Add support for MixRamp tags

Adds mixrampdb and mixrampdelay commands.  Reads MIXRAP_START and
MIXRAMP_END tags from FLAC files and overlaps instead of crossfading.

18 files changed, 423 insertions, 19 deletions

diff --git a/src/command.c b/src/command.c
index a7fccbed4..d514d0698 100644
--- a/src/command.c
+++ b/src/command.c
@@ -76,6 +76,8 @@
 #define COMMAND_STATUS_BITRATE          "bitrate"
 #define COMMAND_STATUS_ERROR            "error"
 #define COMMAND_STATUS_CROSSFADE	"xfade"
+#define COMMAND_STATUS_MIXRAMPDB	"mixrampdb"
+#define COMMAND_STATUS_MIXRAMPDELAY	"mixrampdelay"
 #define COMMAND_STATUS_AUDIO		"audio"
 #define COMMAND_STATUS_UPDATING_DB	"updating_db"
 
@@ -294,6 +296,23 @@ check_bool(struct client *client, bool *value_r, const char *s)
 	return true;
 }
 
+static bool
+check_float(struct client *client, float *value_r, const char *s)
+{
+	float value;
+	char *endptr;
+
+	value = strtof(s, &endptr);
+	if (*endptr != 0 && endptr == s) {
+		command_error(client, ACK_ERROR_ARG,
+			      "Float expected: %s", s);
+		return false;
+	}
+
+	*value_r = value;
+	return true;
+}
+
 static enum command_return
 print_playlist_result(struct client *client,
 		      enum playlist_result result)
@@ -495,6 +514,8 @@ handle_status(struct client *client,
 		      COMMAND_STATUS_PLAYLIST ": %li\n"
 		      COMMAND_STATUS_PLAYLIST_LENGTH ": %i\n"
 		      COMMAND_STATUS_CROSSFADE ": %i\n"
+		      COMMAND_STATUS_MIXRAMPDB ": %f\n"
+		      COMMAND_STATUS_MIXRAMPDELAY ": %f\n"
 		      COMMAND_STATUS_STATE ": %s\n",
 		      volume_level_get(),
 		      playlist_get_repeat(&g_playlist),
@@ -504,6 +525,8 @@ handle_status(struct client *client,
 		      playlist_get_version(&g_playlist),
 		      playlist_get_length(&g_playlist),
 		      (int)(pc_get_cross_fade() + 0.5),
+		      pc_get_mixramp_db(),
+		      pc_get_mixramp_delay(),
 		      state);
 
 	song = playlist_get_current_song(&g_playlist);
@@ -1451,6 +1474,30 @@ handle_crossfade(struct client *client, G_GNUC_UNUSED int argc, char *argv[])
 }
 
 static enum command_return
+handle_mixrampdb(struct client *client, G_GNUC_UNUSED int argc, char *argv[])
+{
+	float db;
+
+	if (!check_float(client, &db, argv[1]))
+		return COMMAND_RETURN_ERROR;
+	pc_set_mixramp_db(db);
+
+	return COMMAND_RETURN_OK;
+}
+
+static enum command_return
+handle_mixrampdelay(struct client *client, G_GNUC_UNUSED int argc, char *argv[])
+{
+	float delay_secs;
+
+	if (!check_float(client, &delay_secs, argv[1]))
+		return COMMAND_RETURN_ERROR;
+	pc_set_mixramp_delay(delay_secs);
+
+	return COMMAND_RETURN_OK;
+}
+
+static enum command_return
 handle_enableoutput(struct client *client, G_GNUC_UNUSED int argc, char *argv[])
 {
 	unsigned device;
@@ -1805,6 +1852,8 @@ static const struct command commands[] = {
 	{ "listplaylists", PERMISSION_READ, 0, 0, handle_listplaylists },
 	{ "load", PERMISSION_ADD, 1, 1, handle_load },
 	{ "lsinfo", PERMISSION_READ, 0, 1, handle_lsinfo },
+	{ "mixrampdb", PERMISSION_CONTROL, 1, 1, handle_mixrampdb },
+	{ "mixrampdelay", PERMISSION_CONTROL, 1, 1, handle_mixrampdelay },
 	{ "move", PERMISSION_CONTROL, 2, 2, handle_move },
 	{ "moveid", PERMISSION_CONTROL, 2, 2, handle_moveid },
 	{ "next", PERMISSION_CONTROL, 0, 0, handle_next },
diff --git a/src/crossfade.c b/src/crossfade.c
index 57a6c0d13..50a35f690 100644
--- a/src/crossfade.c
+++ b/src/crossfade.c
@@ -26,34 +26,111 @@
 
