path: root/net/udpsend~.c

/* udpsend~ started by Martin Peach on 20100110, based on netsend~              */
/* udpsend~ sends audio via udp only.*/
/* It is a PD external, all Max stuff has been removed from the source */
/* ------------------------ netsend~ ------------------------------------------ */
/*                                                                              */
/* Tilde object to send uncompressed audio data to netreceive~.                 */
/* Written by Olaf Matthes <olaf.matthes@gmx.de>.                               */
/* Based on streamout~ by Guenter Geiger.                                       */
/* Get source at http://www.akustische-kunst.org/                               */
/*                                                                              */
/* This program is free software; you can redistribute it and/or                */
/* modify it under the terms of the GNU General Public License                  */
/* as published by the Free Software Foundation; either version 2               */
/* of the License, or (at your option) any later version.                       */
/*                                                                              */
/* See file LICENSE for further informations on licensing terms.                */
/*                                                                              */
/* 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 General Public License for more details.                                 */
/*                                                                              */
/* You should have received a copy of the GNU 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.  */
/*                                                                              */
/* Based on PureData by Miller Puckette and others.                             */
/*                                                                              */
/* This project was commissioned by the Society for Arts and Technology [SAT],  */
/* Montreal, Quebec, Canada, http://www.sat.qc.ca/.                             */
/*                                                                              */
/* ---------------------------------------------------------------------------- */

#include "m_pd.h"

#include "udpsend~.h"

#include <sys/types.h>
#include <string.h>
#include <stdlib.h>
#include <math.h>
#ifndef _WIN32
#include <sys/socket.h>
#include <errno.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <sys/ioctl.h> // for SIOCGIFCONF
#include <net/if.h> // for SIOCGIFCONF
#include <arpa/inet.h>
#include <netdb.h>
#include <sys/time.h>
#include <signal.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdio.h>
#include <pthread.h>
#define SOCKET_ERROR -1
#endif
#ifdef __APPLE__
#include <ifaddrs.h>
#endif
#ifdef _WIN32
#include <winsock2.h>
#include <ws2tcpip.h>
#include <iphlpapi.h> // for interface addresses
#include "pthread.h"
#endif

#ifdef MSG_NOSIGNAL
#define SEND_FLAGS /*MSG_DONTWAIT|*/MSG_NOSIGNAL
#else
#define SEND_FLAGS 0
#endif

#ifndef SOL_IP
#define SOL_IP IPPROTO_IP
#endif


/* ------------------------ udpsend~ ----------------------------- */

static t_class *udpsend_tilde_class;

static t_symbol *ps_nothing, *ps_localhost, *ps_vecsize;
static t_symbol *ps_format, *ps_channels, *ps_framesize;
static t_symbol *ps_sf_float, *ps_sf_16bit, *ps_sf_8bit;
static t_symbol *ps_sf_unknown, *ps_bitrate, *ps_hostname;

typedef struct _udpsend_tilde
{
    t_object        x_obj;
    t_outlet        *x_outlet;
    t_outlet        *x_outlet2;
    t_clock         *x_clock;
    int             x_fd;
    unsigned int    x_multicast_loop_state;
    unsigned int    x_multicast_ttl; /* time to live for multicast */
    t_tag           x_tag;
    t_symbol*       x_hostname;
    int             x_portno;
    int             x_connectstate;
    char            *x_cbuf;
    int             x_cbufsize;
    int             x_blocksize; /* set to DEFAULT_AUDIO_BUFFER_SIZE or user-supplied argument 3 in udpsend_tilde_new() */
    int             x_blockspersend; /* set to x->x_blocksize / x->x_vecsize in udpsend_tilde_perform() */
    int             x_blockssincesend;

    long            x_samplerate; /* samplerate we're running at */
    int             x_vecsize; /* current DSP signal vector size */
    int             x_ninlets; /* number of inlets */
    int             x_channels; /* number of channels we want to stream */
    int             x_format; /* format of streamed audio data */
    int             x_count; /* total number of audio frames */
    t_int           **x_myvec; /* vector we pass on in the DSP routine */

    pthread_mutex_t x_mutex;
    pthread_t       x_childthread; /* a thread to initiate a connection to the remote port */
    pthread_attr_t  x_childthread_attr; /* child thread should have detached attribute so it can be cleaned up after it exits. */
    int             x_childthread_result; /* result from pthread_create. Zero if x_childthread represents a valid thread. */
} t_udpsend_tilde;

