From 9177970bcac0b0a12894b22586b488dd0c134e26 Mon Sep 17 00:00:00 2001 From: Anton Khirnov Date: Thu, 28 Jan 2021 13:23:23 +0100 Subject: [PATCH] lavc/bitstream: templatize for BE/LE Allows using both BE and LE bitstream readers in the same file. --- libavcodec/Makefile | 1 + libavcodec/bitstream.h | 559 +++++++------------------------- libavcodec/bitstream_template.h | 496 ++++++++++++++++++++++++++++ tests/ref/fate/source | 1 + 4 files changed, 609 insertions(+), 448 deletions(-) create mode 100644 libavcodec/bitstream_template.h diff --git a/libavcodec/Makefile b/libavcodec/Makefile index 3ab448dd49..68669b1b46 100644 --- a/libavcodec/Makefile +++ b/libavcodec/Makefile @@ -1252,6 +1252,7 @@ SKIPHEADERS += %_tablegen.h \ aaccoder_trellis.h \ aacenc_quantization.h \ aacenc_quantization_misc.h \ + bitstream_template.h \ $(ARCH)/vpx_arith.h \ SKIPHEADERS-$(CONFIG_AMF) += amfenc.h diff --git a/libavcodec/bitstream.h b/libavcodec/bitstream.h index 6fd321dba5..ef7d8d55c2 100644 --- a/libavcodec/bitstream.h +++ b/libavcodec/bitstream.h @@ -23,6 +23,21 @@ * bitstream reader API header. */ +/* + * Bit order (endianness) is controlled by #defining BITSTREAM_BE and/or + * BITSTREAM_LE before #including this header. The corresponding bitreading + * functions are provided as bits_*_be()/bits_*_le() respectively. + * + * If neither or only BITSTREAM_BE is defined, then the default (unsuffixed) + * bits_*() will resolve to the big-endian implementation. If only BITSTREAM_LE + * is defined, little-endian will be the default. + * + * If both are defined, then the default can be controlled by defining at most + * one of BITSTREAM_DEFAULT_LE/BE. When BITSTREAM_DEFAULT_* is not defined, no + * default is provided and you must always explicitly use the _be() or _le() + * variants. + */ + #ifndef AVCODEC_BITSTREAM_H #define AVCODEC_BITSTREAM_H @@ -42,461 +57,80 @@ #define UNCHECKED_BITSTREAM_READER !CONFIG_SAFE_BITSTREAM_READER #endif -typedef struct BitstreamContext { - uint64_t bits; // stores bits read from the buffer - const uint8_t *buffer, *buffer_end; - const uint8_t *ptr; // pointer to the position inside a buffer - unsigned bits_valid; // number of bits left in bits field - unsigned size_in_bits; -} BitstreamContext; +// select the default endianness, if any +#if defined(BITSTREAM_LE) && defined(BITSTREAM_BE) -/** - * @return - * - 0 on successful refill - * - a negative number when bitstream end is hit - * - * Always succeeds when UNCHECKED_BITSTREAM_READER is enabled. - */ -static inline int bits_priv_refill_64(BitstreamContext *bc) -{ -#if !UNCHECKED_BITSTREAM_READER - if (bc->ptr >= bc->buffer_end) - return -1; +# if defined(BITSTREAM_DEFAULT_BE) && defined(BITSTREAM_DEFAULT_LE) +# error "At most one of BITSTREAM_DEFAULT_BE/LE must be defined" +# elif defined(BITSTREAM_DEFAULT_BE) +# define BITS_DEFAULT_BE +# elif defined(BITSTREAM_DEFAULT_LE) +# define BITS_DEFAULT_LE +# endif + +#elif defined(BITSTREAM_LE) +# define BITS_DEFAULT_LE +#else // select BE if nothing is requested explicitly +# define BITS_DEFAULT_BE +# define BITSTREAM_WANT_BE #endif -#ifdef BITSTREAM_READER_LE - bc->bits = AV_RL64(bc->ptr); -#else - bc->bits = AV_RB64(bc->ptr); -#endif - bc->ptr += 8; - bc->bits_valid = 64; +#if defined(BITS_DEFAULT_LE) - return 0; -} +# define BitstreamContext BitstreamContextLE +# define bits_init bits_init_le +# define bits_init8 bits_init8_le +# define bits_tell