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GCC Code Coverage Report

Directory:	../../../ffmpeg/		Exec	Total	Coverage
File:	src/libavcodec/huffman.c	Lines:	91	97	93.8 %
Date:	2020-01-29 01:05:39	Branches:	92	102	90.2 %


/*
 * Copyright (c) 2006 Konstantin Shishkov
 * Copyright (c) 2007 Loren Merritt
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

/**
 * @file
 * huffman tree builder and VLC generator
 */

#include <stdint.h>

#include "libavutil/qsort.h"
#include "libavutil/common.h"

#include "avcodec.h"
#include "huffman.h"
#include "vlc.h"

/* symbol for Huffman tree node */
#define HNODE -1

typedef struct HeapElem {
    uint64_t val;
    int name;
} HeapElem;

static void heap_sift(HeapElem *h, int root, int size)
{
    while (root * 2 + 1 < size) {
        int child = root * 2 + 1;
        if (child < size - 1 && h[child].val > h[child+1].val)
            child++;
        if (h[root].val > h[child].val) {
            FFSWAP(HeapElem, h[root], h[child]);
            root = child;
        } else
            break;
    }
}

int ff_huff_gen_len_table(uint8_t *dst, const uint64_t *stats, int stats_size, int skip0)
{
    HeapElem *h  = av_malloc_array(sizeof(*h), stats_size);
    int *up      = av_malloc_array(sizeof(*up) * 2, stats_size);
    uint8_t *len = av_malloc_array(sizeof(*len) * 2, stats_size);
    uint16_t *map= av_malloc_array(sizeof(*map), stats_size);
    int offset, i, next;
    int size = 0;
    int ret = 0;

    if (!h || !up || !len || !map) {
        ret = AVERROR(ENOMEM);
        goto end;
    }

    for (i = 0; i<stats_size; i++) {
        dst[i] = 255;
        if (stats[i] || !skip0)
            map[size++] = i;
    }

    for (offset = 1; ; offset <<= 1) {
        for (i=0; i < size; i++) {
            h[i].name = i;
            h[i].val = (stats[map[i]] << 14) + offset;
        }
        for (i = size / 2 - 1; i >= 0; i--)
            heap_sift(h, i, size);

        for (next = size; next < size * 2 - 1; next++) {
            // merge the two smallest entries, and put it back in the heap
            uint64_t min1v = h[0].val;
            up[h[0].name] = next;
            h[0].val = INT64_MAX;
            heap_sift(h, 0, size);
            up[h[0].name] = next;
            h[0].name = next;
            h[0].val += min1v;
            heap_sift(h, 0, size);
        }

        len[2 * size - 2] = 0;
        for (i = 2 * size - 3; i >= size; i--)
            len[i] = len[up[i]] + 1;
        for (i = 0; i < size; i++) {
            dst[map[i]] = len[up[i]] + 1;
            if (dst[map[i]] >= 32) break;
        }
        if (i==size) break;
    }
end:
    av_free(h);
    av_free(up);
    av_free(len);
    av_free(map);
    return ret;
}

static void get_tree_codes(uint32_t *bits, int16_t *lens, uint8_t *xlat,
                           Node *nodes, int node,
                           uint32_t pfx, int pl, int *pos, int no_zero_count)
{
    int s;

    s = nodes[node].sym;
    if (s != HNODE || (no_zero_count && !nodes[node].count)) {
        bits[*pos] = pfx;
        lens[*pos] = pl;
        xlat[*pos] = s;
        (*pos)++;
    } else {
        pfx <<= 1;
        pl++;
        get_tree_codes(bits, lens, xlat, nodes, nodes[node].n0, pfx, pl,
                       pos, no_zero_count);
        pfx |= 1;
        get_tree_codes(bits, lens, xlat, nodes, nodes[node].n0 + 1, pfx, pl,
                       pos, no_zero_count);
    }
}

static int build_huff_tree(VLC *vlc, Node *nodes, int head, int flags, int nb_bits)
{
    int no_zero_count = !(flags & FF_HUFFMAN_FLAG_ZERO_COUNT);
    uint32_t bits[256];
    int16_t lens[256];
    uint8_t xlat[256];
    int pos = 0;

    get_tree_codes(bits, lens, xlat, nodes, head, 0, 0,
                   &pos, no_zero_count);
    return ff_init_vlc_sparse(vlc, nb_bits, pos, lens, 2, 2, bits, 4, 4, xlat, 1, 1, 0);
}