#define NO_CHILDTHREAD 1 /* not zero */

/* function prototypes */
static int udpsend_tilde_sockerror(char *s);
static void udpsend_tilde_sock_err(t_udpsend_tilde *x, char *err_string);
static void udpsend_tilde_closesocket(int fd);
static void udpsend_tilde_notify(t_udpsend_tilde *x);
static void udpsend_tilde_disconnect(t_udpsend_tilde *x);
static void *udpsend_tilde_doconnect(void *zz);
static void udpsend_tilde_connect(t_udpsend_tilde *x, t_symbol *host, t_floatarg fportno);
static void udpsend_tilde_set_multicast_loopback(t_udpsend_tilde *x, t_floatarg loop_state);
static void udpsend_tilde_set_multicast_ttl(t_udpsend_tilde *x, t_floatarg ttl_hops);
static void udpsend_tilde_set_multicast_interface (t_udpsend_tilde *x, t_symbol *s, int argc, t_atom *argv);
static t_int *udpsend_tilde_perform(t_int *w);
static void udpsend_tilde_dsp(t_udpsend_tilde *x, t_signal **sp);
static void udpsend_tilde_channels(t_udpsend_tilde *x, t_floatarg channels);
static void udpsend_tilde_format(t_udpsend_tilde *x, t_symbol* form, t_floatarg bitrate);
static void udpsend_tilde_float(t_udpsend_tilde* x, t_floatarg arg);
static void udpsend_tilde_info(t_udpsend_tilde *x);
static void *udpsend_tilde_new(t_floatarg inlets, t_floatarg blocksize);
static void udpsend_tilde_free(t_udpsend_tilde* x);
void udpsend_tilde_setup(void);

/* functions */
static void udpsend_tilde_notify(t_udpsend_tilde *x)
{
    pthread_mutex_lock(&x->x_mutex);
    x->x_childthread_result = NO_CHILDTHREAD; /* connection thread has ended */
    outlet_float(x->x_outlet, x->x_connectstate); /* we should be connected */
    pthread_mutex_unlock(&x->x_mutex);
}

static void udpsend_tilde_disconnect(t_udpsend_tilde *x)
{
    pthread_mutex_lock(&x->x_mutex);
    if (x->x_fd != -1)
    {
        udpsend_tilde_closesocket(x->x_fd);
        x->x_fd = -1;
        x->x_connectstate = 0;
        outlet_float(x->x_outlet, 0);
    }
    pthread_mutex_unlock(&x->x_mutex);
}

/* udpsend_tilde_doconnect runs in the child thread, which terminates as soon as a connection is  */
static void *udpsend_tilde_doconnect(void *zz)
{
    t_udpsend_tilde     *x = (t_udpsend_tilde *)zz;
    struct sockaddr_in  server;
    struct hostent      *hp;
    int                 intarg = 1;
    int                 sockfd;
    int                 portno;
    int                 broadcast = 1;/* nonzero is true */
    unsigned char       multicast_loop_state;
    unsigned char       multicast_ttl;
    t_symbol            *hostname;
    unsigned int        size;

    pthread_mutex_lock(&x->x_mutex);
    hostname = x->x_hostname;
    portno = x->x_portno;
    pthread_mutex_unlock(&x->x_mutex);

    /* create a socket */
    sockfd = socket(AF_INET, SOCK_DGRAM, 0);
    if (sockfd < 0)
    {
         post("udpsend~: connection to %s on port %d failed", hostname->s_name,portno); 
         udpsend_tilde_sock_err(x, "udpsend~ socket");
         x->x_childthread_result = NO_CHILDTHREAD;
         return (0);
    }

#ifdef SO_BROADCAST
    if( 0 != setsockopt(sockfd, SOL_SOCKET, SO_BROADCAST, (const void *)&broadcast, sizeof(broadcast)))
    {
        udpsend_tilde_sockerror("setting SO_BROADCAST");
    }
#endif /* SO_BROADCAST */

    /* connect socket using hostname provided in command line */
    server.sin_family = AF_INET;
    hp = gethostbyname(x->x_hostname->s_name);
    if (hp == 0)
    {
        post("udpsend~: bad host?");
        x->x_childthread_result = NO_CHILDTHREAD;
        return (0);
    }

#ifdef SO_PRIORITY
    /* set high priority, LINUX only */
    intarg = 6;	/* select a priority between 0 and 7 */
    if (setsockopt(sockfd, SOL_SOCKET, SO_PRIORITY, (const char*)&intarg, sizeof(int)) < 0)
    {
        udpsend_tilde_sockerror("setting SO_PRIORITY");
    }
#endif

    memcpy((char *)&server.sin_addr, (char *)hp->h_addr, hp->h_length);

    if (0xE0000000 == (ntohl(server.sin_addr.s_addr) & 0xF0000000))
        post ("udpsend~: connecting to a multicast address");
    size = sizeof(multicast_loop_state);
    getsockopt(sockfd, IPPROTO_IP, IP_MULTICAST_LOOP, &multicast_loop_state, &size);
    size = sizeof(multicast_ttl);
    getsockopt(sockfd, IPPROTO_IP, IP_MULTICAST_TTL, &multicast_ttl, &size);
    x->x_multicast_loop_state = multicast_loop_state;
    x->x_multicast_ttl = multicast_ttl;

    /* assign client port number */
    server.sin_port = htons((unsigned short)portno);

