
 static struct tag *modTagDup(char *file)
@@ -223,7 +224,7 @@ static struct tag *modTagDup(char *file)
 	MODULE *moduleHandle;
 	char *title;
 
-	if (mod_initMikMod() < 0) {
+	if (!mod_initMikMod()) {
 		DEBUG("modTagDup: Failed to initialize MikMod\n");
 		return NULL;
 	}
diff --git a/src/decoder/mp3_plugin.c b/src/decoder/mp3_plugin.c
index ef5b518f8..d95abc9ca 100644
--- a/src/decoder/mp3_plugin.c
+++ b/src/decoder/mp3_plugin.c
@@ -90,13 +90,13 @@ mad_fixed_to_24_buffer(int32_t *dest, const struct mad_synth *synth,
 	}
 }
 
-static int mp3_plugin_init(void)
+static bool mp3_plugin_init(void)
 {
 	int ret = getBoolConfigParam(CONF_GAPLESS_MP3_PLAYBACK, true);
 	gapless_playback = ret != CONF_BOOL_UNSET
 		? !!ret
 		: DEFAULT_GAPLESS_MP3_PLAYBACK;
-	return 1;
+	return true;
 }
 
 #define MP3_DATA_OUTPUT_BUFFER_SIZE 2048
@@ -210,7 +210,7 @@ static ReplayGainInfo *parse_id3_replay_gain_info(struct id3_tag *tag)
 	char *key;
 	char *value;
 	struct id3_frame *frame;
-	int found = 0;
+	bool found = false;
 	ReplayGainInfo *replay_gain_info;
 
 	replay_gain_info = newReplayGainInfo();
@@ -228,16 +228,16 @@ static ReplayGainInfo *parse_id3_replay_gain_info(struct id3_tag *tag)
 
 		if (strcasecmp(key, "replaygain_track_gain") == 0) {
 			replay_gain_info->trackGain = atof(value);
-			found = 1;
+			found = true;
 		} else if (strcasecmp(key, "replaygain_album_gain") == 0) {
 			replay_gain_info->albumGain = atof(value);
-			found = 1;
+			found = true;
 		} else if (strcasecmp(key, "replaygain_track_peak") == 0) {
 			replay_gain_info->trackPeak = atof(value);
-			found = 1;
+			found = true;
 		} else if (strcasecmp(key, "replaygain_album_peak") == 0) {
 			replay_gain_info->albumPeak = atof(value);
-			found = 1;
+			found = true;
 		}
 
 		free(key);
@@ -989,7 +989,6 @@ mp3_read(struct mp3_data *data, ReplayGainInfo **replay_gain_info_r)
 {
 	struct decoder *decoder = data->decoder;
 	int ret;
-	int skip;
 	enum decoder_command cmd;
 
 	mp3_update_timer_next_frame(data);
@@ -1031,7 +1030,8 @@ mp3_read(struct mp3_data *data, ReplayGainInfo **replay_gain_info_r)
 	}
 
 	while (true) {
-		skip = 0;
+		bool skip = false;
+
 		while ((ret =
 			decode_next_frame_header(data, NULL,
 						 replay_gain_info_r)) == DECODE_CONT
@@ -1039,7 +1039,7 @@ mp3_read(struct mp3_data *data, ReplayGainInfo **replay_gain_info_r)
 		if (ret == DECODE_BREAK || decoder_get_command(decoder) != DECODE_COMMAND_NONE)
 			return false;
 		else if (ret == DECODE_SKIP)
-			skip = 1;
+			skip = true;
 		if (data->mute_frame == MUTEFRAME_NONE) {
 			while ((ret = decodeNextFrame(data)) == DECODE_CONT &&
 			       decoder_get_command(decoder) == DECODE_COMMAND_NONE) ;
@@ -1061,7 +1061,7 @@ static void mp3_audio_format(struct mp3_data *data, struct audio_format *af)
 	af->channels = MAD_NCHANNELS(&(data->frame).header);
 }
 
