FFmpeg coverage

GCC Code Coverage Report

Directory:	../../../ffmpeg/		Exec	Total	Coverage
File:	src/libavcodec/bitstream.c	Lines:	149	178	83.7 %
Date:	2021-04-20 04:37:23	Branches:	163	205	79.5 %


/*
 * Common bit i/o utils
 * Copyright (c) 2000, 2001 Fabrice Bellard
 * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
 * Copyright (c) 2010 Loren Merritt
 *
 * alternative bitstream reader & writer by Michael Niedermayer <michaelni@gmx.at>
 *
 * 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
 * bitstream api.
 */

#include "libavutil/avassert.h"
#include "libavutil/qsort.h"
#include "avcodec.h"
#include "internal.h"
#include "mathops.h"
#include "put_bits.h"
#include "vlc.h"

const uint8_t ff_log2_run[41]={
 0, 0, 0, 0, 1, 1, 1, 1,
 2, 2, 2, 2, 3, 3, 3, 3,
 4, 4, 5, 5, 6, 6, 7, 7,
 8, 9,10,11,12,13,14,15,
16,17,18,19,20,21,22,23,
24,
};

#if FF_API_AVPRIV_PUT_BITS
void avpriv_align_put_bits(PutBitContext *s)
{
    align_put_bits(s);
}
void avpriv_copy_bits(PutBitContext *pb, const uint8_t *src, int length)
{
    ff_copy_bits(pb, src, length);
}
#endif

void ff_put_string(PutBitContext *pb, const char *string, int terminate_string)
{
    while (*string) {
        put_bits(pb, 8, *string);
        string++;
    }
    if (terminate_string)
        put_bits(pb, 8, 0);
}

void ff_copy_bits(PutBitContext *pb, const uint8_t *src, int length)
{
    int words = length >> 4;
    int bits  = length & 15;
    int i;

    if (length == 0)
        return;

    av_assert0(length <= put_bits_left(pb));

    if (CONFIG_SMALL || words < 16 || put_bits_count(pb) & 7) {
        for (i = 0; i < words; i++)
            put_bits(pb, 16, AV_RB16(src + 2 * i));
    } else {
        for (i = 0; put_bits_count(pb) & 31; i++)
            put_bits(pb, 8, src[i]);
        flush_put_bits(pb);
        memcpy(put_bits_ptr(pb), src + i, 2 * words - i);
        skip_put_bytes(pb, 2 * words - i);
    }

    put_bits(pb, bits, AV_RB16(src + 2 * words) >> (16 - bits));
}

/* VLC decoding */

#define GET_DATA(v, table, i, wrap, size)                   \
{                                                           \
    const uint8_t *ptr = (const uint8_t *)table + i * wrap; \
    switch(size) {                                          \
    case 1:                                                 \
        v = *(const uint8_t *)ptr;                          \
        break;                                              \
    case 2:                                                 \
        v = *(const uint16_t *)ptr;                         \
        break;                                              \
    case 4:                                                 \
    default:                                                \
        av_assert1(size == 4);                              \
        v = *(const uint32_t *)ptr;                         \
        break;                                              \
    }                                                       \
}


static int alloc_table(VLC *vlc, int size, int use_static)
{
    int index = vlc->table_size;

    vlc->table_size += size;
    if (vlc->table_size > vlc->table_allocated) {
        if (use_static)
            abort(); // cannot do anything, init_vlc() is used with too little memory
        vlc->table_allocated += (1 << vlc->bits);
        vlc->table = av_realloc_f(vlc->table, vlc->table_allocated, sizeof(VLC_TYPE) * 2);
        if (!vlc->table) {
            vlc->table_allocated = 0;
            vlc->table_size = 0;
            return AVERROR(ENOMEM);
        }
        memset(vlc->table + vlc->table_allocated - (1 << vlc->bits), 0, sizeof(VLC_TYPE) * 2 << vlc->bits);
    }
    return index;
}

