[deb_ffmpeg.git] / ffmpeg / libavcodec / bitstream.c

/*
 * 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/atomic.h"
#include "libavutil/avassert.h"
#include "avcodec.h"
#include "mathops.h"
#include "get_bits.h"
#include "put_bits.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,
};

void avpriv_align_put_bits(PutBitContext *s)
{
    put_bits(s, s->bit_left & 7, 0);
}

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

    if (length == 0)
        return;

    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;                                              \
    default:                                                \
        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;
}

static av_always_inline uint32_t bitswap_32(uint32_t x)
{
    return (uint32_t)ff_reverse[ x        & 0xFF] << 24 |
           (uint32_t)ff_reverse[(x >> 8)  & 0xFF] << 16 |
           (uint32_t)ff_reverse[(x >> 16) & 0xFF] << 8  |
           (uint32_t)ff_reverse[ x >> 24];
}

typedef struct {
    uint8_t bits;
    uint16_t 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 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 initted
 *
 * @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 a internal compiler error in gcc 4.2

    table_size = 1 << table_nb_bits;
    if (table_nb_bits > 30)
       return -1;
    table_index = alloc_table(vlc, table_size, flags & INIT_VLC_USE_NEW_STATIC);
    av_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;
        av_dlog(NULL, "i=%d n=%d code=0x%x\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_LE) {
                j = bitswap_32(code);
                inc = 1 << n;
            }
            for (k = 0; k < nb; k++) {
                int bits = table[j][1];
                av_dlog(NULL, "%4x: code=%d n=%d\n", j, i, n);
                if (bits != 0 && bits != n) {
                    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_LE) ? bitswap_32(code_prefix) >> (32 - table_nb_bits) : code_prefix;
            table[j][1] = -subtable_bits;
            av_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
            i = k-1;
        }
    }

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

    return table_index;
}


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

   'nb_bits' set thee 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.

   'wrap' and 'size' allows to use any memory configuration and types
   (byte/word/long) to store the 'bits', 'codes', and 'symbols' tables.

   'use_static' should be set to 1 for tables, which should be freed
   with av_free_static(), 0 if ff_free_vlc() will be used.
*/
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 *buf;
    int i, j, ret;
    VLCcode localbuf[1500]; // the maximum currently needed is 1296 by rv34
    VLC localvlc, *vlc;

    vlc = vlc_arg;
    vlc->bits = nb_bits;
    if (flags & INIT_VLC_USE_NEW_STATIC) {
        av_assert0(nb_codes + 1 <= FF_ARRAY_ELEMS(localbuf));
        buf = localbuf;
        localvlc = *vlc_arg;
        vlc = &localvlc;
        vlc->table_size = 0;
    } else {
        vlc->table           = NULL;
        vlc->table_allocated = 0;
        vlc->table_size      = 0;

        buf = av_malloc_array((nb_codes + 1), sizeof(VLCcode));
        if (!buf)
            return AVERROR(ENOMEM);
    }


    av_assert0(symbols_size <= 2 || !symbols);
    j = 0;
#define COPY(condition)\
    for (i = 0; i < nb_codes; i++) {                                        \
        GET_DATA(buf[j].bits, bits, i, bits_wrap, bits_size);               \
        if (!(condition))                                                   \
            continue;                                                       \
        if (buf[j].bits > 3*nb_bits || buf[j].bits>32) {                    \
            av_log(NULL, AV_LOG_ERROR, "Too long VLC (%d) in init_vlc\n", buf[j].bits);\
            if (!(flags & INIT_VLC_USE_NEW_STATIC))                         \
                av_free(buf);                                               \
            return -1;                                                      \
        }                                                                   \
        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 in init_vlc\n");       \
            if (!(flags & INIT_VLC_USE_NEW_STATIC))                         \
                av_free(buf);                                               \
            return -1;                                                      \
        }                                                                   \
        if (flags & INIT_VLC_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(buf[j].bits > nb_bits);
    // qsort is the slowest part of init_vlc, and could probably be improved or avoided
    qsort(buf, j, sizeof(VLCcode), compare_vlcspec);
    COPY(buf[j].bits && buf[j].bits <= nb_bits);
    nb_codes = j;

    ret = build_table(vlc, nb_bits, nb_codes, buf, flags);

    if (flags & INIT_VLC_USE_NEW_STATIC) {
        if(vlc->table_size != vlc->table_allocated)
            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 {
        av_free(buf);
        if (ret < 0) {
            av_freep(&vlc->table);
            return ret;
        }
    }
    return 0;
}