-static int
+static bool
 mp3_decode(struct decoder *decoder, struct input_stream *input_stream)
 {
 	struct mp3_data data;
@@ -1073,9 +1073,9 @@ mp3_decode(struct decoder *decoder, struct input_stream *input_stream)
 		if (decoder_get_command(decoder) == DECODE_COMMAND_NONE) {
 			ERROR
 			    ("Input does not appear to be a mp3 bit stream.\n");
-			return -1;
+			return false;
 		}
-		return 0;
+		return true;
 	}
 
 	mp3_audio_format(&data, &audio_format);
@@ -1120,7 +1120,7 @@ mp3_decode(struct decoder *decoder, struct input_stream *input_stream)
 		decoder_command_finished(decoder);
 
 	mp3_data_finish(&data);
-	return 0;
+	return true;
 }
 
 static struct tag *mp3_tag_dup(char *file)
diff --git a/src/decoder/mp4_plugin.c b/src/decoder/mp4_plugin.c
index f6848b508..760b8871b 100644
--- a/src/decoder/mp4_plugin.c
+++ b/src/decoder/mp4_plugin.c
@@ -79,7 +79,7 @@ static uint32_t mp4_inputStreamSeekCallback(void *inStream, uint64_t position)
 		? 0 : -1;
 }
 
-static int
+static bool
 mp4_decode(struct decoder *mpd_decoder, struct input_stream *inStream)
 {
 	mp4ff_t *mp4fh;
@@ -120,7 +120,7 @@ mp4_decode(struct decoder *mpd_decoder, struct input_stream *inStream)
 	if (!mp4fh) {
 		ERROR("Input does not appear to be a mp4 stream.\n");
 		free(mp4cb);
-		return -1;
+		return false;
 	}
 
 	track = mp4_getAACTrack(mp4fh);
@@ -128,7 +128,7 @@ mp4_decode(struct decoder *mpd_decoder, struct input_stream *inStream)
 		ERROR("No AAC track found in mp4 stream.\n");
 		mp4ff_close(mp4fh);
 		free(mp4cb);
-		return -1;
+		return false;
 	}
 
 	decoder = faacDecOpen();
@@ -155,7 +155,7 @@ mp4_decode(struct decoder *mpd_decoder, struct input_stream *inStream)
 		faacDecClose(decoder);
 		mp4ff_close(mp4fh);
 		free(mp4cb);
-		return -1;
+		return false;
 	}
 
 	audio_format.sample_rate = sample_rate;
@@ -171,7 +171,7 @@ mp4_decode(struct decoder *mpd_decoder, struct input_stream *inStream)
 		faacDecClose(decoder);
 		mp4ff_close(mp4fh);
 		free(mp4cb);
-		return -1;
+		return false;
 	}
 	total_time = ((float)file_time) / scale;
 
@@ -181,7 +181,7 @@ mp4_decode(struct decoder *mpd_decoder, struct input_stream *inStream)
 		 faacDecClose(decoder);
 		 mp4ff_close(mp4fh);
 		 free(mp4cb);
-		 return -1;
+		 return false;
 	}
 
 	file_time = 0.0;
@@ -293,12 +293,12 @@ mp4_decode(struct decoder *mpd_decoder, struct input_stream *inStream)
 	free(mp4cb);
 
 	if (!initialized)
-		return -1;
+		return false;
 
 	if (decoder_get_command(mpd_decoder) == DECODE_COMMAND_SEEK && seeking)
 		decoder_command_finished(mpd_decoder);
 
-	return 0;
+	return true;
 }
 
 static struct tag *mp4DataDup(char *file, int *mp4MetadataFound)
diff --git a/src/decoder/mpc_plugin.c b/src/decoder/mpc_plugin.c
index f9c3f34d5..ed7f49fc7 100644
--- a/src/decoder/mpc_plugin.c
+++ b/src/decoder/mpc_plugin.c
@@ -94,7 +94,7 @@ static inline int16_t convertSample(MPC_SAMPLE_FORMAT sample)
 	return val;
 }
 