#define LOCALBUF_ELEMS 1500 // the maximum currently needed is 1296 by rv34

typedef struct VLCcode {
    uint8_t bits;
    VLC_TYPE symbol;
    /** codeword, with the first bit-to-be-read in the msb
     * (even if intended for a little-endian bitstream reader) */
    uint32_t code;
} VLCcode;

static int vlc_common_init(VLC *vlc_arg, int nb_bits, int nb_codes,
                           VLC **vlc, VLC *localvlc, VLCcode **buf,
                           int flags)
{
    *vlc = vlc_arg;
    (*vlc)->bits = nb_bits;
    if (flags & INIT_VLC_USE_NEW_STATIC) {
        av_assert0(nb_codes <= LOCALBUF_ELEMS);
        *localvlc = *vlc_arg;
        *vlc = localvlc;
        (*vlc)->table_size = 0;
    } else {
        (*vlc)->table           = NULL;
        (*vlc)->table_allocated = 0;
        (*vlc)->table_size      = 0;
    }
    if (nb_codes > LOCALBUF_ELEMS) {
        *buf = av_malloc_array(nb_codes, sizeof(VLCcode));
        if (!*buf)
            return AVERROR(ENOMEM);
    }

    return 0;
}

static int compare_vlcspec(const void *a, const void *b)
{
    const VLCcode *sa = a, *sb = b;
    return (sa->code >> 1) - (sb->code >> 1);
}
/**
 * Build VLC decoding tables suitable for use with get_vlc().
 *
 * @param vlc            the context to be initialized
 *
 * @param table_nb_bits  max length of vlc codes to store directly in this table
 *                       (Longer codes are delegated to subtables.)
 *
 * @param nb_codes       number of elements in codes[]
 *
 * @param codes          descriptions of the vlc codes
 *                       These must be ordered such that codes going into the same subtable are contiguous.
 *                       Sorting by VLCcode.code is sufficient, though not necessary.
 */
static int build_table(VLC *vlc, int table_nb_bits, int nb_codes,
                       VLCcode *codes, int flags)
{
    int table_size, table_index, index, code_prefix, symbol, subtable_bits;
    int i, j, k, n, nb, inc;
    uint32_t code;
    volatile VLC_TYPE (* volatile table)[2]; // the double volatile is needed to prevent an internal compiler error in gcc 4.2

    if (table_nb_bits > 30)
       return AVERROR(EINVAL);
    table_size = 1 << table_nb_bits;
    table_index = alloc_table(vlc, table_size, flags & INIT_VLC_USE_NEW_STATIC);
    ff_dlog(NULL, "new table index=%d size=%d\n", table_index, table_size);
    if (table_index < 0)
        return table_index;
    table = (volatile VLC_TYPE (*)[2])&vlc->table[table_index];

    /* first pass: map codes and compute auxiliary table sizes */
    for (i = 0; i < nb_codes; i++) {
        n      = codes[i].bits;
        code   = codes[i].code;
        symbol = codes[i].symbol;
        ff_dlog(NULL, "i=%d n=%d code=0x%"PRIx32"\n", i, n, code);
        if (n <= table_nb_bits) {
            /* no need to add another table */
            j = code >> (32 - table_nb_bits);
            nb = 1 << (table_nb_bits - n);
            inc = 1;
            if (flags & INIT_VLC_OUTPUT_LE) {
                j = bitswap_32(code);
                inc = 1 << n;
            }
            for (k = 0; k < nb; k++) {
                int bits = table[j][1];
                int oldsym  = table[j][0];
                ff_dlog(NULL, "%4x: code=%d n=%d\n", j, i, n);
                if ((bits || oldsym) && (bits != n || oldsym != symbol)) {
                    av_log(NULL, AV_LOG_ERROR, "incorrect codes\n");
                    return AVERROR_INVALIDDATA;
                }
                table[j][1] = n; //bits
                table[j][0] = symbol;
                j += inc;
            }
        } else {
            /* fill auxiliary table recursively */
            n -= table_nb_bits;
            code_prefix = code >> (32 - table_nb_bits);
            subtable_bits = n;
            codes[i].bits = n;
            codes[i].code = code << table_nb_bits;
            for (k = i+1; k < nb_codes; k++) {
                n = codes[k].bits - table_nb_bits;
                if (n <= 0)
                    break;
                code = codes[k].code;
                if (code >> (32 - table_nb_bits) != code_prefix)
                    break;
                codes[k].bits = n;
                codes[k].code = code << table_nb_bits;
                subtable_bits = FFMAX(subtable_bits, n);
            }
            subtable_bits = FFMIN(subtable_bits, table_nb_bits);
            j = (flags & INIT_VLC_OUTPUT_LE) ? bitswap_32(code_prefix) >> (32 - table_nb_bits) : code_prefix;
            table[j][1] = -subtable_bits;
            ff_dlog(NULL, "%4x: n=%d (subtable)\n",
                    j, codes[i].bits + table_nb_bits);
            index = build_table(vlc, subtable_bits, k-i, codes+i, flags);
            if (index < 0)
                return index;
            /* note: realloc has been done, so reload tables */
            table = (volatile VLC_TYPE (*)[2])&vlc->table[table_index];
            table[j][0] = index; //code
            if (table[j][0] != index) {
                avpriv_request_sample(NULL, "strange codes");
                return AVERROR_PATCHWELCOME;
            }
            i = k-1;
        }
    }