/**
 * nodes size must be 2*nb_codes
 * first nb_codes nodes.count must be set
 */
int ff_huff_build_tree(AVCodecContext *avctx, VLC *vlc, int nb_codes, int nb_bits,
                       Node *nodes, HuffCmp cmp, int flags)
{
    int i, j;
    int cur_node;
    int64_t sum = 0;

    for (i = 0; i < nb_codes; i++) {
        nodes[i].sym = i;
        nodes[i].n0 = -2;
        sum += nodes[i].count;
    }

    if (sum >> 31) {
        av_log(avctx, AV_LOG_ERROR,
               "Too high symbol frequencies. "
               "Tree construction is not possible\n");
        return -1;
    }
    AV_QSORT(nodes, nb_codes, Node, cmp);
    cur_node = nb_codes;
    nodes[nb_codes*2-1].count = 0;
    for (i = 0; i < nb_codes * 2 - 1; i += 2) {
        uint32_t cur_count = nodes[i].count + nodes[i+1].count;
        // find correct place to insert new node, and
        // make space for the new node while at it
        for(j = cur_node; j > i + 2; j--){
            if(cur_count > nodes[j-1].count ||
               (cur_count == nodes[j-1].count &&
                !(flags & FF_HUFFMAN_FLAG_HNODE_FIRST)))
                break;
            nodes[j] = nodes[j - 1];
        }
        nodes[j].sym = HNODE;
        nodes[j].count = cur_count;
        nodes[j].n0 = i;
        cur_node++;
    }
    if (build_huff_tree(vlc, nodes, nb_codes * 2 - 2, flags, nb_bits) < 0) {
        av_log(avctx, AV_LOG_ERROR, "Error building tree\n");
        return -1;
    }
    return 0;
}


Generated by: GCOVR (Version 4.1)