-static int
+static bool
 mpc_decode(struct decoder *mpd_decoder, struct input_stream *inStream)
 {
 	mpc_decoder decoder;
@@ -106,7 +106,7 @@ mpc_decode(struct decoder *mpd_decoder, struct input_stream *inStream)
 
 	MPC_SAMPLE_FORMAT sample_buffer[MPC_DECODER_BUFFER_LENGTH];
 
-	int eof = 0;
+	bool eof = false;
 	long ret;
 #define MPC_CHUNK_SIZE 4096
 	char chunk[MPC_CHUNK_SIZE];
@@ -135,9 +135,9 @@ mpc_decode(struct decoder *mpd_decoder, struct input_stream *inStream)
 	if ((ret = mpc_streaminfo_read(&info, &reader)) != ERROR_CODE_OK) {
 		if (decoder_get_command(mpd_decoder) != DECODE_COMMAND_STOP) {
 			ERROR("Not a valid musepack stream\n");
-			return -1;
+			return false;
 		}
-		return 0;
+		return true;
 	}
 
 	mpc_decoder_setup(&decoder, &reader);
@@ -145,9 +145,9 @@ mpc_decode(struct decoder *mpd_decoder, struct input_stream *inStream)
 	if (!mpc_decoder_initialize(&decoder, &info)) {
 		if (decoder_get_command(mpd_decoder) != DECODE_COMMAND_STOP) {
 			ERROR("Not a valid musepack stream\n");
-			return -1;
+			return false;
 		}
-		return 0;
+		return true;
 	}
 
 	audio_format.bits = 16;
@@ -181,7 +181,7 @@ mpc_decode(struct decoder *mpd_decoder, struct input_stream *inStream)
 					 &vbrUpdateAcc, &vbrUpdateBits);
 
 		if (ret <= 0 || decoder_get_command(mpd_decoder) == DECODE_COMMAND_STOP) {
-			eof = 1;
+			eof = true;
 			break;
 		}
 
@@ -212,7 +212,7 @@ mpc_decode(struct decoder *mpd_decoder, struct input_stream *inStream)
 				chunkpos = 0;
 				s16 = (int16_t *) chunk;
 				if (decoder_get_command(mpd_decoder) == DECODE_COMMAND_STOP) {
-					eof = 1;
+					eof = true;
 					break;
 				}
 			}
@@ -233,7 +233,7 @@ mpc_decode(struct decoder *mpd_decoder, struct input_stream *inStream)
 
 	freeReplayGainInfo(replayGainInfo);
 
-	return 0;
+	return true;
 }
 
 static float mpcGetTime(char *file)
diff --git a/src/decoder/oggflac_plugin.c b/src/decoder/oggflac_plugin.c
index c0f194156..87e21e146 100644
--- a/src/decoder/oggflac_plugin.c
+++ b/src/decoder/oggflac_plugin.c
@@ -304,7 +304,7 @@ static int oggflac_decode(struct decoder * mpd_decoder, InputStream * inStream)
 
 	decoder_initialized(mpd_decoder, &data.audio_format, data.total_time);
 
-	while (1) {
+	while (true) {
 		OggFLAC__seekable_stream_decoder_process_single(decoder);
 		if (OggFLAC__seekable_stream_decoder_get_state(decoder) !=
 		    OggFLAC__SEEKABLE_STREAM_DECODER_OK) {
diff --git a/src/decoder/oggvorbis_plugin.c b/src/decoder/oggvorbis_plugin.c
index 2099d2c0f..f4c6de7fe 100644
--- a/src/decoder/oggvorbis_plugin.c
+++ b/src/decoder/oggvorbis_plugin.c
@@ -96,7 +96,7 @@ static const char *ogg_parseComment(const char *comment, const char *needle)
 static void ogg_getReplayGainInfo(char **comments, ReplayGainInfo ** infoPtr)
 {
 	const char *temp;
-	int found = 0;
+	bool found = false;
 
