avcodec: add Direct Stream Transfer (DST) decoder

Signed-off-by: Paul B Mahol <onemda@gmail.com>

1 files changed, 53 insertions, 0 deletions

diff --git a/libavcodec/dsd.h b/libavcodec/dsd.h
new file mode 100644
index 0000000000..42a9a4872e
--- /dev/null
+++ b/libavcodec/dsd.h
@@ -0,0 +1,53 @@
+/*
+ * Direct Stream Digital (DSD) decoder
+ * based on BSD licensed dsd2pcm by Sebastian Gesemann
+ * Copyright (c) 2009, 2011 Sebastian Gesemann. All rights reserved.
+ * Copyright (c) 2014 Peter Ross
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef AVCODEC_DSD_H
+#define AVCODEC_DSD_H
+
+#include "libavcodec/internal.h"
+#include "libavcodec/mathops.h"
+#include "avcodec.h"
+#include "dsd_tablegen.h"
+
+#define HTAPS   48               /** number of FIR constants */
+#define FIFOSIZE 16              /** must be a power of two */
+#define FIFOMASK (FIFOSIZE - 1)  /** bit mask for FIFO offsets */
+
+#if FIFOSIZE * 8 < HTAPS * 2
+#error "FIFOSIZE too small"
+#endif
+
+/**
+ * Per-channel buffer
+ */
+typedef struct DSDContext {
+    unsigned char buf[FIFOSIZE];
+    unsigned pos;
+} DSDContext;
+
+void ff_init_dsd_data(void);
+
+void ff_dsd2pcm_translate(DSDContext* s, size_t samples, int lsbf,
+                          const unsigned char *src, ptrdiff_t src_stride,
+                          float *dst, ptrdiff_t dst_stride);
+#endif /* AVCODEC_DSD_H */