diff options
Diffstat (limited to 'backends')
| -rw-r--r-- | backends/rtpmidi.c | 155 |
1 files changed, 153 insertions, 2 deletions
diff --git a/backends/rtpmidi.c b/backends/rtpmidi.c index 4966a79..611d99b 100644 --- a/backends/rtpmidi.c +++ b/backends/rtpmidi.c @@ -134,6 +134,22 @@ static int rtpmidi_bind_instance(rtpmidi_instance_data* data, char* host, char* return 0; } +static char* rtpmidi_type_name(uint8_t type){ + switch(type){ + case note: + return "note"; + case cc: + return "cc"; + case pressure: + return "pressure"; + case aftertouch: + return "aftertouch"; + case pitchbend: + return "pitch"; + } + return "unknown"; +} + static int rtpmidi_push_peer(rtpmidi_instance_data* data, struct sockaddr_storage sock_addr, socklen_t sock_len){ size_t u, p = data->peers; @@ -616,14 +632,145 @@ static int rtpmidi_handle_applemidi(instance* inst, int fd, uint8_t* frame, size return 0; } +static int rtpmidi_parse(instance* inst, uint8_t* frame, size_t bytes){ + uint16_t length = 0; + size_t offset = 1, decode_time = 0, command_bytes = 0; + uint8_t midi_status = 0; + rtpmidi_channel_ident ident; + channel_value val; + channel* chan = NULL; + + if(!bytes){ + LOGPF("No command section in data on instance %s", inst->name); + return 1; + } + + //calculate midi command section length + length = frame[0] & 0x0F; + if(frame[0] & 0x80){ + //extended header + if(bytes < 2){ + LOGPF("Short command section (%" PRIsize_t " bytes) on %s, missing extended header", bytes, inst->name); + return 1; + } + length <<= 8; + length |= frame[1]; + offset = 2; + } + + command_bytes = offset + length; + DBGPF("%u/%" PRIsize_t " bytes of command section on %s, %s header, %s initial dtime", + length, bytes, inst->name, + (frame[0] & 0x80) ? "extended" : "normal", + (frame[0] & 0x20) ? "has" : "no"); + + if(command_bytes > bytes){ + LOGPF("Short command section on %s, indicated %" PRIsize_t ", had %" PRIsize_t, inst->name, command_bytes, bytes); + return 1; + } + + if(frame[0] & 0x20){ + decode_time = 1; + } + + do{ + //decode delta-time + if(decode_time){ + for(; offset < command_bytes && frame[offset] & 0x80; offset++){ + } + offset++; + } + + //section 3 of rfc6295 states that the first dtime as well as the last command may be omitted + //this may make sense on a low-speed serial line, but on a network... come on. + if(offset >= command_bytes){ + break; + } + + //check for a status byte + //TODO filter sysex + if(frame[offset] & 0x80){ + midi_status = frame[offset]; + offset++; + } + + //having variable encoding in each and every component is super annoying to check for... + if(offset >= command_bytes){ + break; + } + + ident.label = 0; + ident.fields.type = midi_status & 0xF0; + ident.fields.channel = midi_status & 0x0F; + + //single byte command + if(ident.fields.type == aftertouch){ + ident.fields.control = 0; + val.normalised = (double) frame[offset] / 127.0; + offset++; + } + //two-byte command + else{ + offset++; + if(offset >= command_bytes){ + break; + } + + if(ident.fields.type == pitchbend){ + ident.fields.control = 0; + val.normalised = (double)((frame[offset] << 7) | frame[offset - 1]) / 16384.0; + } + else{ + ident.fields.control = frame[offset - 1]; + val.normalised = (double) frame[offset] / 127.0; + } + + //fix-up note off events + if(ident.fields.type == 0x80){ + ident.fields.type = note; + val.normalised = 0; + } + + offset++; + } + + DBGPF("Decoded command type %02X channel %d control %d value %f", + ident.fields.type, ident.fields.channel, ident.fields.control, val.normalised); + + if(cfg.detect){ + if(ident.fields.type == pitchbend || ident.fields.type == aftertouch){ + LOGPF("Incoming data on channel %s.ch%d.%s, value %f", + inst->name, ident.fields.channel, + rtpmidi_type_name(ident.fields.type), val.normalised); + } + else{ + LOGPF("Incoming data on channel %s.ch%d.%s%d, value %f", + inst->name, ident.fields.channel, + rtpmidi_type_name(ident.fields.type), + ident.fields.control, val.normalised); + } + } + + //find channel + chan = mm_channel(inst, ident.label, 0); + if(chan){ + mm_channel_event(chan, val); + } + + decode_time = 1; + } while(offset < command_bytes); + + return 0; +} + static int rtpmidi_handle_data(instance* inst){ - size_t u; rtpmidi_instance_data* data = (rtpmidi_instance_data*) inst->impl; uint8_t frame[RTPMIDI_PACKET_BUFFER] = ""; struct sockaddr_storage sock_addr; socklen_t sock_len = sizeof(sock_addr); rtpmidi_header* rtp_header = (rtpmidi_header*) frame; ssize_t bytes_recv = recvfrom(data->fd, frame, sizeof(frame), 0, (struct sockaddr*) &sock_addr, &sock_len); + size_t u; //TODO receive until EAGAIN if(bytes_recv < 0){ @@ -645,7 +792,11 @@ static int rtpmidi_handle_data(instance* inst){ return 0; } - //TODO parse data + //parse data + if(rtpmidi_parse(inst, frame + sizeof(rtpmidi_header), bytes_recv - sizeof(rtpmidi_header))){ + //returning errors here fails the core loop, so just return 0 to have some logging + return 0; + } //try to learn peers if(data->learn_peers){ |