 	if (*infoPtr)
 		freeReplayGainInfo(*infoPtr);
@@ -106,19 +106,19 @@ static void ogg_getReplayGainInfo(char **comments, ReplayGainInfo ** infoPtr)
 		if ((temp =
 		     ogg_parseComment(*comments, "replaygain_track_gain"))) {
 			(*infoPtr)->trackGain = atof(temp);
-			found = 1;
+			found = true;
 		} else if ((temp = ogg_parseComment(*comments,
 						    "replaygain_album_gain"))) {
 			(*infoPtr)->albumGain = atof(temp);
-			found = 1;
+			found = true;
 		} else if ((temp = ogg_parseComment(*comments,
 						    "replaygain_track_peak"))) {
 			(*infoPtr)->trackPeak = atof(temp);
-			found = 1;
+			found = true;
 		} else if ((temp = ogg_parseComment(*comments,
 						    "replaygain_album_peak"))) {
 			(*infoPtr)->albumPeak = atof(temp);
-			found = 1;
+			found = true;
 		}
 
 		comments++;
@@ -200,7 +200,7 @@ static void putOggCommentsIntoOutputBuffer(char *streamName,
 }
 
 /* public */
-static int
+static bool
 oggvorbis_decode(struct decoder *decoder, struct input_stream *inStream)
 {
 	OggVorbis_File vf;
@@ -218,7 +218,7 @@ oggvorbis_decode(struct decoder *decoder, struct input_stream *inStream)
 	ReplayGainInfo *replayGainInfo = NULL;
 	char **comments;
 	const char *errorStr;
-	int initialized = 0;
+	bool initialized = false;
 
 	data.inStream = inStream;
 	data.decoder = decoder;
@@ -229,7 +229,7 @@ oggvorbis_decode(struct decoder *decoder, struct input_stream *inStream)
 	callbacks.tell_func = ogg_tell_cb;
 	if ((ret = ov_open_callbacks(&data, &vf, NULL, 0, callbacks)) < 0) {
 		if (decoder_get_command(decoder) != DECODE_COMMAND_NONE)
-			return 0;
+			return true;
 
 		switch (ret) {
 		case OV_EREAD:
@@ -253,11 +253,11 @@ oggvorbis_decode(struct decoder *decoder, struct input_stream *inStream)
 		}
 		ERROR("Error decoding Ogg Vorbis stream: %s\n",
 		      errorStr);
-		return -1;
+		return false;
 	}
 	audio_format.bits = 16;
 
-	while (1) {
+	while (true) {
 		if (decoder_get_command(decoder) == DECODE_COMMAND_SEEK) {
 			double seek_where = decoder_seek_where(decoder);
 			if (0 == ov_time_seek_page(&vf, seek_where)) {
@@ -280,7 +280,7 @@ oggvorbis_decode(struct decoder *decoder, struct input_stream *inStream)
 					total_time = 0;
 				decoder_initialized(decoder, &audio_format,
 						    total_time);
-				initialized = 1;
+				initialized = true;
 			}
 			comments = ov_comment(&vf, -1)->user_comments;
 			putOggCommentsIntoOutputBuffer(inStream->meta_name,
@@ -326,7 +326,7 @@ oggvorbis_decode(struct decoder *decoder, struct input_stream *inStream)
 		freeReplayGainInfo(replayGainInfo);
 