    for (i = 0; i < table_size; i++) {
        if (table[i][1] == 0) //bits
            table[i][0] = -1; //codes
    }

    return table_index;
}

static int vlc_common_end(VLC *vlc, int nb_bits, int nb_codes, VLCcode *codes,
                          int flags, VLC *vlc_arg, VLCcode localbuf[LOCALBUF_ELEMS])
{
    int ret = build_table(vlc, nb_bits, nb_codes, codes, flags);

    if (flags & INIT_VLC_USE_NEW_STATIC) {
        if (vlc->table_size != vlc->table_allocated &&
            !(flags & (INIT_VLC_STATIC_OVERLONG & ~INIT_VLC_USE_NEW_STATIC)))
            av_log(NULL, AV_LOG_ERROR, "needed %d had %d\n", vlc->table_size, vlc->table_allocated);
        av_assert0(ret >= 0);
        *vlc_arg = *vlc;
    } else {
        if (codes != localbuf)
            av_free(codes);
        if (ret < 0) {
            av_freep(&vlc->table);
            return ret;
        }
    }
    return 0;
}

/* Build VLC decoding tables suitable for use with get_vlc().

   'nb_bits' sets the decoding table size (2^nb_bits) entries. The
   bigger it is, the faster is the decoding. But it should not be too
   big to save memory and L1 cache. '9' is a good compromise.

   'nb_codes' : number of vlcs codes

   'bits' : table which gives the size (in bits) of each vlc code.

   'codes' : table which gives the bit pattern of of each vlc code.

   'symbols' : table which gives the values to be returned from get_vlc().

   'xxx_wrap' : give the number of bytes between each entry of the
   'bits' or 'codes' tables.

   'xxx_size' : gives the number of bytes of each entry of the 'bits'
   or 'codes' tables. Currently 1,2 and 4 are supported.

   'wrap' and 'size' make it possible to use any memory configuration and types
   (byte/word/long) to store the 'bits', 'codes', and 'symbols' tables.
*/
int ff_init_vlc_sparse(VLC *vlc_arg, int nb_bits, int nb_codes,
                       const void *bits, int bits_wrap, int bits_size,
                       const void *codes, int codes_wrap, int codes_size,
                       const void *symbols, int symbols_wrap, int symbols_size,
                       int flags)
{
    VLCcode localbuf[LOCALBUF_ELEMS], *buf = localbuf;
    int i, j, ret;
    VLC localvlc, *vlc;

    ret = vlc_common_init(vlc_arg, nb_bits, nb_codes, &vlc, &localvlc,
                          &buf, flags);
    if (ret < 0)
        return ret;

    av_assert0(symbols_size <= 2 || !symbols);
    j = 0;
#define COPY(condition)\
    for (i = 0; i < nb_codes; i++) {                                        \
        unsigned len;                                                       \
        GET_DATA(len, bits, i, bits_wrap, bits_size);                       \
        if (!(condition))                                                   \
            continue;                                                       \
        if (len > 3*nb_bits || len > 32) {                                  \
            av_log(NULL, AV_LOG_ERROR, "Too long VLC (%u) in init_vlc\n", len);\
            if (buf != localbuf)                                            \
                av_free(buf);                                               \
            return AVERROR(EINVAL);                                         \
        }                                                                   \
        buf[j].bits = len;                                                  \
        GET_DATA(buf[j].code, codes, i, codes_wrap, codes_size);            \
        if (buf[j].code >= (1LL<<buf[j].bits)) {                            \
            av_log(NULL, AV_LOG_ERROR, "Invalid code %"PRIx32" for %d in "  \
                   "init_vlc\n", buf[j].code, i);                           \
            if (buf != localbuf)                                            \
                av_free(buf);                                               \
            return AVERROR(EINVAL);                                         \
        }                                                                   \
        if (flags & INIT_VLC_INPUT_LE)                                      \
            buf[j].code = bitswap_32(buf[j].code);                          \
        else                                                                \
            buf[j].code <<= 32 - buf[j].bits;                               \
        if (symbols)                                                        \
            GET_DATA(buf[j].symbol, symbols, i, symbols_wrap, symbols_size) \
        else                                                                \
            buf[j].symbol = i;                                              \
        j++;                                                                \
    }
    COPY(len > nb_bits);
    // qsort is the slowest part of init_vlc, and could probably be improved or avoided
    AV_QSORT(buf, j, struct VLCcode, compare_vlcspec);
    COPY(len && len <= nb_bits);
    nb_codes = j;