    /* try to connect */
    if (connect(sockfd, (struct sockaddr *) &server, sizeof (server)) < 0)
    {
        udpsend_tilde_sock_err(x, "udpsend~ connect");
        udpsend_tilde_closesocket(sockfd);
        x->x_childthread_result = NO_CHILDTHREAD;
        return (0);
    }

    post("udpsend~: connected host %s on port %d", hostname->s_name, portno);

    pthread_mutex_lock(&x->x_mutex);
    x->x_fd = sockfd;
    x->x_connectstate = 1;
    clock_delay(x->x_clock, 0);/* udpsend_tilde_notify is called in next clock tick */
    pthread_mutex_unlock(&x->x_mutex);
    return (0);
}

static void udpsend_tilde_connect(t_udpsend_tilde *x, t_symbol *host, t_floatarg fportno)
{
    pthread_mutex_lock(&x->x_mutex);
    if (x->x_childthread_result == 0)
    {
        pthread_mutex_unlock(&x->x_mutex);
        post("udpsend~: already trying to connect");
        return;
    }
    if (x->x_fd != -1)
    {
        pthread_mutex_unlock(&x->x_mutex);
        post("udpsend~: already connected");
        return;
    }

    if (host != ps_nothing)
        x->x_hostname = host;
    else
        x->x_hostname = ps_localhost; /* default host */

    if (!fportno)
        x->x_portno = DEFAULT_PORT;
    else
        x->x_portno = (int)fportno;
    x->x_count = 0;

    /* start child thread to connect */
    /* sender thread should start out detached so its resouces will be freed when it is done */
    if (0!= (x->x_childthread_result = pthread_attr_init(&x->x_childthread_attr)))
    {
        pthread_mutex_unlock(&x->x_mutex);
        post("udpsend~: pthread_attr_init failed: %d", x->x_childthread_result);
        return;
    }
    if(0!= (x->x_childthread_result = pthread_attr_setdetachstate(&x->x_childthread_attr, PTHREAD_CREATE_DETACHED)))
    {
        pthread_mutex_unlock(&x->x_mutex);
        post("udpsend~: pthread_attr_setdetachstate failed: %d", x->x_childthread_result);
        return;
    }
    if (0 != (x->x_childthread_result = pthread_create(&x->x_childthread, &x->x_childthread_attr, udpsend_tilde_doconnect, x)))
    {
        pthread_mutex_unlock(&x->x_mutex);
        post("udpsend~: couldn't create sender thread (%d)", x->x_childthread_result);
        return;
    }
    pthread_mutex_unlock(&x->x_mutex);
}

static void udpsend_tilde_set_multicast_loopback(t_udpsend_tilde *x, t_floatarg loop_state)
{
    int             sockfd = x->x_fd;
    unsigned char   multicast_loop_state = loop_state;
    unsigned int    size;

    if (x->x_fd < 0)
    {
        pd_error(x, "udpsend_tilde_set_multicast_loopback: not connected");
        return;
    }
    if (setsockopt(sockfd, IPPROTO_IP, IP_MULTICAST_LOOP,
        &multicast_loop_state, sizeof(multicast_loop_state)) < 0) 
        udpsend_tilde_sock_err(x, "udpsend_tilde setsockopt IP_MULTICAST_LOOP");
    getsockopt(sockfd, IPPROTO_IP, IP_MULTICAST_LOOP, &multicast_loop_state, &size);
    x->x_multicast_loop_state = multicast_loop_state;
}

static void udpsend_tilde_set_multicast_ttl(t_udpsend_tilde *x, t_floatarg ttl_hops)
{
    int             sockfd = x->x_fd;
    unsigned char   multicast_ttl = ttl_hops;
    unsigned int    size;

    if (x->x_fd < 0)
    {
        pd_error(x, "udpsend_tilde_set_multicast_ttl: not connected");
        return;
    }
    if (setsockopt(sockfd, IPPROTO_IP, IP_MULTICAST_TTL,
        &multicast_ttl, sizeof(multicast_ttl)) < 0) 
        udpsend_tilde_sock_err(x, "udpsend_tilde setsockopt IP_MULTICAST_TTL");
    getsockopt(sockfd, IPPROTO_IP, IP_MULTICAST_TTL, &multicast_ttl, &size);
    x->x_multicast_ttl = multicast_ttl;
}

static void udpsend_tilde_set_multicast_interface (t_udpsend_tilde *x, t_symbol *s, int argc, t_atom *argv)
{
#ifdef _WIN32
    int                 i, n_ifaces = 32;
    PMIB_IPADDRTABLE    pIPAddrTable;
    DWORD               dwSize;
    IN_ADDR             IPAddr;
    int                 if_index = -1;
    int                 found = 0;
    t_symbol            *interfacename = gensym("none");
    struct hostent      *hp = 0;
    struct sockaddr_in  server;

    if (x->x_fd < 0)
    {
        pd_error(x, "udpsend_tilde_set_multicast_interface: not connected");
        return;
    }
    switch (argv[0].a_type)
    {
        case A_FLOAT:
            if_index = (int)atom_getfloat(&argv[0]);
            break;
        case A_SYMBOL:
            interfacename = atom_getsymbol(&argv[0]);    
            break;
        default:
            pd_error(x, "udpsend_tilde_set_multicast_interface: argument not float or symbol");
            return;
    }
    if (if_index == -1)
    {
        hp = gethostbyname(interfacename->s_name); // if interface is a dotted or named IP address (192.168.0.88)
    }
    if (hp != 0) memcpy((char *)&server.sin_addr, (char *)hp->h_addr, hp->h_length);
    else // maybe interface is its index (1) (names aren't available in _WIN32)
    {
        /* get the list of interfaces, IPv4 only */
        dwSize = sizeof(MIB_IPADDRTABLE)*n_ifaces;
        if ((pIPAddrTable = (MIB_IPADDRTABLE *) getbytes(dwSize)) == NULL)
        {
            post("udpsend_tilde: unable to allocate %lu bytes for GetIpAddrTable", dwSize);
            return;
        }
        if (GetIpAddrTable(pIPAddrTable, &dwSize, 0))
        { 
            udpsend_tilde_sock_err(x, "udpsend_tilde_set_multicast_interface: GetIpAddrTable");
            return;
        }

