decoder/faad: make variables more local

src/decoder/FaadDecoderPlugin.cxx

@@ -64,16 +64,13 @@ adts_check_frame(const unsigned char *data)
 static size_t
 adts_find_frame(DecoderBuffer *buffer)
 {
-	size_t length, frame_length;
-	bool ret;
-
 	while (true) {
+		size_t length;
 		const uint8_t *data = (const uint8_t *)
 			decoder_buffer_read(buffer, &length);
 		if (data == nullptr || length < 8) {
 			/* not enough data yet */
-			ret = decoder_buffer_fill(buffer);
-			if (!ret)
+			if (!decoder_buffer_fill(buffer))
 				/* failed */
 				return 0;
 
@@ -95,7 +92,7 @@ adts_find_frame(DecoderBuffer *buffer)
 		}
 
 		/* is it a frame? */
-		frame_length = adts_check_frame(data);
+		const size_t frame_length = adts_check_frame(data);
 		if (frame_length == 0) {
 			/* it's just some random 0xff byte; discard it
 			   and continue searching */
@@ -107,8 +104,7 @@ adts_find_frame(DecoderBuffer *buffer)
 			/* available buffer size is smaller than the
 			   frame will be - attempt to read more
 			   data */
-			ret = decoder_buffer_fill(buffer);
-			if (!ret) {
+			if (!decoder_buffer_fill(buffer)) {
 				/* not enough data; discard this frame
 				   to prevent a possible buffer
 				   overflow */
@@ -129,13 +125,12 @@ adts_find_frame(DecoderBuffer *buffer)
 static float
 adts_song_duration(DecoderBuffer *buffer)
 {
-	unsigned int frames, frame_length;
 	unsigned sample_rate = 0;
-	float frames_per_second;
 
 	/* Read all frames to ensure correct time and bitrate */
+	unsigned frames;
 	for (frames = 0;; frames++) {
-		frame_length = adts_find_frame(buffer);
+		const unsigned frame_length = adts_find_frame(buffer);
 		if (frame_length == 0)
 			break;
 
@@ -153,7 +148,7 @@ adts_song_duration(DecoderBuffer *buffer)
 		decoder_buffer_consume(buffer, frame_length);
 	}
 
-	frames_per_second = (float)sample_rate / 1024.0;
+	float frames_per_second = (float)sample_rate / 1024.0;
 	if (frames_per_second <= 0)
 		return -1;
 
@@ -163,21 +158,17 @@ adts_song_duration(DecoderBuffer *buffer)
 static float
 faad_song_duration(DecoderBuffer *buffer, InputStream &is)
 {
-	size_t fileread;
-	size_t tagsize;
-	size_t length;
-	bool success;
-
 	const auto size = is.GetSize();
-	fileread = size >= 0 ? size : 0;
+	const size_t fileread = size >= 0 ? size : 0;
 
 	decoder_buffer_fill(buffer);
+	size_t length;
 	const uint8_t *data = (const uint8_t *)
 		decoder_buffer_read(buffer, &length);
 	if (data == nullptr)
 		return -1;
 
-	tagsize = 0;
+	size_t tagsize = 0;
 	if (length >= 10 && !memcmp(data, "ID3", 3)) {
 		/* skip the ID3 tag */
 
@@ -186,7 +177,7 @@ faad_song_duration(DecoderBuffer *buffer, InputStream &is)
 
 		tagsize += 10;
 
-		success = decoder_buffer_skip(buffer, tagsize) &&
+		const bool success = decoder_buffer_skip(buffer, tagsize) &&
 			decoder_buffer_fill(buffer);
 		if (!success)
 			return -1;
@@ -211,7 +202,6 @@ faad_song_duration(DecoderBuffer *buffer, InputStream &is)
 		return song_length;
 	} else if (length >= 5 && memcmp(data, "ADIF", 4) == 0) {
 		/* obtain the duration from the ADIF header */
-		unsigned bit_rate;
 		size_t skip_size = (data[4] & 0x80) ? 9 : 0;
 
 		if (8 + skip_size > length)
@@ -219,7 +209,7 @@ faad_song_duration(DecoderBuffer *buffer, InputStream &is)
 			   header */
 			return -1;
 
-		bit_rate = ((data[4 + skip_size] & 0x0F) << 19) |
+		unsigned bit_rate = ((data[4 + skip_size] & 0x0F) << 19) |
 			(data[5 + skip_size] << 11) |
 			(data[6 + skip_size] << 3) |
 			(data[7 + skip_size] & 0xE0);
@@ -240,17 +230,6 @@ static bool
 faad_decoder_init(NeAACDecHandle decoder, DecoderBuffer *buffer,
 		  AudioFormat &audio_format, Error &error)
 {
-	int32_t nbytes;
-	uint32_t sample_rate;
-	uint8_t channels;
-#ifdef HAVE_FAAD_LONG
-	/* neaacdec.h declares all arguments as "unsigned long", but
-	   internally expects uint32_t pointers.  To avoid gcc
-	   warnings, use this workaround. */
-	unsigned long *sample_rate_p = (unsigned long *)(void *)&sample_rate;
-#else
-	uint32_t *sample_rate_p = &sample_rate;
-#endif
 
 	size_t length;
 	const unsigned char *data = (const unsigned char *)
@@ -260,11 +239,21 @@ faad_decoder_init(NeAACDecHandle decoder, DecoderBuffer *buffer,
 		return false;
 	}
 