    return vlc_common_end(vlc, nb_bits, nb_codes, buf,
                          flags, vlc_arg, localbuf);
}

int ff_init_vlc_from_lengths(VLC *vlc_arg, int nb_bits, int nb_codes,
                             const int8_t *lens, int lens_wrap,
                             const void *symbols, int symbols_wrap, int symbols_size,
                             int offset, int flags, void *logctx)
{
    VLCcode localbuf[LOCALBUF_ELEMS], *buf = localbuf;
    VLC localvlc, *vlc;
    uint64_t code;
    int ret, j, len_max = FFMIN(32, 3 * nb_bits);

    ret = vlc_common_init(vlc_arg, nb_bits, nb_codes, &vlc, &localvlc,
                          &buf, flags);
    if (ret < 0)
        return ret;

    j = code = 0;
    for (int i = 0; i < nb_codes; i++, lens += lens_wrap) {
        int len = *lens;
        if (len > 0) {
            unsigned sym;

            buf[j].bits = len;
            if (symbols)
                GET_DATA(sym, symbols, i, symbols_wrap, symbols_size)
            else
                sym = i;
            buf[j].symbol = sym + offset;
            buf[j++].code = code;
        } else if (len <  0) {
            len = -len;
        } else
            continue;
        if (len > len_max || code & ((1U << (32 - len)) - 1)) {
            av_log(logctx, AV_LOG_ERROR, "Invalid VLC (length %u)\n", len);
            goto fail;
        }
        code += 1U << (32 - len);
        if (code > UINT32_MAX + 1ULL) {
            av_log(logctx, AV_LOG_ERROR, "Overdetermined VLC tree\n");
            goto fail;
        }
    }
    return vlc_common_end(vlc, nb_bits, j, buf,
                          flags, vlc_arg, localbuf);
fail:
    if (buf != localbuf)
        av_free(buf);
    return AVERROR_INVALIDDATA;
}

void ff_free_vlc(VLC *vlc)
{
    av_freep(&vlc->table);
}


Generated by: GCOVR (Version 4.2)

