From 6bf0a5cb5034a7e684dcc3500e841785237ce2dd Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 19:32:43 +0200 Subject: Adding upstream version 1:115.7.0. Signed-off-by: Daniel Baumann --- media/libwebp/src/utils/bit_reader_utils.c | 298 +++++++++++++++++++++++++++++ 1 file changed, 298 insertions(+) create mode 100644 media/libwebp/src/utils/bit_reader_utils.c (limited to 'media/libwebp/src/utils/bit_reader_utils.c') diff --git a/media/libwebp/src/utils/bit_reader_utils.c b/media/libwebp/src/utils/bit_reader_utils.c new file mode 100644 index 0000000000..857cd60988 --- /dev/null +++ b/media/libwebp/src/utils/bit_reader_utils.c @@ -0,0 +1,298 @@ +// Copyright 2010 Google Inc. All Rights Reserved. +// +// Use of this source code is governed by a BSD-style license +// that can be found in the COPYING file in the root of the source +// tree. An additional intellectual property rights grant can be found +// in the file PATENTS. All contributing project authors may +// be found in the AUTHORS file in the root of the source tree. +// ----------------------------------------------------------------------------- +// +// Boolean decoder non-inlined methods +// +// Author: Skal (pascal.massimino@gmail.com) + +#ifdef HAVE_CONFIG_H +#include "src/webp/config.h" +#endif + +#include "src/utils/bit_reader_inl_utils.h" +#include "src/utils/utils.h" + +//------------------------------------------------------------------------------ +// VP8BitReader + +void VP8BitReaderSetBuffer(VP8BitReader* const br, + const uint8_t* const start, + size_t size) { + br->buf_ = start; + br->buf_end_ = start + size; + br->buf_max_ = + (size >= sizeof(lbit_t)) ? start + size - sizeof(lbit_t) + 1 + : start; +} + +void VP8InitBitReader(VP8BitReader* const br, + const uint8_t* const start, size_t size) { + assert(br != NULL); + assert(start != NULL); + assert(size < (1u << 31)); // limit ensured by format and upstream checks + br->range_ = 255 - 1; + br->value_ = 0; + br->bits_ = -8; // to load the very first 8bits + br->eof_ = 0; + VP8BitReaderSetBuffer(br, start, size); + VP8LoadNewBytes(br); +} + +void VP8RemapBitReader(VP8BitReader* const br, ptrdiff_t offset) { + if (br->buf_ != NULL) { + br->buf_ += offset; + br->buf_end_ += offset; + br->buf_max_ += offset; + } +} + +const uint8_t kVP8Log2Range[128] = { + 7, 6, 6, 5, 5, 5, 5, 4, 4, 4, 4, 4, 4, 4, 4, + 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, + 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, + 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, + 0 +}; + +// range = ((range - 1) << kVP8Log2Range[range]) + 1 +const uint8_t kVP8NewRange[128] = { + 127, 127, 191, 127, 159, 191, 223, 127, + 143, 159, 175, 191, 207, 223, 239, 127, + 135, 143, 151, 159, 167, 175, 183, 191, + 199, 207, 215, 223, 231, 239, 247, 127, + 131, 135, 139, 143, 147, 151, 155, 159, + 163, 167, 171, 175, 179, 183, 187, 191, + 195, 199, 203, 207, 211, 215, 219, 223, + 227, 231, 235, 239, 243, 247, 251, 127, + 129, 131, 133, 135, 137, 139, 141, 143, + 145, 147, 149, 151, 153, 155, 157, 159, + 161, 163, 165, 167, 169, 171, 173, 175, + 177, 179, 181, 183, 185, 187, 189, 191, + 193, 195, 197, 199, 201, 203, 205, 207, + 209, 211, 213, 215, 217, 219, 221, 223, + 225, 227, 229, 231, 233, 235, 237, 239, + 241, 243, 245, 247, 249, 251, 253, 127 +}; + +void VP8LoadFinalBytes(VP8BitReader* const br) { + assert(br != NULL && br->buf_ != NULL); + // Only read 8bits at a time + if (br->buf_ < br->buf_end_) { + br->bits_ += 8; + br->value_ = (bit_t)(*br->buf_++) | (br->value_ << 8); + } else if (!br->eof_) { + br->value_ <<= 8; + br->bits_ += 8; + br->eof_ = 1; + } else { + br->bits_ = 0; // This is to avoid undefined behaviour with shifts. + } +} + +//------------------------------------------------------------------------------ +// Higher-level calls + +uint32_t VP8GetValue(VP8BitReader* const br, int bits, const char label[]) { + uint32_t v = 0; + while (bits-- > 0) { + v |= VP8GetBit(br, 0x80, label) << bits; + } + return v; +} + +int32_t VP8GetSignedValue(VP8BitReader* const br, int bits, + const char label[]) { + const int value = VP8GetValue(br, bits, label); + return VP8Get(br, label) ? -value : value; +} + +//------------------------------------------------------------------------------ +// VP8LBitReader + +#define VP8L_LOG8_WBITS 4 // Number of bytes needed to store VP8L_WBITS bits. + +#if defined(__arm__) || defined(_M_ARM) || defined(__aarch64__) || \ + defined(__i386__) || defined(_M_IX86) || \ + defined(__x86_64__) || defined(_M_X64) +#define VP8L_USE_FAST_LOAD +#endif + +static const uint32_t kBitMask[VP8L_MAX_NUM_BIT_READ + 1] = { + 0, + 0x000001, 0x000003, 0x000007, 0x00000f, + 0x00001f, 0x00003f, 0x00007f, 0x0000ff, + 0x0001ff, 0x0003ff, 0x0007ff, 0x000fff, + 0x001fff, 0x003fff, 0x007fff, 0x00ffff, + 0x01ffff, 0x03ffff, 0x07ffff, 0x0fffff, + 0x1fffff, 0x3fffff, 0x7fffff, 0xffffff +}; + +void VP8LInitBitReader(VP8LBitReader* const br, const uint8_t* const start, + size_t length) { + size_t i; + vp8l_val_t value = 0; + assert(br != NULL); + assert(start != NULL); + assert(length < 0xfffffff8u); // can't happen with a RIFF chunk. + + br->len_ = length; + br->val_ = 0; + br->bit_pos_ = 0; + br->eos_ = 0; + + if (length > sizeof(br->val_)) { + length = sizeof(br->val_); + } + for (i = 0; i < length; ++i) { + value |= (vp8l_val_t)start[i] << (8 * i); + } + br->val_ = value; + br->pos_ = length; + br->buf_ = start; +} + +void VP8LBitReaderSetBuffer(VP8LBitReader* const br, + const uint8_t* const buf, size_t len) { + assert(br != NULL); + assert(buf != NULL); + assert(len < 0xfffffff8u); // can't happen with a RIFF chunk. + br->buf_ = buf; + br->len_ = len; + // pos_ > len_ should be considered a param error. + br->eos_ = (br->pos_ > br->len_) || VP8LIsEndOfStream(br); +} + +static void VP8LSetEndOfStream(VP8LBitReader* const br) { + br->eos_ = 1; + br->bit_pos_ = 0; // To avoid undefined behaviour with shifts. +} + +// If not at EOS, reload up to VP8L_LBITS byte-by-byte +static void ShiftBytes(VP8LBitReader* const br) { + while (br->bit_pos_ >= 8 && br->pos_ < br->len_) { + br->val_ >>= 8; + br->val_ |= ((vp8l_val_t)br->buf_[br->pos_]) << (VP8L_LBITS - 8); + ++br->pos_; + br->bit_pos_ -= 8; + } + if (VP8LIsEndOfStream(br)) { + VP8LSetEndOfStream(br); + } +} + +void VP8LDoFillBitWindow(VP8LBitReader* const br) { + assert(br->bit_pos_ >= VP8L_WBITS); +#if defined(VP8L_USE_FAST_LOAD) + if (br->pos_ + sizeof(br->val_) < br->len_) { + br->val_ >>= VP8L_WBITS; + br->bit_pos_ -= VP8L_WBITS; + br->val_ |= (vp8l_val_t)HToLE32(WebPMemToUint32(br->buf_ + br->pos_)) << + (VP8L_LBITS - VP8L_WBITS); + br->pos_ += VP8L_LOG8_WBITS; + return; + } +#endif + ShiftBytes(br); // Slow path. +} + +uint32_t VP8LReadBits(VP8LBitReader* const br, int n_bits) { + assert(n_bits >= 0); + // Flag an error if end_of_stream or n_bits is more than allowed limit. + if (!br->eos_ && n_bits <= VP8L_MAX_NUM_BIT_READ) { + const uint32_t val = VP8LPrefetchBits(br) & kBitMask[n_bits]; + const int new_bits = br->bit_pos_ + n_bits; + br->bit_pos_ = new_bits; + ShiftBytes(br); + return val; + } else { + VP8LSetEndOfStream(br); + return 0; + } +} + +//------------------------------------------------------------------------------ +// Bit-tracing tool + +#if (BITTRACE > 0) + +#include // for atexit() +#include +#include + +#define MAX_NUM_LABELS 32 +static struct { + const char* label; + int size; + int count; +} kLabels[MAX_NUM_LABELS]; + +static int last_label = 0; +static int last_pos = 0; +static const uint8_t* buf_start = NULL; +static int init_done = 0; + +static void PrintBitTraces(void) { + int i; + int scale = 1; + int total = 0; + const char* units = "bits"; +#if (BITTRACE == 2) + scale = 8; + units = "bytes"; +#endif + for (i = 0; i < last_label; ++i) total += kLabels[i].size; + if (total < 1) total = 1; // avoid rounding errors + printf("=== Bit traces ===\n"); + for (i = 0; i < last_label; ++i) { + const int skip = 16 - (int)strlen(kLabels[i].label); + const int value = (kLabels[i].size + scale - 1) / scale; + assert(skip > 0); + printf("%s \%*s: %6d %s \t[%5.2f%%] [count: %7d]\n", + kLabels[i].label, skip, "", value, units, + 100.f * kLabels[i].size / total, + kLabels[i].count); + } + total = (total + scale - 1) / scale; + printf("Total: %d %s\n", total, units); +} + +void BitTrace(const struct VP8BitReader* const br, const char label[]) { + int i, pos; + if (!init_done) { + memset(kLabels, 0, sizeof(kLabels)); + atexit(PrintBitTraces); + buf_start = br->buf_; + init_done = 1; + } + pos = (int)(br->buf_ - buf_start) * 8 - br->bits_; + // if there's a too large jump, we've changed partition -> reset counter + if (abs(pos - last_pos) > 32) { + buf_start = br->buf_; + pos = 0; + last_pos = 0; + } + if (br->range_ >= 0x7f) pos += kVP8Log2Range[br->range_ - 0x7f]; + for (i = 0; i < last_label; ++i) { + if (!strcmp(label, kLabels[i].label)) break; + } + if (i == MAX_NUM_LABELS) abort(); // overflow! + kLabels[i].label = label; + kLabels[i].size += pos - last_pos; + kLabels[i].count += 1; + if (i == last_label) ++last_label; + last_pos = pos; +} + +#endif // BITTRACE > 0 + +//------------------------------------------------------------------------------ -- cgit v1.2.3