diff options
Diffstat (limited to 'media/libvpx/libvpx/vp8/encoder/boolhuff.h')
-rw-r--r-- | media/libvpx/libvpx/vp8/encoder/boolhuff.h | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/media/libvpx/libvpx/vp8/encoder/boolhuff.h b/media/libvpx/libvpx/vp8/encoder/boolhuff.h new file mode 100644 index 0000000000..a8c536b99c --- /dev/null +++ b/media/libvpx/libvpx/vp8/encoder/boolhuff.h @@ -0,0 +1,112 @@ +/* + * 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 : boolhuff.h + * + * Description : Bool Coder header file. + * + ****************************************************************************/ +#ifndef VPX_VP8_ENCODER_BOOLHUFF_H_ +#define VPX_VP8_ENCODER_BOOLHUFF_H_ + +#include "vpx_ports/mem.h" +#include "vpx/internal/vpx_codec_internal.h" + +#ifdef __cplusplus +extern "C" { +#endif + +typedef struct { + unsigned int lowvalue; + unsigned int range; + int count; + unsigned int pos; + unsigned char *buffer; + unsigned char *buffer_end; + struct vpx_internal_error_info *error; +} BOOL_CODER; + +void vp8_start_encode(BOOL_CODER *bc, unsigned char *source, + unsigned char *source_end); + +void vp8_encode_value(BOOL_CODER *bc, int data, int bits); +void vp8_stop_encode(BOOL_CODER *bc); +extern const unsigned int vp8_prob_cost[256]; + +DECLARE_ALIGNED(16, extern const unsigned char, vp8_norm[256]); + +static int validate_buffer(const unsigned char *start, size_t len, + const unsigned char *end, + struct vpx_internal_error_info *error) { + if (start + len > start && start + len < end) { + return 1; + } else { + vpx_internal_error(error, VPX_CODEC_CORRUPT_FRAME, + "Truncated packet or corrupt partition "); + } + + return 0; +} +static void vp8_encode_bool(BOOL_CODER *bc, int bit, int probability) { + unsigned int split; + int count = bc->count; + unsigned int range = bc->range; + unsigned int lowvalue = bc->lowvalue; + int shift; + + split = 1 + (((range - 1) * probability) >> 8); + + range = split; + + if (bit) { + lowvalue += split; + range = bc->range - split; + } + + shift = vp8_norm[range]; + + range <<= shift; + count += shift; + + if (count >= 0) { + int offset = shift - count; + + if ((lowvalue << (offset - 1)) & 0x80000000) { + int x = bc->pos - 1; + + while (x >= 0 && bc->buffer[x] == 0xff) { + bc->buffer[x] = (unsigned char)0; + x--; + } + + bc->buffer[x] += 1; + } + + validate_buffer(bc->buffer + bc->pos, 1, bc->buffer_end, bc->error); + bc->buffer[bc->pos++] = (lowvalue >> (24 - offset) & 0xff); + + shift = count; + lowvalue = (int)(((uint64_t)lowvalue << offset) & 0xffffff); + count -= 8; + } + + lowvalue <<= shift; + bc->count = count; + bc->lowvalue = lowvalue; + bc->range = range; +} + +#ifdef __cplusplus +} // extern "C" +#endif + +#endif // VPX_VP8_ENCODER_BOOLHUFF_H_ |