        n_ifaces = pIPAddrTable->dwNumEntries;
        post("udpsend_tilde: %d interface%s available:", n_ifaces, (n_ifaces == 1)?"":"s");
        for (i = 0; i < n_ifaces; i++)
        {
            IPAddr.S_un.S_addr = (u_long) pIPAddrTable->table[i].dwAddr;
            post("[%d]: %s", pIPAddrTable->table[i].dwIndex, inet_ntoa(IPAddr));
            if (pIPAddrTable->table[i].dwIndex == if_index)
            {
                server.sin_addr = IPAddr;
                found = 1;
            }
        }

        if (pIPAddrTable)
        {
            freebytes(pIPAddrTable, dwSize);
            pIPAddrTable = NULL;
        }
        if (! found)
        {
            post("udpsend_tilde_set_multicast_interface: bad host name? (%s)\n", interfacename->s_name);
            return;
        }
    }
    if (setsockopt(x->x_fd, IPPROTO_IP, IP_MULTICAST_IF, (const char *)&server.sin_addr, sizeof(struct in_addr)) == SOCKET_ERROR)
        udpsend_tilde_sock_err(x, "udpsend_tilde setsockopt IP_MULTICAST_IF");
    else post("udpsend_tilde multicast interface is %s", inet_ntoa(server.sin_addr));

#elif defined __APPLE__
    int                 if_index = -1;
    int                 found = 0;
    t_symbol            *interfacename = gensym("none");
    struct ifaddrs      *ifap;
    int                 i = 0;
    int                 n_ifaces = 0;
    struct hostent      *hp = 0;
    struct sockaddr_in  server;
    struct sockaddr     *sa;
    char                ifname[IFNAMSIZ]; /* longest possible interface name */
    
    if (x->x_fd < 0)
    {
        pd_error(x, "udpsend_tilde_set_multicast_interface: not connected");
        return;
    }
    switch (argv[0].a_type)
    {
        case A_FLOAT:
            if_index = (int)atom_getfloat(&argv[0]);
            break;
        case A_SYMBOL:
            interfacename = atom_getsymbol(&argv[0]);    
            break;
        default:
            pd_error(x, "udpsend_tilde_set_multicast_interface: argument not float or symbol");
            return;
    }
    if (if_index == -1)
    {
        hp = gethostbyname(interfacename->s_name); // if interface is a dotted or named IP address (192.168.0.88)
    }
    if (hp != 0) memcpy((char *)&server.sin_addr, (char *)hp->h_addr, hp->h_length);
    else // maybe interface is its name (eth0) or index (1)
    { // scan all the interfaces to get the IP address of interface
        if (getifaddrs(&ifap)) udpsend_tilde_sock_err(x, "udpsend_tilde getifaddrs");
        i = found = n_ifaces = 0;
        while (NULL != ifap)
        {
            sa = ifap->ifa_addr;
            if (AF_INET == sa->sa_family)
            {
                ++n_ifaces;
                strncpy (ifname, ifap->ifa_name, IFNAMSIZ);
                post("[%d]: %s: %s", i, ifname, inet_ntoa(((struct sockaddr_in *)sa)->sin_addr));
                if((i == if_index) || ((if_index == -1) && (!strncmp(interfacename->s_name, ifname, IFNAMSIZ))))
                { // either the index or the name match
                    server.sin_addr = ((struct sockaddr_in *)sa)->sin_addr;
                    found = 1;
                }
            }
            i++;
            ifap = ifap->ifa_next; // next record or NULL
        }
        freeifaddrs(ifap);
        post ("udpsend_tilde: %d interfaces", n_ifaces);
        if (!found) return;
    }
    if (setsockopt(x->x_fd, IPPROTO_IP, IP_MULTICAST_IF, (const char *)&server.sin_addr, sizeof(struct in_addr)))
        udpsend_tilde_sock_err(x, "udpsend_tilde setsockopt IP_MULTICAST_IF");
    else post("udpsend_tilde multicast interface is %s", inet_ntoa(server.sin_addr));
    return;
#else // __linux__
    struct sockaddr_in  server;
    struct sockaddr     *sa;
    struct hostent      *hp = 0;
    struct ifconf       ifc;
    int                 n_ifaces = 32, i, origbuflen, found = 0;
    char                ifname[IFNAMSIZ]; /* longest possible interface name */
    t_symbol            *interface = gensym("none");
    int                 if_index = -1;
    
