falkTX
/
FFmpeg
mirror of https://github.com/falkTX/FFmpeg.git
1
0
Fork 0
Code Issues 0 Releases 338 Wiki Activity
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
86953 Commits
32 Branches
821MB
Tree: caa12027ba
Branches Tags
${ item.name }
Create branch ${ searchTerm }
from 'caa12027ba'
${ noResults }
FFmpeg/libavutil/cpu.c

302 lines
15KB
Raw Blame History 

  1. /*

  2.  * This file is part of FFmpeg.

  3.  *

  4.  * FFmpeg is free software; you can redistribute it and/or

  5.  * modify it under the terms of the GNU Lesser General Public

  6.  * License as published by the Free Software Foundation; either

  7.  * version 2.1 of the License, or (at your option) any later version.

  8.  *

  9.  * FFmpeg is distributed in the hope that it will be useful,

  10.  * but WITHOUT ANY WARRANTY; without even the implied warranty of

  11.  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

  12.  * Lesser General Public License for more details.

  13.  *

  14.  * You should have received a copy of the GNU Lesser General Public

  15.  * License along with FFmpeg; if not, write to the Free Software

  16.  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

  17.  */

  18. 

  19. #include <stdint.h>

  20. #include <stdatomic.h>

  21. 

  22. #include "cpu.h"

  23. #include "cpu_internal.h"

  24. #include "config.h"

  25. #include "opt.h"

  26. #include "common.h"

  27. 

  28. #if HAVE_SCHED_GETAFFINITY

  29. #ifndef _GNU_SOURCE

  30. # define _GNU_SOURCE

  31. #endif

  32. #include <sched.h>

  33. #endif

  34. #if HAVE_GETPROCESSAFFINITYMASK || HAVE_WINRT

  35. #include <windows.h>

  36. #endif

  37. #if HAVE_SYSCTL

  38. #if HAVE_SYS_PARAM_H

  39. #include <sys/param.h>

  40. #endif

  41. #include <sys/types.h>

  42. #include <sys/sysctl.h>

  43. #endif

  44. #if HAVE_UNISTD_H

  45. #include <unistd.h>

  46. #endif

  47. 

  48. static atomic_int cpu_flags = ATOMIC_VAR_INIT(-1);

  49. 

  50. static int get_cpu_flags(void)

  51. {

  52.     if (ARCH_AARCH64)

  53.         return ff_get_cpu_flags_aarch64();

  54.     if (ARCH_ARM)

  55.         return ff_get_cpu_flags_arm();

  56.     if (ARCH_PPC)

  57.         return ff_get_cpu_flags_ppc();

  58.     if (ARCH_X86)

  59.         return ff_get_cpu_flags_x86();

  60.     return 0;

  61. }

  62. 

  63. void av_force_cpu_flags(int arg){

  64.     if (ARCH_X86 &&

  65.            (arg & ( AV_CPU_FLAG_3DNOW    |

  66.                     AV_CPU_FLAG_3DNOWEXT |

  67.                     AV_CPU_FLAG_MMXEXT   |

  68.                     AV_CPU_FLAG_SSE      |

  69.                     AV_CPU_FLAG_SSE2     |

  70.                     AV_CPU_FLAG_SSE2SLOW |

  71.                     AV_CPU_FLAG_SSE3     |

  72.                     AV_CPU_FLAG_SSE3SLOW |

  73.                     AV_CPU_FLAG_SSSE3    |

  74.                     AV_CPU_FLAG_SSE4     |

  75.                     AV_CPU_FLAG_SSE42    |

  76.                     AV_CPU_FLAG_AVX      |

  77.                     AV_CPU_FLAG_AVXSLOW  |

  78.                     AV_CPU_FLAG_XOP      |

  79.                     AV_CPU_FLAG_FMA3     |

  80.                     AV_CPU_FLAG_FMA4     |

  81.                     AV_CPU_FLAG_AVX2     ))

  82.         && !(arg & AV_CPU_FLAG_MMX)) {

  83.         av_log(NULL, AV_LOG_WARNING, "MMX implied by specified flags\n");

  84.         arg |= AV_CPU_FLAG_MMX;

  85.     }

  86. 

