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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 17:32:43 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 17:32:43 +0000 |
commit | 6bf0a5cb5034a7e684dcc3500e841785237ce2dd (patch) | |
tree | a68f146d7fa01f0134297619fbe7e33db084e0aa /media/ffvpx/libavcodec/vlc.c | |
parent | Initial commit. (diff) | |
download | thunderbird-6bf0a5cb5034a7e684dcc3500e841785237ce2dd.tar.xz thunderbird-6bf0a5cb5034a7e684dcc3500e841785237ce2dd.zip |
Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | media/ffvpx/libavcodec/vlc.c | 378 |
1 files changed, 378 insertions, 0 deletions
diff --git a/media/ffvpx/libavcodec/vlc.c b/media/ffvpx/libavcodec/vlc.c new file mode 100644 index 0000000000..96f2b28c7e --- /dev/null +++ b/media/ffvpx/libavcodec/vlc.c @@ -0,0 +1,378 @@ +/* + * API for creating VLC trees + * Copyright (c) 2000, 2001 Fabrice Bellard + * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at> + * Copyright (c) 2010 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 + */ + +#include <inttypes.h> +#include <stdint.h> +#include <stdlib.h> +#include <string.h> + +#include "libavutil/attributes.h" +#include "libavutil/avassert.h" +#include "libavutil/error.h" +#include "libavutil/internal.h" +#include "libavutil/log.h" +#include "libavutil/macros.h" +#include "libavutil/mem.h" +#include "libavutil/qsort.h" +#include "libavutil/reverse.h" +#include "vlc.h" + +#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->table)); + 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->table) << vlc->bits); + } + return index; +} + +#define LOCALBUF_ELEMS 1500 // the maximum currently needed is 1296 by rv34 + +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 VLCcode { + uint8_t bits; + VLCBaseType 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, int nb_bits, int nb_codes, + VLCcode **buf, int flags) +{ + vlc->bits = nb_bits; + vlc->table_size = 0; + if (flags & INIT_VLC_USE_NEW_STATIC) { + av_assert0(nb_codes <= LOCALBUF_ELEMS); + } else { + vlc->table = NULL; + vlc->table_allocated = 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; + VLCElem *table; + + 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 = &vlc->table[table_index]; + + /* first pass: map codes and compute auxiliary table sizes */ + for (int i = 0; i < nb_codes; i++) { + int n = codes[i].bits; + uint32_t code = codes[i].code; + int 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 */ + int j = code >> (32 - table_nb_bits); + int nb = 1 << (table_nb_bits - n); + int inc = 1; + + if (flags & INIT_VLC_OUTPUT_LE) { + j = bitswap_32(code); + inc = 1 << n; + } + for (int k = 0; k < nb; k++) { + int bits = table[j].len; + int oldsym = table[j].sym; + 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].len = n; + table[j].sym = symbol; + j += inc; + } + } else { + /* fill auxiliary table recursively */ + uint32_t code_prefix; + int index, subtable_bits, j, k; + + 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].len = -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 = &vlc->table[table_index]; + table[j].sym = index; + if (table[j].sym != index) { + avpriv_request_sample(NULL, "strange codes"); + return AVERROR_PATCHWELCOME; + } + i = k-1; + } + } + + for (int i = 0; i < table_size; i++) { + if (table[i].len == 0) + table[i].sym = -1; + } + + return table_index; +} + +static int vlc_common_end(VLC *vlc, int nb_bits, int nb_codes, VLCcode *codes, + int flags, 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); + } 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, 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 j, ret; + + ret = vlc_common_init(vlc, nb_bits, nb_codes, &buf, flags); + if (ret < 0) + return ret; + + av_assert0(symbols_size <= 2 || !symbols); + j = 0; +#define COPY(condition)\ + for (int 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, localbuf); +} + +int ff_init_vlc_from_lengths(VLC *vlc, 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; + uint64_t code; + int ret, j, len_max = FFMIN(32, 3 * nb_bits); + + ret = vlc_common_init(vlc, nb_bits, nb_codes, &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, localbuf); +fail: + if (buf != localbuf) + av_free(buf); + return AVERROR_INVALIDDATA; +} + +void ff_free_vlc(VLC *vlc) +{ + av_freep(&vlc->table); +} |