audio_format: wildcards allowed in audio_format configuration

An asterisk means that this attribute should not be enforced, and
stays whatever it used to be.  This way, some configuration values
work like masks.

1 files changed, 47 insertions, 0 deletions

diff --git a/src/audio_format.h b/src/audio_format.h
index a88fc3a4..a4f5ba2e 100644
--- a/src/audio_format.h
+++ b/src/audio_format.h
@@ -91,6 +91,27 @@ static inline bool audio_format_defined(const struct audio_format *af)
 }
 
 /**
+ * Checks whether the specified #audio_format object is full, i.e. all
+ * attributes are defined.  This is more complete than
+ * audio_format_defined(), but slower.
+ */
+static inline bool
+audio_format_fully_defined(const struct audio_format *af)
+{
+	return af->sample_rate != 0 && af->bits != 0 && af->channels != 0;
+}
+
+/**
+ * Checks whether the specified #audio_format object has at least one
+ * defined value.
+ */
+static inline bool
+audio_format_mask_defined(const struct audio_format *af)
+{
+	return af->sample_rate != 0 || af->bits != 0 || af->channels != 0;
+}
+
+/**
  * Checks whether the sample rate is valid.
  *
  * @param sample_rate the sample rate in Hz
@@ -132,6 +153,18 @@ static inline bool audio_format_valid(const struct audio_format *af)
 		audio_valid_channel_count(af->channels);
 }
 
+/**
+ * Returns false if the format mask is not valid for playback with
+ * MPD.  This function performs some basic validity checks.
+ */
+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->channels == 0 || audio_valid_channel_count(af->channels));
+}
+
 static inline bool audio_format_equals(const struct audio_format *a,
 				       const struct audio_format *b)
 {
@@ -141,6 +174,20 @@ static inline bool audio_format_equals(const struct audio_format *a,
 		a->reverse_endian == b->reverse_endian;
 }
 
+static inline void
+audio_format_mask_apply(struct audio_format *af,
+			const struct audio_format *mask)
+{
+	if (mask->sample_rate != 0)
+		af->sample_rate = mask->sample_rate;
+
+	if (mask->bits != 0)
+		af->bits = mask->bits;
+
+	if (mask->channels != 0)
+		af->channels = mask->channels;
+}
+
 /**
  * Returns the size of each (mono) sample in bytes.
  */