pcm_utils: moved code to pcm_resample.c

Separate the resampling code from the rest of pcm_utils.c. Create two sub-libraries: pcm_resample_libsamplerate.c and pcm_resample_fallback.c.
2008-10-23 20:00:51 +02:00
parent 098991f8e8
commit 6b1c54ef96
8 changed files with 308 additions and 176 deletions
@@ -0,0 +1,61 @@
+/* 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 "pcm_resample.h"
+#include "gcc.h"
+
+/* resampling code blatantly ripped from ESD */
+size_t
+pcm_resample_16(uint8_t channels,
+		unsigned src_rate,
+		const int16_t *src_buffer, mpd_unused size_t src_size,
+		unsigned dest_rate,
+		int16_t *dest_buffer, size_t dest_size,
+		mpd_unused struct pcm_resample_state *state)
+{
+	unsigned src_pos, dest_pos = 0;
+	unsigned dest_samples = dest_size / 2;
+	int16_t lsample, rsample;
+
+	switch (channels) {
+	case 1:
+		while (dest_pos < dest_samples) {
+			src_pos = dest_pos * src_rate / dest_rate;
+
+			lsample = src_buffer[src_pos++];
+
+			dest_buffer[dest_pos++] = lsample;
+		}
+		break;
+	case 2:
+		while (dest_pos < dest_samples) {
+			src_pos = dest_pos * src_rate / dest_rate;
+			src_pos &= ~1;
+
+			lsample = src_buffer[src_pos++];
+			rsample = src_buffer[src_pos++];
+
+			dest_buffer[dest_pos++] = lsample;
+			dest_buffer[dest_pos++] = rsample;
+		}
+		break;
+	}
+
+	return dest_size;
+}