    if (x->x_fd < 0)
    {
        pd_error(x, "udpsend_tilde_set_multicast_interface: not connected");
        return;
    }
    switch (argv[0].a_type)
    {
        case A_FLOAT:
            if_index = (int)atom_getfloat(&argv[0]);
            break;
        case A_SYMBOL:
            interface = atom_getsymbol(&argv[0]);    
            break;
        default:
            pd_error(x, "udpsend_tilde_set_multicast_interface: argument not float or symbol");
            return;
    }
    if (if_index == -1)
    {
        hp = gethostbyname(interface->s_name); // if interface is a dotted or named IP address (192.168.0.88)
    }
    if (hp != 0) memcpy((char *)&server.sin_addr, (char *)hp->h_addr, hp->h_length);
    else // maybe interface is its name (eth0) or index (1)
    { // scan all the interfaces to get the IP address of interface
        // find the number of interfaces
        origbuflen = n_ifaces * sizeof (struct ifreq);// save maximum length for free()
        ifc.ifc_len = origbuflen; // SIOCGIFCONF changes it to valid length
        ifc.ifc_buf = (char*)getzbytes(origbuflen);
        if (ifc.ifc_buf != NULL)
        { // 
            if (ioctl(x->x_fd, SIOCGIFCONF, &ifc) < 0) // get list of interfaces
                udpsend_tilde_sock_err(x, "udpsend_tilde_set_multicast_interface: getting list of interfaces");
            else
            {
                n_ifaces = ifc.ifc_len/sizeof(struct ifreq);
                post("udpsend_tilde: %d interface%s available:", n_ifaces, (n_ifaces == 1)?"":"s");
                for(i = 0; i < n_ifaces; i++)
                {
                    sa = (struct sockaddr *)&(ifc.ifc_req[i].ifr_addr);
                    strncpy (ifname, ifc.ifc_req[i].ifr_name, IFNAMSIZ);
                    post("[%d]: %s: %s", i, ifname, inet_ntoa(((struct sockaddr_in *)sa)->sin_addr));
                    if
                    (
                        (i == if_index) ||
                        ((if_index == -1) && (!strncmp(interface->s_name, ifname, IFNAMSIZ)))
                    )
                    {
                        server.sin_addr = ((struct sockaddr_in *)sa)->sin_addr;
                        found = 1;
                    }
                } 
            }
        }
        freebytes(ifc.ifc_buf, origbuflen);

        if (! found)
        {
            post("udpsend_tilde_set_multicast_interface: bad host name? (%s)\n", interface->s_name);
            return;
        }
    }
    if (setsockopt(x->x_fd, IPPROTO_IP, IP_MULTICAST_IF, &server.sin_addr, sizeof(struct in_addr)) < 0)
        udpsend_tilde_sock_err(x, "udpsend_tilde_set_multicast_interface: setsockopt");
    else post("udpsend_tilde multicast interface is %s", inet_ntoa(server.sin_addr));
#endif // _WIN32
}

static t_int *udpsend_tilde_perform(t_int *w)
{
    t_udpsend_tilde* x = (t_udpsend_tilde*) (w[1]);
    int n = (int)(w[2]);
    t_float *in[DEFAULT_AUDIO_CHANNELS];
    const int offset = 3;
    char* bp = NULL;
    int i, length = x->x_blocksize * SF_SIZEOF(x->x_tag.format) * x->x_tag.channels;
    int sent = 0;

    pthread_mutex_lock(&x->x_mutex);

    for (i = 0; i < x->x_ninlets; i++)
        in[i] = (t_float *)(w[offset + i]);

    if (n != x->x_vecsize)	/* resize buffer */
    {
        x->x_vecsize = n;
        x->x_blockspersend = x->x_blocksize / x->x_vecsize;
        x->x_blockssincesend = 0;
        length = x->x_blocksize * SF_SIZEOF(x->x_tag.format) * x->x_tag.channels;
    }

    /* format the buffer */
    switch (x->x_tag.format)
    {
        case SF_FLOAT:
        {
            int32_t* fbuf = (int32_t *)x->x_cbuf + (x->x_blockssincesend * x->x_vecsize * x->x_tag.channels);
            flint fl;

            while (n--)
                for (i = 0; i < x->x_tag.channels; i++)
                {
                    fl.f32 = *(in[i]++);
                    *fbuf++ = htonl(fl.i32);
                }
            break;
        }
        case SF_16BIT:
        {
            short* cibuf = (short *)x->x_cbuf + (x->x_blockssincesend * x->x_vecsize * x->x_tag.channels);

            while (n--) 
                for (i = 0; i < x->x_tag.channels; i++)
                    *cibuf++ = htons((short)floor(32767.5 * *(in[i]++)));/* signed binary */
            break;
        }
        case SF_8BIT:
        {
            unsigned char* cbuf = (unsigned char*)x->x_cbuf + (x->x_blockssincesend * x->x_vecsize * x->x_tag.channels);

            while (n--) 
                for (i = 0; i < x->x_tag.channels; i++)
                    *cbuf++ = (unsigned char)floor(128. * (1.0 + *(in[i]++))); /* offset binary */
            break;
        }
        default:
            break;
    }

    if (!(x->x_blockssincesend < x->x_blockspersend - 1))	/* time to send the buffer */
    {
        x->x_blockssincesend = 0;
        x->x_count++;	/* count data packet we're going to send */