 #include <assert.h>
 #include <string.h>
+#include <stdlib.h>
+#include <glib.h>
+
+#undef G_LOG_DOMAIN
+#define G_LOG_DOMAIN "crossfade"
+
+static float mixramp_interpolate(char *ramp_list, float required_db)
+{
+	float db, secs, last_db = nan(""), last_secs = 0;
+	char *ramp_str, *save_str = NULL;
+
+	/* ramp_list is a string of pairs of dBs and seconds that describe the
+	 * volume profile. Delimiters are semi-colons between pairs and spaces
+	 * between the dB and seconds of a pair.
+	 * The dB values must be monotonically increasing for this to work. */
+
+	while (1) {
+		/* Parse the dB tokens out of the input string. */
+		ramp_str = strtok_r(ramp_list, " ", &save_str);
+
+		/* Tell strtok to continue next time round. */
+		ramp_list = NULL;
+
+		/* Parse the dB value. */
+		if (NULL == ramp_str) {
+			return nan("");
+		}
+		db = (float)atof(ramp_str);
+
+		/* Parse the time. */
+		ramp_str = strtok_r(NULL, ";", &save_str);
+		if (NULL == ramp_str) {
+			return nan("");
+		}
+		secs = (float)atof(ramp_str);
+
+		/* Check for exact match. */
+		if (db == required_db) {
+			return secs;
+		}
+
+		/* Save if too quiet. */
+		if (db < required_db) {
+			last_db = db;
+			last_secs = secs;
+			continue;
+		}
+
+		/* If required db < any stored value, use the least. */
+		if (isnan(last_db)) {
+			return secs;
+		}
+
+		/* Finally, interpolate linearly. */
+		secs = last_secs + (required_db - last_db) * (secs - last_secs) / (db - last_db);
+		return secs;
+	}
+}
 
 unsigned cross_fade_calc(float duration, float total_time,
+			 float mixramp_db, float mixramp_delay,
+			 char *mixramp_start, char *mixramp_prev_end,
 			 const struct audio_format *af,
 			 const struct audio_format *old_format,
 			 unsigned max_chunks)
 {
-	unsigned int chunks;
+	unsigned int chunks = 0;
+	float chunks_f;
+	float mixramp_overlap;
 
-	if (duration <= 0 || duration >= total_time ||
+	if (duration < 0 || duration >= total_time ||
 	    /* we can't crossfade when the audio formats are different */
 	    !audio_format_equals(af, old_format))
 		return 0;
 
-	assert(duration > 0);
+	assert(duration >= 0);
 	assert(audio_format_valid(af));
 
-	chunks = audio_format_time_to_size(af) / CHUNK_SIZE;
-	chunks = (chunks * duration + 0.5);
+	chunks_f = (float)audio_format_time_to_size(af) / (float)CHUNK_SIZE;
+
+	if (isnan(mixramp_delay) || !(mixramp_start) || !(mixramp_prev_end)) {
+		chunks = (chunks_f * duration + 0.5);
+	} else {
+		/* Calculate mixramp overlap.
+		 * FIXME factor in ReplayGain for both songs. */
+		mixramp_overlap = mixramp_interpolate(mixramp_start, mixramp_db)
+		  + mixramp_interpolate(mixramp_prev_end, mixramp_db);
+		if (!isnan(mixramp_overlap) && (mixramp_delay <= mixramp_overlap)) {
+			chunks = (chunks_f * (mixramp_overlap - mixramp_delay));
+			g_debug("will overlap %d chunks, %fs", chunks,
+				mixramp_overlap - mixramp_delay);
+		}
+	}
 
