diff options
| -rw-r--r-- | backends/Makefile | 8 | ||||
| -rw-r--r-- | backends/rtpmidi.c | 691 | ||||
| -rw-r--r-- | backends/rtpmidi.h | 124 | ||||
| -rw-r--r-- | backends/rtpmidi.md | 87 |
4 files changed, 908 insertions, 2 deletions
diff --git a/backends/Makefile b/backends/Makefile index 656e6b6..f0d5c3e 100644 --- a/backends/Makefile +++ b/backends/Makefile @@ -1,7 +1,7 @@ .PHONY: all clean full LINUX_BACKENDS = midi.so evdev.so -WINDOWS_BACKENDS = artnet.dll osc.dll loopback.dll sacn.dll maweb.dll winmidi.dll -BACKENDS = artnet.so osc.so loopback.so sacn.so lua.so maweb.so jack.so +WINDOWS_BACKENDS = artnet.dll osc.dll loopback.dll sacn.dll maweb.dll winmidi.dll rtpmidi.dll +BACKENDS = artnet.so osc.so loopback.so sacn.so lua.so maweb.so jack.so rtpmidi.so OPTIONAL_BACKENDS = ola.so BACKEND_LIB = libmmbackend.o @@ -42,6 +42,10 @@ maweb.dll: ADDITIONAL_OBJS += $(BACKEND_LIB) maweb.dll: LDLIBS += -lws2_32 maweb.dll: CFLAGS += -DMAWEB_NO_LIBSSL +rtpmidi.so: ADDITIONAL_OBJS += $(BACKEND_LIB) +rtpmidi.dll: ADDITIONAL_OBJS += $(BACKEND_LIB) +rtpmidi.dll: LDLIBS += -lws2_32 + winmidi.dll: ADDITIONAL_OBJS += $(BACKEND_LIB) winmidi.dll: LDLIBS += -lwinmm -lws2_32 diff --git a/backends/rtpmidi.c b/backends/rtpmidi.c new file mode 100644 index 0000000..719f823 --- /dev/null +++ b/backends/rtpmidi.c @@ -0,0 +1,691 @@ +#include <string.h> +#include <errno.h> +#include <unistd.h> +#include <fcntl.h> +#include <ctype.h> + +#include "libmmbackend.h" +#include "rtpmidi.h" + +#define BACKEND_NAME "rtpmidi" + +static struct /*_rtpmidi_global*/ { + int mdns_fd; + char* mdns_name; + uint8_t detect; + + size_t announces; + rtpmidi_announce* announce; +} cfg = { + .mdns_fd = -1, + .mdns_name = NULL, + .detect = 0, + .announces = 0, + .announce = NULL +}; + +MM_PLUGIN_API int init(){ + backend rtpmidi = { + .name = BACKEND_NAME, + .conf = rtpmidi_configure, + .create = rtpmidi_instance, + .conf_instance = rtpmidi_configure_instance, + .channel = rtpmidi_channel, + .handle = rtpmidi_set, + .process = rtpmidi_handle, + .start = rtpmidi_start, + .shutdown = rtpmidi_shutdown + }; + + if(sizeof(rtpmidi_channel_ident) != sizeof(uint64_t)){ + fprintf(stderr, "rtpmidi channel identification union out of bounds\n"); + return 1; + } + + if(mm_backend_register(rtpmidi)){ + fprintf(stderr, "Failed to register rtpmidi backend\n"); + return 1; + } + + return 0; +} + +static int rtpmidi_configure(char* option, char* value){ + char* host = NULL, *port = NULL; + + if(!strcmp(option, "mdns-name")){ + if(cfg.mdns_name){ + fprintf(stderr, "Duplicate mdns-name assignment\n"); + return 1; + } + + cfg.mdns_name = strdup(value); + if(!cfg.mdns_name){ + fprintf(stderr, "Failed to allocate memory\n"); + return 1; + } + return 0; + } + else if(!strcmp(option, "mdns-bind")){ + if(cfg.mdns_fd >= 0){ + fprintf(stderr, "Only one mDNS discovery bind is supported\n"); + return 1; + } + + mmbackend_parse_hostspec(value, &host, &port); + + if(!host){ + fprintf(stderr, "Not a valid mDNS bind address: %s\n", value); + return 1; + } + + cfg.mdns_fd = mmbackend_socket(host, (port ? port : RTPMIDI_MDNS_PORT), SOCK_DGRAM, 1, 1); + if(cfg.mdns_fd < 0){ + fprintf(stderr, "Failed to bind mDNS interface: %s\n", value); + return 1; + } + return 0; + } + else if(!strcmp(option, "detect")){ + cfg.detect = 0; + if(!strcmp(value, "on")){ + cfg.detect = 1; + } + return 0; + } + + fprintf(stderr, "Unknown rtpmidi backend option %s\n", option); + return 