 	ov_clear(&vf);
-	return 0;
+	return true;
 }
 
 static struct tag *oggvorbis_TagDup(char *file)
diff --git a/src/decoder/wavpack_plugin.c b/src/decoder/wavpack_plugin.c
index 73336e54d..9f28475cd 100644
--- a/src/decoder/wavpack_plugin.c
+++ b/src/decoder/wavpack_plugin.c
@@ -232,7 +232,7 @@ static ReplayGainInfo *wavpack_replaygain(WavpackContext *wpc)
 	static char replaygain_track_peak[] = "replaygain_track_peak";
 	static char replaygain_album_peak[] = "replaygain_album_peak";
 	ReplayGainInfo *replayGainInfo;
-	int found = 0;
+	bool found = false;
 	char *value;
 
 	replayGainInfo = newReplayGainInfo();
@@ -241,28 +241,28 @@ static ReplayGainInfo *wavpack_replaygain(WavpackContext *wpc)
 	if (value) {
 		replayGainInfo->trackGain = atof(value);
 		free(value);
-		found = 1;
+		found = true;
 	}
 
 	value = wavpack_tag(wpc, replaygain_album_gain);
 	if (value) {
 		replayGainInfo->albumGain = atof(value);
 		free(value);
-		found = 1;
+		found = true;
 	}
 
 	value = wavpack_tag(wpc, replaygain_track_peak);
 	if (value) {
 		replayGainInfo->trackPeak = atof(value);
 		free(value);
-		found = 1;
+		found = true;
 	}
 
 	value = wavpack_tag(wpc, replaygain_album_peak);
 	if (value) {
 		replayGainInfo->albumPeak = atof(value);
 		free(value);
-		found = 1;
+		found = true;
 	}
 
 
@@ -496,7 +496,7 @@ static int wavpack_open_wvc(struct decoder *decoder,
 /*
  * Decodes a stream.
  */
-static int
+static bool
 wavpack_streamdecode(struct decoder * decoder, struct input_stream *is)
 {
 	char error[ERRORLEN];
@@ -516,7 +516,7 @@ wavpack_streamdecode(struct decoder * decoder, struct input_stream *is)
 
 	if (wpc == NULL) {
 		ERROR("failed to open WavPack stream: %s\n", error);
-		return -1;
+		return false;
 	}
 
 	wavpack_decode(decoder, wpc, can_seek(&isp), NULL);
@@ -526,13 +526,14 @@ wavpack_streamdecode(struct decoder * decoder, struct input_stream *is)
 		input_stream_close(&is_wvc);
 	input_stream_close(is);
 
-	return 0;
+	return true;
 }
 
 /*
  * Decodes a file.
  */
-static int wavpack_filedecode(struct decoder * decoder, char *fname)
+static bool
+wavpack_filedecode(struct decoder *decoder, char *fname)
 {
 	char error[ERRORLEN];
 	WavpackContext *wpc;
@@ -543,7 +544,7 @@ static int wavpack_filedecode(struct decoder * decoder, char *fname)
 	                           OPEN_2CH_MAX | OPEN_NORMALIZE, 15);
 	if (wpc == NULL) {
 		ERROR("failed to open WavPack file \"%s\": %s\n", fname, error);
-		return -1;
+		return false;
 	}
 
 	replayGainInfo = wavpack_replaygain(wpc);
@@ -555,7 +556,7 @@ static int wavpack_filedecode(struct decoder * decoder, char *fname)
 
 	WavpackCloseFile(wpc);
 
-	return 0;
+	return true;
 }
 
 static char const *wavpackSuffixes[] = { "wv", NULL };
diff --git a/src/decoder_api.c b/src/decoder_api.c
index 7888ebb95..d9ac186e3 100644
--- a/src/decoder_api.c
+++ b/src/decoder_api.c
@@ -96,7 +96,7 @@ void decoder_seek_error(struct decoder * decoder)
 {
 	assert(dc.command == DECODE_COMMAND_SEEK);
 
-	dc.seekError = 1;
+	dc.seekError = true;
 	decoder_command_finished(decoder);
 }
 
@@ -109,7 +109,7 @@ size_t decoder_read(struct decoder *decoder,
 	assert(inStream != NULL);
 	assert(buffer != NULL);
 
