FFmpeg
tree.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 "libavutil/tree.c"
20 
21 #include <stdint.h>
22 
23 #include "libavutil/common.h"
24 #include "libavutil/lfg.h"
25 #include "libavutil/log.h"
26 
27 static int check(AVTreeNode *t)
28 {
29  if (t) {
30  int left = check(t->child[0]);
31  int right = check(t->child[1]);
32 
33  if (left > 999 || right > 999)
34  return 1000;
35  if (right - left != t->state)
36  return 1000;
37  if (t->state > 1 || t->state < -1)
38  return 1000;
39  return FFMAX(left, right) + 1;
40  }
41  return 0;
42 }
43 
44 static void print(AVTreeNode *t, int depth)
45 {
46  int i;
47  for (i = 0; i < depth * 4; i++)
48  av_log(NULL, AV_LOG_ERROR, " ");
49  if (t) {
50  av_log(NULL, AV_LOG_ERROR, "Node %p %2d %p\n", t, t->state, t->elem);
51  print(t->child[0], depth + 1);
52  print(t->child[1], depth + 1);
53  } else
54  av_log(NULL, AV_LOG_ERROR, "NULL\n");
55 }
56 
57 static int cmp(const void *a, const void *b)
58 {
59  return (const uint8_t *) a - (const uint8_t *) b;
60 }
61 
62 int main(int argc, char **argv)
63 {
64  int i;
65  void *k;
66  AVTreeNode *root = NULL, *node = NULL;
67  AVLFG prng;
68  int log_level = argc <= 1 ? AV_LOG_INFO : atoi(argv[1]);
69 
70  av_log_set_level(log_level);
71 
72  av_lfg_init(&prng, 1);
73 
74  for (i = 0; i < 10000; i++) {
75  intptr_t j = av_lfg_get(&prng) % 86294;
76 
77  if (check(root) > 999) {
78  av_log(NULL, AV_LOG_ERROR, "FATAL error %d\n", i);
79  print(root, 0);
80  return 1;
81  }
82  av_log(NULL, AV_LOG_DEBUG, "inserting %4d\n", (int)j);
83 
84  if (!node)
85  node = av_tree_node_alloc();
86  if (!node) {
87  av_log(NULL, AV_LOG_ERROR, "Memory allocation failure.\n");
88  return 1;
89  }
90  av_tree_insert(&root, (void *)(j + 1), cmp, &node);
91 
92  j = av_lfg_get(&prng) % 86294;
93  {
94  AVTreeNode *node2 = NULL;
95  av_log(NULL, AV_LOG_DEBUG, "removing %4d\n", (int)j);
96  av_tree_insert(&root, (void *)(j + 1), cmp, &node2);
97  k = av_tree_find(root, (void *)(j + 1), cmp, NULL);
98  if (k)
99  av_log(NULL, AV_LOG_ERROR, "removal failure %d\n", i);
100  av_free(node2);
101  }
102  }
103  av_free(node);
104 
105  av_tree_destroy(root);
106 
107  return 0;
108 }
Context structure for the Lagged Fibonacci PRNG.
Definition: lfg.h:33
#define NULL
Definition: coverity.c:32
void av_log_set_level(int level)
Set the log level.
Definition: log.c:385
The reader does not expect b to be semantically here and if the code is changed by maybe adding a a division or other the signedness will almost certainly be mistaken To avoid this confusion a new type was SUINT is the C unsigned type but it holds a signed int to use the same example SUINT a
Definition: undefined.txt:36
int main(int argc, char **argv)
Definition: tree.c:62
void * av_tree_find(const AVTreeNode *t, void *key, int(*cmp)(const void *key, const void *b), void *next[2])
Definition: tree.c:39
struct AVTreeNode * av_tree_node_alloc(void)
Allocate an AVTreeNode.
Definition: tree.c:34
uint8_t
#define av_log(a,...)
void av_tree_destroy(AVTreeNode *t)
Definition: tree.c:146
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:259
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
struct AVTreeNode * child[2]
Definition: tree.c:27
#define AV_LOG_DEBUG
Stuff which is only useful for libav* developers.
Definition: log.h:197
int state
Definition: tree.c:29
#define FFMAX(a, b)
Definition: common.h:94
#define b
Definition: input.c:41
#define AV_LOG_INFO
Standard information.
