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authorMax Kellermann <max@duempel.org>2011-10-08 15:36:29 +0200
committerMax Kellermann <max@duempel.org>2011-10-20 02:55:05 +0200
commit8465c5fe0e154b96edea992fdcb574060934b9e5 (patch)
tree243362cb3db60395f4bdb29170f096b73b3a8937
parent42e248a8da0f2043e752166d4a34615c850384ec (diff)
downloadmpd-8465c5fe0e154b96edea992fdcb574060934b9e5.tar.gz
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pcm_format: implement conversion to float
Diffstat (limited to '')
-rw-r--r--src/pcm_convert.c69
-rw-r--r--src/pcm_format.c135
-rw-r--r--src/pcm_format.h15
3 files changed, 218 insertions, 1 deletions
diff --git a/src/pcm_convert.c b/src/pcm_convert.c
index 58137fd0e..daf1cd234 100644
--- a/src/pcm_convert.c
+++ b/src/pcm_convert.c
@@ -24,6 +24,7 @@
#include "pcm_byteswap.h"
#include "pcm_pack.h"
#include "audio_format.h"
+#include "glib_compat.h"
#include <assert.h>
#include <string.h>
@@ -56,7 +57,6 @@ void pcm_convert_deinit(struct pcm_convert_state *state)
pcm_buffer_deinit(&state->byteswap_buffer);
}
-G_GNUC_UNUSED
static const void *
pcm_convert_channels(struct pcm_buffer *buffer, enum sample_format format,
uint8_t dest_channels,
@@ -312,6 +312,67 @@ pcm_convert_32(struct pcm_convert_state *state,
return buf;
}
+static const float *
+pcm_convert_float(struct pcm_convert_state *state,
+ const struct audio_format *src_format,
+ const void *src_buffer, size_t src_size,
+ const struct audio_format *dest_format, size_t *dest_size_r,
+ GError **error_r)
+{
+ const float *buffer = src_buffer;
+ size_t size = src_size;
+
+ assert(dest_format->format == SAMPLE_FORMAT_FLOAT);
+
+ if (src_format->reverse_endian || dest_format->reverse_endian) {
+ g_set_error_literal(error_r, pcm_convert_quark(), 0,
+ "Reverse endian not supported");
+ return NULL;
+ }
+
+ /* convert channels first, hoping the source format is
+ supported (float is not) */
+
+ if (dest_format->channels != src_format->channels) {
+ buffer = pcm_convert_channels(&state->channels_buffer,
+ src_format->format,
+ dest_format->channels,
+ src_format->channels,
+ buffer, size, &size, error_r);
+ if (buffer == NULL)
+ return NULL;
+ }
+
+ /* convert to float now */
+
+ buffer = pcm_convert_to_float(&state->format_buffer,
+ src_format->format,
+ buffer, size, &size);
+ if (buffer == NULL) {
+ g_set_error(error_r, pcm_convert_quark(), 0,
+ "Conversion from %s to float is not implemented",
+ sample_format_to_string(src_format->format));
+ return NULL;
+ }
+
+ /* resample with float, because this is the best format for
+ libsamplerate */
+
+ if (src_format->sample_rate != dest_format->sample_rate) {
+ buffer = pcm_resample_float(&state->resample,
+ dest_format->channels,
+ src_format->sample_rate,
+ buffer, size,
+ dest_format->sample_rate, &size,
+ error_r);
+ if (buffer == NULL)
+ return NULL;
+ }
+
+ *dest_size_r = size;
+ return buffer;
+}
+
const void *
pcm_convert(struct pcm_convert_state *state,
const struct audio_format *src_format,
@@ -359,6 +420,12 @@ pcm_convert(struct pcm_convert_state *state,
dest_format, dest_size_r,
error_r);
+ case SAMPLE_FORMAT_FLOAT:
+ return pcm_convert_float(state,
+ src_format, src, src_size,
+ dest_format, dest_size_r,
+ error_r);
+
default:
g_set_error(error_r, pcm_convert_quark(), 0,
"PCM conversion to %s is not implemented",
diff --git a/src/pcm_format.c b/src/pcm_format.c
index bb731b2b6..a20d8bb8d 100644
--- a/src/pcm_format.c
+++ b/src/pcm_format.c
@@ -418,3 +418,138 @@ pcm_convert_to_32(struct pcm_buffer *buffer,
return NULL;
}
+
+static void
+pcm_convert_8_to_float(float *out, const int8_t *in, const int8_t *in_end)
+{
+ enum { in_bits = sizeof(*in) * 8 };
+ static const float factor = 2.0f / (1 << in_bits);
+ while (in < in_end)
+ *out++ = (float)*in++ * factor;
+}
+
+static void
+pcm_convert_16_to_float(float *out, const int16_t *in, const int16_t *in_end)
+{
+ enum { in_bits = sizeof(*in) * 8 };
+ static const float factor = 2.0f / (1 << in_bits);
