code.delx.au - pulseaudio/blob - src/modules/rtp/rtp.c

   1 /* $Id$ */
   2
   3 /***
   4   This file is part of polypaudio.
   5
   6   polypaudio is free software; you can redistribute it and/or modify
   7   it under the terms of the GNU Lesser General Public License as published
   8   by the Free Software Foundation; either version 2 of the License,
   9   or (at your option) any later version.
  10
  11   polypaudio is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with polypaudio; if not, write to the Free Software
  18   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  19   USA.
  20 ***/
  21
  22 #ifdef HAVE_CONFIG_H
  23 #include <config.h>
  24 #endif
  25
  26 #include <assert.h>
  27 #include <fcntl.h>
  28 #include <stdlib.h>
  29 #include <string.h>
  30 #include <errno.h>
  31 #include <arpa/inet.h>
  32 #include <unistd.h>
  33
  34 #include <polypcore/log.h>
  35
  36 #include "rtp.h"
  37
  38 pa_rtp_context* pa_rtp_context_init_send(pa_rtp_context *c, int fd, uint32_t ssrc, uint8_t payload) {
  39     assert(c);
  40     assert(fd >= 0);
  41
  42     c->fd = fd;
  43     c->sequence = (uint16_t) (rand()*rand());
  44     c->timestamp = 0;
  45     c->ssrc = ssrc ? ssrc : (uint32_t) (rand()*rand());
  46     c->payload = payload & 127;
  47
  48     return c;
  49 }
  50
  51 #define MAX_IOVECS 16
  52
  53 int pa_rtp_send(pa_rtp_context *c, size_t size, pa_memblockq *q) {
  54     struct iovec iov[MAX_IOVECS];
  55     pa_memblock* mb[MAX_IOVECS];
  56     int iov_idx = 1;
  57     size_t n = 0, skip = 0;
  58
  59     assert(c);
  60     assert(size > 0);
  61     assert(q);
  62
  63     if (pa_memblockq_get_length(q) < size)
  64         return 0;
  65
  66     for (;;) {
  67         int r;
  68         pa_memchunk chunk;
  69
  70         if ((r = pa_memblockq_peek(q, &chunk)) >= 0) {
  71
  72             size_t k = n + chunk.length > size ? size - n : chunk.length;
  73
  74             if (chunk.memblock) {
  75                 iov[iov_idx].iov_base = (uint8_t*) chunk.memblock->data + chunk.index;
  76                 iov[iov_idx].iov_len = k;
  77                 mb[iov_idx] = chunk.memblock;
  78                 iov_idx ++;
  79
  80                 n += k;
  81             }
  82
  83             skip += k;
  84             pa_memblockq_drop(q, &chunk, k);
  85         }
  86
  87         if (r < 0 || !chunk.memblock || n >= size || iov_idx >= MAX_IOVECS) {
  88             uint32_t header[3];
  89             struct msghdr m;
  90             int k, i;
  91
  92             if (n > 0) {
  93                 header[0] = htonl(((uint32_t) 2 << 30) | ((uint32_t) c->payload << 16) | ((uint32_t) c->sequence));
  94                 header[1] = htonl(c->timestamp);
  95                 header[2] = htonl(c->ssrc);
  96
  97                 iov[0].iov_base = header;
  98                 iov[0].iov_len = sizeof(header);
  99
 100                 m.msg_name = NULL;
 101                 m.msg_namelen = 0;
 102                 m.msg_iov = iov;
 103                 m.msg_iovlen = iov_idx;
 104                 m.msg_control = NULL;
 105                 m.msg_controllen = 0;
 106                 m.msg_flags = 0;
 107
 108                 k = sendmsg(c->fd, &m, MSG_DONTWAIT);
 109
 110                 for (i = 1; i < iov_idx; i++)
 111                     pa_memblock_unref(mb[i]);
 112
 113                 c->sequence++;
 114             } else
 115                 k = 0;
 116
 117             c->timestamp += skip;
 118
 119             if (k < 0) {
 120                 if (errno != EAGAIN) /* If the queue is full, just ignore it */
 121                     pa_log(__FILE__": sendmsg() failed: %s", strerror(errno));
 122                 return -1;
 123             }
 124
 125             if (r < 0 || pa_memblockq_get_length(q) < size)
 126                 break;
 127
 128             n = 0;
 129             skip = 0;
 130             iov_idx = 1;
 131         }
 132     }
 133
 134     return 0;
 135 }
 136
 137 pa_rtp_context* pa_rtp_context_init_recv(pa_rtp_context *c, int fd) {
 138     assert(c);
 139
 140     c->fd = fd;
 141     return c;
 142 }
 143
 144 int pa_rtp_recv(pa_rtp_context *c, pa_memchunk *chunk) {
 145     assert(c);
 146     assert(chunk);
 147
 148     return 0;
 149 }
 150
 151 uint8_t pa_rtp_payload_type(const pa_sample_spec *ss) {
 152     assert(ss);
 153
 154     if (ss->format == PA_SAMPLE_ULAW && ss->rate == 8000 && ss->channels == 1)
 155         return 0;
 156     if (ss->format == PA_SAMPLE_ALAW && ss->rate == 8000 && ss->channels == 1)
 157         return 0;
 158     if (ss->format == PA_SAMPLE_S16BE && ss->rate == 44100 && ss->channels == 2)
 159         return 10;
 160     if (ss->format == PA_SAMPLE_S16BE && ss->rate == 44100 && ss->channels == 1)
 161         return 11;
 162
 163     return 127;
 164 }
 165
 166 pa_sample_spec *pa_rtp_sample_spec_fixup(pa_sample_spec * ss) {
 167     assert(ss);
 168
 169     if (!pa_rtp_sample_spec_valid(ss))
 170         ss->format = PA_SAMPLE_S16BE;
 171
 172     assert(pa_rtp_sample_spec_valid(ss));
 173     return ss;
 174 }
 175
 176 int pa_rtp_sample_spec_valid(const pa_sample_spec *ss) {
 177     assert(ss);
 178
 179     if (!pa_sample_spec_valid(ss))
 180         return 0;
 181
 182     return
 183         ss->format == PA_SAMPLE_U8 ||
 184         ss->format == PA_SAMPLE_ALAW ||
 185         ss->format == PA_SAMPLE_ULAW ||
 186         ss->format == PA_SAMPLE_S16BE;
 187 }
 188
 189 void pa_rtp_context_destroy(pa_rtp_context *c) {
 190     assert(c);
 191
 192     close(c->fd);
 193 }