diff options
Diffstat (limited to 'media/libvpx/libvpx/vpx_dsp/bitreader_buffer.c')
-rw-r--r-- | media/libvpx/libvpx/vpx_dsp/bitreader_buffer.c | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/media/libvpx/libvpx/vpx_dsp/bitreader_buffer.c b/media/libvpx/libvpx/vpx_dsp/bitreader_buffer.c new file mode 100644 index 0000000000..f59f1f7cb9 --- /dev/null +++ b/media/libvpx/libvpx/vpx_dsp/bitreader_buffer.c @@ -0,0 +1,44 @@ +/* + * Copyright (c) 2013 The WebM 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. + */ +#include "./vpx_config.h" +#include "./bitreader_buffer.h" + +size_t vpx_rb_bytes_read(struct vpx_read_bit_buffer *rb) { + return (rb->bit_offset + 7) >> 3; +} + +int vpx_rb_read_bit(struct vpx_read_bit_buffer *rb) { + const size_t off = rb->bit_offset; + const size_t p = off >> 3; + const int q = 7 - (int)(off & 0x7); + if (rb->bit_buffer + p < rb->bit_buffer_end) { + const int bit = (rb->bit_buffer[p] >> q) & 1; + rb->bit_offset = off + 1; + return bit; + } else { + if (rb->error_handler != NULL) rb->error_handler(rb->error_handler_data); + return 0; + } +} + +int vpx_rb_read_literal(struct vpx_read_bit_buffer *rb, int bits) { + int value = 0, bit; + for (bit = bits - 1; bit >= 0; bit--) value |= vpx_rb_read_bit(rb) << bit; + return value; +} + +int vpx_rb_read_signed_literal(struct vpx_read_bit_buffer *rb, int bits) { + const int value = vpx_rb_read_literal(rb, bits); + return vpx_rb_read_bit(rb) ? -value : value; +} + +int vpx_rb_read_inv_signed_literal(struct vpx_read_bit_buffer *rb, int bits) { + return vpx_rb_read_signed_literal(rb, bits); +} |