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authorMax Kellermann <max@duempel.org>2009-11-10 17:11:34 +0100
committerMax Kellermann <max@duempel.org>2009-12-02 22:29:50 +0100
commitc412d6251e9cd3abe735b7622af4003502e54f72 (patch)
tree7344c13f62e4cc788c830c05d21bb7b5b47f5866 /src/audio_format.h
parent68c2cfbb4067b2292e1ff1d4e7716ff370903f84 (diff)
downloadmpd-c412d6251e9cd3abe735b7622af4003502e54f72.tar.gz
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audio_format: changed "bits" to "enum sample_format"
This patch prepares support for floating point samples (and probably other formats). It changes the meaning of the "bits" attribute from a bit count to a symbolic value.
Diffstat (limited to 'src/audio_format.h')
-rw-r--r--src/audio_format.h86
1 files changed, 67 insertions, 19 deletions
diff --git a/src/audio_format.h b/src/audio_format.h
index 0c1e425a9..6e7d50c46 100644
--- a/src/audio_format.h
+++ b/src/audio_format.h
@@ -23,6 +23,21 @@
#include <stdint.h>
#include <stdbool.h>
+enum sample_format {
+ SAMPLE_FORMAT_UNDEFINED = 0,
+
+ SAMPLE_FORMAT_S8,
+ SAMPLE_FORMAT_S16,
+
+ /**
+ * Signed 24 bit integer samples, packed in 32 bit integers
+ * (the most significant byte is filled with the sign bit).
+ */
+ SAMPLE_FORMAT_S24_P32,
+
+ SAMPLE_FORMAT_S32,
+};
+
/**
* This structure describes the format of a raw PCM stream.
*/
@@ -35,11 +50,10 @@ struct audio_format {
uint32_t sample_rate;
/**
- * The number of significant bits per sample. Samples are
- * currently always signed. Supported values are 8, 16, 24,
- * 32. 24 bit samples are packed in 32 bit integers.
+ * The format samples are stored in. See the #sample_format
+ * enum for valid values.
*/
- uint8_t bits;
+ uint8_t format;
/**
* The number of channels. Only mono (1) and stereo (2) are
@@ -69,7 +83,7 @@ struct audio_format_string {
static inline void audio_format_clear(struct audio_format *af)
{
af->sample_rate = 0;
- af->bits = 0;
+ af->format = SAMPLE_FORMAT_UNDEFINED;
af->channels = 0;
af->reverse_endian = 0;
}
@@ -80,10 +94,10 @@ static inline void audio_format_clear(struct audio_format *af)
*/
static inline void audio_format_init(struct audio_format *af,
uint32_t sample_rate,
- uint8_t bits, uint8_t channels)
+ enum sample_format format, uint8_t channels)
{
af->sample_rate = sample_rate;
- af->bits = bits;
+ af->format = (uint8_t)format;
af->channels = channels;
af->reverse_endian = 0;
}
@@ -105,7 +119,8 @@ static inline bool audio_format_defined(const struct audio_format *af)
static inline bool
audio_format_fully_defined(const struct audio_format *af)
{
- return af->sample_rate != 0 && af->bits != 0 && af->channels != 0;
+ return af->sample_rate != 0 && af->format != SAMPLE_FORMAT_UNDEFINED &&
+ af->channels != 0;
}
/**
@@ -115,7 +130,8 @@ audio_format_fully_defined(const struct audio_format *af)
static inline bool
audio_format_mask_defined(const struct audio_format *af)
{
- return af->sample_rate != 0 || af->bits != 0 || af->channels != 0;
+ return af->sample_rate != 0 || af->format != SAMPLE_FORMAT_UNDEFINED ||
+ af->channels != 0;
}
/**
@@ -135,9 +151,20 @@ audio_valid_sample_rate(unsigned sample_rate)
* @param bits the number of significant bits per sample
*/
static inline bool
-audio_valid_sample_format(unsigned bits)
+audio_valid_sample_format(enum sample_format format)
{
- return bits == 16 || bits == 24 || bits == 32 || bits == 8;
+ switch (format) {
+ case SAMPLE_FORMAT_S8:
+ case SAMPLE_FORMAT_S16:
+ case SAMPLE_FORMAT_S24_P32:
+ case SAMPLE_FORMAT_S32:
+ return true;
+
+ case SAMPLE_FORMAT_UNDEFINED:
+ break;
+ }
+
+ return false;
}
/**
@@ -156,7 +183,7 @@ audio_valid_channel_count(unsigned channels)
static inline bool audio_format_valid(const struct audio_format *af)
{
return audio_valid_sample_rate(af->sample_rate) &&
- audio_valid_sample_format(af->bits) &&
+ audio_valid_sample_format((enum sample_format)af->format) &&
audio_valid_channel_count(af->channels);
}
@@ -168,7 +195,8 @@ static inline bool audio_format_mask_valid(const struct audio_format *af)
{
return (af->sample_rate == 0 ||
audio_valid_sample_rate(af->sample_rate)) &&
- (af->bits == 0 || audio_valid_sample_format(af->bits)) &&
+ (af->format == SAMPLE_FORMAT_UNDEFINED ||
+ audio_valid_sample_format((enum sample_format)af->format)) &&
(af->channels == 0 || audio_valid_channel_count(af->channels));
}
@@ -176,7 +204,7 @@ static inline bool audio_format_equals(const struct audio_format *a,
const struct audio_format *b)
{
return a->sample_rate == b->sample_rate &&
- a->bits == b->bits &&
+ a->format == b->format &&
a->channels == b->channels &&
a->reverse_endian == b->reverse_endian;
}
@@ -188,8 +216,8 @@ audio_format_mask_apply(struct audio_format *af,
if (mask->sample_rate != 0)
af->sample_rate = mask->sample_rate;
- if (mask->bits != 0)
- af->bits = mask->bits;
+ if (mask->format != SAMPLE_FORMAT_UNDEFINED)
+ af->format = mask->format;
if (mask->channels != 0)
af->channels = mask->channels;
@@ -200,12 +228,22 @@ audio_format_mask_apply(struct audio_format *af,
*/
static inline unsigned audio_format_sample_size(const struct audio_format *af)
{
- if (af->bits <= 8)
+ switch (af->format) {
+ case SAMPLE_FORMAT_S8:
return 1;
- else if (af->bits <= 16)
+
+ case SAMPLE_FORMAT_S16:
return 2;
- else
+
+ case SAMPLE_FORMAT_S24_P32:
+ case SAMPLE_FORMAT_S32:
return 4;
+
+ case SAMPLE_FORMAT_UNDEFINED:
+ break;
+ }
+
+ return 0;
}
/**
@@ -227,6 +265,16 @@ static inline double audio_format_time_to_size(const struct audio_format *af)
}
/**
+ * Renders a #sample_format enum into a string, e.g. for printing it
+ * in a log file.
+ *
+ * @param format a #sample_format enum value
+ * @return the string
+ */
+const char *
+sample_format_to_string(enum sample_format format);
+
+/**
* Renders the #audio_format object into a string, e.g. for printing
* it in a log file.
*