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-rw-r--r--media/ffvpx/libavcodec/bitstream.c363
1 files changed, 363 insertions, 0 deletions
diff --git a/media/ffvpx/libavcodec/bitstream.c b/media/ffvpx/libavcodec/bitstream.c
new file mode 100644
index 000000000..562ca1cb8
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+++ b/media/ffvpx/libavcodec/bitstream.c
@@ -0,0 +1,363 @@
+/*
+ * 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 "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,
+};
+
+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;
+
+ 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; \
+ 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 VLCcode {
+ 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 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
+
+ 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);
+ 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%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];
+ ff_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;
+ 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
+ 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' 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.
+
+ 'wrap' and 'size' make it possible 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 %x for %d in init_vlc\n", buf[j].code, i);\
+ 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
+ AV_QSORT(buf, j, struct 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);
+}
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