-	if (chunks > max_chunks)
+	if (chunks > max_chunks) {
 		chunks = max_chunks;
+		g_warning("audio_buffer_size too small for computed MixRamp overlap");
+	}
 
 	return chunks;
 }
 
 void cross_fade_apply(struct music_chunk *a, const struct music_chunk *b,
 		      const struct audio_format *format,
-		      unsigned int current_chunk, unsigned int num_chunks)
+		      float mix_ratio)
 {
 	size_t size;
 
@@ -61,7 +138,6 @@ void cross_fade_apply(struct music_chunk *a, const struct music_chunk *b,
 	assert(b != NULL);
 	assert(a->length == 0 || b->length == 0 ||
 	       audio_format_equals(&a->audio_format, &b->audio_format));
-	assert(current_chunk <= num_chunks);
 
 	if (a->tag == NULL && b->tag != NULL)
 		/* merge the tag into the destination chunk */
@@ -75,7 +151,7 @@ void cross_fade_apply(struct music_chunk *a, const struct music_chunk *b,
 		b->data,
 		size,
 		format,
-		((float)current_chunk) / num_chunks);
+		mix_ratio);
 
 	if (b->length > a->length) {
 		/* the second buffer is larger than the first one:
diff --git a/src/crossfade.h b/src/crossfade.h
index 81ba91418..d313b4738 100644
--- a/src/crossfade.h
+++ b/src/crossfade.h
@@ -28,6 +28,10 @@ struct music_chunk;
  *
  * @param duration the requested crossfade duration
  * @param total_time total_time the duration of the new song
+ * @param mixramp_db the current mixramp_db setting
+ * @param mixramp_delay the current mixramp_delay setting
+ * @param mixramp_start the next songs mixramp_start tag
+ * @param mixramp_prev_end the last songs mixramp_end setting
  * @param af the audio format of the new song
  * @param old_format the audio format of the current song
  * @param max_chunks the maximum number of chunks
@@ -35,6 +39,8 @@ struct music_chunk;
  * should be disabled for this song change
  */
 unsigned cross_fade_calc(float duration, float total_time,
+			 float mixramp_db, float mixramp_delay,
+			 char *mixramp_start, char *mixramp_prev_end,
 			 const struct audio_format *af,
 			 const struct audio_format *old_format,
 			 unsigned max_chunks);
@@ -51,6 +57,6 @@ unsigned cross_fade_calc(float duration, float total_time,
  */
 void cross_fade_apply(struct music_chunk *a, const struct music_chunk *b,
 		      const struct audio_format *format,
-		      unsigned int current_chunk, unsigned int num_chunks);
+		      float mix_ratio);
 
 #endif
diff --git a/src/decoder/_flac_common.c b/src/decoder/_flac_common.c
index b642121ba..6f6d33f05 100644
--- a/src/decoder/_flac_common.c
+++ b/src/decoder/_flac_common.c
@@ -102,11 +102,6 @@ flac_got_stream_info(struct flac_data *data,
 	if (data->total_frames == 0)
 		data->total_frames = stream_info->total_samples;
 
-	decoder_initialized(data->decoder, &data->audio_format,
-			    data->input_stream->seekable,
-			    (float)data->total_frames /
-			    (float)data->audio_format.sample_rate);
-
 	data->initialized = true;
 }
 
@@ -117,6 +112,8 @@ void flac_metadata_common_cb(const FLAC__StreamMetadata * block,
 		return;
 
 	struct replay_gain_info rgi;
+	char *mixramp_start;
+	char *mixramp_end;
 
 	switch (block->type) {
 	case FLAC__METADATA_TYPE_STREAMINFO:
@@ -126,6 +123,10 @@ void flac_metadata_common_cb(const FLAC__StreamMetadata * block,
 	case FLAC__METADATA_TYPE_VORBIS_COMMENT:
 		if (flac_parse_replay_gain(&rgi, block))
 			decoder_replay_gain(data->decoder, &rgi);
+		if (flac_parse_mixramp(&mixramp_start, &mixramp_end, block)) {
+			g_debug("setting mixramp_tags");
+			decoder_mixramp(data->decoder, mixramp_start, mixramp_end);
+		}
 