Line	Branch	Exec	Source
1			/*
2			* Common bit i/o utils
3			* Copyright (c) 2000, 2001 Fabrice Bellard
4			* Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
5			* Copyright (c) 2010 Loren Merritt
6			*
7			* alternative bitstream reader & writer by Michael Niedermayer <michaelni@gmx.at>
8			*
9			* This file is part of FFmpeg.
10			*
11			* FFmpeg is free software; you can redistribute it and/or
12			* modify it under the terms of the GNU Lesser General Public
13			* License as published by the Free Software Foundation; either
14			* version 2.1 of the License, or (at your option) any later version.
15			*
16			* FFmpeg is distributed in the hope that it will be useful,
17			* but WITHOUT ANY WARRANTY; without even the implied warranty of
18			* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
19			* Lesser General Public License for more details.
20			*
21			* You should have received a copy of the GNU Lesser General Public
22			* License along with FFmpeg; if not, write to the Free Software
23			* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
24			*/
25
26			/**
27			* @file
28			* bitstream api.
29			*/
30
31			#include "libavutil/avassert.h"
32			#include "libavutil/qsort.h"
33			#include "avcodec.h"
34			#include "internal.h"
35			#include "mathops.h"
36			#include "put_bits.h"
37			#include "vlc.h"
38
39			const uint8_t ff_log2_run[41]={
40			0, 0, 0, 0, 1, 1, 1, 1,
41			2, 2, 2, 2, 3, 3, 3, 3,
42			4, 4, 5, 5, 6, 6, 7, 7,
43			8, 9,10,11,12,13,14,15,
44			16,17,18,19,20,21,22,23,
45			24,
46			};
47
48			#if FF_API_AVPRIV_PUT_BITS
49			void avpriv_align_put_bits(PutBitContext *s)
50			{
51			align_put_bits(s);
52			}
53			void avpriv_copy_bits(PutBitContext pb, const uint8_t src, int length)
54			{
55			ff_copy_bits(pb, src, length);
56			}
57			#endif
58
59		1025	void ff_put_string(PutBitContext pb, const char string, int terminate_string)
60			{
61	✓✓	6125	while (*string) {
62		5100	put_bits(pb, 8, *string);
63		5100	string++;
64			}
65	✓✓	1025	if (terminate_string)
66		365	put_bits(pb, 8, 0);
67		1025	}
68
69		1232206	void ff_copy_bits(PutBitContext pb, const uint8_t src, int length)
70			{
71		1232206	int words = length >> 4;
72		1232206	int bits = length & 15;
73			int i;
74
75	✓✓	1232206	if (length == 0)
76		114010	return;
77
78	✗✓	1118196	av_assert0(length <= put_bits_left(pb));
79
80	✓✓✓✓	1118196	if (CONFIG_SMALL \|\| words < 16 \|\| put_bits_count(pb) & 7) {
81	✓✓	7767502	for (i = 0; i < words; i++)
82		6664080	put_bits(pb, 16, AV_RB16(src + 2 * i));
83			} else {
84	✓✓	35902	for (i = 0; put_bits_count(pb) & 31; i++)
85		21128	put_bits(pb, 8, src[i]);
86		14774	flush_put_bits(pb);
87		14774	memcpy(put_bits_ptr(pb), src + i, 2 * words - i);
88		14774	skip_put_bytes(pb, 2 * words - i);
89			}
90
91		1118196	put_bits(pb, bits, AV_RB16(src + 2 * words) >> (16 - bits));
92			}
93
94			/* VLC decoding */
95
96			#define GET_DATA(v, table, i, wrap, size) \
97			{ \
98			const uint8_t ptr = (const uint8_t )table + i * wrap; \
99			switch(size) { \
100			case 1: \
101			v = (const uint8_t )ptr; \
102			break; \
103			case 2: \
104			v = (const uint16_t )ptr; \
105			break; \
106			case 4: \
107			default: \
108			av_assert1(size == 4); \
109			v = (const uint32_t )ptr; \
110			break; \
111			} \
112			}
113
114
115		434979	static int alloc_table(VLC *vlc, int size, int use_static)
116			{
117		434979	int index = vlc->table_size;
118
119		434979	vlc->table_size += size;
120	✓✓	434979	if (vlc->table_size > vlc->table_allocated) {
121	✗✓	49653	if (use_static)
122			abort(); // cannot do anything, init_vlc() is used with too little memory
123		49653	vlc->table_allocated += (1 << vlc->bits);
124		49653	vlc->table = av_realloc_f(vlc->table, vlc->table_allocated, sizeof(VLC_TYPE) * 2);
