jack1/include/port.h

/*
    Copyright (C) 2001 Paul Davis

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as published by
    the Free Software Foundation; either version 2.1 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

 */

#ifndef __jack_port_h__
#define __jack_port_h__

#include <pthread.h>
#include <jack/types.h>
#include <jack/jslist.h>
#include "shm.h"

#define JACK_PORT_NAME_SIZE 256
#define JACK_PORT_TYPE_SIZE 32

/* The relatively low value of this constant reflects the fact that
 * JACK currently only knows about *2* port types.  (May 2006)
 *
 * Further, the 4 covers:
 *   - a single non-negotiated audio format
 *   - music data (ie. MIDI)
 *   - video
 *   - one other
 *
 * which is probably enough for more than just the foreseeable future.
 */
#define JACK_MAX_PORT_TYPES 4
#define JACK_AUDIO_PORT_TYPE 0
#define JACK_MIDI_PORT_TYPE 1

/* these should probably go somewhere else, but not in <jack/types.h> */
#define JACK_CLIENT_NAME_SIZE 33

/* JACK shared memory segments are limited to MAX_INT32, they can be
 * shared between 32-bit and 64-bit clients.
 */
#define JACK_SHM_MAX (MAX_INT32)
typedef int32_t jack_port_type_id_t;

#define JACK_BACKEND_ALIAS "system"

/* Port type structure.
 *
 *  (1) One for each port type is part of the engine's jack_control_t
 *  shared memory structure.
 *
 *  (2) One for each port type is appended to the engine's
 *  jack_client_connect_result_t response.  The client reads them into
 *  its local memory, using them to attach the corresponding shared
 *  memory segments.
 */
typedef struct _jack_port_type_info {

	jack_port_type_id_t ptype_id;
	const char type_name[JACK_PORT_TYPE_SIZE];

	/* If == 1, then a buffer to handle nframes worth of data has
	 * sizeof(jack_default_audio_sample_t) * nframes bytes.
	 *
	 * If > 1, the buffer allocated for input mixing will be
	 * this value times sizeof(jack_default_audio_sample_t)
	 * * nframes bytes in size.  For non-audio data types,
	 * it may have a different value.
	 *
	 * If < 0, the value should be ignored, and buffer_size
	 * should be used.
	 */
	int32_t buffer_scale_factor;

	/* ignored unless buffer_scale_factor is < 0. see above */
	jack_shmsize_t buffer_size;

	jack_shm_registry_index_t shm_registry_index;

	jack_shmsize_t zero_buffer_offset;

} POST_PACKED_STRUCTURE jack_port_type_info_t;

/* Allocated by the engine in shared memory. */
typedef struct _jack_port_shared {

	jack_port_type_id_t ptype_id;   /* index into port type array */
	jack_shmsize_t offset;          /* buffer offset in shm segment */
	jack_port_id_t id;              /* index into engine port array */
	jack_uuid_t uuid;
	uint32_t flags;
	char name[JACK_CLIENT_NAME_SIZE + JACK_PORT_NAME_SIZE];
	char alias1[JACK_CLIENT_NAME_SIZE + JACK_PORT_NAME_SIZE];
	char alias2[JACK_CLIENT_NAME_SIZE + JACK_PORT_NAME_SIZE];
	jack_uuid_t client_id;          /* who owns me */

	volatile jack_nframes_t latency;
	volatile jack_nframes_t total_latency;
	volatile jack_latency_range_t playback_latency;
	volatile jack_latency_range_t capture_latency;
	volatile uint8_t monitor_requests;

	char has_mixdown;               /* port has a mixdown function */
	char in_use;
	char unused;                    /* legacy locked field */

} POST_PACKED_STRUCTURE jack_port_shared_t;

typedef struct _jack_port_functions {

	/* Function to initialize port buffer. Cannot be NULL.
	 * NOTE: This must take a buffer rather than jack_port_t as it is called
	 * in jack_engine_place_buffers() before any port creation.
	 * A better solution is to make jack_engine_place_buffers to be type-specific,
	 * but this works.
	 */
	void (*buffer_init)(void *buffer, size_t size, jack_nframes_t);

	/* Function to mixdown multiple inputs to a buffer.  Can be NULL,
	 * indicating that multiple input connections are not legal for
	 * this data type.
	 */
	void (*mixdown)(jack_port_t *, jack_nframes_t);

} jack_port_functions_t;

/**
 * Get port functions.
 * @param ptid port type id.
 *
 * @return pointer to port type functions or NULL if port type is unknown.
 */
/*const*/ jack_port_functions_t *
jack_get_port_functions(jack_port_type_id_t ptid);


/* Allocated by the client in local memory. */
struct _jack_port {
	void                    **client_segment_base;
	void                     *mix_buffer;
	jack_port_type_info_t    *type_info;    /* shared memory type info */
	struct _jack_port_shared *shared;       /* corresponding shm struct */
	struct _jack_port        *tied;         /* locally tied source port */
	jack_port_functions_t fptr;
	pthread_mutex_t connection_lock;
	JSList                   *connections;
};

/*  Inline would be cleaner, but it needs to be fast even in
 *  non-optimized code.  jack_output_port_buffer() only handles output
 *  ports.  jack_port_buffer() works for both input and output ports.
 */
#define jack_port_buffer(p) \
	((void*)((p)->mix_buffer ? (p)->mix_buffer : \
		 *(p)->client_segment_base + (p)->shared->offset))
#define jack_output_port_buffer(p) \
	((void*)(*(p)->client_segment_base + (p)->shared->offset))

/* not for use by JACK applications */
size_t jack_port_type_buffer_size(jack_port_type_info_t* port_type_info, jack_nframes_t nframes);

#endif /* __jack_port_h__ */