/* * Copyright (c) 2016, Alliance for Open Media. All rights reserved * * This source code is subject to the terms of the BSD 2 Clause License and * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License * was not distributed with this source code in the LICENSE file, you can * obtain it at www.aomedia.org/license/software. If the Alliance for Open * Media Patent License 1.0 was not distributed with this source code in the * PATENTS file, you can obtain it at www.aomedia.org/license/patent. */ #include <assert.h> #include <limits.h> #include <stdlib.h> #include "config/aom_config.h" #include "aom_dsp/bitwriter_buffer.h" int aom_wb_is_byte_aligned(const struct aom_write_bit_buffer *wb) { return (wb->bit_offset % CHAR_BIT == 0); } uint32_t aom_wb_bytes_written(const struct aom_write_bit_buffer *wb) { return wb->bit_offset / CHAR_BIT + (wb->bit_offset % CHAR_BIT > 0); } void aom_wb_write_bit(struct aom_write_bit_buffer *wb, int bit) { const int off = (int)wb->bit_offset; const int p = off / CHAR_BIT; const int q = CHAR_BIT - 1 - off % CHAR_BIT; if (q == CHAR_BIT - 1) { // Zero next char and write bit wb->bit_buffer[p] = bit << q; } else { wb->bit_buffer[p] &= ~(1 << q); wb->bit_buffer[p] |= bit << q; } wb->bit_offset = off + 1; } void aom_wb_overwrite_bit(struct aom_write_bit_buffer *wb, int bit) { // Do not zero bytes but overwrite exisiting values const int off = (int)wb->bit_offset; const int p = off / CHAR_BIT; const int q = CHAR_BIT - 1 - off % CHAR_BIT; wb->bit_buffer[p] &= ~(1 << q); wb->bit_buffer[p] |= bit << q; wb->bit_offset = off + 1; } void aom_wb_write_literal(struct aom_write_bit_buffer *wb, int data, int bits) { assert(bits <= 31); int bit; for (bit = bits - 1; bit >= 0; bit--) aom_wb_write_bit(wb, (data >> bit) & 1); } void aom_wb_write_unsigned_literal(struct aom_write_bit_buffer *wb, uint32_t data, int bits) { assert(bits <= 32); int bit; for (bit = bits - 1; bit >= 0; bit--) aom_wb_write_bit(wb, (data >> bit) & 1); } void aom_wb_overwrite_literal(struct aom_write_bit_buffer *wb, int data, int bits) { int bit; for (bit = bits - 1; bit >= 0; bit--) aom_wb_overwrite_bit(wb, (data >> bit) & 1); } void aom_wb_write_inv_signed_literal(struct aom_write_bit_buffer *wb, int data, int bits) { aom_wb_write_literal(wb, data, bits + 1); }