 		if (data->tag != NULL)
 			flac_vorbis_comments_to_tag(data->tag, NULL,
diff --git a/src/decoder/flac_decoder_plugin.c b/src/decoder/flac_decoder_plugin.c
index 022ee7045..e89e2ea11 100644
--- a/src/decoder/flac_decoder_plugin.c
+++ b/src/decoder/flac_decoder_plugin.c
@@ -247,9 +247,14 @@ flac_decoder_initialize(struct flac_data *data, FLAC__StreamDecoder *sd,
 		return false;
 	}
 
-	if (data->initialized)
+	if (data->initialized) {
 		/* done */
+		decoder_initialized(data->decoder, &data->audio_format,
+				    data->input_stream->seekable,
+				    (float)data->total_frames /
+				    (float)data->audio_format.sample_rate);
 		return true;
+	}
 
 	if (data->input_stream->seekable)
 		/* allow the workaround below only for nonseekable
diff --git a/src/decoder/flac_metadata.c b/src/decoder/flac_metadata.c
index 926cd3af7..68d15f6d4 100644
--- a/src/decoder/flac_metadata.c
+++ b/src/decoder/flac_metadata.c
@@ -80,6 +80,49 @@ flac_parse_replay_gain(struct replay_gain_info *rgi,
 	return found;
 }
 
+static bool
+flac_find_string_comment(const FLAC__StreamMetadata *block,
+			 const char *cmnt, char **str)
+{
+	int offset;
+	size_t pos;
+	int len;
+	unsigned char tmp, *p;
+
+	*str = NULL;
+	offset = FLAC__metadata_object_vorbiscomment_find_entry_from(block, 0,
+								     cmnt);
+	if (offset < 0)
+		return false;
+
+	pos = strlen(cmnt) + 1; /* 1 is for '=' */
+	len = block->data.vorbis_comment.comments[offset].length - pos;
+	if (len <= 0)
+		return false;
+
+	p = &block->data.vorbis_comment.comments[offset].entry[pos];
+	tmp = p[len];
+	p[len] = '\0';
+	*str = strdup((char *)p);
+	p[len] = tmp;
+
+	return true;
+}
+
+bool
+flac_parse_mixramp(char **mixramp_start, char **mixramp_end,
+		   const FLAC__StreamMetadata *block)
+{
+	bool found = false;
+
+	if (flac_find_string_comment(block, "mixramp_start", mixramp_start))
+		found = true;
+	if (flac_find_string_comment(block, "mixramp_end", mixramp_end))
+		found = true;
+
+	return found;
+}
+
 /**
  * Checks if the specified name matches the entry's name, and if yes,
  * returns the comment value (not null-temrinated).
diff --git a/src/decoder/flac_metadata.h b/src/decoder/flac_metadata.h
index 3cc333617..06e691d1d 100644
--- a/src/decoder/flac_metadata.h
+++ b/src/decoder/flac_metadata.h
@@ -37,6 +37,10 @@ bool
 flac_parse_replay_gain(struct replay_gain_info *rgi,
 		       const FLAC__StreamMetadata *block);
 
+bool
+flac_parse_mixramp(char **mixramp_start, char **mixramp_end,
+		   const FLAC__StreamMetadata *block);
+
 void
 flac_vorbis_comments_to_tag(struct tag *tag, const char *char_tnum,
 			    const FLAC__StreamMetadata_VorbisComment *comment);
diff --git a/src/decoder/mad_decoder_plugin.c b/src/decoder/mad_decoder_plugin.c
index 379cb9b8a..6f6ee8fa4 100644
--- a/src/decoder/mad_decoder_plugin.c
+++ b/src/decoder/mad_decoder_plugin.c
@@ -347,6 +347,47 @@ parse_id3_replay_gain_info(struct replay_gain_info *replay_gain_info,
 }
 #endif
 