1; +} + +static int rtpmidi_bind_instance(rtpmidi_instance_data* data, char* host, char* port){ + struct sockaddr_storage sock_addr = { + 0 + }; + socklen_t sock_len = sizeof(sock_addr); + char control_port[32]; + + //bind to random port if none supplied + data->fd = mmbackend_socket(host, port ? port : "0", SOCK_DGRAM, 1, 0); + if(data->fd < 0){ + return 1; + } + + //bind control port + if(data->mode == apple){ + if(getsockname(data->fd, (struct sockaddr*) &sock_addr, &sock_len)){ + fprintf(stderr, "Failed to fetch data port information: %s\n", strerror(errno)); + return 1; + } + + snprintf(control_port, sizeof(control_port), "%d", be16toh(((struct sockaddr_in*)&sock_addr)->sin_port) - 1); + data->control_fd = mmbackend_socket(host, control_port, SOCK_DGRAM, 1, 0); + if(data->control_fd < 0){ + fprintf(stderr, "Failed to bind control port %s\n", control_port); + return 1; + } + } + + return 0; +} + +static int rtpmidi_push_peer(rtpmidi_instance_data* data, struct sockaddr_storage sock_addr, socklen_t sock_len){ + size_t u; + + for(u = 0; u < data->peers; u++){ + //check whether the peer is already in the list + if(sock_len == data->peer[u].dest_len && !memcmp(&data->peer[u].dest, &sock_addr, sock_len)){ + return 0; + } + } + + data->peer = realloc(data->peer, (data->peers + 1) * sizeof(rtpmidi_peer)); + if(!data->peer){ + fprintf(stderr, "Failed to allocate memory\n"); + data->peers = 0; + return 1; + } + + data->peer[data->peers].dest = sock_addr; + data->peer[data->peers].dest_len = sock_len; + + data->peers++; + return 0; +} + +static int rtpmidi_push_invite(instance* inst, char* peer){ + size_t u, p; + + //check whether the instance is already in the announce list + for(u = 0; u < cfg.announces; u++){ + if(cfg.announce[u].inst == inst){ + break; + } + } + + //add to the announce list + if(u == cfg.announces){ + cfg.announce = realloc(cfg.announce, (cfg.announces + 1) * sizeof(rtpmidi_announce)); + if(!cfg.announce){ + fprintf(stderr, "Failed to allocate memory\n"); + cfg.announces = 0; + return 1; + } + + cfg.announce[u].inst = inst; + cfg.announce[u].invites = 0; + cfg.announce[u].invite = NULL; + + cfg.announces++; + } + + //check whether the peer is already in the invite list + for(p = 0; p < cfg.announce[u].invites; p++){ + if(!strcmp(cfg.announce[u].invite[p], peer)){ + return 0; + } + } + + //extend the invite list + cfg.announce[u].invite = realloc(cfg.announce[u].invite, (cfg.announce[u].invites + 1) * sizeof(char*)); + if(!cfg.announce[u].invite){ + fprintf(stderr, "Failed to allocate memory\n"); + cfg.announce[u].invites = 0; + return 1; + } + + //append the new invitee + cfg.announce[u].invite[p] = strdup(peer); + if(!cfg.announce[u].invite[p]){ + fprintf(stderr, "Failed to allocate memory\n"); + return 1; + } + + cfg.announce[u].invites++; + return 0; +} + +static int rtpmidi_configure_instance(instance* inst, char* option, char* value){ + rtpmidi_instance_data* data = (rtpmidi_instance_data*) inst->impl; + char* host = NULL, *port = NULL; + struct sockaddr_storage sock_addr; + socklen_t sock_len = sizeof(sock_addr); + + if(!strcmp(option, "mode")){ + if(!strcmp(value, "direct")){ + data->mode = direct; + return 0; + } + else if(!strcmp(value, "apple")){ + data->mode = apple; + return 0; + } + fprintf(stderr, "Unknown rtpmidi instance mode %s for instance %s\n", value, inst->name); + return 1; + } + else if(!strcmp(option, "ssrc")){ + data->ssrc = strtoul(value, NULL, 0); + if(!data->ssrc){ + fprintf(stderr, "Random SSRC will be generated for rtpmidi instance %s\n", inst->name); + } + return 0; + } + else if(!strcmp(option, "bind")){ + if(data->mode == unconfigured){ + fprintf(stderr, "Please specify mode for instance %s before setting bind host\n", inst->name); + return 1; + } + + mmbackend_parse_hostspec(value, &host, &port); + + if(!host){ + fprintf(stderr, "Could not parse bind host specification %s for instance %s\n", value, inst->name); + return 1; + } + + return rtpmidi_bind_instance(data, host, port); + } + else if(!strcmp(option, "learn")){ + if(data->mode != direct){ + fprintf(stderr, "The rtpmidi 'learn' option is only valid for direct mode instances\n"); + return 1; + } + data->learn_peers = 0; + if(!strcmp(value, "true")){ + data->learn_peers = 1; + } + return 0; + } + else if(!strcmp(option, "peer")){ + mmbackend_parse_hostspec(value, &host, &port); + if(!host || !port){ + fprintf(stderr, "Invalid peer %s configured on rtpmidi instance %s\n", value, inst->name); + return 1; + } + + if(mmbackend_parse_sockaddr(host, port, &sock_addr, &sock_len)){ + fprintf(stderr, "Failed to resolve peer %s configured on rtpmidi instance %s\n", value, inst->name); + return 1; + } + + return rtpmidi_push_peer(data, sock_addr, sock_len); + } + else if(!strcmp(option, "session")){ + if(data->mode != apple){ + fprintf(stderr, "The rtpmidi 'session' option is only valid for apple mode instances\n"); + return 1; + } + free(data->session_name); + data->session_name = strdup(value); + if(!data->session_name){ + fprintf(stderr, "Failed to allocate memory\n"); + return 1; + } + return 0; + } + else if(!strcmp(option, "invite")){ + if(data->mode != apple){ + fprintf(stderr, "The rtpmidi 'invite' option is only valid for apple mode instances\n"); + return 1; + } + + return rtpmidi_push_invite(inst, value); + } + else if(!strcmp(option, "join")){ + if(data->mode != apple){ + fprintf(stderr, "The rtpmidi 'join' option is only valid for apple mode instances\n"); + return 1; + } + free(data->accept); + data->accept = strdup(value); + if(!data->accept){ + fprintf(stderr, "Failed to allocate memory\n"); + return 1; + } + return 0; + } + + fprintf(stderr, "Unknown rtpmidi instance option %s\n", option); + return 1; +} + +static instance* rtpmidi_instance(){ + rtpmidi_instance_data* data = NULL; + instance* inst = mm_instance(); + + if(!inst){ + return NULL; + } + + data = calloc(1, sizeof(rtpmidi_instance_data)); + if(!data){ + fprintf(stderr, "Failed to allocate memory\n"); + return NULL; + } + data->fd = -1; + data->control_fd = -1; + + inst->impl = data; + return inst; +} + +static channel* rtpmidi_channel(instance* inst, char* spec, uint8_t flags){ + char* next_token = spec; + rtpmidi_channel_ident ident = { + .label = 0 + }; + + if(!strncmp(spec, "ch", 2)){ + next_token += 2; + if(!strncmp(spec, "channel", 7)){ + next_token = spec + 7; + } + } + else{ + fprintf(stderr, "Invalid rtpmidi channel specification %s\n", spec); + return NULL; + } + + ident.fields.channel = strtoul(next_token, &next_token, 10); + if(ident.fields.channel > 15){ + fprintf(stderr, "rtpmidi channel out of range in channel spec %s\n", spec); + return NULL; + } + + if(*next_token != '.'){ + fprintf(stderr, "rtpmidi channel specification %s does not conform to channel<X>.