125	✗✓	49653	if (!vlc->table) {
126			vlc->table_allocated = 0;
127			vlc->table_size = 0;
128			return AVERROR(ENOMEM);
129			}
130		49653	memset(vlc->table + vlc->table_allocated - (1 << vlc->bits), 0, sizeof(VLC_TYPE) * 2 << vlc->bits);
131			}
132		434979	return index;
133			}
134
135			#define LOCALBUF_ELEMS 1500 // the maximum currently needed is 1296 by rv34
136
137			typedef struct VLCcode {
138			uint8_t bits;
139			VLC_TYPE symbol;
140			/** codeword, with the first bit-to-be-read in the msb
141			* (even if intended for a little-endian bitstream reader) */
142			uint32_t code;
143			} VLCcode;
144
145		58257	static int vlc_common_init(VLC *vlc_arg, int nb_bits, int nb_codes,
146			VLC *vlc, VLC localvlc, VLCcode **buf,
147			int flags)
148			{
149		58257	*vlc = vlc_arg;
150		58257	(*vlc)->bits = nb_bits;
151	✓✓	58257	if (flags & INIT_VLC_USE_NEW_STATIC) {
152	✗✓	31464	av_assert0(nb_codes <= LOCALBUF_ELEMS);
153		31464	localvlc = vlc_arg;
154		31464	*vlc = localvlc;
155		31464	(*vlc)->table_size = 0;
156			} else {
157		26793	(*vlc)->table = NULL;
158		26793	(*vlc)->table_allocated = 0;
159		26793	(*vlc)->table_size = 0;
160			}
161	✓✓	58257	if (nb_codes > LOCALBUF_ELEMS) {
162		120	*buf = av_malloc_array(nb_codes, sizeof(VLCcode));
163	✗✓	120	if (!*buf)
164			return AVERROR(ENOMEM);
165			}
166
167		58257	return 0;
168			}
169
170		20392081	static int compare_vlcspec(const void a, const void b)
171			{
172		20392081	const VLCcode sa = a, sb = b;
173		20392081	return (sa->code >> 1) - (sb->code >> 1);
174			}
175			/**
176			* Build VLC decoding tables suitable for use with get_vlc().
177			*
178			* @param vlc the context to be initialized
179			*
180			* @param table_nb_bits max length of vlc codes to store directly in this table
181			* (Longer codes are delegated to subtables.)
182			*
183			* @param nb_codes number of elements in codes[]
184			*
185			* @param codes descriptions of the vlc codes
186			* These must be ordered such that codes going into the same subtable are contiguous.
187			* Sorting by VLCcode.code is sufficient, though not necessary.
188			*/
189		434979	static int build_table(VLC *vlc, int table_nb_bits, int nb_codes,
190			VLCcode *codes, int flags)
191			{
192			int table_size, table_index, index, code_prefix, symbol, subtable_bits;
193			int i, j, k, n, nb, inc;
194			uint32_t code;
195			volatile VLC_TYPE (* volatile table)[2]; // the double volatile is needed to prevent an internal compiler error in gcc 4.2
196
197	✗✓	434979	if (table_nb_bits > 30)
198			return AVERROR(EINVAL);
199		434979	table_size = 1 << table_nb_bits;
200		434979	table_index = alloc_table(vlc, table_size, flags & INIT_VLC_USE_NEW_STATIC);
201			ff_dlog(NULL, "new table index=%d size=%d\n", table_index, table_size);
202	✗✓	434979	if (table_index < 0)
203			return table_index;
204		434979	table = (volatile VLC_TYPE (*)[2])&vlc->table[table_index];
205
206			/* first pass: map codes and compute auxiliary table sizes */
207	✓✓	5377102	for (i = 0; i < nb_codes; i++) {
208		4942123	n = codes[i].bits;
209		4942123	code = codes[i].code;
210		4942123	symbol = codes[i].symbol;
211			ff_dlog(NULL, "i=%d n=%d code=0x%"PRIx32"\n", i, n, code);
212	✓✓	4942123	if (n <= table_nb_bits) {
213			/* no need to add another table */
214		4565401	j = code >> (32 - table_nb_bits);
215		4565401	nb = 1 << (table_nb_bits - n);
216		4565401	inc = 1;
217	✓✓	4565401	if (flags & INIT_VLC_OUTPUT_LE) {
218		455435	j = bitswap_32(code);
219		455435	inc = 1 << n;
220			}
221	✓✓	44679710	for (k = 0; k < nb; k++) {
222		40114309	int bits = table[j][1];
223		40114309	int oldsym = table[j][0];
224			ff_dlog(NULL, "%4x: code=%d n=%d\n", j, i, n);
