midi: don't convert Midi in nodes

Avoid doing conversions in the nodes between Midi formats, just assume
the imput is what we expect and output what we naturally produce.

For ALSA this means we produce and consume Midi1 or Midi2 depending on the
configurtation.

All of the other modules (ffado, RTP, netjack and VBAN) really only
produce and consume MIDI1.

Set the default MIDI format to MIDI1 in ALSA.

Whith this change, almost everything now produces and consumes MIDI1
again (previously the buffer format was forced to MIDI2).

The problem is that MIDI2 to and from MIDI1 conversion has problems in
some cases in PipeWire and ALSA and breaks compatibility with some
hardware.

The idea is to let elements produce their prefered format and that the
control mixer also negotiates and converts to the node prefered format.
There is then a mix of MIDI2 and MIDI1 on ports but with the control
port adapting, this should not be a problem.

There is one remaining problem to make this work, the port format is
taken from the node port and not the mixer port, which would then expose
the prefered format on the port and force negotiation to it with the
peer instead of in the mixer.

See #5183

spa/plugins/alsa/alsa-seq-bridge.c

@@ -501,6 +501,7 @@ impl_node_port_enum_params(void *object, int seq,
 	struct seq_state *this = object;
 	struct seq_port *port;
 	struct spa_pod *param;
+	struct spa_pod_frame f[1];
 	struct spa_pod_builder b = { 0 };
 	uint8_t buffer[1024];
 	struct spa_result_node_params result;
@@ -524,10 +525,18 @@ impl_node_port_enum_params(void *object, int seq,
 	case SPA_PARAM_EnumFormat:
 		if (result.index > 0)
 			return 0;
-		param = spa_pod_builder_add_object(&b,
-			SPA_TYPE_OBJECT_Format, SPA_PARAM_EnumFormat,
+		spa_pod_builder_push_object(&b, &f[0],
+			SPA_TYPE_OBJECT_Format, SPA_PARAM_EnumFormat);
+		spa_pod_builder_add(&b,
 			SPA_FORMAT_mediaType,      SPA_POD_Id(SPA_MEDIA_TYPE_application),
-			SPA_FORMAT_mediaSubtype,   SPA_POD_Id(SPA_MEDIA_SUBTYPE_control));
+			SPA_FORMAT_mediaSubtype,   SPA_POD_Id(SPA_MEDIA_SUBTYPE_control),
+			0);
+		if (port->control_types != 0) {
+			spa_pod_builder_add(&b,
+				SPA_FORMAT_CONTROL_types,  SPA_POD_Int(port->control_types),
+				0);
+		}
+		param = spa_pod_builder_pop(&b, &f[0]);
 		break;
 
 	case SPA_PARAM_Format:
@@ -535,10 +544,18 @@ impl_node_port_enum_params(void *object, int seq,
 			return -EIO;
 		if (result.index > 0)
 			return 0;
-		param = spa_pod_builder_add_object(&b,
-			SPA_TYPE_OBJECT_Format, SPA_PARAM_Format,
+		spa_pod_builder_push_object(&b, &f[0],
+			SPA_TYPE_OBJECT_Format, SPA_PARAM_EnumFormat);
+		spa_pod_builder_add(&b,
 			SPA_FORMAT_mediaType,      SPA_POD_Id(SPA_MEDIA_TYPE_application),
-			SPA_FORMAT_mediaSubtype,   SPA_POD_Id(SPA_MEDIA_SUBTYPE_control));
+			SPA_FORMAT_mediaSubtype,   SPA_POD_Id(SPA_MEDIA_SUBTYPE_control),
+			0);
+		if (port->control_types != 0) {
+			spa_pod_builder_add(&b,
+				SPA_FORMAT_CONTROL_types,  SPA_POD_Int(port->control_types),
+				0);
+		}
+		param = spa_pod_builder_pop(&b, &f[0]);
 		break;
 
 	case SPA_PARAM_Buffers:
@@ -955,7 +972,7 @@ impl_init(const struct spa_handle_factory *factory,
 	this->quantum_limit = 8192;
 	this->min_pool_size = 500;
 	this->max_pool_size = 2000;
-	this->ump = true;
+	this->ump = false;
 
 	for (i = 0; info && i < info->n_items; i++) {
 		const char *k = info->items[i].key;

spa/plugins/alsa/alsa-seq.c

@@ -620,9 +620,8 @@ static int process_read(struct seq_state *state)
 {
 	struct seq_stream *stream = &state->streams[SPA_DIRECTION_OUTPUT];
 	const bool ump = state->ump;
-	uint32_t *data;
+	void *data;
 	uint8_t midi1_data[MAX_EVENT_SIZE];
-	uint32_t ump_data[MAX_EVENT_SIZE];
 	long size;
 	int res = -1;
 	struct seq_port *port;
@@ -633,9 +632,6 @@ static int process_read(struct seq_state *state)
 		uint64_t ev_time, diff;
 		uint32_t offset;
 		void *event;
-		uint8_t *midi1_ptr;
-		size_t midi1_size = 0;
-		uint64_t ump_state = 0;
 		snd_seq_event_type_t SPA_UNUSED type;
 
 		if (ump) {
@@ -702,7 +698,7 @@ static int process_read(struct seq_state *state)
 #ifdef HAVE_ALSA_UMP
 			snd_seq_ump_event_t *ev = event;
 
