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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 00:47:55 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 00:47:55 +0000 |
commit | 26a029d407be480d791972afb5975cf62c9360a6 (patch) | |
tree | f435a8308119effd964b339f76abb83a57c29483 /third_party/libwebrtc/rtc_base/bit_buffer.h | |
parent | Initial commit. (diff) | |
download | firefox-26a029d407be480d791972afb5975cf62c9360a6.tar.xz firefox-26a029d407be480d791972afb5975cf62c9360a6.zip |
Adding upstream version 124.0.1.upstream/124.0.1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'third_party/libwebrtc/rtc_base/bit_buffer.h')
-rw-r--r-- | third_party/libwebrtc/rtc_base/bit_buffer.h | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/third_party/libwebrtc/rtc_base/bit_buffer.h b/third_party/libwebrtc/rtc_base/bit_buffer.h new file mode 100644 index 0000000000..fe50b2b76e --- /dev/null +++ b/third_party/libwebrtc/rtc_base/bit_buffer.h @@ -0,0 +1,100 @@ +/* + * Copyright 2015 The WebRTC Project Authors. All rights reserved. + * + * Use of this source code is governed by a BSD-style license + * that can be found in the LICENSE 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. + */ + +#ifndef RTC_BASE_BIT_BUFFER_H_ +#define RTC_BASE_BIT_BUFFER_H_ + +#include <stddef.h> // For size_t. +#include <stdint.h> // For integer types. + +#include "absl/strings/string_view.h" +#include "api/units/data_size.h" + +namespace rtc { + +// A BitBuffer API for write operations. Supports symmetric write APIs to the +// reading APIs of BitstreamReader. +// Sizes/counts specify bits/bytes, for clarity. +// Byte order is assumed big-endian/network. +class BitBufferWriter { + public: + static constexpr webrtc::DataSize kMaxLeb128Length = + webrtc::DataSize::Bytes(10); + + // Constructs a bit buffer for the writable buffer of `bytes`. + BitBufferWriter(uint8_t* bytes, size_t byte_count); + + BitBufferWriter(const BitBufferWriter&) = delete; + BitBufferWriter& operator=(const BitBufferWriter&) = delete; + + // Gets the current offset, in bytes/bits, from the start of the buffer. The + // bit offset is the offset into the current byte, in the range [0,7]. + void GetCurrentOffset(size_t* out_byte_offset, size_t* out_bit_offset); + + // The remaining bits in the byte buffer. + uint64_t RemainingBitCount() const; + + // Moves current position `byte_count` bytes forward. Returns false if + // there aren't enough bytes left in the buffer. + bool ConsumeBytes(size_t byte_count); + // Moves current position `bit_count` bits forward. Returns false if + // there aren't enough bits left in the buffer. + bool ConsumeBits(size_t bit_count); + + // Sets the current offset to the provied byte/bit offsets. The bit + // offset is from the given byte, in the range [0,7]. + bool Seek(size_t byte_offset, size_t bit_offset); + + // Writes byte-sized values from the buffer. Returns false if there isn't + // enough data left for the specified type. + bool WriteUInt8(uint8_t val); + bool WriteUInt16(uint16_t val); + bool WriteUInt32(uint32_t val); + + // Writes bit-sized values to the buffer. Returns false if there isn't enough + // room left for the specified number of bits. + bool WriteBits(uint64_t val, size_t bit_count); + + // Writes value in range [0, num_values - 1] + // See ReadNonSymmetric documentation for the format, + // Call SizeNonSymmetricBits to get number of bits needed to store the value. + // Returns false if there isn't enough room left for the value. + bool WriteNonSymmetric(uint32_t val, uint32_t num_values); + // Returns number of bits required to store `val` with NonSymmetric encoding. + static size_t SizeNonSymmetricBits(uint32_t val, uint32_t num_values); + + // Writes the exponential golomb encoded version of the supplied value. + // Returns false if there isn't enough room left for the value. + bool WriteExponentialGolomb(uint32_t val); + // Writes the signed exponential golomb version of the supplied value. + // Signed exponential golomb values are just the unsigned values mapped to the + // sequence 0, 1, -1, 2, -2, etc. in order. + bool WriteSignedExponentialGolomb(int32_t val); + + // Writes the Leb128 encoded value. + bool WriteLeb128(uint64_t val); + + // Writes the string as bytes of data. + bool WriteString(absl::string_view data); + + private: + // The buffer, as a writable array. + uint8_t* const writable_bytes_; + // The total size of `bytes_`. + const size_t byte_count_; + // The current offset, in bytes, from the start of `bytes_`. + size_t byte_offset_; + // The current offset, in bits, into the current byte. + size_t bit_offset_; +}; + +} // namespace rtc + +#endif // RTC_BASE_BIT_BUFFER_H_ |