Active Sensing messages are sent by many devices in the background and would only interfere with the actual messages that amidi is supposed to capture. Therefore, amidi ignores them by default. However, there are also devices that send Clock messages with the same problem, so it is a better idea to filter them out, too.

Reported-by: Martin Tarenskeen m.tarenskeen@gmail.com Signed-off-by: Clemens Ladisch clemens@ladisch.de --- amidi/amidi.1 | 19 ++++++++++++++----- amidi/amidi.c | 13 +++++++++++-- 2 files changed, 25 insertions(+), 7 deletions(-)

diff --git a/amidi/amidi.1 b/amidi/amidi.1 index 1b4cfb1..86beb27 100644 --- a/amidi/amidi.1 +++ b/amidi/amidi.1 @@ -1,4 +1,4 @@ -.TH AMIDI 1 "26 Jun 2006" +.TH AMIDI 1 "16 Apr 2016"

.SH NAME amidi - read from and write to ALSA RawMIDI ports @@ -80,9 +80,11 @@ to record a Standard MIDI (.mid) file, use .B arecordmidi(1).

.B amidi -will filter out any Active Sensing bytes (FEh), unless the +will filter out any Active Sensing and Clock bytes (FEh, F8h), unless the .I -a -option has been given. +or +.I -c +options have been given.

.TP .I -S, --send-hex="..." @@ -91,9 +93,11 @@ Sends the bytes specified as hexadecimal numbers to the MIDI port. .TP .I -d, --dump Prints data received from the MIDI port as hexadecimal bytes. -Active Sensing bytes (FEh) will not be shown, unless the +Active Sensing and Clock bytes (FEh, F8h) will not be shown, unless the .I -a -option has been given. +or +.I -c +options have been given.

This option is useful for debugging.

@@ -111,6 +115,11 @@ to stop receiving data. Does not ignore Active Sensing bytes (FEh) when saving or printing received MIDI commands.

+.TP +.I -c, --clock +Does not ignore Clock bytes (F8h) when saving or printing received +MIDI commands. + .SH EXAMPLES

.TP diff --git a/amidi/amidi.c b/amidi/amidi.c index cedf18c..58ac814 100644 --- a/amidi/amidi.c +++ b/amidi/amidi.c @@ -77,7 +77,8 @@ static void usage(void) "-d, --dump print received data as hexadecimal bytes\n" "-t, --timeout=seconds exits when no data has been received\n" " for the specified duration\n" - "-a, --active-sensing don't ignore active sensing bytes\n"); + "-a, --active-sensing include active sensing bytes\n" + "-c, --clock include clock bytes\n"); }

static void version(void) @@ -419,10 +420,12 @@ int main(int argc, char *argv[]) {"dump", 0, NULL, 'd'}, {"timeout", 1, NULL, 't'}, {"active-sensing", 0, NULL, 'a'}, + {"clock", 0, NULL, 'c'}, { } }; int c, err, ok = 0; int ignore_active_sensing = 1; + int ignore_clock = 1; int do_send_hex = 0;

while ((c = getopt_long(argc, argv, short_options, @@ -463,6 +466,9 @@ int main(int argc, char *argv[]) case 'a': ignore_active_sensing = 0; break; + case 'c': + ignore_clock = 0; + break; default: error("Try `amidi --help' for more information."); return 1; @@ -589,7 +595,10 @@ int main(int argc, char *argv[]) } length = 0; for (i = 0; i < err; ++i) - if (!ignore_active_sensing || buf[i] != 0xfe) + if ((buf[i] != MIDI_CMD_COMMON_CLOCK && + buf[i] != MIDI_CMD_COMMON_SENSING) || + (buf[i] == MIDI_CMD_COMMON_CLOCK && !ignore_clock) || + (buf[i] == MIDI_CMD_COMMON_SENSING && !ignore_active_sensing)) buf[length++] = buf[i]; if (length == 0) continue;

The timeout is not supposed to expire when ignored messages are received. This cannot be handled with the poll() timeout, so add a separate timer.