+ while (in < in_end)
+ *out++ = (float)*in++ * factor;
+}
+
+static void
+pcm_convert_24_to_float(float *out, const int32_t *in, const int32_t *in_end)
+{
+ enum { in_bits = 24 };
+ static const float factor = 2.0f / (1 << in_bits);
+ while (in < in_end)
+ *out++ = (float)*in++ * factor;
+}
+
+static void
+pcm_convert_32_to_float(float *out, const int32_t *in, const int32_t *in_end)
+{
+ enum { in_bits = sizeof(*in) * 8 };
+ static const float factor = 0.5f / (1 << (in_bits - 2));
+ while (in < in_end)
+ *out++ = (float)*in++ * factor;
+}
+
+static float *
+pcm_allocate_8_to_float(struct pcm_buffer *buffer,
+ const int8_t *src, size_t src_size,
+ size_t *dest_size_r)
+{
+ float *dest;
+ *dest_size_r = src_size / sizeof(*src) * sizeof(*dest);
+ dest = pcm_buffer_get(buffer, *dest_size_r);
+ pcm_convert_8_to_float(dest, src, pcm_end_pointer(src, src_size));
+ return dest;
+}
+
+static float *
+pcm_allocate_16_to_float(struct pcm_buffer *buffer,
+ const int16_t *src, size_t src_size,
+ size_t *dest_size_r)
+{
+ float *dest;
+ *dest_size_r = src_size * 2;
+ assert(*dest_size_r == src_size / sizeof(*src) * sizeof(*dest));
+ dest = pcm_buffer_get(buffer, *dest_size_r);
+ pcm_convert_16_to_float(dest, src, pcm_end_pointer(src, src_size));
+ return dest;
+}
+
+static float *
+pcm_allocate_24_to_float(struct pcm_buffer *buffer,
+ const uint8_t *src,
+ size_t src_size, size_t *dest_size_r)
+{
+ /* convert to S24_P32 first */
+ int32_t *tmp = pcm_allocate_24_to_24p32(buffer, src, src_size,
+ dest_size_r);
+
+ /* convert to float in-place */
+ float *dest = (float *)tmp;
+ pcm_convert_24_to_float(dest, tmp, pcm_end_pointer(tmp, *dest_size_r));
+ return dest;
+}
+
+static float *
+pcm_allocate_24p32_to_float(struct pcm_buffer *buffer,
+ const int32_t *src, size_t src_size,
+ size_t *dest_size_r)
+{
+ *dest_size_r = src_size;
+ float *dest = pcm_buffer_get(buffer, *dest_size_r);
+ pcm_convert_24_to_float(dest, src, pcm_end_pointer(src, src_size));
+ return dest;
+}
+
+static float *
+pcm_allocate_32_to_float(struct pcm_buffer *buffer,
+ const int32_t *src, size_t src_size,
+ size_t *dest_size_r)
+{
+ *dest_size_r = src_size;
+ float *dest = pcm_buffer_get(buffer, *dest_size_r);
+ pcm_convert_32_to_float(dest, src, pcm_end_pointer(src, src_size));
+ return dest;
+}
+
+const float *
+pcm_convert_to_float(struct pcm_buffer *buffer,
+ enum sample_format src_format, const void *src,
+ size_t src_size, size_t *dest_size_r)
+{
+ switch (src_format) {
+ case SAMPLE_FORMAT_UNDEFINED:
+ break;
+
+ case SAMPLE_FORMAT_S8:
+ return pcm_allocate_8_to_float(buffer,
+ src, src_size, dest_size_r);
+
+ case SAMPLE_FORMAT_S16:
+ return pcm_allocate_16_to_float(buffer,
+ src, src_size, dest_size_r);
+
+ case SAMPLE_FORMAT_S24:
+ return pcm_allocate_24_to_float(buffer,
+ src, src_size, dest_size_r);
+
+ case SAMPLE_FORMAT_S24_P32:
+ return pcm_allocate_24p32_to_float(buffer,
+ src, src_size, dest_size_r);
+
+ case SAMPLE_FORMAT_S32:
+ return pcm_allocate_32_to_float(buffer,
+ src, src_size, dest_size_r);
+
+ case SAMPLE_FORMAT_FLOAT:
+ *dest_size_r = src_size;
+ return src;
+ }
+
+ return NULL;
+}
diff --git a/src/pcm_format.h b/src/pcm_format.h
index 54cc32020..48bcd0662 100644
--- a/src/pcm_format.h
+++ b/src/pcm_format.h
@@ -75,4 +75,19 @@ pcm_convert_to_32(struct pcm_buffer *buffer,
enum sample_format src_format, const void *src,
size_t src_size, size_t *dest_size_r);
+/**
+ * Converts PCM samples to 32 bit floating point.
+ *
+ * @param buffer a pcm_buffer object
+ * @param bits the number of in the source buffer
+ * @param src the source PCM buffer
+ * @param src_size the size of #src in bytes
+ * @param dest_size_r returns the number of bytes of the destination buffer
+ * @return the destination buffer
+ */
+const float *
+pcm_convert_to_float(struct pcm_buffer *buffer,
+ enum sample_format src_format, const void *src,
+ size_t src_size, size_t *dest_size_r);
+
#endif