void ff_free_vlc(VLC *vlc)
{
    av_freep(&vlc->table);
}
Commit	Line	Data
2ba45a60 DM	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/atomic.h"
	32	#include "libavutil/avassert.h"
	33	#include "avcodec.h"
	34	#include "mathops.h"
	35	#include "get_bits.h"
	36	#include "put_bits.h"
	37
	38	const uint8_t ff_log2_run[41]={
	39	0, 0, 0, 0, 1, 1, 1, 1,
	40	2, 2, 2, 2, 3, 3, 3, 3,
	41	4, 4, 5, 5, 6, 6, 7, 7,
	42	8, 9,10,11,12,13,14,15,
	43	16,17,18,19,20,21,22,23,
	44	24,
	45	};
	46
	47	void avpriv_align_put_bits(PutBitContext *s)
	48	{
	49	put_bits(s, s->bit_left & 7, 0);
	50	}
	51
	52	void avpriv_put_string(PutBitContext pb, const char string,
	53	int terminate_string)
	54	{
	55	while (*string) {
	56	put_bits(pb, 8, *string);
	57	string++;
	58	}
	59	if (terminate_string)
	60	put_bits(pb, 8, 0);
	61	}
	62
	63	void avpriv_copy_bits(PutBitContext pb, const uint8_t src, int length)
	64	{
65	int words = length >> 4;
66	int bits = length & 15;
67	int i;
68
69	if (length == 0)
70	return;
71
72	if (CONFIG_SMALL \|\| words < 16 \|\| put_bits_count(pb) & 7) {
73	for (i = 0; i < words; i++)
74	put_bits(pb, 16, AV_RB16(src + 2 * i));
75	} else {
76	for (i = 0; put_bits_count(pb) & 31; i++)
77	put_bits(pb, 8, src[i]);
78	flush_put_bits(pb);
79	memcpy(put_bits_ptr(pb), src + i, 2 * words - i);
80	skip_put_bytes(pb, 2 * words - i);
81	}
82
83	put_bits(pb, bits, AV_RB16(src + 2 * words) >> (16 - bits));
84	}
85
86	/* VLC decoding */
87
88	#define GET_DATA(v, table, i, wrap, size) \
89	{ \
90	const uint8_t ptr = (const uint8_t )table + i * wrap; \
91	switch(size) { \
92	case 1: \
93	v = (const uint8_t )ptr; \
94	break; \
95	case 2: \
96	v = (const uint16_t )ptr; \
97	break; \
98	default: \
99	v = (const uint32_t )ptr; \
100	break; \
101	} \
102	}
103
104
105	static int alloc_table(VLC *vlc, int size, int use_static)
106	{
107	int index = vlc->table_size;
108
109	vlc->table_size += size;
110	if (vlc->table_size > vlc->table_allocated) {
111	if (use_static)
112	abort(); // cannot do anything, init_vlc() is used with too little memory
113	vlc->table_allocated += (1 << vlc->bits);
114	vlc->table = av_realloc_f(vlc->table, vlc->table_allocated, sizeof(VLC_TYPE) * 2);
115	if (!vlc->table) {
116	vlc->table_allocated = 0;
117	vlc->table_size = 0;
118	return AVERROR(ENOMEM);
119	}
120	memset(vlc->table + vlc->table_allocated - (1 << vlc->bits), 0, sizeof(VLC_TYPE) * 2 << vlc->bits);
121	}
122	return index;
123	}
124
125	static av_always_inline uint32_t bitswap_32(uint32_t x)
126	{
127	return (uint32_t)ff_reverse[ x & 0xFF] << 24 \|
128	(uint32_t)ff_reverse[(x >> 8) & 0xFF] << 16 \|
129	(uint32_t)ff_reverse[(x >> 16) & 0xFF] << 8 \|
130	(uint32_t)ff_reverse[ x >> 24];
131	}
132
133	typedef struct {
134	uint8_t bits;
135	uint16_t symbol;
136	/** codeword, with the first bit-to-be-read in the msb
137	* (even if intended for a little-endian bitstream reader) */
138	uint32_t code;
139	} VLCcode;
140
141	static int compare_vlcspec(const void a, const void b)
142	{
143	const VLCcode sa = a, sb = b;
144	return (sa->code >> 1) - (sb->code >> 1);
145	}
146	/**
147	* Build VLC decoding tables suitable for use with get_vlc().
148	*
149	* @param vlc the context to be initted
150	*
151	* @param table_nb_bits max length of vlc codes to store directly in this table
152	* (Longer codes are delegated to subtables.)