+#ifdef HAVE_ID3TAG
+static bool
+parse_id3_mixramp(char **mixramp_start, char **mixramp_end,
+		  struct id3_tag *tag)
+{
+	int i;
+	char *key;
+	char *value;
+	struct id3_frame *frame;
+	bool found = false;
+
+	*mixramp_start = NULL;
+	*mixramp_end = NULL;
+
+	for (i = 0; (frame = id3_tag_findframe(tag, "TXXX", i)); i++) {
+		if (frame->nfields < 3)
+			continue;
+
+		key = (char *)
+		    id3_ucs4_latin1duplicate(id3_field_getstring
+					     (&frame->fields[1]));
+		value = (char *)
+		    id3_ucs4_latin1duplicate(id3_field_getstring
+					     (&frame->fields[2]));
+
+		if (g_ascii_strcasecmp(key, "mixramp_start") == 0) {
+			*mixramp_start = strdup(value);
+			found = true;
+		} else if (g_ascii_strcasecmp(key, "mixramp_end") == 0) {
+			*mixramp_end = strdup(value);
+			found = true;
+		}
+
+		free(key);
+		free(value);
+	}
+
+	return found;
+}
+#endif
+
 static void mp3_parse_id3(struct mp3_data *data, size_t tagsize,
 			  struct tag **mpd_tag)
 {
@@ -403,10 +444,16 @@ static void mp3_parse_id3(struct mp3_data *data, size_t tagsize,
 
 	if (data->decoder != NULL) {
 		struct replay_gain_info rgi;
+		char *mixramp_start;
+		char *mixramp_end;
 		if (parse_id3_replay_gain_info(&rgi, id3_tag)) {
 			decoder_replay_gain(data->decoder, &rgi);
 			data->found_replay_gain = true;
 		}
+		if (parse_id3_mixramp(&mixramp_start, &mixramp_end, id3_tag)) {
+			g_debug("setting mixramp_tags");
+			decoder_mixramp(data->decoder, mixramp_start, mixramp_end);
+		}
 	}
 
 	id3_tag_delete(id3_tag);
diff --git a/src/decoder_api.c b/src/decoder_api.c
index fc7ed3900..948ccb567 100644
--- a/src/decoder_api.c
+++ b/src/decoder_api.c
@@ -427,3 +427,15 @@ decoder_replay_gain(struct decoder *decoder,
 	} else
 		decoder->replay_gain_serial = 0;
 }
+
+void
+decoder_mixramp(struct decoder *decoder,
+		char *mixramp_start, char *mixramp_end)
+{
+	assert(decoder != NULL);
+	struct decoder_control *dc = decoder->dc;
+	assert(dc != NULL);
+
+	dc_mixramp_start(dc, mixramp_start);
+	dc_mixramp_end(dc, mixramp_end);
+}
diff --git a/src/decoder_api.h b/src/decoder_api.h
index 8c7133251..e2b645f6d 100644
--- a/src/decoder_api.h
+++ b/src/decoder_api.h
@@ -157,4 +157,15 @@ void
 decoder_replay_gain(struct decoder *decoder,
 		    const struct replay_gain_info *replay_gain_info);
 
+/**
+ * Store MixRamp tags.
+ *
+ * @param decoder the decoder object
+ * @param mixramp_start the mixramp_start tag; may be NULL to invalidate
+ * @param mixramp_end the mixramp_end tag; may be NULL to invalidate
+ */
+void
+decoder_mixramp(struct decoder *decoder,
+		char *mixramp_start, char *mixramp_end);
+
 #endif
diff --git a/src/decoder_control.c b/src/decoder_control.c
index eeb4670a0..7388d307f 100644
--- a/src/decoder_control.c
+++ b/src/decoder_control.c
@@ -22,6 +22,10 @@
 #include "player_control.h"
 
 #include <assert.h>
+#include <malloc.h>
+
+#undef G_LOG_DOMAIN
+#define G_LOG_DOMAIN "decoder_control"
 
 void
 dc_init(struct decoder_control *dc)
@@ -33,6 +37,10 @@ dc_init(struct decoder_control *dc)
 
 	dc->state = DECODE_STATE_STOP;
 	dc->command = DECODE_COMMAND_NONE;
+
+	dc->mixramp_start = NULL;
+	dc->mixramp_end = NULL;
+	dc->mixramp_prev_end = NULL;
 }
 
 void
@@ -40,6 +48,15 @@ dc_deinit(struct decoder_control *dc)
 {
 	g_cond_free(dc->cond);
 	g_mutex_free(dc->mutex);
+	if (dc->mixramp_start)
+		free(dc->mixramp_start);
+	if (dc->mixramp_end)
+		free(dc->mixramp_end);
+	if (dc->mixramp_prev_end)
+		free(dc->mixramp_prev_end);
+	dc->mixramp_start = NULL;
+	dc->mixramp_end = NULL;
+	dc->mixramp_prev_end = NULL;
 }
 
 static void
@@ -147,3 +164,36 @@ dc_quit(struct decoder_control *dc)
 	g_thread_join(dc->thread);
 	dc->thread = NULL;
 }
+
+void
+dc_mixramp_start(struct decoder_control *dc, char *mixramp_start)
+{
+	assert(dc != NULL);
+
+	if (dc->mixramp_start)
+		free(dc->mixramp_start);
+	dc->mixramp_start = mixramp_start;
+	g_debug("mixramp_start = %s", mixramp_start ? mixramp_start : "NULL");
+}
+
+void
+dc_mixramp_end(struct decoder_control *dc, char *mixramp_end)
+{
+	assert(dc != NULL);
+
+	if (dc->mixramp_end)
+		free(dc->mixramp_end);
+	dc->mixramp_end = mixramp_end;
+	g_debug("mixramp_end = %s", mixramp_end ? mixramp_end : "NULL");
+}
+
+void
+dc_mixramp_prev_end(struct decoder_control *dc, char *mixramp_prev_end)
+{
+	assert(dc != NULL);
+
+	if (dc->mixramp_prev_end)
+		free(dc->mixramp_prev_end);
+	dc->mixramp_prev_end = mixramp_prev_end;
+	g_debug("mixramp_prev_end = %s", mixramp_prev_end ? mixramp_prev_end : "NULL");
+}
diff --git a/src/decoder_control.h b/src/decoder_control.h
index 9c6f6e88c..7794258c9 100644
--- a/src/decoder_control.h
+++ b/src/decoder_control.h
@@ -89,6 +89,10 @@ struct decoder_control {
 	 * owns this object, and is responsible for freeing it.
 	 */
 	struct music_pipe *pipe;
+
+	char *mixramp_start;
+	char *mixramp_end;
+	char *mixramp_prev_end;
 };
 
 void
@@ -235,4 +239,13 @@ dc_seek(struct decoder_control *dc, double where);
 void
 dc_quit(struct decoder_control *dc);
 
+void
+dc_mixramp_start(struct decoder_control *dc, char *mixramp_start);
+
+void
+dc_mixramp_end(struct decoder_control *dc, char *mixramp_end);
+
+void
+dc_mixramp_prev_end(struct decoder_control *dc, char *mixramp_prev_end);
+
 #endif
diff --git a/src/decoder_thread.c b/src/decoder_thread.c
index 99fa2c7e2..3eab61295 100644
--- a/src/decoder_thread.c
+++ b/src/decoder_thread.c
@@ -23,6 +23,7 @@
 #include "decoder_internal.h"
 #include "decoder_list.h"
 #include "decoder_plugin.h"
+#include "decoder_api.h"
 #include "input_stream.h"
 #include "player_control.h"
 #include "pipe.h"
@@ -36,6 +37,9 @@
 