        if (x->x_fd != -1)
        {
            bp = (char *)x->x_cbuf;
            /* fill in the header tag */
            x->x_tag.tag[0] = 'T';
            x->x_tag.tag[1] = 'A';
            x->x_tag.tag[2] = 'G';
            x->x_tag.tag[3] = '!';
            x->x_tag.framesize = htonl(length);
            x->x_tag.count = htonl(x->x_count);
            /* send the format tag */
            if (send(x->x_fd, (char*)&x->x_tag, sizeof(t_tag), SEND_FLAGS) < 0)
            {
                udpsend_tilde_sockerror("send tag");
                pthread_mutex_unlock(&x->x_mutex);
                udpsend_tilde_disconnect(x);
                return (w + offset + x->x_ninlets);
            }
            if (length != 0)
/* UDP: max. packet size is 64k (incl. headers) so we have to split */
            {
#ifdef __APPLE__
                /* WARNING: due to a 'bug' (maybe Apple would call it a feature?) in OS X
                    send calls with data packets larger than 16k fail with error number 40!
                    Thus we have to split the data packets into several packets that are 
                    16k in size. The other side will reassemble them again. */
                int size = DEFAULT_UDP_PACKT_SIZE;
                if (length < size)  /* maybe data fits into one packet? */
                    size = length;
                /* send the buffer */
                for (sent = 0; sent < length;)
                {
                    int ret = 0;
                    ret = send(x->x_fd, bp, size, SEND_FLAGS);
                    if (ret <= 0)
                    {
                        udpsend_tilde_sockerror("send data");
                        pthread_mutex_unlock(&x->x_mutex);
                        udpsend_tilde_disconnect(x);
                        return (w + offset + x->x_ninlets);
                    }
                    else
                    {
                        bp += ret;
                        sent += ret;
                        if ((length - sent) < size)
                            size = length - sent;
                    }
                }
#else
                /* If there is any data, send the buffer, the OS might segment it into smaller packets */
                int ret = send(x->x_fd, bp, length, SEND_FLAGS);
                if (ret <= 0)
                {
                    post ("udpsend~: sending length %ld", length);
                    udpsend_tilde_sockerror("send data");
                    pthread_mutex_unlock(&x->x_mutex);
                    udpsend_tilde_disconnect(x);
                    return (w + offset + x->x_ninlets);
                }
#endif
            }
        }

/* check whether user has updated any parameters */
        if (x->x_tag.channels != x->x_channels)
        {
            x->x_tag.channels = x->x_channels;
        }
        if (x->x_tag.format != x->x_format)
        {
            x->x_tag.format = x->x_format;
        }
    }
    else
    {
        x->x_blockssincesend++;
    }
    pthread_mutex_unlock(&x->x_mutex);
    return (w + offset + x->x_ninlets);
}

static void udpsend_tilde_dsp(t_udpsend_tilde *x, t_signal **sp)
{
    int i;

    pthread_mutex_lock(&x->x_mutex);

    x->x_myvec[0] = (t_int*)x;
    x->x_myvec[1] = (t_int*)sp[0]->s_n;

    x->x_samplerate = sp[0]->s_sr;

    for (i = 0; i < x->x_ninlets; i++)
    {
        x->x_myvec[2 + i] = (t_int*)sp[i]->s_vec;
    }

    pthread_mutex_unlock(&x->x_mutex);

    if (DEFAULT_AUDIO_BUFFER_SIZE % sp[0]->s_n)
    {
        error("udpsend~: signal vector size too large (needs to be even divisor of %d)", DEFAULT_AUDIO_BUFFER_SIZE);
    }
    else
    {
        dsp_addv(udpsend_tilde_perform, x->x_ninlets + 2, (t_int*)x->x_myvec);
    }
}

static void udpsend_tilde_channels(t_udpsend_tilde *x, t_floatarg channels)
{
    pthread_mutex_lock(&x->x_mutex);
    if (channels >= 0 && channels <= x->x_ninlets)
    {
        x->x_channels = (int)channels;
        post("udpsend~: channels set to %d", (int)channels);
    }
    else post ("udpsend~ number of channels must be between 0 and %d", x->x_ninlets);
    pthread_mutex_unlock(&x->x_mutex);
}

static void udpsend_tilde_format(t_udpsend_tilde *x, t_symbol* form, t_floatarg bitrate)
{
    pthread_mutex_lock(&x->x_mutex);
    if (!strncmp(form->s_name,"float", 5) && x->x_tag.format != SF_FLOAT)
    {
        x->x_format = (int)SF_FLOAT;
    }
    else if (!strncmp(form->s_name,"16bit", 5) && x->x_tag.format != SF_16BIT)
    {
        x->x_format = (int)SF_16BIT;
    }
    else if (!strncmp(form->s_name,"8bit", 4) && x->x_tag.format != SF_8BIT)
    {
        x->x_format = (int)SF_8BIT;
    }

    post("udpsend~: format set to %s", form->s_name);
    pthread_mutex_unlock(&x->x_mutex);
}

static void udpsend_tilde_float(t_udpsend_tilde* x, t_floatarg arg)
{
    if (arg == 0.0)
        udpsend_tilde_disconnect(x);
    else
        udpsend_tilde_connect(x,x->x_hostname,(float) x->x_portno);
}

