refactor pcm reader framework

[fdkaac.git] / src / pcm_float_converter.c

diff --git a/src/pcm_float_converter.c b/src/pcm_float_converter.c
new file mode 100644 (file)
index 0000000..594879f
--- /dev/null
+++ b/src/pcm_float_converter.c
@@ -0,0 +1,85 @@
+/* 
+ * Copyright (C) 2013 nu774
+ * For conditions of distribution and use, see copyright notice in COPYING
+ */
+#if HAVE_CONFIG_H
+#  include "config.h"
+#endif
+#include <stdlib.h>
+#include <string.h>
+#if HAVE_STDINT_H
+#  include <stdint.h>
+#endif
+#include "pcm_reader.h"
+
+typedef struct pcm_float_converter_t {
+    pcm_reader_vtbl_t *vtbl;
+    pcm_reader_t *src;
+    pcm_sample_description_t format;
+} pcm_float_converter_t;
+
+static inline pcm_reader_t *get_source(pcm_reader_t *reader)
+{
+    return ((pcm_float_converter_t *)reader)->src;
+}
+
+static const
+pcm_sample_description_t *get_format(pcm_reader_t *reader)
+{
+    return &((pcm_float_converter_t *)reader)->format;
+}
+
+static int64_t get_length(pcm_reader_t *reader)
+{
+    return pcm_get_length(get_source(reader));
+}
+
+static int64_t get_position(pcm_reader_t *reader)
+{
+    return pcm_get_position(get_source(reader));
+}
+
+static int read_frames(pcm_reader_t *reader, void *buffer, unsigned nframes)
+{
+    unsigned i;
+    pcm_float_converter_t *self = (pcm_float_converter_t *)reader;
+    const pcm_sample_description_t *sfmt = pcm_get_format(self->src);
+    nframes = pcm_read_frames(self->src, buffer, nframes);
+    if (!(sfmt->sample_type & PCM_TYPE_FLOAT)) {
+        int32_t *ip = buffer;
+        float   *op = buffer;
+        unsigned i, count = nframes * sfmt->channels_per_frame;
+        for (i = 0; i < count; ++i)
+            op[i] = ip[i] / 2147483648.0f;
+    }
+    return nframes;
+}
+
+static void teardown(pcm_reader_t **reader)
+{
+    pcm_float_converter_t *self = (pcm_float_converter_t *)*reader;
+    pcm_teardown(&self->src);
+    free(self);
+    *reader = 0;
+}
+
+static pcm_reader_vtbl_t my_vtable = {
+    get_format, get_length, get_position, read_frames, teardown
+};
+
+pcm_reader_t *pcm_open_float_converter(pcm_reader_t *reader)
+{
+    pcm_float_converter_t *self = 0;
+    pcm_sample_description_t *fmt;
+
+    if ((self = calloc(1, sizeof(pcm_float_converter_t))) == 0)
+        return 0;
+    self->src = reader;
+    self->vtbl = &my_vtable;
+    memcpy(&self->format, pcm_get_format(reader), sizeof(self->format));
+    fmt = &self->format;
+    fmt->bits_per_channel = 32;
+    fmt->sample_type = PCM_TYPE_FLOAT;
+    fmt->bytes_per_frame = 4 * fmt->channels_per_frame;
+    return (pcm_reader_t *)self;
+}