[FFmpeg-cvslog] avcodec/bitstream: Move code for initializing VLCs to file of its own
Andreas Rheinhardt
git at videolan.org
Tue Mar 22 01:04:20 EET 2022
ffmpeg | branch: master | Andreas Rheinhardt <andreas.rheinhardt at outlook.com> | Thu Mar 17 11:33:02 2022 +0100| [495de744fa949eb789441349736bedc2301d0b61] | committer: Andreas Rheinhardt
avcodec/bitstream: Move code for initializing VLCs to file of its own
bitstream.c is currently the disjoint union of three parts:
The first part is ff_log2_run, the second part are some auxiliary
functions for the PutBits-API; and the third part is the code
for creating VLCs. This commit moves the latter into a file of its own.
This has the advantage of making one of the hacks in tableprint_vlc.h
redundant as vlc.c does not include config.h (whereas the PutBits-API
part does).
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=495de744fa949eb789441349736bedc2301d0b61
---
libavcodec/Makefile | 1 +
libavcodec/bitstream.c | 349 ----------------------------------------
libavcodec/tableprint_vlc.h | 4 +-
libavcodec/vlc.c | 378 ++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 380 insertions(+), 352 deletions(-)
diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index dc6dc8a4bb..fb8b0e824b 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -55,6 +55,7 @@ OBJS = ac3_parser.o \
qsv_api.o \
raw.o \
utils.o \
+ vlc.o \
vorbis_parser.o \
xiph.o \
diff --git a/libavcodec/bitstream.c b/libavcodec/bitstream.c
index 04817f9a84..36a980646d 100644
--- a/libavcodec/bitstream.c
+++ b/libavcodec/bitstream.c
@@ -28,23 +28,13 @@
* bitstream api.
*/
-#include <inttypes.h>
#include <stdint.h>
-#include <stdlib.h>
#include <string.h>
#include "config.h"
#include "libavutil/avassert.h"
-#include "libavutil/error.h"
-#include "libavutil/internal.h"
#include "libavutil/intreadwrite.h"
-#include "libavutil/log.h"
-#include "libavutil/macros.h"
-#include "libavutil/mem.h"
-#include "libavutil/qsort.h"
-#include "libavutil/reverse.h"
#include "put_bits.h"
-#include "vlc.h"
const uint8_t ff_log2_run[41]={
0, 0, 0, 0, 1, 1, 1, 1,
@@ -89,342 +79,3 @@ void ff_copy_bits(PutBitContext *pb, const uint8_t *src, int length)
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
-
-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;
- 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, 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, index, code_prefix, symbol, subtable_bits;
- int i, j, k, n, nb, inc;
- VLC_TYPE (*table)[2];
- uint32_t code;
-
- 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 (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 = &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, 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 i, 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 (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);
-}
diff --git a/libavcodec/tableprint_vlc.h b/libavcodec/tableprint_vlc.h
index 924f97b466..d53ae5799f 100644
--- a/libavcodec/tableprint_vlc.h
+++ b/libavcodec/tableprint_vlc.h
@@ -23,7 +23,6 @@
#ifndef AVCODEC_TABLEPRINT_VLC_H
#define AVCODEC_TABLEPRINT_VLC_H
-#define FFMPEG_CONFIG_H
#define AVUTIL_LOG_H
#define av_log(a, ...) while(0)
#define ff_dlog(a, ...) while(0)
@@ -37,9 +36,8 @@
#define avpriv_request_sample(...)
#include "tableprint.h"
#include "vlc.h"
-#include "mathtables.c"
#include "libavutil/reverse.c"
-#include "bitstream.c"
+#include "vlc.c"
#define REPLACE_DEFINE2(type) write_##type##_array
#define REPLACE_DEFINE(type) REPLACE_DEFINE2(type)
diff --git a/libavcodec/vlc.c b/libavcodec/vlc.c
new file mode 100644
index 0000000000..1a9bd8e6d2
--- /dev/null
+++ b/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 at 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_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
+
+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;
+ 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, 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;
+ VLC_TYPE (*table)[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 = &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][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 */
+ 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][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 = &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 (int 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, 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);
+}
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