From c412d6251e9cd3abe735b7622af4003502e54f72 Mon Sep 17 00:00:00 2001 From: Max Kellermann Date: Tue, 10 Nov 2009 17:11:34 +0100 Subject: 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. --- src/audio_format.h | 86 ++++++++++++++++++++++++++++++++++++++++++------------ 1 file changed, 67 insertions(+), 19 deletions(-) (limited to 'src/audio_format.h') diff --git a/src/audio_format.h b/src/audio_format.h index 0c1e425a..6e7d50c4 100644 --- a/src/audio_format.h +++ b/src/audio_format.h @@ -23,6 +23,21 @@ #include #include +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; } /** @@ -226,6 +264,16 @@ static inline double audio_format_time_to_size(const struct audio_format *af) return af->sample_rate * audio_format_frame_size(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. -- cgit v1.2.3