bits_tell_le +# define bits_size bits_size_le +# define bits_left bits_left_le +# define bits_read_bit bits_read_bit_le +# define bits_read_nz bits_read_nz_le +# define bits_read bits_read_le +# define bits_read_63 bits_read_63_le +# define bits_read_64 bits_read_64_le +# define bits_read_signed bits_read_signed_le +# define bits_peek_nz bits_peek_nz_le +# define bits_peek bits_peek_le +# define bits_peek_signed bits_peek_signed_le +# define bits_skip bits_skip_le +# define bits_seek bits_seek_le +# define bits_align bits_align_le +# define bits_read_xbits bits_read_xbits_le +# define bits_decode012 bits_decode012_le +# define bits_decode210 bits_decode210_le +# define bits_apply_sign bits_apply_sign_le +# define bits_read_vlc bits_read_vlc_le + +#elif defined(BITS_DEFAULT_BE) + +# define BitstreamContext BitstreamContextBE +# define bits_init bits_init_be +# define bits_init8 bits_init8_be +# define bits_tell bits_tell_be +# define bits_size bits_size_be +# define bits_left bits_left_be +# define bits_read_bit bits_read_bit_be +# define bits_read_nz bits_read_nz_be +# define bits_read bits_read_be +# define bits_read_63 bits_read_63_be +# define bits_read_64 bits_read_64_be +# define bits_read_signed bits_read_signed_be +# define bits_peek_nz bits_peek_nz_be +# define bits_peek bits_peek_be +# define bits_peek_signed bits_peek_signed_be +# define bits_skip bits_skip_be +# define bits_seek bits_seek_be +# define bits_align bits_align_be +# define bits_read_xbits bits_read_xbits_be +# define bits_decode012 bits_decode012_be +# define bits_decode210 bits_decode210_be +# define bits_apply_sign bits_apply_sign_be +# define bits_read_vlc bits_read_vlc_be -/** - * @return - * - 0 on successful refill - * - a negative number when bitstream end is hit - * - * Always succeeds when UNCHECKED_BITSTREAM_READER is enabled. - */ -static inline int bits_priv_refill_32(BitstreamContext *bc) -{ -#if !UNCHECKED_BITSTREAM_READER - if (bc->ptr >= bc->buffer_end) - return -1; #endif -#ifdef BITSTREAM_READER_LE - bc->bits |= (uint64_t)AV_RL32(bc->ptr) << bc->bits_valid; -#else - bc->bits |= (uint64_t)AV_RB32(bc->ptr) << (32 - bc->bits_valid); -#endif - bc->ptr += 4; - bc->bits_valid += 32; - - return 0; -} - -/** - * Initialize BitstreamContext. - * @param buffer bitstream buffer, must be AV_INPUT_BUFFER_PADDING_SIZE bytes - * larger than the actual read bits because some optimized bitstream - * readers read 32 or 64 bits at once and could read over the end - * @param bit_size the size of the buffer in bits - * @return 0 on success, AVERROR_INVALIDDATA if the buffer_size would overflow. - */ -static inline int bits_init(BitstreamContext *bc, const uint8_t *buffer, - unsigned int bit_size) -{ - unsigned int buffer_size; - - if (bit_size > INT_MAX - 7 || !buffer) { - bc->buffer = NULL; - bc->ptr = NULL; - bc->bits_valid = 0; - return AVERROR_INVALIDDATA; - } - - buffer_size = (bit_size + 7) >> 3; - - bc->buffer = buffer; - bc->buffer_end = buffer + buffer_size; - bc->ptr = bc->buffer; - bc->size_in_bits = bit_size; - bc->bits_valid = 0; - bc->bits = 0; - - bits_priv_refill_64(bc); - - return 0; -} - -/** - * Initialize BitstreamContext. - * @param buffer bitstream buffer, must be AV_INPUT_BUFFER_PADDING_SIZE bytes - * larger than the actual read bits because some optimized bitstream - * readers read 32 or 64 bits at once and could read over the end - * @param byte_size the size of