 #include <unistd.h>
 
+#undef G_LOG_DOMAIN
+#define G_LOG_DOMAIN "decoder_thread"
+
 static enum decoder_command
 decoder_lock_get_command(struct decoder_control *dc)
 {
@@ -430,6 +434,13 @@ decoder_task(gpointer arg)
 
 		switch (dc->command) {
 		case DECODE_COMMAND_START:
+			g_debug("clearing mixramp tags");
+			dc_mixramp_start(dc, NULL);
+			dc_mixramp_prev_end(dc, dc->mixramp_end);
+			dc->mixramp_end = NULL; /* Don't free, it's copied above. */
+
+                        /* fall through */
+
 		case DECODE_COMMAND_SEEK:
 			decoder_run(dc);
 
diff --git a/src/pcm_mix.c b/src/pcm_mix.c
index 9a8aaeaca..28129608b 100644
--- a/src/pcm_mix.c
+++ b/src/pcm_mix.c
@@ -137,7 +137,16 @@ pcm_mix(void *buffer1, const void *buffer2, size_t size,
 	const struct audio_format *format, float portion1)
 {
 	int vol1;
-	float s = sin(M_PI_2 * portion1);
+	float s;
+
+	/* portion1 is between 0.0 and 1.0 for crossfading, MixRamp uses NaN
+	 * to signal mixing rather than fading */
+	if (isnan(portion1)) {
+		pcm_add(buffer1, buffer2, size, PCM_VOLUME_1, PCM_VOLUME_1, format);
+		return;
+	}
+
+	s = sin(M_PI_2 * portion1);
 	s *= s;
 
 	vol1 = s * PCM_VOLUME_1 + 0.5;
diff --git a/src/player_control.c b/src/player_control.c
index d8aed14ba..30a530a6a 100644
--- a/src/player_control.c
+++ b/src/player_control.c
@@ -30,6 +30,7 @@
 
 #include <assert.h>
 #include <stdio.h>
+#include <math.h>
 
 struct player_control pc;
 
@@ -45,6 +46,8 @@ void pc_init(unsigned buffer_chunks, unsigned int buffered_before_play)
 	pc.error = PLAYER_ERROR_NOERROR;
 	pc.state = PLAYER_STATE_STOP;
 	pc.cross_fade_seconds = 0;
+	pc.mixramp_db = 0;
+	pc.mixramp_delay_seconds = nanf("");
 }
 
 void pc_deinit(void)
@@ -305,6 +308,34 @@ pc_set_cross_fade(float cross_fade_seconds)
 	idle_add(IDLE_OPTIONS);
 }
 
+float
+pc_get_mixramp_db(void)
+{
+	return pc.mixramp_db;
+}
+
+void
+pc_set_mixramp_db(float mixramp_db)
+{
+	pc.mixramp_db = mixramp_db;
+
+	idle_add(IDLE_OPTIONS);
+}
+
+float
+pc_get_mixramp_delay(void)
+{
+	return pc.mixramp_delay_seconds;
+}
+
+void
+pc_set_mixramp_delay(float mixramp_delay_seconds)
+{
+	pc.mixramp_delay_seconds = mixramp_delay_seconds;
+
+	idle_add(IDLE_OPTIONS);
+}
+
 double
 pc_get_total_play_time(void)
 {
diff --git a/src/player_control.h b/src/player_control.h
index 9735b01fd..76c47609a 100644
--- a/src/player_control.h
+++ b/src/player_control.h
@@ -111,6 +111,8 @@ struct player_control {
 	const struct song *errored_song;
 	double seek_where;
 	float cross_fade_seconds;
+	float mixramp_db;
+	float mixramp_delay_seconds;
 	double total_play_time;
 };
 
@@ -250,6 +252,18 @@ pc_set_cross_fade(float cross_fade_seconds);
 float
 pc_get_cross_fade(void);
 
+void
+pc_set_mixramp_db(float mixramp_db);
+
+float
+pc_get_mixramp_db(void);
+
+void
+pc_set_mixramp_delay(float mixramp_delay_seconds);
+
+float
+pc_get_mixramp_delay(void);
+
 double
 pc_get_total_play_time(void);
 
diff --git a/src/player_thread.c b/src/player_thread.c
index 2496f0cdb..d3f5d7ccb 100644
--- a/src/player_thread.c
+++ b/src/player_thread.c
@@ -644,13 +644,21 @@ play_next_chunk(struct player *player)
 		}
 
 		if (other_chunk != NULL) {
+			float mix_ratio;
+
 			chunk = music_pipe_shift(player->pipe);
 			assert(chunk != NULL);
 