Definition: log.h:187
static int cmp(const void *a, const void *b)
Definition: tree.c:57
Tag MUST be and< 10hcoeff half pel interpolation filter coefficients, hcoeff[0] are the 2 middle coefficients[1] are the next outer ones and so on, resulting in a filter like:...eff[2], hcoeff[1], hcoeff[0], hcoeff[0], hcoeff[1], hcoeff[2]...the sign of the coefficients is not explicitly stored but alternates after each coeff and coeff[0] is positive, so...,+,-,+,-,+,+,-,+,-,+,...hcoeff[0] is not explicitly stored but found by subtracting the sum of all stored coefficients with signs from 32 hcoeff[0]=32-hcoeff[1]-hcoeff[2]-...a good choice for hcoeff and htaps is htaps=6 hcoeff={40,-10, 2}an alternative which requires more computations at both encoder and decoder side and may or may not be better is htaps=8 hcoeff={42,-14, 6,-2}ref_frames minimum of the number of available reference frames and max_ref_frames for example the first frame after a key frame always has ref_frames=1spatial_decomposition_type wavelet type 0 is a 9/7 symmetric compact integer wavelet 1 is a 5/3 symmetric compact integer wavelet others are reserved stored as delta from last, last is reset to 0 if always_reset||keyframeqlog quality(logarithmic quantizer scale) stored as delta from last, last is reset to 0 if always_reset||keyframemv_scale stored as delta from last, last is reset to 0 if always_reset||keyframe FIXME check that everything works fine if this changes between framesqbias dequantization bias stored as delta from last, last is reset to 0 if always_reset||keyframeblock_max_depth maximum depth of the block tree stored as delta from last, last is reset to 0 if always_reset||keyframequant_table quantization tableHighlevel bitstream structure:==============================--------------------------------------------|Header|--------------------------------------------|------------------------------------|||Block0||||split?||||yes no||||.........intra?||||:Block01:yes no||||:Block02:.................||||:Block03::y DC::ref index:||||:Block04::cb DC::motion x:||||.........:cr DC::motion y:||||.................|||------------------------------------||------------------------------------|||Block1|||...|--------------------------------------------|------------------------------------|||Y subbands||Cb subbands||Cr subbands||||------||------||------|||||LL0||HL0||||LL0||HL0||||LL0||HL0|||||------||------||------||||------||------||------|||||LH0||HH0||||LH0||HH0||||LH0||HH0|||||------||------||------||||------||------||------|||||HL1||LH1||||HL1||LH1||||HL1||LH1|||||------||------||------||||------||------||------|||||HH1||HL2||||HH1||HL2||||HH1||HL2|||||...||...||...|||------------------------------------|--------------------------------------------Decoding process:=================------------|||Subbands|------------||||------------|Intra DC||||LL0 subband prediction------------|\Dequantization-------------------\||Reference frames|\IDWT|--------------|Motion\|||Frame 0||Frame 1||Compensation.OBMC v-------|--------------|--------------.\------> Frame n output Frame Frame<----------------------------------/|...|-------------------Range Coder:============Binary Range Coder:-------------------The implemented range coder is an adapted version based upon"Range encoding: an algorithm for removing redundancy from a digitised message."by G.N.N.Martin.The symbols encoded by the Snow range coder are bits(0|1).The associated probabilities are not fix but change depending on the symbol mix seen so far.bit seen|new state---------+-----------------------------------------------0|256-state_transition_table[256-old_state];1|state_transition_table[old_state];state_transition_table={0, 0, 0, 0, 0, 0, 0, 0, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 190, 191, 192, 194, 194, 195, 196, 197, 198, 199, 200, 201, 202, 202, 204, 205, 206, 207, 208, 209, 209, 210, 211, 212, 213, 215, 215, 216, 217, 218, 219, 220, 220, 222, 223, 224, 225, 226, 227, 227, 229, 229, 230, 231, 232, 234, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 248, 0, 0, 0, 0, 0, 0, 0};FIXME Range Coding of integers:-------------------------FIXME Neighboring Blocks:===================left and top are set to the respective blocks unless they are outside of the image in which case they are set to the Null block top-left is set to the top left block unless it is outside of the image in which case it is set to the left block if this block has no larger parent block or it is at the left side of its parent block and the top right block is not outside of the image then the top right block is used for top-right else the top-left block is used Null block y, cb, cr are 128 level, ref, mx and my are 0 Motion Vector Prediction:=========================1.the motion vectors of all the neighboring blocks are scaled to compensate for the difference of reference frames scaled_mv=(mv *(256 *(current_reference+1)/(mv.reference+1))+128)> the median of the scaled left
Definition: snow.txt:206
static unsigned int av_lfg_get(AVLFG *c)
Get the next random unsigned 32-bit number using an ALFG.
Definition: lfg.h:53
static int check(AVTreeNode *t)
Definition: tree.c:27
av_cold void av_lfg_init(AVLFG *c, unsigned int seed)
Definition: lfg.c:32
common internal and external API header
#define av_free(p)
void * av_tree_insert(AVTreeNode **tp, void *key, int(*cmp)(const void *key, const void *b), AVTreeNode **next)
Insert or remove an element.
Definition: tree.c:59
static void print(AVTreeNode *t, int depth)
Definition: tree.c:44
void * elem
Definition: tree.c:28