-			data = (uint32_t*)&ev->ump[0];
+			data = &ev->ump[0];
 			size = spa_ump_message_size(snd_ump_msg_hdr_type(ev->ump[0])) * 4;
 #else
 			spa_assert_not_reached();
@@ -715,34 +711,21 @@ static int process_read(struct seq_state *state)
 				spa_log_warn(state->log, "decode failed: %s", snd_strerror(size));
 				continue;
 			}
-
-			midi1_ptr = midi1_data;
-			midi1_size = size;
+			data = midi1_data;
 		}
 
-		do {
-			if (!ump) {
-				data = ump_data;
-				size = spa_ump_from_midi(&midi1_ptr, &midi1_size,
-						ump_data, sizeof(ump_data), 0, &ump_state);
-				if (size <= 0)
-					break;
-			}
+		spa_log_trace_fp(state->log, "event %d time:%"PRIu64" offset:%d size:%ld port:%d.%d",
+				type, ev_time, offset, size, addr->client, addr->port);
 
-			spa_log_trace_fp(state->log, "event %d time:%"PRIu64" offset:%d size:%ld port:%d.%d",
-					type, ev_time, offset, size, addr->client, addr->port);
+		spa_pod_builder_control(&port->builder, offset, ump ? SPA_CONTROL_UMP : SPA_CONTROL_Midi );
+		spa_pod_builder_bytes(&port->builder, data, size);
 
-			spa_pod_builder_control(&port->builder, offset, SPA_CONTROL_UMP);
-			spa_pod_builder_bytes(&port->builder, data, size);
-
-			/* make sure we can fit at least one control event of max size otherwise
-			 * we keep the event in the queue and try to copy it in the next cycle */
-			if (port->builder.state.offset +
-					sizeof(struct spa_pod_control) +
-					MAX_EVENT_SIZE > port->buffer->buf->datas[0].maxsize)
-				goto done;
-
-		} while (!ump);
+		/* make sure we can fit at least one control event of max size otherwise
+		 * we keep the event in the queue and try to copy it in the next cycle */
+		if (port->builder.state.offset +
+				sizeof(struct spa_pod_control) +
+				MAX_EVENT_SIZE > port->buffer->buf->datas[0].maxsize)
+			goto done;
         }
 
 done:
@@ -819,7 +802,6 @@ static int process_write(struct seq_state *state)
 		const void *c_body;
 		uint64_t out_time;
 		snd_seq_real_time_t out_rt;
-		bool first = true;
 
 		if (io->status != SPA_STATUS_HAVE_DATA ||
 		    io->buffer_id >= port->n_buffers)
@@ -844,9 +826,6 @@ static int process_write(struct seq_state *state)
 			size_t body_size;
 			uint8_t *body;
 
-			if (c.type != SPA_CONTROL_UMP)
-				continue;
-
 			body = (uint8_t*)c_body;
 			body_size = c.value.size;
 
@@ -861,6 +840,9 @@ static int process_write(struct seq_state *state)
 #ifdef HAVE_ALSA_UMP
 				snd_seq_ump_event_t ev;
 
+				if (c.type != SPA_CONTROL_UMP)
+					continue;
+
 				snd_seq_ump_ev_clear(&ev);
 				snd_seq_ev_set_ump_data(&ev, body, SPA_MIN(sizeof(ev.ump), (size_t)body_size));
 				snd_seq_ev_set_source(&ev, state->event.addr.port);
@@ -878,26 +860,26 @@ static int process_write(struct seq_state *state)
 #endif
 			} else {
 				snd_seq_event_t ev;
-				uint8_t data[MAX_EVENT_SIZE];
-				int size;
-				uint64_t st = 0;
+				int size = 0;
+				long s;
+
+				if (c.type != SPA_CONTROL_Midi)
+					continue;
 
 				while (body_size > 0) {
-					if ((size = spa_ump_to_midi((const uint32_t **)&body, &body_size,
-									data, sizeof(data), &st)) <= 0)
-						break;
-
-					if (first)
+					if (size == 0)
 						snd_seq_ev_clear(&ev);
 
-					if ((size = snd_midi_event_encode(stream->codec, data, size, &ev)) < 0) {
+					if ((s = snd_midi_event_encode(stream->codec, body, body_size, &ev)) < 0) {
 						spa_log_warn(state->log, "failed to encode event: %s",
 								snd_strerror(size));
 						snd_midi_event_reset_encode(stream->codec);
-						first = true;
+						size = 0;
 						continue;
 					}
-					first = false;
+					body += s;
+					body_size -= s;
+					size += s;
 					if (ev.type == SND_SEQ_EVENT_NONE)
 						/* this can happen when the event is not complete yet, like
 						 * a sysex message and we need to encode some more data. */
@@ -913,7 +895,7 @@ static int process_write(struct seq_state *state)
 						spa_log_warn(state->log, "failed to output event: %s",
 								snd_strerror(err));
 					}
-					first = true;
+					size = 0;
 				}
 			}
 		}

spa/plugins/alsa/alsa-seq.h

@@ -82,6 +82,8 @@ struct seq_port {
 	struct spa_pod_builder builder;
 	struct spa_pod_frame frame;
 
+	uint32_t control_types;
+
 	struct spa_audio_info current_format;
 	unsigned int have_format:1;
 	unsigned int active:1;