225	✓✓✗✓ ✓✗✗✓	40114309	if ((bits \|\| oldsym) && (bits != n \|\| oldsym != symbol)) {
226			av_log(NULL, AV_LOG_ERROR, "incorrect codes\n");
227			return AVERROR_INVALIDDATA;
228			}
229		40114309	table[j][1] = n; //bits
230		40114309	table[j][0] = symbol;
231		40114309	j += inc;
232			}
233			} else {
234			/* fill auxiliary table recursively */
235		376722	n -= table_nb_bits;
236		376722	code_prefix = code >> (32 - table_nb_bits);
237		376722	subtable_bits = n;
238		376722	codes[i].bits = n;
239		376722	codes[i].code = code << table_nb_bits;
240	✓✓	3453565	for (k = i+1; k < nb_codes; k++) {
241		3441323	n = codes[k].bits - table_nb_bits;
242	✓✓	3441323	if (n <= 0)
243		37283	break;
244		3404040	code = codes[k].code;
245	✓✓	3404040	if (code >> (32 - table_nb_bits) != code_prefix)
246		327197	break;
247		3076843	codes[k].bits = n;
248		3076843	codes[k].code = code << table_nb_bits;
249		3076843	subtable_bits = FFMAX(subtable_bits, n);
250			}
251		376722	subtable_bits = FFMIN(subtable_bits, table_nb_bits);
252	✓✓	376722	j = (flags & INIT_VLC_OUTPUT_LE) ? bitswap_32(code_prefix) >> (32 - table_nb_bits) : code_prefix;
253		376722	table[j][1] = -subtable_bits;
254			ff_dlog(NULL, "%4x: n=%d (subtable)\n",
255			j, codes[i].bits + table_nb_bits);
256		376722	index = build_table(vlc, subtable_bits, k-i, codes+i, flags);
257	✗✓	376722	if (index < 0)
258			return index;
259			/* note: realloc has been done, so reload tables */
260		376722	table = (volatile VLC_TYPE (*)[2])&vlc->table[table_index];
261		376722	table[j][0] = index; //code
262	✗✓	376722	if (table[j][0] != index) {
263			avpriv_request_sample(NULL, "strange codes");
264			return AVERROR_PATCHWELCOME;
265			}
266		376722	i = k-1;
267			}
268			}
269
270	✓✓	41431845	for (i = 0; i < table_size; i++) {
271	✓✓	40996866	if (table[i][1] == 0) //bits
272		505835	table[i][0] = -1; //codes
273			}
274
275		434979	return table_index;
276			}
277
278		58257	static int vlc_common_end(VLC vlc, int nb_bits, int nb_codes, VLCcode codes,
279			int flags, VLC *vlc_arg, VLCcode localbuf[LOCALBUF_ELEMS])
280			{
281		58257	int ret = build_table(vlc, nb_bits, nb_codes, codes, flags);
282
283	✓✓	58257	if (flags & INIT_VLC_USE_NEW_STATIC) {
284	✓✓	31464	if (vlc->table_size != vlc->table_allocated &&
285	✗✓	6312	!(flags & (INIT_VLC_STATIC_OVERLONG & ~INIT_VLC_USE_NEW_STATIC)))
286			av_log(NULL, AV_LOG_ERROR, "needed %d had %d\n", vlc->table_size, vlc->table_allocated);
287	✗✓	31464	av_assert0(ret >= 0);
288		31464	vlc_arg = vlc;
289			} else {
290	✓✓	26793	if (codes != localbuf)
291		120	av_free(codes);
292	✗✓	26793	if (ret < 0) {
293			av_freep(&vlc->table);
294			return ret;
295			}
296			}
297		58257	return 0;
298			}
299
300			/* Build VLC decoding tables suitable for use with get_vlc().
301
302			'nb_bits' sets the decoding table size (2^nb_bits) entries. The
303			bigger it is, the faster is the decoding. But it should not be too
304			big to save memory and L1 cache. '9' is a good compromise.
305
306			'nb_codes' : number of vlcs codes
307
308			'bits' : table which gives the size (in bits) of each vlc code.
309
310			'codes' : table which gives the bit pattern of of each vlc code.
311
312			'symbols' : table which gives the values to be returned from get_vlc().
313
314			'xxx_wrap' : give the number of bytes between each entry of the
315			'bits' or 'codes' tables.
316
317			'xxx_size' : gives the number of bytes of each entry of the 'bits'
318			or 'codes' tables. Currently 1,2 and 4 are supported.
319
320			'wrap' and 'size' make it possible to use any memory configuration and types
321			(byte/word/long) to store the 'bits', 'codes', and 'symbols' tables.
322			*/
323		36874	int ff_init_vlc_sparse(VLC *vlc_arg, int nb_bits, int nb_codes,