153	*
154	* @param nb_codes number of elements in codes[]
155	*
156	* @param codes descriptions of the vlc codes
157	* These must be ordered such that codes going into the same subtable are contiguous.
158	* Sorting by VLCcode.code is sufficient, though not necessary.
159	*/
160	static int build_table(VLC *vlc, int table_nb_bits, int nb_codes,
161	VLCcode *codes, int flags)
162	{
163	int table_size, table_index, index, code_prefix, symbol, subtable_bits;
164	int i, j, k, n, nb, inc;
165	uint32_t code;
166	volatile VLC_TYPE (* volatile table)[2]; // the double volatile is needed to prevent a internal compiler error in gcc 4.2
167
168	table_size = 1 << table_nb_bits;
169	if (table_nb_bits > 30)
170	return -1;
171	table_index = alloc_table(vlc, table_size, flags & INIT_VLC_USE_NEW_STATIC);
172	av_dlog(NULL, "new table index=%d size=%d\n", table_index, table_size);
173	if (table_index < 0)
174	return table_index;
175	table = (volatile VLC_TYPE (*)[2])&vlc->table[table_index];
176
177	/* first pass: map codes and compute auxiliary table sizes */
178	for (i = 0; i < nb_codes; i++) {
179	n = codes[i].bits;
180	code = codes[i].code;
181	symbol = codes[i].symbol;
182	av_dlog(NULL, "i=%d n=%d code=0x%x\n", i, n, code);
183	if (n <= table_nb_bits) {
184	/* no need to add another table */
185	j = code >> (32 - table_nb_bits);
186	nb = 1 << (table_nb_bits - n);
187	inc = 1;
188	if (flags & INIT_VLC_LE) {
189	j = bitswap_32(code);
190	inc = 1 << n;
191	}
192	for (k = 0; k < nb; k++) {
193	int bits = table[j][1];
194	av_dlog(NULL, "%4x: code=%d n=%d\n", j, i, n);
195	if (bits != 0 && bits != n) {
196	av_log(NULL, AV_LOG_ERROR, "incorrect codes\n");
197	return AVERROR_INVALIDDATA;
198	}
199	table[j][1] = n; //bits
200	table[j][0] = symbol;
201	j += inc;
202	}
203	} else {
204	/* fill auxiliary table recursively */
205	n -= table_nb_bits;
206	code_prefix = code >> (32 - table_nb_bits);
207	subtable_bits = n;
208	codes[i].bits = n;
209	codes[i].code = code << table_nb_bits;
210	for (k = i+1; k < nb_codes; k++) {
211	n = codes[k].bits - table_nb_bits;
212	if (n <= 0)
213	break;
214	code = codes[k].code;
215	if (code >> (32 - table_nb_bits) != code_prefix)
216	break;
217	codes[k].bits = n;
218	codes[k].code = code << table_nb_bits;
219	subtable_bits = FFMAX(subtable_bits, n);
220	}
221	subtable_bits = FFMIN(subtable_bits, table_nb_bits);
222	j = (flags & INIT_VLC_LE) ? bitswap_32(code_prefix) >> (32 - table_nb_bits) : code_prefix;
223	table[j][1] = -subtable_bits;
224	av_dlog(NULL, "%4x: n=%d (subtable)\n",
225	j, codes[i].bits + table_nb_bits);
226	index = build_table(vlc, subtable_bits, k-i, codes+i, flags);
227	if (index < 0)
228	return index;
229	/* note: realloc has been done, so reload tables */
230	table = (volatile VLC_TYPE (*)[2])&vlc->table[table_index];
231	table[j][0] = index; //code
232	i = k-1;
233	}
234	}
235
236	for (i = 0; i < table_size; i++) {
237	if (table[i][1] == 0) //bits
238	table[i][0] = -1; //codes
239	}
240
241	return table_index;
242	}
243
244
245	/* Build VLC decoding tables suitable for use with get_vlc().
246
247	'nb_bits' set thee decoding table size (2^nb_bits) entries. The
248	bigger it is, the faster is the decoding. But it should not be too
249	big to save memory and L1 cache. '9' is a good compromise.
250