  87.     atomic_store_explicit(&cpu_flags, arg, memory_order_relaxed);

  88. }

  89. 

  90. int av_get_cpu_flags(void)

  91. {

  92.     int flags = atomic_load_explicit(&cpu_flags, memory_order_relaxed);

  93.     if (flags == -1) {

  94.         flags = get_cpu_flags();

  95.         atomic_store_explicit(&cpu_flags, flags, memory_order_relaxed);

  96.     }

  97.     return flags;

  98. }

  99. 

  100. void av_set_cpu_flags_mask(int mask)

  101. {

  102.     atomic_store_explicit(&cpu_flags, get_cpu_flags() & mask,

  103.                           memory_order_relaxed);

  104. }

  105. 

  106. int av_parse_cpu_flags(const char *s)

  107. {

  108. #define CPUFLAG_MMXEXT   (AV_CPU_FLAG_MMX      | AV_CPU_FLAG_MMXEXT | AV_CPU_FLAG_CMOV)

  109. #define CPUFLAG_3DNOW    (AV_CPU_FLAG_3DNOW    | AV_CPU_FLAG_MMX)

  110. #define CPUFLAG_3DNOWEXT (AV_CPU_FLAG_3DNOWEXT | CPUFLAG_3DNOW)

  111. #define CPUFLAG_SSE      (AV_CPU_FLAG_SSE      | CPUFLAG_MMXEXT)

  112. #define CPUFLAG_SSE2     (AV_CPU_FLAG_SSE2     | CPUFLAG_SSE)

  113. #define CPUFLAG_SSE2SLOW (AV_CPU_FLAG_SSE2SLOW | CPUFLAG_SSE2)

  114. #define CPUFLAG_SSE3     (AV_CPU_FLAG_SSE3     | CPUFLAG_SSE2)

  115. #define CPUFLAG_SSE3SLOW (AV_CPU_FLAG_SSE3SLOW | CPUFLAG_SSE3)

  116. #define CPUFLAG_SSSE3    (AV_CPU_FLAG_SSSE3    | CPUFLAG_SSE3)

  117. #define CPUFLAG_SSE4     (AV_CPU_FLAG_SSE4     | CPUFLAG_SSSE3)

  118. #define CPUFLAG_SSE42    (AV_CPU_FLAG_SSE42    | CPUFLAG_SSE4)

  119. #define CPUFLAG_AVX      (AV_CPU_FLAG_AVX      | CPUFLAG_SSE42)

  120. #define CPUFLAG_AVXSLOW  (AV_CPU_FLAG_AVXSLOW  | CPUFLAG_AVX)

  121. #define CPUFLAG_XOP      (AV_CPU_FLAG_XOP      | CPUFLAG_AVX)

  122. #define CPUFLAG_FMA3     (AV_CPU_FLAG_FMA3     | CPUFLAG_AVX)

  123. #define CPUFLAG_FMA4     (AV_CPU_FLAG_FMA4     | CPUFLAG_AVX)

  124. #define CPUFLAG_AVX2     (AV_CPU_FLAG_AVX2     | CPUFLAG_AVX)

  125. #define CPUFLAG_BMI2     (AV_CPU_FLAG_BMI2     | AV_CPU_FLAG_BMI1)

  126. #define CPUFLAG_AESNI    (AV_CPU_FLAG_AESNI    | CPUFLAG_SSE42)

  127.     static const AVOption cpuflags_opts[] = {

  128.         { "flags"   , NULL, 0, AV_OPT_TYPE_FLAGS, { .i64 = 0 }, INT64_MIN, INT64_MAX, .unit = "flags" },

  129. #if   ARCH_PPC

  130.         { "altivec" , NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_ALTIVEC  },    .unit = "flags" },

  131. #elif ARCH_X86

  132.         { "mmx"     , NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_MMX      },    .unit = "flags" },

  133.         { "mmxext"  , NULL, 0, AV_OPT_TYPE_CONST, { .i64 = CPUFLAG_MMXEXT       },    .unit = "flags" },

  134.         { "sse"     , NULL, 0, AV_OPT_TYPE_CONST, { .i64 = CPUFLAG_SSE          },    .unit = "flags" },

