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-rw-r--r-- | src/gallium/auxiliary/vl/vl_rbsp.h | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/src/gallium/auxiliary/vl/vl_rbsp.h b/src/gallium/auxiliary/vl/vl_rbsp.h new file mode 100644 index 00000000000..2e3da8e1d28 --- /dev/null +++ b/src/gallium/auxiliary/vl/vl_rbsp.h @@ -0,0 +1,164 @@ +/************************************************************************** + * + * Copyright 2013 Advanced Micro Devices, Inc. + * All Rights Reserved. + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the + * "Software"), to deal in the Software without restriction, including + * without limitation the rights to use, copy, modify, merge, publish, + * distribute, sub license, and/or sell copies of the Software, and to + * permit persons to whom the Software is furnished to do so, subject to + * the following conditions: + * + * The above copyright notice and this permission notice (including the + * next paragraph) shall be included in all copies or substantial portions + * of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS + * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. + * IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR + * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, + * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE + * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. + * + **************************************************************************/ + +/* + * Authors: + * Christian König <christian.koenig@amd.com> + * + */ + +/* + * Functions for reading the raw byte sequence payload of H.264 + */ + +#ifndef vl_rbsp_h +#define vl_rbsp_h + +#include "vl/vl_vlc.h" + +struct vl_rbsp { + struct vl_vlc nal; + unsigned escaped; +}; + +/** + * Initialize the RBSP object + */ +static INLINE void vl_rbsp_init(struct vl_rbsp *rbsp, struct vl_vlc *nal, unsigned num_bits) +{ + unsigned bits_left = vl_vlc_bits_left(nal); + + /* copy the position */ + rbsp->nal = *nal; + + rbsp->escaped = 0; + + /* search for the end of the NAL unit */ + while (vl_vlc_search_byte(nal, num_bits, 0x00)) { + if (vl_vlc_peekbits(nal, 24) == 0x000001 || + vl_vlc_peekbits(nal, 32) == 0x00000001) { + vl_vlc_limit(&rbsp->nal, bits_left - vl_vlc_bits_left(nal)); + return; + } + vl_vlc_eatbits(nal, 8); + } +} + +/** + * Make at least 16 more bits available + */ +static INLINE void vl_rbsp_fillbits(struct vl_rbsp *rbsp) +{ + unsigned valid = vl_vlc_valid_bits(&rbsp->nal); + unsigned i, bits; + + /* abort if we still have enough bits */ + if (valid >= 32) + return; + + vl_vlc_fillbits(&rbsp->nal); + + /* abort if we have less than 24 bits left in this nal */ + if (vl_vlc_bits_left(&rbsp->nal) < 24) + return; + + /* check that we have enough bits left from the last fillbits */ + assert(valid >= rbsp->escaped); + + /* handle the already escaped bits */ + valid -= rbsp->escaped; + + /* search for the emulation prevention three byte */ + rbsp->escaped = 16; + bits = vl_vlc_valid_bits(&rbsp->nal); + for (i = valid + 24; i <= bits; i += 8) { + if ((vl_vlc_peekbits(&rbsp->nal, i) & 0xffffff) == 0x3) { + vl_vlc_removebits(&rbsp->nal, i - 8, 8); + rbsp->escaped = bits - i; + bits -= 8; + i += 8; + } + } +} + +/** + * Return an unsigned integer from the first n bits + */ +static INLINE unsigned vl_rbsp_u(struct vl_rbsp *rbsp, unsigned n) +{ + if (n == 0) + return 0; + + vl_rbsp_fillbits(rbsp); + return vl_vlc_get_uimsbf(&rbsp->nal, n); +} + +/** + * Return an unsigned exponential Golomb encoded integer + */ +static INLINE unsigned vl_rbsp_ue(struct vl_rbsp *rbsp) +{ + unsigned bits = 0; + + vl_rbsp_fillbits(rbsp); + while (!vl_vlc_get_uimsbf(&rbsp->nal, 1)) + ++bits; + + return (1 << bits) - 1 + vl_rbsp_u(rbsp, bits); +} + +/** + * Return an signed exponential Golomb encoded integer + */ +static INLINE signed vl_rbsp_se(struct vl_rbsp *rbsp) +{ + signed codeNum = vl_rbsp_ue(rbsp); + if (codeNum & 1) + return (codeNum + 1) >> 1; + else + return -(codeNum >> 1); +} + +/** + * Are more data available in the RBSP ? + */ +static INLINE bool vl_rbsp_more_data(struct vl_rbsp *rbsp) +{ + unsigned bits, value; + + if (vl_vlc_bits_left(&rbsp->nal) > 8) + return TRUE; + + bits = vl_vlc_valid_bits(&rbsp->nal); + value = vl_vlc_peekbits(&rbsp->nal, bits); + if (value == 0 || value == (1 << (bits - 1))) + return FALSE; + + return TRUE; +} + +#endif /* vl_rbsp_h */ |