the buffer in bytes - * @return 0 on success, AVERROR_INVALIDDATA if the buffer_size would overflow - */ -static inline int bits_init8(BitstreamContext *bc, const uint8_t *buffer, - unsigned int byte_size) -{ - if (byte_size > INT_MAX / 8) - return AVERROR_INVALIDDATA; - return bits_init(bc, buffer, byte_size * 8); -} - -/** - * Return number of bits already read. - */ -static inline int bits_tell(const BitstreamContext *bc) -{ - return (bc->ptr - bc->buffer) * 8 - bc->bits_valid; -} - -/** - * Return buffer size in bits. - */ -static inline int bits_size(const BitstreamContext *bc) -{ - return bc->size_in_bits; -} - -/** - * Return the number of the bits left in a buffer. - */ -static inline int bits_left(const BitstreamContext *bc) -{ - return (bc->buffer - bc->ptr) * 8 + bc->size_in_bits + bc->bits_valid; -} - -static inline uint64_t bits_priv_val_show(BitstreamContext *bc, unsigned int n) -{ - av_assert2(n > 0 && n <= 64); - -#ifdef BITSTREAM_READER_LE - return bc->bits & (UINT64_MAX >> (64 - n)); -#else - return bc->bits >> (64 - n); -#endif -} - -static inline void bits_priv_skip_remaining(BitstreamContext *bc, unsigned int n) -{ -#ifdef BITSTREAM_READER_LE - bc->bits >>= n; -#else - bc->bits <<= n; -#endif - bc->bits_valid -= n; -} - -static inline uint64_t bits_priv_val_get(BitstreamContext *bc, unsigned int n) -{ - uint64_t ret; - - av_assert2(n > 0 && n < 64); - - ret = bits_priv_val_show(bc, n); - bits_priv_skip_remaining(bc, n); - - return ret; -} - -/** - * Return one bit from the buffer. - */ -static inline unsigned int bits_read_bit(BitstreamContext *bc) -{ - if (!bc->bits_valid && bits_priv_refill_64(bc) < 0) - return 0; - - return bits_priv_val_get(bc, 1); -} - -/** - * Return n bits from the buffer, n has to be in the 1-32 range. - * May be faster than bits_read() when n is not a compile-time constant and is - * known to be non-zero; - */ -static inline uint32_t bits_read_nz(BitstreamContext *bc, unsigned int n) -{ - av_assert2(n > 0 && n <= 32); - - if (n > bc->bits_valid) { - if (bits_priv_refill_32(bc) < 0) - bc->bits_valid = n; - } - - return bits_priv_val_get(bc, n); -} - -/** - * Return n bits from the buffer, n has to be in the 0-32 range. - */ -static inline uint32_t bits_read(BitstreamContext *bc, unsigned int n) -{ - av_assert2(n <= 32); - - if (!n) - return 0; - - return bits_read_nz(bc, n); -} - -/** - * Return n bits from the buffer, n has to be in the 0-63 range. - */ -static inline uint64_t bits_read_63(BitstreamContext *bc, unsigned int n) -{ - uint64_t ret = 0; - unsigned left = 0; - - av_assert2(n <= 63); - - if (!n) - return 0; - - if (n > bc->bits_valid) { - left = bc->bits_valid; - n -= left; - - if (left) - ret = bits_priv_val_get(bc, left); - - if (bits_priv_refill_64(bc) < 0) - bc->bits_valid = n; - - } - -#ifdef BITSTREAM_READER_LE - ret = bits_priv_val_get(bc, n) << left | ret; -#else - ret = bits_priv_val_get(bc, n) | ret << n; -#endif - - return ret; -} - -/** - * Return n bits from the buffer, n has to be in the 0-64 range. - */ -static inline uint64_t bits_read_64(BitstreamContext *bc, unsigned int n) -{ - av_assert2(n <= 64); - - if (n == 64) { - uint64_t ret = bits_read_63(bc, 63); -#ifdef BITSTREAM_READER_LE - return ret | ((uint64_t)bits_read_bit(bc) << 63); -#else - return (ret << 1) | (uint64_t)bits_read_bit(bc); -#endif - } - return bits_read_63(bc, n); -} - -/** - * Return n bits from the buffer as a