-	nbytes = NeAACDecInit(decoder,
-			      /* deconst hack, libfaad requires this */
-			      const_cast<unsigned char *>(data),
-			     length,
-			     sample_rate_p, &channels);
+	uint8_t channels;
+	uint32_t sample_rate;
+#ifdef HAVE_FAAD_LONG
+	/* neaacdec.h declares all arguments as "unsigned long", but
+	   internally expects uint32_t pointers.  To avoid gcc
+	   warnings, use this workaround. */
+	unsigned long *sample_rate_p = (unsigned long *)(void *)&sample_rate;
+#else
+	uint32_t *sample_rate_p = &sample_rate;
+#endif
+	long nbytes = NeAACDecInit(decoder,
+				   /* deconst hack, libfaad requires this */
+				   const_cast<unsigned char *>(data),
+				   length,
+				   sample_rate_p, &channels);
 	if (nbytes < 0) {
 		error.Set(faad_decoder_domain, "Not an AAC stream");
 		return false;
@@ -304,15 +293,13 @@ faad_decoder_decode(NeAACDecHandle decoder, DecoderBuffer *buffer,
 static float
 faad_get_file_time_float(InputStream &is)
 {
-	DecoderBuffer *buffer;
-	float length;
+	DecoderBuffer *const buffer =
+		decoder_buffer_new(nullptr, is,
+				   FAAD_MIN_STREAMSIZE * MAX_CHANNELS);
 
-	buffer = decoder_buffer_new(nullptr, is,
-				    FAAD_MIN_STREAMSIZE * MAX_CHANNELS);
-	length = faad_song_duration(buffer, is);
+	float length = faad_song_duration(buffer, is);
 
 	if (length < 0) {
-		bool ret;
 		AudioFormat audio_format;
 
 		NeAACDecHandle decoder = NeAACDecOpen();
@@ -324,9 +311,8 @@ faad_get_file_time_float(InputStream &is)
 
 		decoder_buffer_fill(buffer);
 
-		ret = faad_decoder_init(decoder, buffer, audio_format,
-					IgnoreError());
-		if (ret)
+		if (faad_decoder_init(decoder, buffer, audio_format,
+				      IgnoreError()))
 			length = 0;
 
 		NeAACDecClose(decoder);
@@ -345,31 +331,25 @@ faad_get_file_time_float(InputStream &is)
 static int
 faad_get_file_time(InputStream &is)
 {
-	int file_time = -1;
-	float length;
-
-	if ((length = faad_get_file_time_float(is)) >= 0)
-		file_time = length + 0.5;
+	float length = faad_get_file_time_float(is);
+	if (length < 0)
+		return -1;
 
-	return file_time;
+	return int(length + 0.5);
 }
 
 static void
 faad_stream_decode(Decoder &mpd_decoder, InputStream &is)
 {
-	float total_time = 0;
-	AudioFormat audio_format;
-	bool ret;
-	uint16_t bit_rate = 0;
-	DecoderBuffer *buffer;
+	DecoderBuffer *const buffer =
+		decoder_buffer_new(&mpd_decoder, is,
+				   FAAD_MIN_STREAMSIZE * MAX_CHANNELS);
 
-	buffer = decoder_buffer_new(&mpd_decoder, is,
-				    FAAD_MIN_STREAMSIZE * MAX_CHANNELS);
-	total_time = faad_song_duration(buffer, is);
+	const float total_time = faad_song_duration(buffer, is);
 
 	/* create the libfaad decoder */
 
-	NeAACDecHandle decoder = NeAACDecOpen();
+	const NeAACDecHandle decoder = NeAACDecOpen();
 
 	NeAACDecConfigurationPtr config =
 		NeAACDecGetCurrentConfiguration(decoder);
@@ -387,8 +367,8 @@ faad_stream_decode(Decoder &mpd_decoder, InputStream &is)
 	/* initialize it */
 
 	Error error;
-	ret = faad_decoder_init(decoder, buffer, audio_format, error);
-	if (!ret) {
+	AudioFormat audio_format;
+	if (!faad_decoder_init(decoder, buffer, audio_format, error)) {
 		LogError(error);
 		NeAACDecClose(decoder);
 		decoder_buffer_free(buffer);
@@ -402,21 +382,20 @@ faad_stream_decode(Decoder &mpd_decoder, InputStream &is)
 	/* the decoder loop */
 
 	DecoderCommand cmd;
+	uint16_t bit_rate = 0;
 	do {
-		size_t frame_size;
-		const void *decoded;
-		NeAACDecFrameInfo frame_info;
-
 		/* find the next frame */
 
-		frame_size = adts_find_frame(buffer);
+		const size_t frame_size = adts_find_frame(buffer);
 		if (frame_size == 0)
 			/* end of file */
 			break;
 
 		/* decode it */
 
-		decoded = faad_decoder_decode(decoder, buffer, &frame_info);
+		NeAACDecFrameInfo frame_info;
+		const void *const decoded =
+			faad_decoder_decode(decoder, buffer, &frame_info);
 
 		if (frame_info.error > 0) {
 			FormatWarning(faad_decoder_domain,
@@ -468,7 +447,6 @@ faad_scan_stream(InputStream &is,
 		 const struct tag_handler *handler, void *handler_ctx)
 {
 	int file_time = faad_get_file_time(is);
-
 	if (file_time < 0)
 		return false;