  135.         { "sse2"    , NULL, 0, AV_OPT_TYPE_CONST, { .i64 = CPUFLAG_SSE2         },    .unit = "flags" },

  136.         { "sse2slow", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = CPUFLAG_SSE2SLOW     },    .unit = "flags" },

  137.         { "sse3"    , NULL, 0, AV_OPT_TYPE_CONST, { .i64 = CPUFLAG_SSE3         },    .unit = "flags" },

  138.         { "sse3slow", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = CPUFLAG_SSE3SLOW     },    .unit = "flags" },

  139.         { "ssse3"   , NULL, 0, AV_OPT_TYPE_CONST, { .i64 = CPUFLAG_SSSE3        },    .unit = "flags" },

  140.         { "atom"    , NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_ATOM     },    .unit = "flags" },

  141.         { "sse4.1"  , NULL, 0, AV_OPT_TYPE_CONST, { .i64 = CPUFLAG_SSE4         },    .unit = "flags" },

  142.         { "sse4.2"  , NULL, 0, AV_OPT_TYPE_CONST, { .i64 = CPUFLAG_SSE42        },    .unit = "flags" },

  143.         { "avx"     , NULL, 0, AV_OPT_TYPE_CONST, { .i64 = CPUFLAG_AVX          },    .unit = "flags" },

  144.         { "avxslow" , NULL, 0, AV_OPT_TYPE_CONST, { .i64 = CPUFLAG_AVXSLOW      },    .unit = "flags" },

  145.         { "xop"     , NULL, 0, AV_OPT_TYPE_CONST, { .i64 = CPUFLAG_XOP          },    .unit = "flags" },

  146.         { "fma3"    , NULL, 0, AV_OPT_TYPE_CONST, { .i64 = CPUFLAG_FMA3         },    .unit = "flags" },

  147.         { "fma4"    , NULL, 0, AV_OPT_TYPE_CONST, { .i64 = CPUFLAG_FMA4         },    .unit = "flags" },

  148.         { "avx2"    , NULL, 0, AV_OPT_TYPE_CONST, { .i64 = CPUFLAG_AVX2         },    .unit = "flags" },

  149.         { "bmi1"    , NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_BMI1     },    .unit = "flags" },

  150.         { "bmi2"    , NULL, 0, AV_OPT_TYPE_CONST, { .i64 = CPUFLAG_BMI2         },    .unit = "flags" },

  151.         { "3dnow"   , NULL, 0, AV_OPT_TYPE_CONST, { .i64 = CPUFLAG_3DNOW        },    .unit = "flags" },

  152.         { "3dnowext", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = CPUFLAG_3DNOWEXT     },    .unit = "flags" },

  153.         { "cmov",     NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_CMOV     },    .unit = "flags" },

  154.         { "aesni"   , NULL, 0, AV_OPT_TYPE_CONST, { .i64 = CPUFLAG_AESNI        },    .unit = "flags" },

  155. #elif ARCH_ARM

  156.         { "armv5te",  NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_ARMV5TE  },    .unit = "flags" },

  157.         { "armv6",    NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_ARMV6    },    .unit = "flags" },

  158.         { "armv6t2",  NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_ARMV6T2  },    .unit = "flags" },

  159.         { "vfp",      NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_VFP      },    .unit = "flags" },

  160.         { "vfp_vm",   NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_VFP_VM   },    .unit = "flags" },

  161.         { "vfpv3",    NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_VFPV3    },    .unit = "flags" },

  162.         { "neon",     NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_NEON     },    .unit = "flags" },

  163. #elif ARCH_AARCH64

  164.         { "armv8",    NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_ARMV8    },    .unit = "flags" },

  165.         { "neon",     NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_NEON     },    .unit = "flags" },

  166.         { "vfp",      NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_VFP      },    .unit = "flags" },

  167. #endif

  168.         { NULL },

  169.     };

  170.     static const AVClass class = {

  171.         .class_name = "cpuflags",

  172.         .item_name  = av_default_item_name,

  173.         .option     = cpuflags_opts,

  174.         .version    = LIBAVUTIL_VERSION_INT,

  175.     };

  176. 