signed integer. - * n has to be in the 0-32 range. - */ -static inline int32_t bits_read_signed(BitstreamContext *bc, unsigned int n) -{ - return sign_extend(bits_read(bc, n), n); -} - -/** - * Return n bits from the buffer but do not change the buffer state. - * n has to be in the 1-32 range. May - */ -static inline uint32_t bits_peek_nz(BitstreamContext *bc, unsigned int n) -{ - av_assert2(n > 0 && n <= 32); - - if (n > bc->bits_valid) - bits_priv_refill_32(bc); - - return bits_priv_val_show(bc, n); -} - -/** - * Return n bits from the buffer but do not change the buffer state. - * n has to be in the 0-32 range. - */ -static inline uint32_t bits_peek(BitstreamContext *bc, unsigned int n) -{ - av_assert2(n <= 32); - - if (!n) - return 0; - - return bits_peek_nz(bc, n); -} - -/** - * Return n bits from the buffer as a signed integer, - * do not change the buffer state. - * n has to be in the 0-32 range. - */ -static inline int bits_peek_signed(BitstreamContext *bc, unsigned int n) -{ - return sign_extend(bits_peek(bc, n), n); -} - -/** - * Skip n bits in the buffer. - */ -static inline void bits_skip(BitstreamContext *bc, unsigned int n) -{ - if (n < bc->bits_valid) - bits_priv_skip_remaining(bc, n); - else { - n -= bc->bits_valid; - bc->bits = 0; - bc->bits_valid = 0; - - if (n >= 64) { - unsigned int skip = n / 8; - - n -= skip * 8; - bc->ptr += skip; - } - bits_priv_refill_64(bc); - if (n) - bits_priv_skip_remaining(bc, n); - } -} - -/** - * Seek to the given bit position. - */ -static inline void bits_seek(BitstreamContext *bc, unsigned pos) -{ - bc->ptr = bc->buffer; - bc->bits = 0; - bc->bits_valid = 0; - - bits_skip(bc, pos); -} - -/** - * Skip bits to a byte boundary. - */ -static inline const uint8_t *bits_align(BitstreamContext *bc) -{ - unsigned int n = -bits_tell(bc) & 7; - if (n) - bits_skip(bc, n); - return bc->buffer + (bits_tell(bc) >> 3); -} - -/** - * Read MPEG-1 dc-style VLC (sign bit + mantissa with no MSB). - * If MSB not set it is negative. - * @param n length in bits - */ -static inline int bits_read_xbits(BitstreamContext *bc, unsigned int n) -{ - int32_t cache = bits_peek(bc, 32); - int sign = ~cache >> 31; - bits_priv_skip_remaining(bc, n); - - return ((((uint32_t)(sign ^ cache)) >> (32 - n)) ^ sign) - sign; -} - -/** - * Return decoded truncated unary code for the values 0, 1, 2. - */ -static inline int bits_decode012(BitstreamContext *bc) -{ - if (!bits_read_bit(bc)) - return 0; - else - return bits_read_bit(bc) + 1; -} - -/** - * Return decoded truncated unary code for the values 2, 1, 0. - */ -static inline int bits_decode210(BitstreamContext *bc) -{ - if (bits_read_bit(bc)) - return 0; - else - return 2 - bits_read_bit(bc); -} - -/* Read sign bit and flip the sign of the provided value accordingly. */ -static inline int bits_apply_sign(BitstreamContext *bc, int val) -{ - int sign = bits_read_signed(bc, 1); - return (val ^ sign) - sign; -} - -static inline int bits_skip_1stop_8data(BitstreamContext *s) -{ - if (bits_left(s) <= 0) - return AVERROR_INVALIDDATA; - - while (bits_read_bit(s)) { - bits_skip(s, 8); - if (bits_left(s) <= 0) - return AVERROR_INVALIDDATA; - } - - return 0; -} - -/** - * Return the LUT element for the given bitstream configuration. - */ -static inline int bits_priv_set_idx(BitstreamContext *bc, int code, int *n, int *nb_bits, - const VLCElem *table) -{ - unsigned idx; - - *nb_bits = -*n; - idx = bits_peek(bc, *nb_bits) + code; - *n = table[idx].len; - - return table[idx].sym; -} - -/** - * Parse a vlc code. - * @param bits is the number of bits which will be read at once, must be - * identical to nb_bits in init_vlc() - * @param max_depth is the number of times bits bits must be read to completely - * read the longest vlc code - * = (max_vlc_length + bits - 1) / bits - * If the vlc code is invalid and max_depth=1, then no bits will be removed. - * If the vlc code is invalid and max_depth>1, then the number of bits removed - * is undefined. - */ -static inline int bits_read_vlc(BitstreamContext *bc, const VLCElem *table, - int bits, int max_depth) -{ - int nb_bits; - unsigned idx = bits_peek(bc, bits); - int code = table[idx].sym; - int n = table[idx].len; - - if (max_depth > 1 && n < 0) { - bits_priv_skip_remaining(bc, bits); - code = bits_priv_set_idx(bc, code, &n, &nb_bits, table); - if (max_depth > 2 && n < 0) { - bits_priv_skip_remaining(bc, nb_bits); - code = bits_priv_set_idx(bc, code, &n, &nb_bits, table); - } - } - bits_priv_skip_remaining(bc, n); - - return code; -} +#undef BITS_DEFAULT_LE +#undef BITS_DEFAULT_BE #define BITS_RL_VLC(level, run, bc, table, bits, max_depth) \ do { \ @@ -527,3 +161,32 @@ static inline int bits_read_vlc(BitstreamContext *bc, const VLCElem *table, } while (0) #endif /* AVCODEC_BITSTREAM_H */ + +// the following is deliberately outside of the standard #include guards + +#if defined(BITSTREAM_LE) && !defined(BITSTREAM_WANT_LE) +# define BITSTREAM_WANT_LE +#endif + +#if defined(BITSTREAM_BE) && !defined(BITSTREAM_WANT_BE) +# define BITSTREAM_WANT_BE +#endif + +#if defined(BITSTREAM_WANT_LE) && !defined(AVCODEC_BITSTREAM_LE) +#define AVCODEC_BITSTREAM_LE + +#define BITSTREAM_TEMPLATE_LE +#include "bitstream_template.h" +#undef BITSTREAM_TEMPLATE_LE + +#endif + +#if defined(BITSTREAM_WANT_BE) && !defined(AVCODEC_BITSTREAM_BE) +#define AVCODEC_BITSTREAM_BE + +#include "bitstream_template.h" + +#endif + +#undef BITSTREAM_WANT_LE +#undef BITSTREAM_WANT_BE diff --git a/libavcodec/bitstream_template.h b/libavcodec/bitstream_template.h new file mode 100644 index 0000000000..f2c14fc4d3 --- /dev/null +++ b/libavcodec/bitstream_template.h @@ -0,0 +1,496 @@ +/* + * Copyright (c) 2016 Alexandra Hájková + * + * 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 + */ + +#ifdef BITSTREAM_TEMPLATE_LE +# define BS_SUFFIX_LOWER _le +# define BS_SUFFIX_UPPER LE +#else +# define BS_SUFFIX_LOWER _be +# define BS_SUFFIX_UPPER BE +#endif + +#define BS_JOIN(x, y, z) x ## y ## z +#define BS_JOIN3(x, y, z) BS_JOIN(x, y, z) +#define BS_FUNC(x) BS_JOIN3(bits_, x, BS_SUFFIX_LOWER) + +#define BSCTX BS_JOIN3(Bitstream, Context, BS_SUFFIX_UPPER) + +typedef struct BSCTX { + uint64_t bits; // stores bits read from the buffer + const uint8_t *buffer, *buffer_end; + const uint8_t *ptr; // pointer to the position inside a buffer + unsigned bits_valid; // number of bits left in bits field + unsigned size_in_bits; +} BSCTX; + +/** + * @return + * - 0 on successful refill + * - a negative number when bitstream end is hit + * + * Always succeeds when UNCHECKED_BITSTREAM_READER is enabled. + */ +static inline int BS_FUNC(priv_refill_64)(BSCTX *bc) +{ +#if !UNCHECKED_BITSTREAM_READER + if (bc->ptr >= bc->buffer_end) + return -1; +#endif + +#ifdef BITSTREAM_TEMPLATE_LE + bc->bits = AV_RL64(bc->ptr); +#else + bc->bits = AV_RB64(bc->ptr); +#endif + bc->ptr += 8; + bc->bits_valid = 64; + + return 0; +} + +/** + * @return + * - 0 on successful refill + * - a negative number when bitstream end is hit + * + * Always succeeds when UNCHECKED_BITSTREAM_READER is enabled. + */ +static inline int BS_FUNC(priv_refill_32)(BSCTX *bc) +{ +#if !UNCHECKED_BITSTREAM_READER + if (bc->ptr >= bc->buffer_end) + return -1; +#endif + +#ifdef BITSTREAM_TEMPLATE_LE + bc->bits |= (uint64_t)AV_RL32(bc->ptr) << bc->bits_valid; +#else + bc->bits |= (uint64_t)AV_RB32(bc->ptr) << (32 - bc->bits_valid); +#endif + bc->ptr += 4; + bc->bits_valid += 32; + + return 0; +} + +/** + * Initialize BitstreamContext. + * @param buffer bitstream buffer, must be AV_INPUT_BUFFER_PADDING_SIZE bytes + * larger than the actual read bits because some optimized bitstream + * readers read 32 or 64 bits at once and could read over the end + * @param bit_size the size of the buffer in bits + * @return 0 on success, AVERROR_INVALIDDATA if the buffer_size would overflow. + */ +static inline int BS_FUNC(init)(BSCTX *bc, const uint8_t *buffer, + unsigned int bit_size) +{ + unsigned int buffer_size; + + if (bit_size > INT_MAX - 7 || !buffer) { + bc->buffer = NULL; + bc->ptr = NULL; + bc->bits_valid = 0; + return AVERROR_INVALIDDATA; + } + + buffer_size = (bit_size + 7) >> 3; + + bc->buffer = buffer; + bc->buffer_end = buffer + buffer_size; + bc->ptr = bc->buffer; + bc->size_in_bits = bit_size; + bc->bits_valid = 0; + bc->bits = 0; + + BS_FUNC(priv_refill_64)(bc); + + return 0; +} + +/** + * Initialize BitstreamContext. + * @param buffer bitstream buffer, must be AV_INPUT_BUFFER_PADDING_SIZE bytes + * larger than the actual read bits because some optimized bitstream + * readers read 32 or 64 bits at once and could read over the end + * @param byte_size the size of the buffer in bytes + * @return 0 on success, AVERROR_INVALIDDATA if the buffer_size would overflow + */ +static inline int BS_FUNC(init8)(BSCTX *bc, const uint8_t *buffer, + unsigned int byte_size) +{ + if (byte_size > INT_MAX / 8) + return AVERROR_INVALIDDATA; + return BS_FUNC(init)(bc, buffer, byte_size * 8); +} + +/** + * Return number of bits already read. + */ +static inline int BS_FUNC(tell)(const BSCTX *bc) +{ + return (bc->ptr - bc->buffer) * 8 - bc->bits_valid; +} + +/** + * Return buffer size in bits. + */ +static inline int BS_FUNC(size)(const BSCTX *bc) +{ + return bc->size_in_bits; +} + +/** + * Return the number of the bits left in a buffer. + */ +static inline int BS_FUNC(left)(const BSCTX *bc) +{ + return (bc->buffer - bc->ptr) * 8 + bc->size_in_bits + bc->bits_valid; +} + +static inline uint64_t BS_FUNC(priv_val_show)(BSCTX *bc, unsigned int n) +{ + av_assert2(n > 0 && n <= 64); + +#ifdef BITSTREAM_TEMPLATE_LE + return bc->bits & (UINT64_MAX >> (64 - n)); +#else + return bc->bits >> (64 - n); +#endif +} + +static inline void BS_FUNC(priv_skip_remaining)(BSCTX *bc, unsigned int n) +{ +#ifdef BITSTREAM_TEMPLATE_LE + bc->bits >>= n; +#else + bc->bits <<= n; +#endif + bc->bits_valid -= n; +} + +static inline uint64_t BS_FUNC(priv_val_get)(BSCTX *bc, unsigned int n) +{ + uint64_t ret; + + av_assert2(n > 0 && n < 64); + + ret = BS_FUNC(priv_val_show)(bc, n); + BS_FUNC(priv_skip_remaining)(bc, n); + + return ret; +} + +/** + * Return one bit from the buffer. + */ +static inline unsigned int BS_FUNC(read_bit)(BSCTX *bc) +{ + if (!bc->bits_valid && BS_FUNC(priv_refill_64)(bc) < 0) + return 0; + + return