diff options
Diffstat (limited to 'third_party/aom/aom_dsp/bitwriter_buffer.c')
-rw-r--r-- | third_party/aom/aom_dsp/bitwriter_buffer.c | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/third_party/aom/aom_dsp/bitwriter_buffer.c b/third_party/aom/aom_dsp/bitwriter_buffer.c new file mode 100644 index 000000000..1b3dd2913 --- /dev/null +++ b/third_party/aom/aom_dsp/bitwriter_buffer.c @@ -0,0 +1,61 @@ +/* + * 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 <limits.h> +#include <stdlib.h> + +#include "./aom_config.h" +#include "./bitwriter_buffer.h" + +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) { + 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); +} |