Reported-by: Martin Tarenskeen m.tarenskeen@gmail.com Signed-off-by: Clemens Ladisch clemens@ladisch.de --- amidi/amidi.c | 69 ++++++++++++++++++++++++++++++++++++++++++++------------- 1 file changed, 53 insertions(+), 16 deletions(-)

diff --git a/amidi/amidi.c b/amidi/amidi.c index 58ac814..290df48 100644 --- a/amidi/amidi.c +++ b/amidi/amidi.c @@ -25,9 +25,11 @@ #include <stdarg.h> #include <string.h> #include <ctype.h> +#include <math.h> #include <getopt.h> #include <errno.h> #include <signal.h> +#include <sys/timerfd.h> #include <sys/types.h> #include <sys/poll.h> #include <sys/stat.h> @@ -37,6 +39,8 @@ #include "aconfig.h" #include "version.h"

+#define NSEC_PER_SEC 1000000000L + static int do_device_list, do_rawmidi_list; static char *port_name = "default"; static char *send_file_name; @@ -46,7 +50,7 @@ static char *send_data; static int send_data_length; static int receive_file; static int dump; -static int timeout; +static float timeout; static int stop; static snd_rawmidi_t *input, **inputp; static snd_rawmidi_t *output, **outputp; @@ -427,6 +431,7 @@ int main(int argc, char *argv[]) int ignore_active_sensing = 1; int ignore_clock = 1; int do_send_hex = 0; + struct itimerspec itimerspec = { .it_interval = { 0, 0 } };

while ((c = getopt_long(argc, argv, short_options, long_options, NULL)) != -1) { @@ -461,7 +466,7 @@ int main(int argc, char *argv[]) dump = 1; break; case 't': - timeout = atoi(optarg); + timeout = atof(optarg); break; case 'a': ignore_active_sensing = 0; @@ -552,40 +557,64 @@ int main(int argc, char *argv[])

if (inputp) { int read = 0; - int npfds, time = 0; + int npfds; struct pollfd *pfds;

- timeout *= 1000; - npfds = snd_rawmidi_poll_descriptors_count(input); + npfds = 1 + snd_rawmidi_poll_descriptors_count(input); pfds = alloca(npfds * sizeof(struct pollfd)); - snd_rawmidi_poll_descriptors(input, pfds, npfds); + + if (timeout > 0) { + pfds[0].fd = timerfd_create(CLOCK_MONOTONIC, 0); + if (pfds[0].fd == -1) { + error("cannot create timer: %s", strerror(errno)); + goto _exit; + } + pfds[0].events = POLLIN; + } else { + pfds[0].fd = -1; + } + + snd_rawmidi_poll_descriptors(input, &pfds[1], npfds - 1); + signal(SIGINT, sig_handler); + + if (timeout > 0) { + float timeout_int; + + itimerspec.it_value.tv_nsec = modff(timeout, &timeout_int) * NSEC_PER_SEC; + itimerspec.it_value.tv_sec = timeout_int; + err = timerfd_settime(pfds[0].fd, 0, &itimerspec, NULL); + if (err < 0) { + error("cannot set timer: %s", strerror(errno)); + goto _exit; + } + } for (;;) { unsigned char buf[256]; int i, length; unsigned short revents;

- err = poll(pfds, npfds, 200); + err = poll(pfds, npfds, -1); if (stop || (err < 0 && errno == EINTR)) break; if (err < 0) { error("poll failed: %s", strerror(errno)); break; } - if (err == 0) { - time += 200; - if (timeout && time >= timeout) - break; - continue; - } - if ((err = snd_rawmidi_poll_descriptors_revents(input, pfds, npfds, &revents)) < 0) { + + err = snd_rawmidi_poll_descriptors_revents(input, &pfds[1], npfds - 1, &revents); + if (err < 0) { error("cannot get poll events: %s", snd_strerror(errno)); break; } if (revents & (POLLERR | POLLHUP)) break; - if (!(revents & POLLIN)) + if (!(revents & POLLIN)) { + if (pfds[0].revents & POLLIN) + break; continue; + } + err = snd_rawmidi_read(input, buf, sizeof(buf)); if (err == -EAGAIN) continue; @@ -603,7 +632,7 @@ int main(int argc, char *argv[]) if (length == 0) continue; read += length; - time = 0; + if (receive_file != -1) write(receive_file, buf, length); if (dump) { @@ -611,6 +640,14 @@ int main(int argc, char *argv[]) print_byte(buf[i]); fflush(stdout); } + + if (timeout > 0) { + err = timerfd_settime(pfds[0].fd, 0, &itimerspec, NULL); + if (err < 0) { + error("cannot set timer: %s", strerror(errno)); + break; + } + } } if (isatty(fileno(stdout))) printf("\n%d bytes read\n", read);