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seq: Add API functions to set different tempo base values

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MIDI2 Set Tempo message uses 10ns-based values, and we need to update
the API to change the base time unit.

This patch adds a few new API functions:
- snd_seq_has_queue_tempo_base() returns 1 if the client supports a
  new tempo-base value; if 0, it's an old system and application has
  to use the tempo in the fixed 1us unit
- the tempo base can be changed with
  snd_seq_queue_tempo_set_tempo_base(), provided in nsec unit;
  the value has to be either 10 or 1000 (or 0 as default, equivalent
  with 1000)

The protocol version is checked and fallback to the fixed 1us base for
the old clients.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Iwai 2024-07-03 15:00:20 +02:00
parent 568b2ac1db
commit 24c7f42733
6 changed files with 74 additions and 3 deletions
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3
include/seq.h
View file

@ -506,13 +506,16 @@ unsigned int snd_seq_queue_tempo_get_tempo(const snd_seq_queue_tempo_t *info);
int snd_seq_queue_tempo_get_ppq(const snd_seq_queue_tempo_t *info);
unsigned int snd_seq_queue_tempo_get_skew(const snd_seq_queue_tempo_t *info);
unsigned int snd_seq_queue_tempo_get_skew_base(const snd_seq_queue_tempo_t *info);
unsigned int snd_seq_queue_tempo_get_tempo_base(const snd_seq_queue_tempo_t *info);
void snd_seq_queue_tempo_set_tempo(snd_seq_queue_tempo_t *info, unsigned int tempo);
void snd_seq_queue_tempo_set_ppq(snd_seq_queue_tempo_t *info, int ppq);
void snd_seq_queue_tempo_set_skew(snd_seq_queue_tempo_t *info, unsigned int skew);
void snd_seq_queue_tempo_set_skew_base(snd_seq_queue_tempo_t *info, unsigned int base);
void snd_seq_queue_tempo_set_tempo_base(snd_seq_queue_tempo_t *info, unsigned int tempo_base);
int snd_seq_get_queue_tempo(snd_seq_t *handle, int q, snd_seq_queue_tempo_t *tempo);
int snd_seq_set_queue_tempo(snd_seq_t *handle, int q, snd_seq_queue_tempo_t *tempo);
int snd_seq_has_queue_tempo_base(snd_seq_t *handle);
/*
*/

7
include/sound/uapi/asequencer.h
View file

@ -26,7 +26,7 @@
#include <sound/asound.h>
/** version of the sequencer */
#define SNDRV_SEQ_VERSION SNDRV_PROTOCOL_VERSION(1, 0, 3)
#define SNDRV_SEQ_VERSION SNDRV_PROTOCOL_VERSION(1, 0, 4)
/**
* definition of sequencer event types
@ -539,11 +539,12 @@ struct snd_seq_queue_status {
/* queue tempo */
struct snd_seq_queue_tempo {
int queue; /* sequencer queue */
unsigned int tempo; /* current tempo, us/tick */
unsigned int tempo; /* current tempo, us/tick (or different time-base below) */
int ppq; /* time resolution, ticks/quarter */
unsigned int skew_value; /* queue skew */
unsigned int skew_base; /* queue skew base */
char reserved[24]; /* for the future */
unsigned short tempo_base; /* tempo base in nsec unit; either 10 or 1000 */
char reserved[22]; /* for the future */
};