-	while (1) {
+	while (true) {
 		/* XXX don't allow decoder==NULL */
 		if (decoder != NULL &&
 		    (dc.command != DECODE_COMMAND_SEEK ||
diff --git a/src/decoder_api.h b/src/decoder_api.h
index fbd259859..808eb979e 100644
--- a/src/decoder_api.h
+++ b/src/decoder_api.h
@@ -58,7 +58,7 @@ struct decoder_plugin {
 	 * have/need one this must return < 0 if there is an error and
 	 * >= 0 otherwise
 	 */
-	int (*init)(void);
+	bool (*init)(void);
 
 	/**
 	 * optional, set this to NULL if the InputPlugin doesn't have/need one
@@ -75,9 +75,9 @@ struct decoder_plugin {
 	 * this will be used to decode InputStreams, and is
 	 * recommended for files and networked (HTTP) connections.
 	 *
-	 * returns -1 on error, 0 on success
+	 * returns false on error, true on success
 	 */
-	int (*stream_decode)(struct decoder *, struct input_stream *);
+	bool (*stream_decode)(struct decoder *, struct input_stream *);
 
 	/**
 	 * use this if and only if your InputPlugin can only be passed
@@ -86,7 +86,7 @@ struct decoder_plugin {
 	 *
 	 * returns -1 on error, 0 on success
 	 */
-	int (*file_decode)(struct decoder *, char *path);
+	bool (*file_decode)(struct decoder *, char *path);
 
 	/**
 	 * file should be the full path!  Returns NULL if a tag cannot
diff --git a/src/decoder_control.c b/src/decoder_control.c
index 1b9b3029d..9587d3980 100644
--- a/src/decoder_control.c
+++ b/src/decoder_control.c
@@ -85,20 +85,20 @@ dc_stop(struct notify *notify)
 		dc_command(notify, DECODE_COMMAND_STOP);
 }
 
-int
+bool
 dc_seek(struct notify *notify, double where)
 {
 	assert(where >= 0.0);
 
 	if (dc.state == DECODE_STATE_STOP || !dc.seekable)
-		return -1;
+		return false;
 
 	dc.seekWhere = where;
-	dc.seekError = 0;
+	dc.seekError = false;
 	dc_command(notify, DECODE_COMMAND_SEEK);
 
 	if (dc.seekError)
-		return -1;
+		return false;
 
-	return 0;
+	return true;
 }
diff --git a/src/decoder_control.h b/src/decoder_control.h
index 0d163257d..d03d28a46 100644
--- a/src/decoder_control.h
+++ b/src/decoder_control.h
@@ -44,8 +44,8 @@ struct decoder_control {
 	volatile enum decoder_state state;
 	volatile enum decoder_command command;
 	volatile uint16_t error;
-	volatile int8_t seekError;
-	volatile int8_t seekable;
+	bool seekError;
+	bool seekable;
 	volatile double seekWhere;
 	struct audio_format audioFormat;
 	struct song *current_song;
@@ -59,13 +59,13 @@ void dc_init(void);
 
 void dc_deinit(void);
 
-static inline int decoder_is_idle(void)
+static inline bool decoder_is_idle(void)
 {
 	return dc.state == DECODE_STATE_STOP &&
 		dc.command != DECODE_COMMAND_START;
 }
 
-static inline int decoder_is_starting(void)
+static inline bool decoder_is_starting(void)
 {
 	return dc.command == DECODE_COMMAND_START ||
 		dc.state == DECODE_STATE_START;
@@ -93,7 +93,7 @@ dc_start_async(struct song *song);
 void
 dc_stop(struct notify *notify);
 
-int
+bool
 dc_seek(struct notify *notify, double where);
 
 #endif
diff --git a/src/decoder_list.c b/src/decoder_list.c
index 252418154..57a013ec9 100644
--- a/src/decoder_list.c
+++ b/src/decoder_list.c
@@ -41,7 +41,7 @@ void decoder_plugin_load(struct decoder_plugin * inputPlugin)
 	if (!inputPlugin->name)
 		return;
 
