FFmpeg
utils.c
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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 
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 unsigned av_int_list_length_for_size(unsigned elsize,
55  const void *list, uint64_t term)
56 {
57  unsigned i;
58 
59  if (!list)
60  return 0;
61 #define LIST_LENGTH(type) \
62  { type t = term, *l = (type *)list; for (i = 0; l[i] != t; i++); }
63  switch (elsize) {
64  case 1: LIST_LENGTH(uint8_t); break;
65  case 2: LIST_LENGTH(uint16_t); break;
66  case 4: LIST_LENGTH(uint32_t); break;
67  case 8: LIST_LENGTH(uint64_t); break;
68  default: av_assert0(!"valid element size");
69  }
70  return i;
71 }
72 
73 char *av_fourcc_make_string(char *buf, uint32_t fourcc)
74 {
75  int i;
76  char *orig_buf = buf;
77  size_t buf_size = AV_FOURCC_MAX_STRING_SIZE;
78 
79  for (i = 0; i < 4; i++) {
80  const int c = fourcc & 0xff;
81  const int print_chr = (c >= '0' && c <= '9') ||
82  (c >= 'a' && c <= 'z') ||
83  (c >= 'A' && c <= 'Z') ||
84  (c && strchr(". -_", c));
85  const int len = snprintf(buf, buf_size, print_chr ? "%c" : "[%d]", c);
86  if (len < 0)
87  break;
88  buf += len;
89  buf_size = buf_size > len ? buf_size - len : 0;
90  fourcc >>= 8;
91  }
92 
93  return orig_buf;
94 }
95 
97 {
98  return (AVRational){1, AV_TIME_BASE};
99 }
100 
101 void av_assert0_fpu(void) {
102 #if HAVE_MMX_INLINE
103  uint16_t state[14];
104  __asm__ volatile (
105  "fstenv %0 \n\t"
106  : "+m" (state)
107  :
108  : "memory"
109  );
110  av_assert0((state[4] & 3) == 3);
111 #endif
112 }
AVMEDIA_TYPE_SUBTITLE
@ AVMEDIA_TYPE_SUBTITLE
Definition: avutil.h:204
AVPictureType
AVPictureType
Definition: avutil.h:272
AV_FOURCC_MAX_STRING_SIZE
#define AV_FOURCC_MAX_STRING_SIZE
Definition: avutil.h:346
av_assert0_fpu
void av_assert0_fpu(void)
Assert that floating point operations can be executed.
Definition: utils.c:101
avassert.h
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
av_assert0
#define av_assert0(cond)
assert() equivalent, that is always enabled.
Definition: avassert.h:37
av_int_list_length_for_size
unsigned av_int_list_length_for_size(unsigned elsize, const void *list, uint64_t term)
Compute the length of an integer list.
Definition: utils.c:54
AVMEDIA_TYPE_DATA
@ AVMEDIA_TYPE_DATA
Opaque data information usually continuous.
Definition: avutil.h:203
NULL
#define NULL
Definition: coverity.c:32
AVRational
Rational number (pair of numerator and denominator).
Definition: rational.h:58
AV_PICTURE_TYPE_SI
@ AV_PICTURE_TYPE_SI
Switching Intra.
Definition: avutil.h:278
AV_PICTURE_TYPE_I
@ AV_PICTURE_TYPE_I
Intra.
Definition: avutil.h:274
list
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining list
Definition: filter_design.txt:25
AV_PICTURE_TYPE_SP
@ AV_PICTURE_TYPE_SP
Switching Predicted.
Definition: avutil.h:279
c
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
AVMediaType
AVMediaType
Definition: avutil.h:199
av_get_time_base_q
AVRational av_get_time_base_q(void)
Return the fractional representation of the internal time base.
Definition: utils.c:96
av_fourcc_make_string
char * av_fourcc_make_string(char *buf, uint32_t fourcc)
Fill the provided buffer with a string containing a FourCC (four-character code) representation.
Definition: utils.c:73
LIST_LENGTH
#define LIST_LENGTH(type)
av_get_picture_type_char
char av_get_picture_type_char(enum AVPictureType pict_type)
Return a single letter to describe the given picture type pict_type.
Definition: utils.c:40
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:271
AV_TIME_BASE
#define AV_TIME_BASE
Internal time base represented as integer.
Definition: avutil.h:254
AVMEDIA_TYPE_ATTACHMENT
@ AVMEDIA_TYPE_ATTACHMENT
Opaque data information usually sparse.
Definition: avutil.h:205
len
int len
Definition: vorbis_enc_data.h:426
__asm__
__asm__(".macro parse_r var r\n\t" "\\var = -1\n\t" _IFC_REG(0) _IFC_REG(1) _IFC_REG(2) _IFC_REG(3) _IFC_REG(4) _IFC_REG(5) _IFC_REG(6) _IFC_REG(7) _IFC_REG(8) _IFC_REG(9) _IFC_REG(10) _IFC_REG(11) _IFC_REG(12) _IFC_REG(13) _IFC_REG(14) _IFC_REG(15) _IFC_REG(16) _IFC_REG(17) _IFC_REG(18) _IFC_REG(19) _IFC_REG(20) _IFC_REG(21) _IFC_REG(22) _IFC_REG(23) _IFC_REG(24) _IFC_REG(25) _IFC_REG(26) _IFC_REG(27) _IFC_REG(28) _IFC_REG(29) _IFC_REG(30) _IFC_REG(31) ".iflt \\var\n\t" ".error \"Unable to parse register name \\r\"\n\t" ".endif\n\t" ".endm")
av_get_media_type_string
const char * av_get_media_type_string(enum AVMediaType media_type)
Return a string describing the media_type enum, NULL if media_type is unknown.
Definition: utils.c:28
AV_PICTURE_TYPE_B
@ AV_PICTURE_TYPE_B
Bi-dir predicted.
Definition: avutil.h:276
state
static struct @326 state
AV_PICTURE_TYPE_P
@ AV_PICTURE_TYPE_P
Predicted.
Definition: avutil.h:275
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
avutil.h
AV_PICTURE_TYPE_BI
@ AV_PICTURE_TYPE_BI
BI type.
Definition: avutil.h:280
AV_PICTURE_TYPE_S
@ AV_PICTURE_TYPE_S
S(GMC)-VOP MPEG-4.
Definition: avutil.h:277
fourcc
uint32_t fourcc
Definition: vaapi_decode.c:241
snprintf
#define snprintf
Definition: snprintf.h:34