251	'nb_codes' : number of vlcs codes
252
253	'bits' : table which gives the size (in bits) of each vlc code.
254
255	'codes' : table which gives the bit pattern of of each vlc code.
256
257	'symbols' : table which gives the values to be returned from get_vlc().
258
259	'xxx_wrap' : give the number of bytes between each entry of the
260	'bits' or 'codes' tables.
261
262	'xxx_size' : gives the number of bytes of each entry of the 'bits'
263	or 'codes' tables.
264
265	'wrap' and 'size' allows to use any memory configuration and types
266	(byte/word/long) to store the 'bits', 'codes', and 'symbols' tables.
267
268	'use_static' should be set to 1 for tables, which should be freed
269	with av_free_static(), 0 if ff_free_vlc() will be used.
270	*/
271	int ff_init_vlc_sparse(VLC *vlc_arg, int nb_bits, int nb_codes,
272	const void *bits, int bits_wrap, int bits_size,
273	const void *codes, int codes_wrap, int codes_size,
274	const void *symbols, int symbols_wrap, int symbols_size,
275	int flags)
276	{
277	VLCcode *buf;
278	int i, j, ret;
279	VLCcode localbuf[1500]; // the maximum currently needed is 1296 by rv34
280	VLC localvlc, *vlc;
281
282	vlc = vlc_arg;
283	vlc->bits = nb_bits;
284	if (flags & INIT_VLC_USE_NEW_STATIC) {
285	av_assert0(nb_codes + 1 <= FF_ARRAY_ELEMS(localbuf));
286	buf = localbuf;
287	localvlc = *vlc_arg;
288	vlc = &localvlc;
289	vlc->table_size = 0;
290	} else {
291	vlc->table = NULL;
292	vlc->table_allocated = 0;
293	vlc->table_size = 0;
294
295	buf = av_malloc_array((nb_codes + 1), sizeof(VLCcode));
296	if (!buf)
297	return AVERROR(ENOMEM);
298	}
299
300
301	av_assert0(symbols_size <= 2 \|\| !symbols);
302	j = 0;
303	#define COPY(condition)\
304	for (i = 0; i < nb_codes; i++) { \
305	GET_DATA(buf[j].bits, bits, i, bits_wrap, bits_size); \
306	if (!(condition)) \
307	continue; \
308	if (buf[j].bits > 3*nb_bits \|\| buf[j].bits>32) { \
309	av_log(NULL, AV_LOG_ERROR, "Too long VLC (%d) in init_vlc\n", buf[j].bits);\
310	if (!(flags & INIT_VLC_USE_NEW_STATIC)) \
311	av_free(buf); \
312	return -1; \
313	} \
314	GET_DATA(buf[j].code, codes, i, codes_wrap, codes_size); \
315	if (buf[j].code >= (1LL<<buf[j].bits)) { \
316	av_log(NULL, AV_LOG_ERROR, "Invalid code in init_vlc\n"); \
317	if (!(flags & INIT_VLC_USE_NEW_STATIC)) \
318	av_free(buf); \
319	return -1; \
320	} \
321	if (flags & INIT_VLC_LE) \
322	buf[j].code = bitswap_32(buf[j].code); \
323	else \
324	buf[j].code <<= 32 - buf[j].bits; \
325	if (symbols) \
326	GET_DATA(buf[j].symbol, symbols, i, symbols_wrap, symbols_size) \
327	else \
328	buf[j].symbol = i; \
329	j++; \
330	}
331	COPY(buf[j].bits > nb_bits);
332	// qsort is the slowest part of init_vlc, and could probably be improved or avoided
333	qsort(buf, j, sizeof(VLCcode), compare_vlcspec);
334	COPY(buf[j].bits && buf[j].bits <= nb_bits);
335	nb_codes = j;
336
337	ret = build_table(vlc, nb_bits, nb_codes, buf, flags);
338
339	if (flags & INIT_VLC_USE_NEW_STATIC) {
340	if(vlc->table_size != vlc->table_allocated)
341	av_log(NULL, AV_LOG_ERROR, "needed %d had %d\n", vlc->table_size, vlc->table_allocated);
342
343	av_assert0(ret >= 0);
344	vlc_arg = vlc;
345	} else {
346	av_free(buf);
347	if (ret < 0) {
348	av_freep(&vlc->table);
349	return ret;
350	}
351	}
352	return 0;
353	}
354
355
356	void ff_free_vlc(VLC *vlc)
357	{
358	av_freep(&vlc->table);
359	}