  177.     int flags = 0, ret;

  178.     const AVClass *pclass = &class;

  179. 

  180.     if ((ret = av_opt_eval_flags(&pclass, &cpuflags_opts[0], s, &flags)) < 0)

  181.         return ret;

  182. 

  183.     return flags & INT_MAX;

  184. }

  185. 

  186. int av_parse_cpu_caps(unsigned *flags, const char *s)

  187. {

  188.         static const AVOption cpuflags_opts[] = {

  189.         { "flags"   , NULL, 0, AV_OPT_TYPE_FLAGS, { .i64 = 0 }, INT64_MIN, INT64_MAX, .unit = "flags" },

  190. #if   ARCH_PPC

  191.         { "altivec" , NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_ALTIVEC  },    .unit = "flags" },

  192. #elif ARCH_X86

  193.         { "mmx"     , NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_MMX      },    .unit = "flags" },

  194.         { "mmx2"    , NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_MMX2     },    .unit = "flags" },

  195.         { "mmxext"  , NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_MMX2     },    .unit = "flags" },

  196.         { "sse"     , NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_SSE      },    .unit = "flags" },

  197.         { "sse2"    , NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_SSE2     },    .unit = "flags" },

  198.         { "sse2slow", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_SSE2SLOW },    .unit = "flags" },

  199.         { "sse3"    , NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_SSE3     },    .unit = "flags" },

  200.         { "sse3slow", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_SSE3SLOW },    .unit = "flags" },

  201.         { "ssse3"   , NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_SSSE3    },    .unit = "flags" },

  202.         { "atom"    , NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_ATOM     },    .unit = "flags" },

  203.         { "sse4.1"  , NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_SSE4     },    .unit = "flags" },

  204.         { "sse4.2"  , NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_SSE42    },    .unit = "flags" },

  205.         { "avx"     , NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_AVX      },    .unit = "flags" },

  206.         { "avxslow" , NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_AVXSLOW  },    .unit = "flags" },

  207.         { "xop"     , NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_XOP      },    .unit = "flags" },

  208.         { "fma3"    , NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_FMA3     },    .unit = "flags" },

  209.         { "fma4"    , NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_FMA4     },    .unit = "flags" },

  210.         { "avx2"    , NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_AVX2     },    .unit = "flags" },

  211.         { "bmi1"    , NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_BMI1     },    .unit = "flags" },

  212.         { "bmi2"    , NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_BMI2     },    .unit = "flags" },

  213.         { "3dnow"   , NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_3DNOW    },    .unit = "flags" },

  214.         { "3dnowext", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_3DNOWEXT },    .unit = "flags" },

  215.         { "cmov",     NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_CMOV     },    .unit = "flags" },

  216.         { "aesni",    NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_AESNI    },    .unit = "flags" },

  217. 

  218. #define CPU_FLAG_P2 AV_CPU_FLAG_CMOV | AV_CPU_FLAG_MMX

  219. #define CPU_FLAG_P3 CPU_FLAG_P2 | AV_CPU_FLAG_MMX2 | AV_CPU_FLAG_SSE

  220. #define CPU_FLAG_P4 CPU_FLAG_P3| AV_CPU_FLAG_SSE2

  221.         { "pentium2", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = CPU_FLAG_P2          },    .unit = "flags" },

  222.         { "pentium3", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = CPU_FLAG_P3          },    .unit = "flags" },

  223.         { "pentium4", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = CPU_FLAG_P4          },    .unit = "flags" },

  224. 

  225. #define CPU_FLAG_K62 AV_CPU_FLAG_MMX | AV_CPU_FLAG_3DNOW

  226. #define CPU_FLAG_ATHLON   CPU_FLAG_K62 | AV_CPU_FLAG_CMOV | AV_CPU_FLAG_3DNOWEXT | AV_CPU_FLAG_MMX2

  227. #define CPU_FLAG_ATHLONXP CPU_FLAG_ATHLON | AV_CPU_FLAG_SSE

  228. #define CPU_FLAG_K8  CPU_FLAG_ATHLONXP | AV_CPU_FLAG_SSE2

  229.         { "k6",       NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_MMX      },    .unit = "flags" },

