libavutil/utils.c

   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 "config.h"
  20 #include "avutil.h"
  21 #include "avassert.h"
  22
  23 /**
  24  * @file
  25  * various utility functions
  26  */
  27
  28 const char *av_get_media_type_string(enum AVMediaType media_type)
  29 {
  30     switch (media_type) {
  31     case AVMEDIA_TYPE_VIDEO:      return "video";
  32     case AVMEDIA_TYPE_AUDIO:      return "audio";
  33     case AVMEDIA_TYPE_DATA:       return "data";
  34     case AVMEDIA_TYPE_SUBTITLE:   return "subtitle";
  35     case AVMEDIA_TYPE_ATTACHMENT: return "attachment";
  36     default:                      return NULL;
  37     }
  38 }
  39
  40 char av_get_picture_type_char(enum AVPictureType pict_type)
  41 {
  42     switch (pict_type) {
  43     case AV_PICTURE_TYPE_I:  return 'I';
  44     case AV_PICTURE_TYPE_P:  return 'P';
  45     case AV_PICTURE_TYPE_B:  return 'B';
  46     case AV_PICTURE_TYPE_S:  return 'S';
  47     case AV_PICTURE_TYPE_SI: return 'i';
  48     case AV_PICTURE_TYPE_SP: return 'p';
  49     case AV_PICTURE_TYPE_BI: return 'b';
  50     default:                 return '?';
  51     }
  52 }
  53
  54 #if FF_API_OPT_INT_LIST
  55 unsigned av_int_list_length_for_size(unsigned elsize,
  56                                      const void *list, uint64_t term)
  57 {
  58     unsigned i;
  59
  60     if (!list)
  61         return 0;
  62 #define LIST_LENGTH(type) \
  63     { type t = term, *l = (type *)list; for (i = 0; l[i] != t; i++); }
  64     switch (elsize) {
  65     case 1: LIST_LENGTH(uint8_t);  break;
  66     case 2: LIST_LENGTH(uint16_t); break;
  67     case 4: LIST_LENGTH(uint32_t); break;
  68     case 8: LIST_LENGTH(uint64_t); break;
  69     default: av_assert0(!"valid element size");
  70     }
  71     return i;
  72 }
  73 #endif
  74
  75 char *av_fourcc_make_string(char *buf, uint32_t fourcc)
  76 {
  77     int i;
  78     char *orig_buf = buf;
  79     size_t buf_size = AV_FOURCC_MAX_STRING_SIZE;
  80
  81     for (i = 0; i < 4; i++) {
  82         const int c = fourcc & 0xff;
  83         const int print_chr = (c >= '0' && c <= '9') ||
  84                               (c >= 'a' && c <= 'z') ||
  85                               (c >= 'A' && c <= 'Z') ||
  86                               (c && strchr(". -_", c));
  87         const int len = snprintf(buf, buf_size, print_chr ? "%c" : "[%d]", c);
  88         if (len < 0)
  89             break;
  90         buf += len;
  91         buf_size = buf_size > len ? buf_size - len : 0;
  92         fourcc >>= 8;
  93     }
  94
  95     return orig_buf;
  96 }
  97
  98 AVRational av_get_time_base_q(void)
  99 {
 100     return (AVRational){1, AV_TIME_BASE};
 101 }
 102
 103 void av_assert0_fpu(void) {
 104 #if HAVE_MMX_INLINE
 105     uint16_t state[14];
 106      __asm__ volatile (
 107         "fstenv %0 \n\t"
 108         : "+m" (state)
 109         :
 110         : "memory"
 111     );
 112     av_assert0((state[4] & 3) == 3);
 113 #endif
 114 }