<control><Y>\n", spec); + return NULL; + } + + next_token++; + + if(!strncmp(next_token, "cc", 2)){ + ident.fields.type = cc; + next_token += 2; + } + else if(!strncmp(next_token, "note", 4)){ + ident.fields.type = note; + next_token += 4; + } + else if(!strncmp(next_token, "pressure", 8)){ + ident.fields.type = pressure; + next_token += 8; + } + else if(!strncmp(next_token, "pitch", 5)){ + ident.fields.type = pitchbend; + } + else if(!strncmp(next_token, "aftertouch", 10)){ + ident.fields.type = aftertouch; + } + else{ + fprintf(stderr, "Unknown rtpmidi channel control type in spec %s\n", spec); + return NULL; + } + + ident.fields.control = strtoul(next_token, NULL, 10); + + if(ident.label){ + return mm_channel(inst, ident.label, 1); + } + return NULL; +} + +static int rtpmidi_set(instance* inst, size_t num, channel** c, channel_value* v){ + rtpmidi_instance_data* data = (rtpmidi_instance_data*) inst->impl; + uint8_t frame[RTPMIDI_PACKET_BUFFER] = ""; + rtpmidi_header* rtp_header = (rtpmidi_header*) frame; + rtpmidi_command_header* command_header = (rtpmidi_command_header*) (frame + sizeof(rtpmidi_header)); + size_t offset = sizeof(rtpmidi_header) + sizeof(rtpmidi_command_header), u = 0; + uint8_t* payload = frame + offset; + rtpmidi_channel_ident ident; + + rtp_header->vpxcc = RTPMIDI_HEADER_MAGIC; + //some receivers seem to have problems reading rfcs and interpreting the marker bit correctly + rtp_header->mpt = (data->mode == apple ? 0 : 0x80) | RTPMIDI_HEADER_TYPE; + rtp_header->sequence = htobe16(data->sequence++); + rtp_header->timestamp = mm_timestamp() * 10; //just assume 100msec resolution because rfc4695 handwaves it + rtp_header->ssrc = htobe32(data->ssrc); + + //midi command section header + //TODO enable the journal bit here + command_header->flags = 0xA0; //extended length header, first entry in list has dtime + + //midi list + for(u = 0; u < num; u++){ + ident.label = c[u]->ident; + + //encode timestamp + payload[0] = 0; + + //encode midi command + payload[1] = ident.fields.type | ident.fields.channel; + payload[2] = ident.fields.control; + payload[3] = v[u].normalised * 127.0; + + if(ident.fields.type == pitchbend){ + payload[2] = ((int)(v[u].normalised * 16384.0)) & 0x7F; + payload[3] = (((int)(v[u].normalised * 16384.0)) >> 7) & 0x7F; + } + //channel-wide aftertouch is only 2 bytes + else if(ident.fields.type == aftertouch){ + payload[2] = payload[3]; + payload -= 1; + offset -= 1; + } + + payload += 4; + offset += 4; + } + + //update command section length + //FIXME this might overrun, might check the number of events at some point + command_header->flags |= (((offset - sizeof(rtpmidi_header) - sizeof(rtpmidi_command_header)) & 0x0F00) >> 8); + command_header->length = ((offset - sizeof(rtpmidi_header) - sizeof(rtpmidi_command_header)) & 0xFF); + + //TODO journal section + + for(u = 0; u < data->peers; u++){ + sendto(data->fd, frame, offset, 0, (struct sockaddr*) &data->peer[u].dest, data->peer[u].dest_len); + } + + return 0; +} + +static int rtpmidi_handle_applemidi(instance* inst, int fd, uint8_t* frame, size_t bytes, struct sockaddr_storage* peer, socklen_t peer_len){ + rtpmidi_instance_data* data = (rtpmidi_instance_data*) inst->impl; + apple_command* command = (apple_command*) frame; + size_t u; + + //find peer if already in list + for(u = 0; u < data->peers; u++){ + if(data->peer[u].dest_len == peer_len + && !memcmp(&data->peer[u].dest, peer, peer_len)){ + break; + } + } + + if(!strncmp((char*) command->command, APPLEMIDI_INVITE, 2)){ + //TODO check whether