/* send stream info */
static void udpsend_tilde_info(t_udpsend_tilde *x)
{
    t_atom list[2];
    t_symbol *sf_format;
    t_float bitrate;

    bitrate = (t_float)((SF_SIZEOF(x->x_tag.format) * x->x_samplerate * 8 * x->x_tag.channels) / 1000.);

    switch (x->x_tag.format)
    {
        case SF_FLOAT:
        {
            sf_format = ps_sf_float;
            break;
        }
        case SF_16BIT:
        {
            sf_format = ps_sf_16bit;
            break;
        }
        case SF_8BIT:
        {
            sf_format = ps_sf_8bit;
            break;
        }
        default:
        {
            sf_format = ps_sf_unknown;
            break;
        }
    }

    /* --- stream information (t_tag) --- */

    /* audio format */
    SETSYMBOL(list, (t_symbol *)sf_format);
    outlet_anything(x->x_outlet2, ps_format, 1, list);

    /* channels */
    SETFLOAT(list, (t_float)x->x_tag.channels);
    outlet_anything(x->x_outlet2, ps_channels, 1, list);

    /* current signal vector size */
    SETFLOAT(list, (t_float)x->x_vecsize);
    outlet_anything(x->x_outlet2, ps_vecsize, 1, list);

    /* framesize */
    SETFLOAT(list, (t_float)(ntohl(x->x_tag.framesize)));
    outlet_anything(x->x_outlet2, ps_framesize, 1, list);

    /* bitrate */
    SETFLOAT(list, (t_float)bitrate);
    outlet_anything(x->x_outlet2, ps_bitrate, 1, list);

    /* IP address */
    SETSYMBOL(list, (t_symbol *)x->x_hostname);
    outlet_anything(x->x_outlet2, ps_hostname, 1, list);
}

static void *udpsend_tilde_new(t_floatarg inlets, t_floatarg blocksize)
{
    int i;

    t_udpsend_tilde *x = (t_udpsend_tilde *)pd_new(udpsend_tilde_class);
    if (x)
    {
        for (i = sizeof(t_object); i < (int)sizeof(t_udpsend_tilde); i++)
            ((char *)x)[i] = 0; 

        if ((int)inlets < 1 || (int)inlets > DEFAULT_AUDIO_CHANNELS)
        {
            error("udpsend~: Number of channels must be between 1 and %d", DEFAULT_AUDIO_CHANNELS);
            return NULL;
        }
        x->x_ninlets = (int)inlets;
        for (i = 1; i < x->x_ninlets; i++)
            inlet_new(&x->x_obj, &x->x_obj.ob_pd, &s_signal, &s_signal);
 
        x->x_outlet = outlet_new(&x->x_obj, &s_float);
        x->x_outlet2 = outlet_new(&x->x_obj, &s_list);
        x->x_clock = clock_new(x, (t_method)udpsend_tilde_notify);

        x->x_myvec = (t_int **)t_getbytes(sizeof(t_int *) * (x->x_ninlets + 3));
        if (!x->x_myvec)
        {
            error("udpsend~: out of memory");
            return NULL;
        }

        pthread_mutex_init(&x->x_mutex, 0);

        x->x_hostname = ps_localhost;
        x->x_portno = DEFAULT_PORT;
        x->x_connectstate = 0;
        x->x_childthread_result = NO_CHILDTHREAD;
        x->x_fd = -1;

        x->x_tag.format = x->x_format = SF_FLOAT;
        x->x_tag.channels = x->x_channels = x->x_ninlets;
        x->x_vecsize = 64; /* this is updated in the perform routine udpsend_tilde_perform */
        x->x_cbuf = NULL;
        if (blocksize == 0) x->x_blocksize = DEFAULT_AUDIO_BUFFER_SIZE; 
        else if (DEFAULT_AUDIO_BUFFER_SIZE%(int)blocksize)
        {
            error("udpsend~: blocksize must fit snugly in %d", DEFAULT_AUDIO_BUFFER_SIZE);
            return NULL;
        } 
        else x->x_blocksize = (int)blocksize; //DEFAULT_AUDIO_BUFFER_SIZE; /* <-- the only place blocksize is set */
        x->x_blockspersend = x->x_blocksize / x->x_vecsize; /* 1024/64 = 16 blocks */
        x->x_blockssincesend = 0;
        x->x_cbufsize = x->x_blocksize * sizeof(t_float) * x->x_ninlets;
        x->x_cbuf = (char *)t_getbytes(x->x_cbufsize);

#ifndef _WIN32
        /* we don't want to get signaled in case send() fails */
        signal(SIGPIPE, SIG_IGN);
#endif
    }

    return (x);
}

static void udpsend_tilde_free(t_udpsend_tilde* x)
{
    udpsend_tilde_disconnect(x);

