import dsd2pcm_src.zip

[this is the code from dsd2pcm_src.zip, published on a forum by
Sebastian Gesemann.  Upon request, he has given permission to
redistribute and modify his code, without referring to a specific
license. - mk]

1 files changed, 64 insertions, 0 deletions

diff --git a/src/dsd2pcm/dsd2pcm.h b/src/dsd2pcm/dsd2pcm.h
new file mode 100644
index 00000000..26f6b6f1
--- /dev/null
+++ b/src/dsd2pcm/dsd2pcm.h
@@ -0,0 +1,64 @@
+#ifndef DSD2PCM_H_INCLUDED
+#define DSD2PCM_H_INCLUDED
+
+#include <stddef.h>
+#include <string.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct dsd2pcm_ctx_s;
+
+typedef struct dsd2pcm_ctx_s dsd2pcm_ctx;
+
+/**
+ * initializes a "dsd2pcm engine" for one channel
+ * (precomputes tables and allocates memory)
+ *
+ * This is the only function that is not thread-safe in terms of the
+ * POSIX thread-safety definition because it modifies global state
+ * (lookup tables are computed during the first call)
+ */
+extern dsd2pcm_ctx* dsd2pcm_init();
+
+/**
+ * deinitializes a "dsd2pcm engine"
+ * (releases memory, don't forget!)
+ */
+extern void dsd2pcm_destroy(dsd2pcm_ctx *ctx);
+
+/**
+ * clones the context and returns a pointer to the
+ * newly allocated copy
+ */
+extern dsd2pcm_ctx* dsd2pcm_clone(dsd2pcm_ctx *ctx);
+
+/**
+ * resets the internal state for a fresh new stream
+ */
+extern void dsd2pcm_reset(dsd2pcm_ctx *ctx);
+
+/**
+ * "translates" a stream of octets to a stream of floats
+ * (8:1 decimation)
+ * @param ctx -- pointer to abstract context (buffers)
+ * @param samples -- number of octets/samples to "translate"
+ * @param src -- pointer to first octet (input)
+ * @param src_stride -- src pointer increment
+ * @param lsbitfirst -- bitorder, 0=msb first, 1=lsbfirst
+ * @param dst -- pointer to first float (output)
+ * @param dst_stride -- dst pointer increment
+ */
+extern void dsd2pcm_translate(dsd2pcm_ctx *ctx,
+	size_t samples,
+	const unsigned char *src, ptrdiff_t src_stride,
+	int lsbitfirst,
+	float *dst, ptrdiff_t dst_stride);
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
+#endif /* include guard DSD2PCM_H_INCLUDED */
+