decoder/flac: calculate bit rate in flac_common_write()

Removed the "bit_rate" attribute from the flac_data struct.  Pass the
number of bytes since the last call to flac_common_write(), and let
it calculate the bit rate.

src/decoder/_flac_common.c

@@ -40,7 +40,6 @@ flac_data_init(struct flac_data *data, struct decoder * decoder,
 
 	data->time = 0;
 	data->position = 0;
-	data->bit_rate = 0;
 	data->decoder = decoder;
 	data->input_stream = input_stream;
 	data->replay_gain_info = NULL;
@@ -110,12 +109,14 @@ void flac_error_common_cb(const char *plugin,
 
 FLAC__StreamDecoderWriteStatus
 flac_common_write(struct flac_data *data, const FLAC__Frame * frame,
-		  const FLAC__int32 *const buf[])
+		  const FLAC__int32 *const buf[],
+		  FLAC__uint64 nbytes)
 {
 	enum decoder_command cmd;
 	size_t buffer_size = frame->header.blocksize *
 		audio_format_frame_size(&data->audio_format);
 	void *buffer;
+	unsigned bit_rate;
 
 	buffer = pcm_buffer_get(&data->buffer, buffer_size);
 
@@ -123,9 +124,15 @@ flac_common_write(struct flac_data *data, const FLAC__Frame * frame,
 		     data->audio_format.bits, buf,
 		     0, frame->header.blocksize);
 
+	if (nbytes > 0)
+		bit_rate = nbytes * 8 * frame->header.sample_rate /
+			(1000 * frame->header.blocksize);
+	else
+		bit_rate = 0;
+
 	cmd = decoder_data(data->decoder, data->input_stream,
 			   buffer, buffer_size,
-			   data->time, data->bit_rate,
+			   data->time, bit_rate,
 			   data->replay_gain_info);
 	data->next_frame += frame->header.blocksize;
 	switch (cmd) {

src/decoder/_flac_common.h

@@ -57,7 +57,6 @@ struct flac_data {
 	FLAC__uint64 next_frame;
 
 	float time;
-	unsigned int bit_rate;
 	struct audio_format audio_format;
 	FLAC__uint64 position;
 	struct decoder *decoder;
@@ -83,7 +82,8 @@ void flac_error_common_cb(const char *plugin,
 
 FLAC__StreamDecoderWriteStatus
 flac_common_write(struct flac_data *data, const FLAC__Frame * frame,
-		  const FLAC__int32 *const buf[]);
+		  const FLAC__int32 *const buf[],
+		  FLAC__uint64 nbytes);
 
 #if defined(FLAC_API_VERSION_CURRENT) && FLAC_API_VERSION_CURRENT > 7
 

src/decoder/flac_plugin.c

@@ -194,22 +194,23 @@ flac_write_cb(const FLAC__StreamDecoder *dec, const FLAC__Frame *frame,
 	FLAC__uint32 samples = frame->header.blocksize;
 	struct flac_data *data = (struct flac_data *) vdata;
 	float timeChange;
-	FLAC__uint64 newPosition = 0;
+	FLAC__uint64 nbytes = 0;
 
 	timeChange = ((float)samples) / frame->header.sample_rate;
 	data->time += timeChange;
 
-	FLAC__stream_decoder_get_decode_position(dec, &newPosition);
-	if (data->position && newPosition >= data->position) {
-		assert(timeChange >= 0);
-
-		data->bit_rate =
-		    ((newPosition - data->position) * 8.0 / timeChange)
-		    / 1000 + 0.5;
+	if (FLAC__stream_decoder_get_decode_position(dec, &nbytes)) {
+		if (data->position > 0 && nbytes > data->position) {
+			nbytes -= data->position;
+			data->position += nbytes;
+		} else {
+			data->position = nbytes;
+			nbytes = 0;
 		}
-	data->position = newPosition;
+	} else
+		nbytes = 0;
 
-	return flac_common_write(data, frame, buf);
+	return flac_common_write(data, frame, buf, nbytes);
 }
 
 static struct tag *

src/decoder/oggflac_plugin.c

@@ -161,7 +161,7 @@ oggflac_write_cb(G_GNUC_UNUSED const OggFLAC__SeekableStreamDecoder *decoder,
 	time_change = ((float)samples) / frame->header.sample_rate;
 	data->time += time_change;
 
-	return flac_common_write(data, frame, buf);
+	return flac_common_write(data, frame, buf, 0);
 }
 
 /* used by TagDup */