    /* free the memory */
    if (x->x_cbuf)t_freebytes(x->x_cbuf, x->x_cbufsize);
    if (x->x_myvec)t_freebytes(x->x_myvec, sizeof(t_int) * (x->x_ninlets + 3));

    clock_free(x->x_clock);

    pthread_mutex_destroy(&x->x_mutex);
}

void udpsend_tilde_setup(void)
{
    udpsend_tilde_class = class_new(gensym("udpsend~"), (t_newmethod)udpsend_tilde_new, (t_method)udpsend_tilde_free,
        sizeof(t_udpsend_tilde), 0, A_DEFFLOAT, A_DEFFLOAT, A_NULL);
    class_addmethod(udpsend_tilde_class, nullfn, gensym("signal"), 0);
    class_addmethod(udpsend_tilde_class, (t_method)udpsend_tilde_dsp, gensym("dsp"), 0);
    class_addfloat(udpsend_tilde_class, udpsend_tilde_float);
    class_addmethod(udpsend_tilde_class, (t_method)udpsend_tilde_info, gensym("info"), 0);
    class_addmethod(udpsend_tilde_class, (t_method)udpsend_tilde_connect, gensym("connect"), A_DEFSYM, A_DEFFLOAT, 0);
    class_addmethod(udpsend_tilde_class, (t_method)udpsend_tilde_set_multicast_ttl, gensym("multicast_ttl"), A_DEFFLOAT, 0);
    class_addmethod(udpsend_tilde_class, (t_method)udpsend_tilde_set_multicast_loopback, gensym("multicast_loopback"), A_DEFFLOAT, 0);
    class_addmethod(udpsend_tilde_class, (t_method)udpsend_tilde_set_multicast_interface, gensym("multicast_interface"), A_GIMME, 0);
    class_addmethod(udpsend_tilde_class, (t_method)udpsend_tilde_disconnect, gensym("disconnect"), 0);
    class_addmethod(udpsend_tilde_class, (t_method)udpsend_tilde_channels, gensym("channels"), A_FLOAT, 0);
    class_addmethod(udpsend_tilde_class, (t_method)udpsend_tilde_format, gensym("format"), A_SYMBOL, A_DEFFLOAT, 0);
    class_sethelpsymbol(udpsend_tilde_class, gensym("udpsend~"));
    post("udpsend~ v%s, (c) 2004-2005 Olaf Matthes, 2010 Martin Peach", VERSION);
    post("udpsend~ Default blocksize is %d", DEFAULT_AUDIO_BUFFER_SIZE);

    ps_nothing = gensym("");
    ps_localhost = gensym("localhost");
    ps_hostname = gensym("ipaddr");
    ps_format = gensym("format");
    ps_channels = gensym("channels");
    ps_vecsize = gensym("vecsize");
    ps_framesize = gensym("framesize");
    ps_bitrate = gensym("bitrate");
    ps_sf_float = gensym("_float_");
    ps_sf_16bit = gensym("_16bit_");
    ps_sf_8bit = gensym("_8bit_");
    ps_sf_unknown = gensym("_unknown_");
}

/* Utility functions */

static void udpsend_tilde_sock_err(t_udpsend_tilde *x, char *err_string)
{
/* prints the last error from errno or WSAGetLastError() */
#ifdef _WIN32
    void            *lpMsgBuf;
    unsigned long   errornumber = WSAGetLastError();
    int             len = 0, i;
    char            *cp;

    if (len = FormatMessageA((FORMAT_MESSAGE_ALLOCATE_BUFFER|FORMAT_MESSAGE_FROM_SYSTEM|FORMAT_MESSAGE_IGNORE_INSERTS)
        , NULL, errornumber, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), (LPSTR)&lpMsgBuf, 0, NULL))
    {
        cp = (char *)lpMsgBuf;
        for(i = 0; i < len; ++i)
        {
            if (cp[i] < 0x20)
            { /* end string at first weird character */
                cp[i] = 0;
                break;
            }
        }
        pd_error(x, "%s: %s (%d)", err_string, lpMsgBuf, errornumber);
        LocalFree(lpMsgBuf);
    }
#else
    pd_error(x, "%s: %s (%d)", err_string, strerror(errno), errno);
#endif
}

static int udpsend_tilde_sockerror(char *s)
{
#ifdef _WIN32
    int err = WSAGetLastError();
    if (err == 10054) return 1;
    else if (err == 10053) post("udpsend~: %s: software caused connection abort (%d)", s, err);
    else if (err == 10055) post("udpsend~: %s: no buffer space available (%d)", s, err);
    else if (err == 10060) post("udpsend~: %s: connection timed out (%d)", s, err);
    else if (err == 10061) post("udpsend~: %s: connection refused (%d)", s, err);
    else post("udpsend~: %s: %s (%d)", s, strerror(err), err);
#else
    int err = errno;
    post("udpsend~: %s: %s (%d)", s, strerror(err), err);
#endif
#ifdef _WIN32
    if (err == WSAEWOULDBLOCK)
#endif
#ifndef _WIN32
    if (err == EAGAIN)
#endif
    {
        return 1;	/* recoverable error */
    }
    return 0;	/* indicate non-recoverable error */
}

static void udpsend_tilde_closesocket(int fd)
{
#ifndef _WIN32
    close(fd);
#endif
#ifdef _WIN32
    closesocket(fd);
#endif
}

/* fin udpsend~.c */