the session is in the accept list + } + else if(!strncmp((char*) command->command, APPLEMIDI_ACCEPT, 2)){ + //TODO mark peer as in-session, start timesync + } + else if(!strncmp((char*) command->command, APPLEMIDI_REJECT, 2)){ + //TODO mark peer as rejected (or retry invitation) + } + else if(!strncmp((char*) command->command, APPLEMIDI_LEAVE, 2)){ + //TODO mark peer as disconnected, retry invitation + } + else if(!strncmp((char*) command->command, APPLEMIDI_SYNC, 2)){ + //TODO respond with sync answer + } + else if(!strncmp((char*) command->command, APPLEMIDI_FEEDBACK, 2)){ + //ignore + } + else{ + fprintf(stderr, "Unknown AppleMIDI session command %02X %02X\n", command->command[0], command->command[1]); + } + + 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); + + //TODO receive until EAGAIN + if(bytes_recv < 0){ + fprintf(stderr, "rtpmidi failed to receive for instance %s\n", inst->name); + return 1; + } + + if(bytes_recv < sizeof(rtpmidi_header)){ + fprintf(stderr, "Skipping short packet on rtpmidi instance %s\n", inst->name); + return 0; + } + + //FIXME might want to filter data input from sources that are not registered peers + if(data->mode == apple && rtp_header->vpxcc == 0xFF && rtp_header->mpt == 0xFF){ + return rtpmidi_handle_applemidi(inst, data->fd, frame, bytes_recv, &sock_addr, sock_len); + } + else if(rtp_header->vpxcc != RTPMIDI_HEADER_MAGIC || RTPMIDI_GET_TYPE(rtp_header->mpt) != RTPMIDI_HEADER_TYPE){ + fprintf(stderr, "rtpmidi instance %s received frame with invalid header magic\n", inst->name); + return 0; + } + + //TODO parse data + + //try to learn peers + if(data->learn_peers){ + for(u = 0; u < data->peers; u++){ + if(data->peer[u].dest_len == sock_len + && !memcmp(&data->peer[u].dest, &sock_addr, sock_len)){ + break; + } + } + + if(u == data->peers){ + fprintf(stderr, "rtpmidi instance %s learned new peer\n", inst->name); + return rtpmidi_push_peer(data, sock_addr, sock_len); + } + } + return 0; +} + +static int rtpmidi_handle_control(instance* inst){ + 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); + ssize_t bytes_recv = recvfrom(data->control_fd, frame, sizeof(frame), 0, (struct sockaddr*) &sock_addr, &sock_len); + + if(bytes_recv < 0){ + fprintf(stderr, "rtpmidi failed to receive for instance %s\n", inst->name); + return 1; + } + + //the shortest applemidi packet is still larger than the rtpmidi header, so use that as bar + if(bytes_recv < sizeof(rtpmidi_header)){ + fprintf(stderr, "Skipping short packet on rtpmidi instance %s\n", inst->name); + return 0; + } + + if(data->mode == apple && frame[0] == 0xFF && frame[1] == 0xFF){ + return rtpmidi_handle_applemidi(inst, data->control_fd, frame, bytes_recv, &sock_addr, sock_len); + } + + fprintf(stderr, "Unknown session protocol frame received on rtpmidi instance %s\n", inst->name); + return 0; +} + +static int rtpmidi_handle(size_t num, managed_fd* fds){ + size_t u; + int rv = 0; + instance* inst = NULL; + rtpmidi_instance_data* data = NULL; + + //TODO handle mDNS discovery frames + + if(!num){ + return 0; + } + + for(u = 0; u < num; u++){ + if(!fds[u].impl){ + //TODO handle mDNS discovery input + } + else{ + //handle rtp/control input + inst = (instance*) fds[u].impl; + data = (rtpmidi_instance_data*) inst->impl; + if(fds[u].fd == data->fd){ + rv |= rtpmidi_handle_data(inst); + } + else if(fds[u].fd == data->control_fd){ + rv |= rtpmidi_handle_control(inst); + } + else{ + fprintf(stderr, "rtpmidi