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-rw-r--r--src/crossfade.c62
1 files changed, 62 insertions, 0 deletions
diff --git a/src/crossfade.c b/src/crossfade.c
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+++ b/src/crossfade.c
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+/* the Music Player Daemon (MPD)
+ * Copyright (C) 2003-2007 by Warren Dukes (warren.dukes@gmail.com)
+ * Copyright (C) 2008 Max Kellermann <max@duempel.org>
+ * This project's homepage is: http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include "crossfade.h"
+#include "audio.h"
+#include "pcm_utils.h"
+
+unsigned cross_fade_calc(float duration, float total_time,
+ const AudioFormat * af,
+ unsigned max_chunks)
+{
+ unsigned int chunks;
+
+ if (duration <= 0 || duration >= total_time ||
+ !isCurrentAudioFormat(af))
+ return 0;
+
+ assert(duration > 0);
+ assert(af->bits > 0);
+ assert(af->channels > 0);
+ assert(af->sampleRate > 0);
+
+ chunks = audio_format_time_to_size(af) / CHUNK_SIZE;
+ chunks = (chunks * duration + 0.5);
+
+ if (chunks > max_chunks)
+ chunks = max_chunks;
+
+ return chunks;
+}
+
+void cross_fade_apply(ob_chunk * a, const ob_chunk * b,
+ const AudioFormat * format,
+ unsigned int current_chunk, unsigned int num_chunks)
+{
+ assert(current_chunk <= num_chunks);
+
+ pcm_mix(a->data,
+ b->data,
+ a->chunkSize,
+ b->chunkSize,
+ format,
+ ((float)current_chunk) / num_chunks);
+ if (b->chunkSize > a->chunkSize)
+ a->chunkSize = b->chunkSize;
+}