BS_FUNC(priv_val_get)(bc, 1); +} + +/** + * Return n bits from the buffer, n has to be in the 1-32 range. + * May be faster than bits_read() when n is not a compile-time constant and is + * known to be non-zero; + */ +static inline uint32_t BS_FUNC(read_nz)(BSCTX *bc, unsigned int n) +{ + av_assert2(n > 0 && n <= 32); + + if (n > bc->bits_valid) { + if (BS_FUNC(priv_refill_32)(bc) < 0) + bc->bits_valid = n; + } + + return BS_FUNC(priv_val_get)(bc, n); +} + +/** + * Return n bits from the buffer, n has to be in the 0-32 range. + */ +static inline uint32_t BS_FUNC(read)(BSCTX *bc, unsigned int n) +{ + av_assert2(n <= 32); + + if (!n) + return 0; + + return BS_FUNC(read_nz)(bc, n); +} + +/** + * Return n bits from the buffer, n has to be in the 0-63 range. + */ +static inline uint64_t BS_FUNC(read_63)(BSCTX *bc, unsigned int n) +{ + uint64_t ret = 0; + unsigned left = 0; + + av_assert2(n <= 63); + + if (!n) + return 0; + + if (n > bc->bits_valid) { + left = bc->bits_valid; + n -= left; + + if (left) + ret = BS_FUNC(priv_val_get)(bc, left); + + if (BS_FUNC(priv_refill_64)(bc) < 0) + bc->bits_valid = n; + + } + +#ifdef BITSTREAM_TEMPLATE_LE + ret = BS_FUNC(priv_val_get)(bc, n) << left | ret; +#else + ret = BS_FUNC(priv_val_get)(bc, n) | ret << n; +#endif + + return ret; +} + +/** + * Return n bits from the buffer, n has to be in the 0-64 range. + */ +static inline uint64_t BS_FUNC(read_64)(BSCTX *bc, unsigned int n) +{ + av_assert2(n <= 64); + + if (n == 64) { + uint64_t ret = BS_FUNC(read_63)(bc, 63); +#ifdef BITSTREAM_TEMPLATE_LE + return ret | ((uint64_t)BS_FUNC(read_bit)(bc) << 63); +#else + return (ret << 1) | (uint64_t)BS_FUNC(read_bit)(bc); +#endif + } + return BS_FUNC(read_63)(bc, n); +} + +/** + * Return n bits from the buffer as a signed integer. + * n has to be in the 0-32 range. + */ +static inline int32_t BS_FUNC(read_signed)(BSCTX *bc, unsigned int n) +{ + return sign_extend(BS_FUNC(read)(bc, n), n); +} + +/** + * Return n bits from the buffer but do not change the buffer state. + * n has to be in the 1-32 range. May + */ +static inline uint32_t BS_FUNC(peek_nz)(BSCTX *bc, unsigned int n) +{ + av_assert2(n > 0 && n <= 32); + + if (n > bc->bits_valid) + BS_FUNC(priv_refill_32)(bc); + + return BS_FUNC(priv_val_show)(bc, n); +} + +/** + * Return n bits from the buffer but do not change the buffer state. + * n has to be in the 0-32 range. + */ +static inline uint32_t BS_FUNC(peek)(BSCTX *bc, unsigned int n) +{ + av_assert2(n <= 32); + + if (!n) + return 0; + + return BS_FUNC(peek_nz)(bc, n); +} + +/** + * Return n bits from the buffer as a signed integer, + * do not change the buffer state. + * n has to be in the 0-32 range. + */ +static inline int BS_FUNC(peek_signed)(BSCTX *bc, unsigned int n) +{ + return sign_extend(BS_FUNC(peek)(bc, n), n); +} + +/** + * Skip n bits in the buffer. + */ +static inline void BS_FUNC(skip)(BSCTX *bc, unsigned int n) +{ + if (n < bc->bits_valid) + BS_FUNC(priv_skip_remaining)(bc, n); + else { + n -= bc->bits_valid; + bc->bits = 0; + bc->bits_valid = 0; + + if (n >= 64) { + unsigned int skip = n / 8; + + n -= skip * 8; + bc->ptr += skip; + } + BS_FUNC(priv_refill_64)(bc); + if (n) + BS_FUNC(priv_skip_remaining)(bc, n); + } +} + +/** + * Seek to the given bit position. + */ +static inline void BS_FUNC(seek)(BSCTX *bc, unsigned pos) +{ + bc->ptr = bc->buffer; + bc->bits = 0; + bc->bits_valid = 0; + + BS_FUNC(skip)(bc, pos); +} + +/** + * Skip