signaled descriptor not recognized\n"); + } + } + } + + return rv; +} + +static int rtpmidi_start(size_t n, instance** inst){ + size_t u, fds = 0; + rtpmidi_instance_data* data = NULL; + + //if mdns name defined and no socket, bind default values + if(cfg.mdns_name && cfg.mdns_fd < 0){ + cfg.mdns_fd = mmbackend_socket(RTPMIDI_DEFAULT_HOST, RTPMIDI_MDNS_PORT, SOCK_DGRAM, 1, 1); + if(cfg.mdns_fd < 0){ + return 1; + } + } + + //register mdns fd to core + if(cfg.mdns_fd >= 0){ + if(mm_manage_fd(cfg.mdns_fd, BACKEND_NAME, 1, NULL)){ + fprintf(stderr, "rtpmidi failed to register mDNS socket with core\n"); + return 1; + } + fds++; + } + else{ + fprintf(stderr, "No mDNS discovery interface bound, AppleMIDI session discovery disabled\n"); + } + + for(u = 0; u < n; u++){ + data = (rtpmidi_instance_data*) inst[u]->impl; + //check whether instances are explicitly configured to a mode + if(data->mode == unconfigured){ + fprintf(stderr, "rtpmidi instance %s is missing a mode configuration\n", inst[u]->name); + return 1; + } + + //generate random ssrc's + if(!data->ssrc){ + data->ssrc = rand() << 16 | rand(); + } + + //if not bound, bind to default + if(data->fd < 0 && rtpmidi_bind_instance(data, RTPMIDI_DEFAULT_HOST, NULL)){ + fprintf(stderr, "Failed to bind default sockets for rtpmidi instance %s\n", inst[u]->name); + return 1; + } + + //register fds to core + if(mm_manage_fd(data->fd, BACKEND_NAME, 1, inst[u]) || (data->control_fd >= 0 && mm_manage_fd(data->control_fd, BACKEND_NAME, 1, inst[u]))){ + fprintf(stderr, "rtpmidi failed to register instance socket with core\n"); + return 1; + } + fds += (data->control_fd >= 0) ? 2 : 1; + } + + fprintf(stderr, "rtpmidi backend registered %" PRIsize_t " descriptors to core\n", fds); + return 0; +} + +static int rtpmidi_shutdown(size_t n, instance** inst){ + rtpmidi_instance_data* data = NULL; + size_t u; + + for(u = 0; u < n; u++){ + data = (rtpmidi_instance_data*) inst[u]->impl; + if(data->fd >= 0){ + close(data->fd); + } + + if(data->control_fd >= 0){ + close(data->control_fd); + } + + free(data->session_name); + data->session_name = NULL; + + free(data->accept); + data->accept = NULL; + + free(data->peer); + data->peer = NULL; + data->peers = 0; + + free(inst[u]->impl); + inst[u]->impl = NULL; + } + + //TODO free announces + free(cfg.mdns_name); + if(cfg.mdns_fd >= 0){ + close(cfg.mdns_fd); + } + + return 0; +} diff --git a/backends/rtpmidi.h b/backends/rtpmidi.h new file mode 100644 index 0000000..2652db7 --- /dev/null +++ b/backends/rtpmidi.h @@ -0,0 +1,124 @@ +#ifndef _WIN32 +#include <sys/socket.h> +#endif +#include "midimonster.h" + +MM_PLUGIN_API int init(); +static int rtpmidi_configure(char* option, char* value); +static int rtpmidi_configure_instance(instance* instance, char* option, char* value); +static instance* rtpmidi_instance(); +static channel* rtpmidi_channel(instance* instance, char* spec, uint8_t flags); +static int rtpmidi_set(instance* inst, size_t num, channel** c, channel_value* v); +static int rtpmidi_handle(size_t num, managed_fd* fds); +static int rtpmidi_start(size_t n, instance** inst); +static int rtpmidi_shutdown(size_t n, instance** inst); + +#define RTPMIDI_PACKET_BUFFER 8192 +#define RTPMIDI_DEFAULT_HOST "::" +#define RTPMIDI_MDNS_PORT "5353" +#define RTPMIDI_HEADER_MAGIC 0x80 +#define RTPMIDI_HEADER_TYPE 0x61 +#define RTPMIDI_GET_TYPE(a) ((a) & 0x7F) + +#define APPLEMIDI_INVITE "IN" +#define APPLEMIDI_ACCEPT "OK" +#define APPLEMIDI_REJECT "NO" +#define APPLEMIDI_LEAVE "BY" +#define APPLEMIDI_SYNC "CK" +#define APPLEMIDI_FEEDBACK "RS" + +enum /*_rtpmidi_channel_type*/ { + none = 0, + note = 0x90, + cc = 0xB0, + pressure = 0xA0, + aftertouch = 0xD0, + pitchbend = 0xE0 +}; + +typedef enum /*_rtpmidi_instance_mode*/ { + unconfigured = 0, + direct, + apple +} rtpmidi_instance_mode; + +typedef union { + struct { + uint8_t pad[5]; + uint8_t type; + uint8_t channel; + uint8_t control; + } fields; + uint64_t label; +} rtpmidi_channel_ident; + +typedef struct /*_rtpmidi_peer*/ { + struct sockaddr_storage dest; + socklen_t dest_len; + uint32_t ssrc; +} rtpmidi_peer; + +typedef struct /*_rtmidi_instance_data*/ { + rtpmidi_instance_mode mode; + + int fd; + int control_fd; + + size_t peers; + rtpmidi_peer* peer; + uint32_t ssrc; + uint16_t sequence; + + //apple-midi config + char* session_name; + char* accept; + + //direct mode config + uint8_t learn_peers; +} rtpmidi_instance_data; + +typedef struct /*rtpmidi_announced_instance*/ { + instance* inst; + size_t invites; + char** invite; +} rtpmidi_announce; + +#pragma pack(push, 1) +typedef struct /*_apple_session_command*/ { + uint16_t res1; + uint8_t command[2]; + uint32_t version; + uint32_t token; + uint32_t ssrc; + //char* name +} apple_command; + +typedef struct /*_apple_session_sync*/ { + uint16_t res1; + uint8_t command[2]; + uint32_t ssrc; + uint8_t count; + uint8_t res2[3]; + uint64_t timestamp[3]; +} apple_sync; + +typedef struct /*_apple_session_feedback*/ { + uint16_t res1; + uint8_t command[2]; + uint32_t ssrc; + uint32_t sequence; +} apple_feedback; + +typedef struct /*_rtp_midi_header*/ { + uint8_t vpxcc; + uint8_t mpt; + uint16_t sequence; + uint32_t timestamp; + uint32_t ssrc; +} rtpmidi_header; + +typedef struct /*_rtp_midi_command*/ { + uint8_t flags; + uint8_t length; +} rtpmidi_command_header; +#pragma pack(pop) diff --git a/backends/rtpmidi.md b/backends/rtpmidi.md new file mode 100644 index 0000000..d42df6f --- /dev/null +++ b/backends/rtpmidi.md @@ -0,0 +1,87 @@ +### The `rtpmidi` backend + +This backend provides read-write access to RTP MIDI streams, which transfer MIDI data +over the network. + +As the specification for RTP MIDI does not normatively indicate any method +for session management, most vendors define their own standards for this. +The MIDIMonster supports the following session management methods, which are +selectable per-instance, with some methods requiring additional global configuration: + +* Direct connection: The instance will send and receive data from peers configured in the + instance configuration +* Direct connection with peer learning: The instance will send and receive data from peers + configured in the instance configuration as well as previously unknown peers that + voluntarily send data to the instance. +* AppleMIDI session management: + +Note that instances that receive data from multiple peers will combine all inputs into one +stream, which may lead to inconsistencies during playback. + +#### Global configuration + +| Option | Example value | Default value | Description | +|---------------|-----------------------|-----------------------|-----------------------| +| `detect` | `on` | `off` | Output channel specifications for any events coming in on configured instances to help with configuration | +| `mdns-bind` | `10.1.2.1 5353` | `:: 5353` | Bind host for the mDNS discovery server | +| `mdns-name` | `computer1` | none | mDNS hostname to announce, also used as AppleMIDI peer name | + +#### Instance configuration + +Common instance configuration parameters + +| Option | Example value | Default value | Description | +|---------------|-----------------------|-----------------------|-----------------------| +| `ssrc` | `0xDEADBEEF` | Randomly generated | 32-bit synchronization source identifier | +| `mode` | `direct` | none | Instance session management mode (`direct` or `apple`) | +| `peer` | `10.1.2.3 9001` | none | MIDI session peer, may be specified multiple times. Bypasses session discovery protocols | + +`direct` mode instance configuration parameters + +| Option | Example value | Default value | Description | +|---------------|-----------------------|-----------------------|-----------------------| +| `bind` | `10.1.2.1 9001` | `:: <random>` | Local network address to bind to | +| `learn` | `true` | `false` | Accept new peers for data exchange at runtime | + +`apple` mode instance configuration parameters + +| Option | Example value | Default value | Description | +|---------------|-----------------------|-----------------------|-----------------------| +| `bind` | `10.1.2.1 9001` | `:: <random>` | Local network address to bind to (note that AppleMIDI requires two consecutive port numbers to be allocated) | +| `session` | `Just Jamming` | `MIDIMonster` | Session name to announce via mDNS | +| `invite` | `pad` | none | Devices to send invitations to when discovered (the special value `*` invites all discovered peers). Setting this option makes the instance a session initiator. May be specified multiple times | +| `join` | `Just Jamming` | none | Session for which to accept invitations (the special value `*` accepts all invitations). Setting this option makes the instance a session participant | +| `peer` | `10.1.2.3 9001` | none | Configure a direct session peer, bypassing AppleMIDI discovery. May be specified multiple times | + +Note that AppleMIDI session discovery requires mDNS functionality, thus the `mdns-name` global parameter +(and, depending on your setup, the `mdns-bind` parameter) need to be configured properly. + +#### Channel specification + +The `rtpmidi` backend supports mapping different MIDI events to MIDIMonster channels. The currently supported event types are + +* `cc` - Control Changes +* `note` - Note On/Off messages +* `pressure` - Note pressure/aftertouch messages +* `aftertouch` - Channel-wide aftertouch messages +* `pitch` - Channel pitchbend messages + +A MIDIMonster channel is specified using the syntax `channel<channel>.<type><index>`. The shorthand `ch` may be +used instead of the word `channel` (Note that `channel` here refers to the MIDI channel number). + +The `pitch` and `aftertouch` events are channel-wide, thus they can be specified as `channel<channel>.<type>`. + +MIDI channels range from `0` to `15`. Each MIDI channel consists of 128 notes (numbered `0` through `127`), which +additionally each have a pressure control, 128 CC's (numbered likewise), a channel pressure control (also called +'channel aftertouch') and a pitch control which may all be mapped to individual MIDIMonster channels. + +Example mappings: + +``` +rmidi1.ch0.note9 > rmidi2.channel1.cc4 +rmidi1.channel15.pressure1 > rmidi1.channel0.note0 +rmidi1.ch1.aftertouch > rmidi2.ch2.cc0 +rmidi1.ch0.pitch > rmidi2.ch1.pitch +``` + +#### Known bugs / problems |