[PATCH alsa-lib] seq: Add API functions to set different tempo base values
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 --- include/seq.h | 3 ++ include/sound/uapi/asequencer.h | 7 ++-- src/Versions.in.in | 3 ++ src/seq/seq.c | 58 +++++++++++++++++++++++++++++++++ src/seq/seq_hw.c | 5 +++ src/seq/seq_local.h | 1 + 6 files changed, 74 insertions(+), 3 deletions(-)
diff --git a/include/seq.h b/include/seq.h index e55f5c16fada..3bad5dd9762c 100644 --- a/include/seq.h +++ b/include/seq.h @@ -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);
/* */ diff --git a/include/sound/uapi/asequencer.h b/include/sound/uapi/asequencer.h index b913f31daa2d..923dfdddfc76 100644 --- a/include/sound/uapi/asequencer.h +++ b/include/sound/uapi/asequencer.h @@ -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 */ };
diff --git a/src/Versions.in.in b/src/Versions.in.in index 1c40d461dce4..90849277c983 100644 --- a/src/Versions.in.in +++ b/src/Versions.in.in @@ -206,6 +206,9 @@ ALSA_1.2.13 { #ifdef HAVE_SEQ_SYMS @SYMBOL_PREFIX@snd_seq_create_ump_endpoint; @SYMBOL_PREFIX@snd_seq_create_ump_block; + @SYMBOL_PREFIX@snd_seq_queue_tempo_get_tempo_base; + @SYMBOL_PREFIX@snd_seq_queue_tempo_set_tempo_base; + @SYMBOL_PREFIX@snd_seq_has_tempo_base; #endif #ifdef HAVE_RAWMIDI_SYMS @SYMBOL_PREFIX@snd_ump_endpoint_info_clear; diff --git a/src/seq/seq.c b/src/seq/seq.c index a18f67e2632e..d0ecedf0838f 100644 --- a/src/seq/seq.c +++ b/src/seq/seq.c @@ -490,6 +490,21 @@ the buffer is flushed by #snd_seq_drain_output() call. You can schedule the event in a certain queue so that the tempo change happens at the scheduled time, too.
+The tempo is set as default in microsecond unit as defined for +Standard MIDI Format 1. But since the value in MIDI2 Set Tempo message +is based on 10-nanosecand unit, sequencer queue also allows to set up +in 10-nanosecond unit. For that, change the tempo-base value in +#snd_seq_queue_tempo_t to 10 via #snd_seq_queue_tempo_set_tempo_base() +along with the 10-nanobased tempo value. The default tempo base is 1000, +i.e. 1 microsecond. +Currently the API supports only either 0, 10 or 1000 as the tempo-base +(where 0 is treated as 1000). + +The older kernel might not support the different tempo-base, and setting a +different value from 1000 would fail. The application may heck the +availability of tempo-base change via #snd_seq_has_tempo_base() function +beforehand, and re-calculate in microsecond unit as fallback. + \subsection seq_ev_start Starting and stopping a queue
To start, stop, or continue a queue, you need to send a queue-control @@ -3878,6 +3893,19 @@ unsigned int snd_seq_queue_tempo_get_skew_base(const snd_seq_queue_tempo_t *info return info->skew_base; }
+/** + * \brief Get the tempo base of a queue_status container + * \param info queue_status container + * \return tempo base time in nsec unit + * + * \sa snd_seq_get_queue_tempo() + */ +unsigned int snd_seq_queue_tempo_get_tempo_base(const snd_seq_queue_tempo_t *info) +{ + assert(info); + return info->tempo_base; +} + /** * \brief Set the tempo of a queue_status container * \param info queue_status container @@ -3933,6 +3961,21 @@ void snd_seq_queue_tempo_set_skew_base(snd_seq_queue_tempo_t *info, unsigned int info->skew_base = base; }
+/** + * \brief Set the tempo base of a queue_status container + * \param info queue_status container + * \param tempo_base tempo base time in nsec unit + * + * \sa snd_seq_get_queue_tempo() + */ +void snd_seq_queue_tempo_set_tempo_base(snd_seq_queue_tempo_t *info, unsigned int tempo_base) +{ + assert(info); + if (!tempo_base) + tempo_base = 1000; + info->tempo_base = tempo_base; +} + /** * \brief obtain the current tempo of the queue * \param seq sequencer handle @@ -3962,10 +4005,25 @@ int snd_seq_get_queue_tempo(snd_seq_t *seq, int q, snd_seq_queue_tempo_t * tempo int snd_seq_set_queue_tempo(snd_seq_t *seq, int q, snd_seq_queue_tempo_t * tempo) { assert(seq && tempo); + if (!seq->has_queue_tempo_base && + tempo->tempo_base && tempo->tempo_base != 1000) + return -EINVAL; tempo->queue = q; return seq->ops->set_queue_tempo(seq, tempo); }
+/** + * \brief inquiry the support of tempo base change + * \param seq sequencer handle + * \return 1 if the client supports the tempo base change, 0 if not + * + * \sa snd_seq_get_queue_tempo() + */ +int snd_seq_has_queue_tempo_base(snd_seq_t *seq) +{ + assert(seq); + return seq->has_queue_tempo_base; +}
/*----------------------------------------------------------------*/
diff --git a/src/seq/seq_hw.c b/src/seq/seq_hw.c index eeaf26e16d1c..e88a7b22b052 100644 --- a/src/seq/seq_hw.c +++ b/src/seq/seq_hw.c @@ -275,12 +275,15 @@ static int snd_seq_hw_get_queue_tempo(snd_seq_t *seq, snd_seq_queue_tempo_t * te /*SYSERR("SNDRV_SEQ_IOCTL_GET_QUEUE_TEMPO failed");*/ return -errno; } + if (!seq->has_queue_tempo_base) + tempo->tempo_base = 1000; return 0; }
static int snd_seq_hw_set_queue_tempo(snd_seq_t *seq, snd_seq_queue_tempo_t * tempo) { snd_seq_hw_t *hw = seq->private_data; + if (ioctl(hw->fd, SNDRV_SEQ_IOCTL_SET_QUEUE_TEMPO, tempo) < 0) { /*SYSERR("SNDRV_SEQ_IOCTL_SET_QUEUE_TEMPO failed");*/ return -errno; @@ -587,6 +590,8 @@ int snd_seq_hw_open(snd_seq_t **handle, const char *name, int streams, int mode) seq->ops = &snd_seq_hw_ops; seq->private_data = hw; seq->packet_size = sizeof(snd_seq_event_t); + seq->has_queue_tempo_base = ver >= SNDRV_PROTOCOL_VERSION(1, 0, 4); + client = snd_seq_hw_client_id(seq); if (client < 0) { snd_seq_close(seq); diff --git a/src/seq/seq_local.h b/src/seq/seq_local.h index 263029702739..00a7615afeae 100644 --- a/src/seq/seq_local.h +++ b/src/seq/seq_local.h @@ -94,6 +94,7 @@ struct _snd_seq { size_t tmpbufsize; /* size of errbuf */ size_t packet_size; /* input packet alignment size */ int midi_version; /* current protocol version */ + int has_queue_tempo_base; /* support queue tempo-base? */
unsigned int num_ump_groups; /* number of UMP groups */ snd_ump_endpoint_info_t *ump_ep; /* optional UMP info */
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Takashi Iwai