bits to a byte boundary. + */ +static inline const uint8_t *BS_FUNC(align)(BSCTX *bc) +{ + unsigned int n = -BS_FUNC(tell)(bc) & 7; + if (n) + BS_FUNC(skip)(bc, n); + return bc->buffer + (BS_FUNC(tell)(bc) >> 3); +} + +/** + * Read MPEG-1 dc-style VLC (sign bit + mantissa with no MSB). + * If MSB not set it is negative. + * @param n length in bits + */ +static inline int BS_FUNC(read_xbits)(BSCTX *bc, unsigned int n) +{ + int32_t cache = BS_FUNC(peek)(bc, 32); + int sign = ~cache >> 31; + BS_FUNC(priv_skip_remaining)(bc, n); + + return ((((uint32_t)(sign ^ cache)) >> (32 - n)) ^ sign) - sign; +} + +/** + * Return decoded truncated unary code for the values 0, 1, 2. + */ +static inline int BS_FUNC(decode012)(BSCTX *bc) +{ + if (!BS_FUNC(read_bit)(bc)) + return 0; + else + return BS_FUNC(read_bit)(bc) + 1; +} + +/** + * Return decoded truncated unary code for the values 2, 1, 0. + */ +static inline int BS_FUNC(decode210)(BSCTX *bc) +{ + if (BS_FUNC(read_bit)(bc)) + return 0; + else + return 2 - BS_FUNC(read_bit)(bc); +} + +/* Read sign bit and flip the sign of the provided value accordingly. */ +static inline int BS_FUNC(apply_sign)(BSCTX *bc, int val) +{ + int sign = BS_FUNC(read_signed)(bc, 1); + return (val ^ sign) - sign; +} + +static inline int BS_FUNC(skip_1stop_8data)(BSCTX *s) +{ + if (BS_FUNC(left)(s) <= 0) + return AVERROR_INVALIDDATA; + + while (BS_FUNC(read_bit)(s)) { + BS_FUNC(skip)(s, 8); + if (BS_FUNC(left)(s) <= 0) + return AVERROR_INVALIDDATA; + } + + return 0; +} + +/** + * Return the LUT element for the given bitstream configuration. + */ +static inline int BS_FUNC(priv_set_idx)(BSCTX *bc, int code, int *n, + int *nb_bits, const VLCElem *table) +{ + unsigned idx; + + *nb_bits = -*n; + idx = BS_FUNC(peek)(bc, *nb_bits) + code; + *n = table[idx].len; + + return table[idx].sym; +} + +/** + * Parse a vlc code. + * @param bits is the number of bits which will be read at once, must be + * identical to nb_bits in init_vlc() + * @param max_depth is the number of times bits bits must be read to completely + * read the longest vlc code + * = (max_vlc_length + bits - 1) / bits + * If the vlc code is invalid and max_depth=1, then no bits will be removed. + * If the vlc code is invalid and max_depth>1, then the number of bits removed + * is undefined. + */ +static inline int BS_FUNC(read_vlc)(BSCTX *bc, const VLCElem *table, + int bits, int max_depth) +{ + int nb_bits; + unsigned idx = BS_FUNC(peek)(bc, bits); + int code = table[idx].sym; + int n = table[idx].len; + + if (max_depth > 1 && n < 0) { + BS_FUNC(priv_skip_remaining)(bc, bits); + code = BS_FUNC(priv_set_idx)(bc, code, &n, &nb_bits, table); + if (max_depth > 2 && n < 0) { + BS_FUNC(priv_skip_remaining)(bc, nb_bits); + code = BS_FUNC(priv_set_idx)(bc, code, &n, &nb_bits, table); + } + } + BS_FUNC(priv_skip_remaining)(bc, n); + + return code; +} + +#undef BSCTX +#undef BS_FUNC +#undef BS_JOIN3 +#undef BS_JOIN +#undef BS_SUFFIX_UPPER +#undef BS_SUFFIX_LOWER diff --git a/tests/ref/fate/source b/tests/ref/fate/source index 16ea7ef9c1..3b7ea9c379 100644 --- a/tests/ref/fate/source +++ b/tests/ref/fate/source @@ -21,6 +21,7 @@ Headers without standard inclusion guards: compat/djgpp/math.h compat/float/float.h compat/float/limits.h +libavcodec/bitstream_template.h tools/decode_simple.h Use of av_clip() where av_clip_uintp2() could be used: Use of av_clip() where av_clip_intp2() could be used: