cinelerra-5.1/cinelerra/samples.C

   1
   2 /*
   3  * CINELERRA
   4  * Copyright (C) 2009 Adam Williams <broadcast at earthling dot net>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  *
  20  */
  21
  22
  23
  24 // An object which contains samples
  25
  26
  27 #include "bcresources.h"
  28 #include "bcwindowbase.h"
  29 #include "samples.h"
  30 #include <stdio.h>
  31 #include <sys/shm.h>
  32 #include <unistd.h>
  33
  34
  35 Samples::Samples()
  36 {
  37         reset();
  38 }
  39
  40 // Allocate number of samples
  41 Samples::Samples(int samples)
  42 {
  43         reset();
  44         allocate(samples, 1);
  45 }
  46
  47 Samples::Samples(Samples *src)
  48 {
  49         reset();
  50         int src_sz = src->get_allocated();
  51         if( use_shm ) {
  52                 share(src->get_shmid());
  53                 set_allocated(src_sz);
  54         }
  55         else {
  56                 share(src->data);
  57                 set_allocated(0);
  58         }
  59         set_offset(src->get_offset());
  60 }
  61
  62 Samples::~Samples()
  63 {
  64         clear_objects();
  65 }
  66
  67 void Samples::reset()
  68 {
  69         BC_Resources *resources = BC_WindowBase::get_resources();
  70         use_shm = !resources || !resources->use_shm ? 0 : 1;
  71         shmid = -1;
  72         data = 0;
  73         allocated = 0;
  74         offset = 0;
  75 }
  76
  77 void Samples::clear_objects()
  78 {
  79         if(use_shm)
  80         {
  81                 if(data) shmdt(data);
  82         }
  83         else if( allocated )
  84         {
  85                 delete [] data;
  86         }
  87
  88         reset();
  89 }
  90
  91
  92 void Samples::share(int shmid)
  93 {
  94         if(data)
  95         {
  96                 if(use_shm)
  97                         shmdt(data);
  98                 else
  99                         delete [] data;
 100         }
 101
 102         this->use_shm = 1;
 103         data = (double*)shmat(shmid, NULL, 0);
 104         this->allocated = 0;
 105         this->shmid = shmid;
 106 }
 107 void Samples::share(double *buffer)
 108 {
 109         if(data)
 110         {
 111                 if(use_shm)
 112                         shmdt(data);
 113                 else
 114                         delete [] data;
 115         }
 116         this->use_shm = 0;
 117         data = buffer;
 118         this->allocated = 0;
 119         this->shmid = -1;
 120 }
 121
 122
 123 void Samples::allocate(int samples, int use_shm)
 124 {
 125         if( !this->use_shm ) use_shm = 0;
 126         if( data &&
 127                 this->allocated >= samples &&
 128                 this->use_shm == use_shm ) return;
 129
 130         if( data ) {
 131                 if( this->use_shm )
 132                         shmdt(data);
 133                 else
 134                         delete [] data;
 135         }
 136
 137         this->use_shm = use_shm;
 138
 139         if( use_shm ) {
 140                 shmid = shmget(IPC_PRIVATE,
 141                         (samples + 1) * sizeof(double),
 142                         IPC_CREAT | 0777);
 143                 data = (double*)shmat(shmid, NULL, 0);
 144         // This causes it to automatically delete when the program exits.
 145                 shmctl(shmid, IPC_RMID, 0);
 146         }
 147         else {
 148                 shmid = -1;
 149                 data = new double[samples];
 150         }
 151
 152         this->allocated = samples;
 153 }
 154
 155 // Get the buffer
 156 double* Samples::get_data()
 157 {
 158         return data + offset;
 159 }
 160
 161 // Get number of samples allocated
 162 int Samples::get_allocated()
 163 {
 164         return allocated;
 165 }
 166
 167 // Set number of samples allocated
 168 void Samples::set_allocated(int allocated)
 169 {
 170         this->allocated = allocated;
 171 }
 172
 173 int Samples::get_shmid()
 174 {
 175         return shmid;
 176 }
 177
 178 void Samples::set_offset(int offset)
 179 {
 180         this->offset = offset;
 181 }
 182
 183 int Samples::get_offset()
 184 {
 185         return offset;
 186 }
 187