mdw@git.distorted.org.uk Git - disorder/blob - clients/playrtp-alsa.c

   1 /*
   2  * This file is part of DisOrder.
   3  * Copyright (C) 2008 Richard Kettlewell
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  18  * USA
  19  */
  20 /** @file clients/playrtp-alsa.c
  21  * @brief RTP player - ALSA support
  22  *
  23  * This has been rewritten to use the @ref alsabg.h interface and is therefore
  24  * now closely modelled on @ref playrtp-coreaudio.c.  Given a similar interface
  25  * wrapping OSS the whole of playrtp could probably be greatly simplified.
  26  */
  27
  28 #include <config.h>
  29
  30 #if HAVE_ALSA_ASOUNDLIB_H
  31 #include "types.h"
  32
  33 #include <poll.h>
  34 #include <alsa/asoundlib.h>
  35 #include <assert.h>
  36 #include <pthread.h>
  37 #include <arpa/inet.h>
  38
  39 #include "mem.h"
  40 #include "log.h"
  41 #include "vector.h"
  42 #include "heap.h"
  43 #include "playrtp.h"
  44 #include "alsabg.h"
  45
  46 /** @brief Callback from alsa_bg_collect() */
  47 static int playrtp_alsa_supply(void *dst,
  48                                unsigned supply_nsamples) {
  49   unsigned samples_available;
  50
  51   pthread_mutex_lock(&lock);
  52   const struct packet *p = playrtp_next_packet();
  53   if(p && contains(p, next_timestamp)) {
  54     /* This packet is ready to play */
  55     const uint32_t packet_end = p->timestamp + p->nsamples;
  56     const uint32_t offset = next_timestamp - p->timestamp;
  57     const uint16_t *src = (void *)(p->samples_raw + offset);
  58     samples_available = packet_end - next_timestamp;
  59     if(samples_available > supply_nsamples)
  60       samples_available = supply_nsamples;
  61     next_timestamp += samples_available;
  62     memcpy(dst, src, samples_available * sizeof (int16_t));
  63     /* We don't bother junking the packet - that'll be dealt with next time
  64      * round */
  65   } else {
  66     /* No packet is ready to play (and there might be no packet at all) */
  67     samples_available = p ? p->timestamp - next_timestamp : supply_nsamples;
  68     if(samples_available > supply_nsamples)
  69       samples_available = supply_nsamples;
  70     /*info("infill %d", samples_available);*/
  71     next_timestamp += samples_available;
  72     /* Unlike Core Audio the buffer is not guaranteed to be 0-filled */
  73     memset(dst, 0, samples_available * sizeof (int16_t));
  74   }
  75   pthread_mutex_unlock(&lock);
  76   return samples_available;
  77 }
  78
  79 void playrtp_alsa(void) {
  80   alsa_bg_init(device ? device : "default",
  81                playrtp_alsa_supply);
  82   pthread_mutex_lock(&lock);
  83   for(;;) {
  84     /* Wait for the buffer to fill up a bit */
  85     playrtp_fill_buffer();
  86     /* Start playing now */
  87     info("Playing...");
  88     next_timestamp = pheap_first(&packets)->timestamp;
  89     active = 1;
  90     alsa_bg_enable();
  91     /* Wait until the buffer empties out */
  92     while(nsamples >= minbuffer
  93           || (nsamples > 0
  94               && contains(pheap_first(&packets), next_timestamp))) {
  95       pthread_cond_wait(&cond, &lock);
  96     }
  97     /* Stop playing for a bit until the buffer re-fills */
  98     alsa_bg_disable();
  99     active = 0;
 100     /* Go back round */
 101   }
 102 }
 103
 104 #endif
 105
 106 /*
 107 Local Variables:
 108 c-basic-offset:2
 109 comment-column:40
 110 fill-column:79
 111 indent-tabs-mode:nil
 112 End:
 113 */