  230.         { "k62",      NULL, 0, AV_OPT_TYPE_CONST, { .i64 = CPU_FLAG_K62         },    .unit = "flags" },

  231.         { "athlon",   NULL, 0, AV_OPT_TYPE_CONST, { .i64 = CPU_FLAG_ATHLON      },    .unit = "flags" },

  232.         { "athlonxp", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = CPU_FLAG_ATHLONXP    },    .unit = "flags" },

  233.         { "k8",       NULL, 0, AV_OPT_TYPE_CONST, { .i64 = CPU_FLAG_K8          },    .unit = "flags" },

  234. #elif ARCH_ARM

  235.         { "armv5te",  NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_ARMV5TE  },    .unit = "flags" },

  236.         { "armv6",    NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_ARMV6    },    .unit = "flags" },

  237.         { "armv6t2",  NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_ARMV6T2  },    .unit = "flags" },

  238.         { "vfp",      NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_VFP      },    .unit = "flags" },

  239.         { "vfp_vm",   NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_VFP_VM   },    .unit = "flags" },

  240.         { "vfpv3",    NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_VFPV3    },    .unit = "flags" },

  241.         { "neon",     NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_NEON     },    .unit = "flags" },

  242.         { "setend",   NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_SETEND   },    .unit = "flags" },

  243. #elif ARCH_AARCH64

  244.         { "armv8",    NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_ARMV8    },    .unit = "flags" },

  245.         { "neon",     NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_NEON     },    .unit = "flags" },

  246.         { "vfp",      NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AV_CPU_FLAG_VFP      },    .unit = "flags" },

  247. #endif

  248.         { NULL },

  249.     };

  250.     static const AVClass class = {

  251.         .class_name = "cpuflags",

  252.         .item_name  = av_default_item_name,

  253.         .option     = cpuflags_opts,

  254.         .version    = LIBAVUTIL_VERSION_INT,

  255.     };

  256.     const AVClass *pclass = &class;

  257. 

  258.     return av_opt_eval_flags(&pclass, &cpuflags_opts[0], s, flags);

  259. }

  260. 

  261. int av_cpu_count(void)

  262. {

  263.     static volatile int printed;

  264. 

  265.     int nb_cpus = 1;

  266. #if HAVE_WINRT

  267.     SYSTEM_INFO sysinfo;

  268. #endif

  269. #if HAVE_SCHED_GETAFFINITY && defined(CPU_COUNT)

  270.     cpu_set_t cpuset;

  271. 

  272.     CPU_ZERO(&cpuset);

  273. 

  274.     if (!sched_getaffinity(0, sizeof(cpuset), &cpuset))

  275.         nb_cpus = CPU_COUNT(&cpuset);

  276. #elif HAVE_GETPROCESSAFFINITYMASK

  277.     DWORD_PTR proc_aff, sys_aff;

  278.     if (GetProcessAffinityMask(GetCurrentProcess(), &proc_aff, &sys_aff))

  279.         nb_cpus = av_popcount64(proc_aff);

  280. #elif HAVE_SYSCTL && defined(HW_NCPU)

  281.     int mib[2] = { CTL_HW, HW_NCPU };

  282.     size_t len = sizeof(nb_cpus);

  283. 

  284.     if (sysctl(mib, 2, &nb_cpus, &len, NULL, 0) == -1)

  285.         nb_cpus = 0;

  286. #elif HAVE_SYSCONF && defined(_SC_NPROC_ONLN)

  287.     nb_cpus = sysconf(_SC_NPROC_ONLN);

  288. #elif HAVE_SYSCONF && defined(_SC_NPROCESSORS_ONLN)

  289.     nb_cpus = sysconf(_SC_NPROCESSORS_ONLN);

  290. #elif HAVE_WINRT

  291.     GetNativeSystemInfo(&sysinfo);

  292.     nb_cpus = sysinfo.dwNumberOfProcessors;

  293. #endif

  294. 

  295.     if (!printed) {

  296.         av_log(NULL, AV_LOG_DEBUG, "detected %d logical cores\n", nb_cpus);

  297.         printed = 1;

  298.     }

  299. 

  300.     return nb_cpus;

  301. }