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.

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,

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

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).

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);

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);