-	if (inputPlugin->init != NULL && inputPlugin->init() < 0)
+	if (inputPlugin->init != NULL && !inputPlugin->init())
 		return;
 
 	insertInList(inputPlugin_list, inputPlugin->name, (void *)inputPlugin);
diff --git a/src/decoder_thread.c b/src/decoder_thread.c
index 3bbe1f347..e26e2e534 100644
--- a/src/decoder_thread.c
+++ b/src/decoder_thread.c
@@ -73,12 +73,12 @@ static void decodeStart(void)
 	if (dc.command == DECODE_COMMAND_STOP)
 		goto stop;
 
-	ret = DECODE_ERROR_UNKTYPE;
+	ret = false;
 	if (!song_is_file(song)) {
 		unsigned int next = 0;
 
 		/* first we try mime types: */
-		while (ret && (plugin = decoder_plugin_from_mime_type(inStream.mime, next++))) {
+		while ((plugin = decoder_plugin_from_mime_type(inStream.mime, next++))) {
 			if (plugin->stream_decode == NULL)
 				continue;
 			if (!(plugin->stream_types & INPUT_PLUGIN_STREAM_URL))
@@ -94,7 +94,7 @@ static void decodeStart(void)
 		if (plugin == NULL) {
 			const char *s = getSuffix(path_max_fs);
 			next = 0;
-			while (ret && (plugin = decoder_plugin_from_suffix(s, next++))) {
+			while ((plugin = decoder_plugin_from_suffix(s, next++))) {
 				if (plugin->stream_decode == NULL)
 					continue;
 				if (!(plugin->stream_types &
@@ -124,7 +124,7 @@ static void decodeStart(void)
 	} else {
 		unsigned int next = 0;
 		const char *s = getSuffix(path_max_fs);
-		while (ret && (plugin = decoder_plugin_from_suffix(s, next++))) {
+		while ((plugin = decoder_plugin_from_suffix(s, next++))) {
 			if (!plugin->stream_types & INPUT_PLUGIN_STREAM_FILE)
 				continue;
 
@@ -150,11 +150,10 @@ static void decodeStart(void)
 
 	ob_flush();
 
-	if (ret < 0 || ret == DECODE_ERROR_UNKTYPE) {
-		if (ret != DECODE_ERROR_UNKTYPE)
-			dc.error = DECODE_ERROR_FILE;
-		else
-			dc.error = DECODE_ERROR_UNKTYPE;
+	if (!ret) {
+		dc.error = plugin == NULL
+			? DECODE_ERROR_UNKTYPE
+			: DECODE_ERROR_FILE;
 	}
 
 stop:
diff --git a/src/player_thread.c b/src/player_thread.c
index 48702b6a3..0c2407eac 100644
--- a/src/player_thread.c
+++ b/src/player_thread.c
@@ -105,10 +105,10 @@ static int waitOnDecode(struct player *player)
 	return 0;
 }
 
-static int decodeSeek(struct player *player)
+static bool decodeSeek(struct player *player)
 {
-	int ret = -1;
 	double where;
+	bool ret;
 
 	if (decoder_current_song() != pc.next_song) {
 		dc_stop(&pc.notify);
@@ -125,7 +125,7 @@ static int decodeSeek(struct player *player)
 		where = 0.0;
 
 	ret = dc_seek(&pc.notify, where);
-	if (ret == 0)
+	if (ret)
 		pc.elapsedTime = where;
 
 	player_command_finished();
@@ -173,7 +173,7 @@ static void processDecodeInput(struct player *player)
 
 	case PLAYER_COMMAND_SEEK:
 		dropBufferedAudio();
-		if (decodeSeek(player) == 0) {
+		if (decodeSeek(player)) {
 			player->xfade = XFADE_UNKNOWN;
 
 			/* abort buffering when the user has requested