/* * Bytestream functions * copyright (c) 2006 Baptiste Coudurier * * This file is part of Libav. * * Libav 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. * * Libav 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 Libav; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #ifndef AVCODEC_BYTESTREAM_H #define AVCODEC_BYTESTREAM_H #include #include "libavutil/common.h" #include "libavutil/intreadwrite.h" typedef struct { const uint8_t *buffer, *buffer_end, *buffer_start; } GetByteContext; #define DEF_T(type, name, bytes, read, write) \ static av_always_inline type bytestream_get_ ## name(const uint8_t **b){\ (*b) += bytes;\ return read(*b - bytes);\ }\ static av_always_inline void bytestream_put_ ##name(uint8_t **b, const type value){\ write(*b, value);\ (*b) += bytes;\ }\ static av_always_inline type bytestream2_get_ ## name ## u(GetByteContext *g)\ {\ return bytestream_get_ ## name(&g->buffer);\ }\ static av_always_inline type bytestream2_get_ ## name(GetByteContext *g)\ {\ if (g->buffer_end - g->buffer < bytes)\ return 0;\ return bytestream2_get_ ## name ## u(g);\ }\ static av_always_inline type bytestream2_peek_ ## name(GetByteContext *g)\ {\ if (g->buffer_end - g->buffer < bytes)\ return 0;\ return read(g->buffer);\ } #define DEF(name, bytes, read, write) \ DEF_T(unsigned int, name, bytes, read, write) #define DEF64(name, bytes, read, write) \ DEF_T(uint64_t, name, bytes, read, write) DEF64(le64, 8, AV_RL64, AV_WL64) DEF (le32, 4, AV_RL32, AV_WL32) DEF (le24, 3, AV_RL24, AV_WL24) DEF (le16, 2, AV_RL16, AV_WL16) DEF64(be64, 8, AV_RB64, AV_WB64) DEF (be32, 4, AV_RB32, AV_WB32) DEF (be24, 3, AV_RB24, AV_WB24) DEF (be16, 2, AV_RB16, AV_WB16) DEF (byte, 1, AV_RB8 , AV_WB8 ) #undef DEF #undef DEF64 #undef DEF_T #if HAVE_BIGENDIAN # define bytestream2_get_ne16 bytestream2_get_be16 # define bytestream2_get_ne24 bytestream2_get_be24 # define bytestream2_get_ne32 bytestream2_get_be32 # define bytestream2_get_ne64 bytestream2_get_be64 # define bytestream2_get_ne16u bytestream2_get_be16u # define bytestream2_get_ne24u bytestream2_get_be24u # define bytestream2_get_ne32u bytestream2_get_be32u # define bytestream2_get_ne64u bytestream2_get_be64u # define bytestream2_put_ne16 bytestream2_put_be16 # define bytestream2_put_ne24 bytestream2_put_be24 # define bytestream2_put_ne32 bytestream2_put_be32 # define bytestream2_put_ne64 bytestream2_put_be64 # define bytestream2_peek_ne16 bytestream2_peek_be16 # define bytestream2_peek_ne24 bytestream2_peek_be24 # define bytestream2_peek_ne32 bytestream2_peek_be32 # define bytestream2_peek_ne64 bytestream2_peek_be64 #else # define bytestream2_get_ne16 bytestream2_get_le16 # define bytestream2_get_ne24 bytestream2_get_le24 # define bytestream2_get_ne32 bytestream2_get_le32 # define bytestream2_get_ne64 bytestream2_get_le64 # define bytestream2_get_ne16u bytestream2_get_le16u # define bytestream2_get_ne24u bytestream2_get_le24u # define bytestream2_get_ne32u bytestream2_get_le32u # define bytestream2_get_ne64u bytestream2_get_le64u # define bytestream2_put_ne16 bytestream2_put_le16 # define bytestream2_put_ne24 bytestream2_put_le24 # define bytestream2_put_ne32 bytestream2_put_le32 # define bytestream2_put_ne64 bytestream2_put_le64 # define bytestream2_peek_ne16 bytestream2_peek_le16 # define bytestream2_peek_ne24 bytestream2_peek_le24 # define bytestream2_peek_ne32 bytestream2_peek_le32 # define bytestream2_peek_ne64 bytestream2_peek_le64 #endif static av_always_inline void bytestream2_init(GetByteContext *g, const uint8_t *buf, int buf_size) { g->buffer = buf; g->buffer_start = buf; g->buffer_end = buf + buf_size; } static av_always_inline unsigned int bytestream2_get_bytes_left(GetByteContext *g) { return g->buffer_end - g->buffer; } static av_always_inline void bytestream2_skip(GetByteContext *g, unsigned int size) { g->buffer += FFMIN(g->buffer_end - g->buffer, size); } static av_always_inline int bytestream2_tell(GetByteContext *g) { return (int)(g->buffer - g->buffer_start); } static av_always_inline int bytestream2_seek(GetByteContext *g, int offset, int whence) { switch (whence) { case SEEK_CUR: offset = av_clip(offset, -(g->buffer - g->buffer_start), g->buffer_end - g->buffer); g->buffer += offset; break; case SEEK_END: offset = av_clip(offset, -(g->buffer_end - g->buffer_start), 0); g->buffer = g->buffer_end + offset; break; case SEEK_SET: offset = av_clip(offset, 0, g->buffer_end - g->buffer_start); g->buffer = g->buffer_start + offset; break; default: return AVERROR(EINVAL); } return bytestream2_tell(g); } static av_always_inline unsigned int bytestream2_get_buffer(GetByteContext *g, uint8_t *dst, unsigned int size) { int size2 = FFMIN(g->buffer_end - g->buffer, size); memcpy(dst, g->buffer, size2); g->buffer += size2; return size2; } static av_always_inline unsigned int bytestream_get_buffer(const uint8_t **b, uint8_t *dst, unsigned int size) { memcpy(dst, *b, size); (*b) += size; return size; } static av_always_inline void bytestream_put_buffer(uint8_t **b, const uint8_t *src, unsigned int size) { memcpy(*b, src, size); (*b) += size; } #endif /* AVCODEC_BYTESTREAM_H */