Line	Branch	Exec	Source
1			/*
2			* Copyright (c) 2006 Konstantin Shishkov
3			* Copyright (c) 2007 Loren Merritt
4			*
5			* This file is part of FFmpeg.
6			*
7			* FFmpeg is free software; you can redistribute it and/or
8			* modify it under the terms of the GNU Lesser General Public
9			* License as published by the Free Software Foundation; either
10			* version 2.1 of the License, or (at your option) any later version.
11			*
12			* FFmpeg is distributed in the hope that it will be useful,
13			* but WITHOUT ANY WARRANTY; without even the implied warranty of
14			* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15			* Lesser General Public License for more details.
16			*
17			* You should have received a copy of the GNU Lesser General Public
18			* License along with FFmpeg; if not, write to the Free Software
19			* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20			*/
21
22			/**
23			* @file
24			* huffman tree builder and VLC generator
25			*/
26
27			#include <stdint.h>
28
29			#include "libavutil/qsort.h"
30			#include "libavutil/common.h"
31
32			#include "avcodec.h"
33			#include "huffman.h"
34			#include "vlc.h"
35
36			/* symbol for Huffman tree node */
37			#define HNODE -1
38
39			typedef struct HeapElem {
40			uint64_t val;
41			int name;
42			} HeapElem;
43
44		1973140	static void heap_sift(HeapElem *h, int root, int size)
45			{
46	✓✓	14116069	while (root * 2 + 1 < size) {
47		13354908	int child = root * 2 + 1;
48	✓✓✓✓	13354908	if (child < size - 1 && h[child].val > h[child+1].val)
49		6177070	child++;
50	✓✓	13354908	if (h[root].val > h[child].val) {
51		12142929	FFSWAP(HeapElem, h[root], h[child]);
52		12142929	root = child;
53			} else
54		1211979	break;
55			}
56		1973140	}
57
58		2446	int ff_huff_gen_len_table(uint8_t dst, const uint64_t stats, int stats_size, int skip0)
59			{
60		2446	HeapElem h = av_malloc_array(sizeof(h), stats_size);
61		2446	int up = av_malloc_array(sizeof(up) * 2, stats_size);
62		2446	uint8_t len = av_malloc_array(sizeof(len) * 2, stats_size);
63		2446	uint16_t map= av_malloc_array(sizeof(map), stats_size);
64			int offset, i, next;
65		2446	int size = 0;
66		2446	int ret = 0;
67
68	✓✗✓✗ ✓✗✗✓	2446	if (!h \|\| !up \|\| !len \|\| !map) {
69			ret = AVERROR(ENOMEM);
70			goto end;
71			}
72
73	✓✓	877454	for (i = 0; i<stats_size; i++) {
74		875008	dst[i] = 255;
75	✓✓✗✓	875008	if (stats[i] \|\| !skip0)
76		791317	map[size++] = i;
77			}
78
79		2446	for (offset = 1; ; offset <<= 1) {
80	✓✓	793763	for (i=0; i < size; i++) {
81		791317	h[i].name = i;
82		791317	h[i].val = (stats[map[i]] << 14) + offset;
83			}
84	✓✓	397844	for (i = size / 2 - 1; i >= 0; i--)
85		395398	heap_sift(h, i, size);
86
87	✓✓	791317	for (next = size; next < size * 2 - 1; next++) {
88			// merge the two smallest entries, and put it back in the heap
89		788871	uint64_t min1v = h[0].val;
90		788871	up[h[0].name] = next;
91		788871	h[0].val = INT64_MAX;
92		788871	heap_sift(h, 0, size);
93		788871	up[h[0].name] = next;
94		788871	h[0].name = next;
95		788871	h[0].val += min1v;
96		788871	heap_sift(h, 0, size);
97			}
98
99		2446	len[2 * size - 2] = 0;
100	✓✓	788871	for (i = 2 * size - 3; i >= size; i--)
101		786425	len[i] = len[up[i]] + 1;
102	✓✓	793763	for (i = 0; i < size; i++) {
103		791317	dst[map[i]] = len[up[i]] + 1;
104	✗✓	791317	if (dst[map[i]] >= 32) break;
105			}
106	✓✗	2446	if (i==size) break;
107			}
108		2446	end:
109		2446	av_free(h);
110		2446	av_free(up);
111		2446	av_free(len);
112		2446	av_free(map);
113		2446	return ret;
114			}
115
116		319323	static void get_tree_codes(uint32_t bits, int16_t lens, uint8_t *xlat,
117			Node *nodes, int node,
118			uint32_t pfx, int pl, int *pos, int no_zero_count)
119			{
120			int s;
121
122		319323	s = nodes[node].sym;
123	✓✓✓✓ ✗✓	319323	if (s != HNODE \|\| (no_zero_count && !nodes[node].count)) {
124		162210	bits[*pos] = pfx;
125		162210	lens[*pos] = pl;
126		162210	xlat[*pos] = s;
127		162210	(*pos)++;
128			} else {
129		157113	pfx <<= 1;
130		157113	pl++;
131		157113	get_tree_codes(bits, lens, xlat, nodes, nodes[node].n0, pfx, pl,
132			pos, no_zero_count);
133		157113	pfx \|= 1;
134		157113	get_tree_codes(bits, lens, xlat, nodes, nodes[node].n0 + 1, pfx, pl,
135			pos, no_zero_count);
136			}
137		319323	}
138
139		5097	static int build_huff_tree(VLC vlc, Node nodes, int head, int flags, int nb_bits)
140			{
141		5097	int no_zero_count = !(flags & FF_HUFFMAN_FLAG_ZERO_COUNT);
142			uint32_t bits[256];
143			int16_t lens[256];
144			uint8_t xlat[256];
145		5097	int pos = 0;
146
147		5097	get_tree_codes(bits, lens, xlat, nodes, head, 0, 0,
148			&pos, no_zero_count);
149		5097	return ff_init_vlc_sparse(vlc, nb_bits, pos, lens, 2, 2, bits, 4, 4, xlat, 1, 1, 0);
150			}
151
152
153			/**
154			* nodes size must be 2*nb_codes
155			* first nb_codes nodes.count must be set
156			*/
157		5097	int ff_huff_build_tree(AVCodecContext avctx, VLC vlc, int nb_codes, int nb_bits,
158			Node *nodes, HuffCmp cmp, int flags)
159			{
160			int i, j;
161			int cur_node;
162		5097	int64_t sum = 0;
163
164	✓✓	167307	for (i = 0; i < nb_codes; i++) {
165		162210	nodes[i].sym = i;
166		162210	nodes[i].n0 = -2;
167		162210	sum += nodes[i].count;
168			}
169
170	✗✓	5097	if (sum >> 31) {
171			av_log(avctx, AV_LOG_ERROR,
172			"Too high symbol frequencies. "
173			"Tree construction is not possible\n");
174			return -1;
175			}
176	✓✓✓✓ ✓✓✓✓ ✓✓✓✓ ✓✓✓✓ ✓✓✓✓ ✓✓✓✓ ✓✓✓✓ ✓✓✓✓ ✓✓✓✓ ✓✓✓✓ ✓✓✓✓	851113	AV_QSORT(nodes, nb_codes, Node, cmp);
177		5097	cur_node = nb_codes;
178		5097	nodes[nb_codes*2-1].count = 0;
179	✓✓	167307	for (i = 0; i < nb_codes * 2 - 1; i += 2) {
180		162210	uint32_t cur_count = nodes[i].count + nodes[i+1].count;
181			// find correct place to insert new node, and
182			// make space for the new node while at it
183	✓✓	5708460	for(j = cur_node; j > i + 2; j--){
184	✓✓	5685299	if(cur_count > nodes[j-1].count \|\|
185	✓✓	5617648	(cur_count == nodes[j-1].count &&
186	✓✓	101452	!(flags & FF_HUFFMAN_FLAG_HNODE_FIRST)))
187			break;
188		5546250	nodes[j] = nodes[j - 1];
189			}
190		162210	nodes[j].sym = HNODE;
191		162210	nodes[j].count = cur_count;
192		162210	nodes[j].n0 = i;
193		162210	cur_node++;
194			}
195	✗✓	5097	if (build_huff_tree(vlc, nodes, nb_codes * 2 - 2, flags, nb_bits) < 0) {
196			av_log(avctx, AV_LOG_ERROR, "Error building tree\n");
197			return -1;
198			}
199		5097	return 0;
200			}