/** * FreeRDP: A Remote Desktop Protocol Implementation * RemoteFX Codec Library - Bit Stream * * Copyright 2011 Vic Lee * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #ifndef FREERDP_LIB_CODEC_RFX_BITSTREAM_H #define FREERDP_LIB_CODEC_RFX_BITSTREAM_H #include struct _RFX_BITSTREAM { BYTE* buffer; int nbytes; int byte_pos; int bits_left; }; typedef struct _RFX_BITSTREAM RFX_BITSTREAM; #define rfx_bitstream_attach(bs, _buffer, _nbytes) do { \ bs->buffer = (BYTE*) (_buffer); \ bs->nbytes = (_nbytes); \ bs->byte_pos = 0; \ bs->bits_left = 8; } while (0) #define rfx_bitstream_get_bits(bs, _nbits, _r) do { \ int nbits = _nbits; \ int b; \ UINT16 n = 0; \ while (bs->byte_pos < bs->nbytes && nbits > 0) \ { \ b = nbits; \ if (b > bs->bits_left) \ b = bs->bits_left; \ if (n) \ n <<= b; \ n |= (bs->buffer[bs->byte_pos] >> (bs->bits_left - b)) & ((1 << b) - 1); \ bs->bits_left -= b; \ nbits -= b; \ if (bs->bits_left == 0) \ { \ bs->bits_left = 8; \ bs->byte_pos++; \ } \ } \ _r = n; } while (0) #define rfx_bitstream_put_bits(bs, _bits, _nbits) do { \ UINT16 bits = (_bits); \ int nbits = (_nbits); \ int b; \ while (bs->byte_pos < bs->nbytes && nbits > 0) \ { \ b = nbits; \ if (b > bs->bits_left) \ b = bs->bits_left; \ bs->buffer[bs->byte_pos] |= ((bits >> (nbits - b)) & ((1 << b) - 1)) << (bs->bits_left - b); \ bs->bits_left -= b; \ nbits -= b; \ if (bs->bits_left == 0) \ { \ bs->bits_left = 8; \ bs->byte_pos++; \ } \ } } while (0) #define rfx_bitstream_eos(_bs) ((_bs)->byte_pos >= (_bs)->nbytes) #define rfx_bitstream_left(_bs) ((_bs)->byte_pos >= (_bs)->nbytes ? 0 : ((_bs)->nbytes - (_bs)->byte_pos - 1) * 8 + (_bs)->bits_left) #define rfx_bitstream_get_processed_bytes(_bs) ((_bs)->bits_left < 8 ? (_bs)->byte_pos + 1 : (_bs)->byte_pos) #endif /* FREERDP_LIB_CODEC_RFX_BITSTREAM_H */