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Diffstat (limited to 'vp9/encoder/vp9_boolhuff.h')
-rw-r--r-- | vp9/encoder/vp9_boolhuff.h | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/vp9/encoder/vp9_boolhuff.h b/vp9/encoder/vp9_boolhuff.h new file mode 100644 index 000000000..c3f340d1b --- /dev/null +++ b/vp9/encoder/vp9_boolhuff.h @@ -0,0 +1,115 @@ +/* + * Copyright (c) 2010 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. + */ + + +/**************************************************************************** +* +* Module Title : vp9_boolhuff.h +* +* Description : Bool Coder header file. +* +****************************************************************************/ +#ifndef VP9_ENCODER_VP9_BOOLHUFF_H_ +#define VP9_ENCODER_VP9_BOOLHUFF_H_ + +#include "vpx_ports/mem.h" + +typedef struct { + unsigned int lowvalue; + unsigned int range; + unsigned int value; + int count; + unsigned int pos; + uint8_t *buffer; + + // Variables used to track bit costs without outputing to the bitstream + unsigned int measure_cost; + unsigned long bit_counter; +} vp9_writer; + +extern const unsigned int vp9_prob_cost[256]; + +void vp9_start_encode(vp9_writer *bc, uint8_t *buffer); +void vp9_stop_encode(vp9_writer *bc); + +DECLARE_ALIGNED(16, extern const unsigned char, vp9_norm[256]); + +static void vp9_write(vp9_writer *br, int bit, int probability) { + unsigned int split; + int count = br->count; + unsigned int range = br->range; + unsigned int lowvalue = br->lowvalue; + register unsigned int shift; + +#ifdef ENTROPY_STATS +#if defined(SECTIONBITS_OUTPUT) + + if (bit) + Sectionbits[active_section] += vp9_prob_cost[255 - probability]; + else + Sectionbits[active_section] += vp9_prob_cost[probability]; + +#endif +#endif + + split = 1 + (((range - 1) * probability) >> 8); + + range = split; + + if (bit) { + lowvalue += split; + range = br->range - split; + } + + shift = vp9_norm[range]; + + range <<= shift; + count += shift; + + if (count >= 0) { + int offset = shift - count; + + if ((lowvalue << (offset - 1)) & 0x80000000) { + int x = br->pos - 1; + + while (x >= 0 && br->buffer[x] == 0xff) { + br->buffer[x] = 0; + x--; + } + + br->buffer[x] += 1; + } + + br->buffer[br->pos++] = (lowvalue >> (24 - offset)); + lowvalue <<= offset; + shift = count; + lowvalue &= 0xffffff; + count -= 8; + } + + lowvalue <<= shift; + br->count = count; + br->lowvalue = lowvalue; + br->range = range; +} + +static void vp9_write_bit(vp9_writer *w, int bit) { + vp9_write(w, bit, 128); // vp9_prob_half +} + +static void vp9_write_literal(vp9_writer *w, int data, int bits) { + int bit; + + for (bit = bits - 1; bit >= 0; bit--) + vp9_write_bit(w, 1 & (data >> bit)); +} + + +#endif // VP9_ENCODER_VP9_BOOLHUFF_H_ |