+			if (isnan(pc.mixramp_delay_seconds)) {
+				mix_ratio = ((float)cross_fade_position)
+					     / player->cross_fade_chunks;
+			} else {
+				mix_ratio = nan("");
+			}
+
 			cross_fade_apply(chunk, other_chunk,
 					 &dc->out_audio_format,
-					 cross_fade_position,
-					 player->cross_fade_chunks);
+					 mix_ratio);
 			music_buffer_return(player_buffer, other_chunk);
 		} else {
 			/* there are not enough decoded chunks yet */
@@ -865,6 +873,10 @@ static void do_play(struct decoder_control *dc)
 			   for it */
 			player.cross_fade_chunks =
 				cross_fade_calc(pc.cross_fade_seconds, dc->total_time,
+						pc.mixramp_db,
+						pc.mixramp_delay_seconds,
+						dc->mixramp_start,
+						dc->mixramp_prev_end,
 						&dc->out_audio_format,
 						&player.play_audio_format,
 						music_buffer_size(player_buffer) -
diff --git a/src/playlist_state.c b/src/playlist_state.c
index 93e64ccba..9f057332d 100644
--- a/src/playlist_state.c
+++ b/src/playlist_state.c
@@ -40,6 +40,8 @@
 #define PLAYLIST_STATE_FILE_CURRENT		"current: "
 #define PLAYLIST_STATE_FILE_TIME		"time: "
 #define PLAYLIST_STATE_FILE_CROSSFADE		"crossfade: "
+#define PLAYLIST_STATE_FILE_MIXRAMPDB		"mixrampdb: "
+#define PLAYLIST_STATE_FILE_MIXRAMPDELAY	"mixrampdelay: "
 #define PLAYLIST_STATE_FILE_PLAYLIST_BEGIN	"playlist_begin"
 #define PLAYLIST_STATE_FILE_PLAYLIST_END	"playlist_end"
 
@@ -90,6 +92,10 @@ playlist_state_save(FILE *fp, const struct playlist *playlist)
 		playlist->queue.consume);
 	fprintf(fp, "%s%i\n", PLAYLIST_STATE_FILE_CROSSFADE,
 		(int)(pc_get_cross_fade()));
+	fprintf(fp, "%s%f\n", PLAYLIST_STATE_FILE_MIXRAMPDB,
+		pc_get_mixramp_db());
+	fprintf(fp, "%s%f\n", PLAYLIST_STATE_FILE_MIXRAMPDELAY,
+		pc_get_mixramp_delay());
 	fprintf(fp, "%s\n", PLAYLIST_STATE_FILE_PLAYLIST_BEGIN);
 	queue_save(fp, &playlist->queue);
 	fprintf(fp, "%s\n", PLAYLIST_STATE_FILE_PLAYLIST_END);
@@ -168,6 +174,10 @@ playlist_state_restore(const char *line, FILE *fp, struct playlist *playlist)
 				playlist_set_consume(playlist, false);
 		} else if (g_str_has_prefix(buffer, PLAYLIST_STATE_FILE_CROSSFADE)) {
 			pc_set_cross_fade(atoi(buffer + strlen(PLAYLIST_STATE_FILE_CROSSFADE)));
+		} else if (g_str_has_prefix(buffer, PLAYLIST_STATE_FILE_MIXRAMPDB)) {
+			pc_set_mixramp_db(atof(buffer + strlen(PLAYLIST_STATE_FILE_MIXRAMPDB)));
+		} else if (g_str_has_prefix(buffer, PLAYLIST_STATE_FILE_MIXRAMPDELAY)) {
+			pc_set_mixramp_delay(atof(buffer + strlen(PLAYLIST_STATE_FILE_MIXRAMPDELAY)));
 		} else if (g_str_has_prefix(buffer, PLAYLIST_STATE_FILE_RANDOM)) {
 			random_mode =
 				strcmp(buffer + strlen(PLAYLIST_STATE_FILE_RANDOM),