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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 17:32:43 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 17:32:43 +0000 |
commit | 6bf0a5cb5034a7e684dcc3500e841785237ce2dd (patch) | |
tree | a68f146d7fa01f0134297619fbe7e33db084e0aa /media/ffvpx/libavcodec/vpx_rac.h | |
parent | Initial commit. (diff) | |
download | thunderbird-6bf0a5cb5034a7e684dcc3500e841785237ce2dd.tar.xz thunderbird-6bf0a5cb5034a7e684dcc3500e841785237ce2dd.zip |
Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | media/ffvpx/libavcodec/vpx_rac.h | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/media/ffvpx/libavcodec/vpx_rac.h b/media/ffvpx/libavcodec/vpx_rac.h new file mode 100644 index 0000000000..b158cc0754 --- /dev/null +++ b/media/ffvpx/libavcodec/vpx_rac.h @@ -0,0 +1,135 @@ +/* + * Copyright (C) 2006 Aurelien Jacobs <aurel@gnuage.org> + * + * This file is part of FFmpeg. + * + * FFmpeg is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * FFmpeg is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +/** + * @file + * Common VP5-VP9 range decoder stuff + */ + +#ifndef AVCODEC_VPX_RAC_H +#define AVCODEC_VPX_RAC_H + +#include <stdint.h> + +#include "config.h" +#include "libavutil/attributes.h" +#include "bytestream.h" + +typedef struct VPXRangeCoder { + int high; + int bits; /* stored negated (i.e. negative "bits" is a positive number of + bits left) in order to eliminate a negate in cache refilling */ + const uint8_t *buffer; + const uint8_t *end; + unsigned int code_word; + int end_reached; +} VPXRangeCoder; + +extern const uint8_t ff_vpx_norm_shift[256]; +int ff_vpx_init_range_decoder(VPXRangeCoder *c, const uint8_t *buf, int buf_size); + +/** + * returns 1 if the end of the stream has been reached, 0 otherwise. + */ +static av_always_inline int vpx_rac_is_end(VPXRangeCoder *c) +{ + if (c->end <= c->buffer && c->bits >= 0) + c->end_reached ++; + return c->end_reached > 10; +} + +static av_always_inline unsigned int vpx_rac_renorm(VPXRangeCoder *c) +{ + int shift = ff_vpx_norm_shift[c->high]; + int bits = c->bits; + unsigned int code_word = c->code_word; + + c->high <<= shift; + code_word <<= shift; + bits += shift; + if(bits >= 0 && c->buffer < c->end) { + code_word |= bytestream_get_be16(&c->buffer) << bits; + bits -= 16; + } + c->bits = bits; + return code_word; +} + +#if ARCH_ARM +#include "arm/vpx_arith.h" +#elif ARCH_X86 +#include "x86/vpx_arith.h" +#endif + +#ifndef vpx_rac_get_prob +#define vpx_rac_get_prob vpx_rac_get_prob +static av_always_inline int vpx_rac_get_prob(VPXRangeCoder *c, uint8_t prob) +{ + unsigned int code_word = vpx_rac_renorm(c); + unsigned int low = 1 + (((c->high - 1) * prob) >> 8); + unsigned int low_shift = low << 16; + int bit = code_word >= low_shift; + + c->high = bit ? c->high - low : low; + c->code_word = bit ? code_word - low_shift : code_word; + + return bit; +} +#endif + +#ifndef vpx_rac_get_prob_branchy +// branchy variant, to be used where there's a branch based on the bit decoded +static av_always_inline int vpx_rac_get_prob_branchy(VPXRangeCoder *c, int prob) +{ + unsigned long code_word = vpx_rac_renorm(c); + unsigned low = 1 + (((c->high - 1) * prob) >> 8); + unsigned low_shift = low << 16; + + if (code_word >= low_shift) { + c->high -= low; + c->code_word = code_word - low_shift; + return 1; + } + + c->high = low; + c->code_word = code_word; + return 0; +} +#endif + +static av_always_inline int vpx_rac_get(VPXRangeCoder *c) +{ + unsigned int code_word = vpx_rac_renorm(c); + /* equiprobable */ + int low = (c->high + 1) >> 1; + unsigned int low_shift = low << 16; + int bit = code_word >= low_shift; + if (bit) { + c->high -= low; + code_word -= low_shift; + } else { + c->high = low; + } + + c->code_word = code_word; + return bit; +} + +#endif /* AVCODEC_VPX_RAC_H */ |