324			const void *bits, int bits_wrap, int bits_size,
325			const void *codes, int codes_wrap, int codes_size,
326			const void *symbols, int symbols_wrap, int symbols_size,
327			int flags)
328			{
329		36874	VLCcode localbuf[LOCALBUF_ELEMS], *buf = localbuf;
330			int i, j, ret;
331			VLC localvlc, *vlc;
332
333		36874	ret = vlc_common_init(vlc_arg, nb_bits, nb_codes, &vlc, &localvlc,
334			&buf, flags);
335	✗✓	36874	if (ret < 0)
336			return ret;
337
338	✗✓✗✗	36874	av_assert0(symbols_size <= 2 \|\| !symbols);
339		36874	j = 0;
340			#define COPY(condition)\
341			for (i = 0; i < nb_codes; i++) { \
342			unsigned len; \
343			GET_DATA(len, bits, i, bits_wrap, bits_size); \
344			if (!(condition)) \
345			continue; \
346			if (len > 3*nb_bits \|\| len > 32) { \
347			av_log(NULL, AV_LOG_ERROR, "Too long VLC (%u) in init_vlc\n", len);\
348			if (buf != localbuf) \
349			av_free(buf); \
350			return AVERROR(EINVAL); \
351			} \
352			buf[j].bits = len; \
353			GET_DATA(buf[j].code, codes, i, codes_wrap, codes_size); \
354			if (buf[j].code >= (1LL<<buf[j].bits)) { \
355			av_log(NULL, AV_LOG_ERROR, "Invalid code %"PRIx32" for %d in " \
356			"init_vlc\n", buf[j].code, i); \
357			if (buf != localbuf) \
358			av_free(buf); \
359			return AVERROR(EINVAL); \
360			} \
361			if (flags & INIT_VLC_INPUT_LE) \
362			buf[j].code = bitswap_32(buf[j].code); \
363			else \
364			buf[j].code <<= 32 - buf[j].bits; \
365			if (symbols) \
366			GET_DATA(buf[j].symbol, symbols, i, symbols_wrap, symbols_size) \
367			else \
368			buf[j].symbol = i; \
369			j++; \
370			}
371	✓✓✓✓ ✓✓✗✗ ✓✗✗✓ ✓✓✗✓ ✗✗✓✓ ✓✓✓✓ ✗✓✓	3287686	COPY(len > nb_bits);
372			// qsort is the slowest part of init_vlc, and could probably be improved or avoided
373	✓✓✓✓ ✓✓✓✓ ✓✓✓✓ ✓✓✓✓ ✓✓✓✓ ✓✓✓✓ ✓✓✓✓ ✓✓✓✓ ✓✓✓✓ ✓✓✓✓ ✓✓✓✓	17164393	AV_QSORT(buf, j, struct VLCcode, compare_vlcspec);
374	✓✓✓✓ ✓✓✓✓ ✗✗✓✗ ✗✓✓✓ ✗✓✗✗ ✓✓✓✓ ✓✓✗✓ ✓	3287686	COPY(len && len <= nb_bits);
375		36874	nb_codes = j;
376
377		36874	return vlc_common_end(vlc, nb_bits, nb_codes, buf,
378			flags, vlc_arg, localbuf);
379			}
380
381		21383	int ff_init_vlc_from_lengths(VLC *vlc_arg, int nb_bits, int nb_codes,
382			const int8_t *lens, int lens_wrap,
383			const void *symbols, int symbols_wrap, int symbols_size,
384			int offset, int flags, void *logctx)
385			{
386		21383	VLCcode localbuf[LOCALBUF_ELEMS], *buf = localbuf;
387			VLC localvlc, *vlc;
388			uint64_t code;
389		21383	int ret, j, len_max = FFMIN(32, 3 * nb_bits);
390
391		21383	ret = vlc_common_init(vlc_arg, nb_bits, nb_codes, &vlc, &localvlc,
392			&buf, flags);
393	✗✓	21383	if (ret < 0)
394			return ret;
395
396		21383	j = code = 0;
397	✓✓	1420488	for (int i = 0; i < nb_codes; i++, lens += lens_wrap) {
398		1399105	int len = *lens;
399	✓✓	1399105	if (len > 0) {
400			unsigned sym;
401
402		1395533	buf[j].bits = len;
403	✓✓	1395533	if (symbols)
404	✓✓✗	1391496	GET_DATA(sym, symbols, i, symbols_wrap, symbols_size)
405			else
406		4037	sym = i;
407		1395533	buf[j].symbol = sym + offset;
408		1395533	buf[j++].code = code;
409	✓✓	3572	} else if (len < 0) {
410		1504	len = -len;
411			} else
412		2068	continue;
413	✓✗✗✓	1397037	if (len > len_max \|\| code & ((1U << (32 - len)) - 1)) {
414			av_log(logctx, AV_LOG_ERROR, "Invalid VLC (length %u)\n", len);
415			goto fail;
416			}
417		1397037	code += 1U << (32 - len);
418	✗✓	1397037	if (code > UINT32_MAX + 1ULL) {
419			av_log(logctx, AV_LOG_ERROR, "Overdetermined VLC tree\n");
420			goto fail;
421			}
422			}
423		21383	return vlc_common_end(vlc, nb_bits, j, buf,
424			flags, vlc_arg, localbuf);
425			fail:
426			if (buf != localbuf)
427			av_free(buf);
428			return AVERROR_INVALIDDATA;
429			}
430
431		31075	void ff_free_vlc(VLC *vlc)
432			{
433		31075	av_freep(&vlc->table);
434		31075	}