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00022 #ifndef AVCODEC_BYTESTREAM_H
00023 #define AVCODEC_BYTESTREAM_H
00024
00025 #include <string.h>
00026 #include "libavutil/common.h"
00027 #include "libavutil/intreadwrite.h"
00028
00029 typedef struct {
00030 const uint8_t *buffer, *buffer_end, *buffer_start;
00031 } GetByteContext;
00032
00033 #define DEF_T(type, name, bytes, read, write) \
00034 static av_always_inline type bytestream_get_ ## name(const uint8_t **b){\
00035 (*b) += bytes;\
00036 return read(*b - bytes);\
00037 }\
00038 static av_always_inline void bytestream_put_ ##name(uint8_t **b, const type value){\
00039 write(*b, value);\
00040 (*b) += bytes;\
00041 }\
00042 static av_always_inline type bytestream2_get_ ## name ## u(GetByteContext *g)\
00043 {\
00044 return bytestream_get_ ## name(&g->buffer);\
00045 }\
00046 static av_always_inline type bytestream2_get_ ## name(GetByteContext *g)\
00047 {\
00048 if (g->buffer_end - g->buffer < bytes)\
00049 return 0;\
00050 return bytestream2_get_ ## name ## u(g);\
00051 }\
00052 static av_always_inline type bytestream2_peek_ ## name(GetByteContext *g)\
00053 {\
00054 if (g->buffer_end - g->buffer < bytes)\
00055 return 0;\
00056 return read(g->buffer);\
00057 }
00058
00059 #define DEF(name, bytes, read, write) \
00060 DEF_T(unsigned int, name, bytes, read, write)
00061 #define DEF64(name, bytes, read, write) \
00062 DEF_T(uint64_t, name, bytes, read, write)
00063
00064 DEF64(le64, 8, AV_RL64, AV_WL64)
00065 DEF (le32, 4, AV_RL32, AV_WL32)
00066 DEF (le24, 3, AV_RL24, AV_WL24)
00067 DEF (le16, 2, AV_RL16, AV_WL16)
00068 DEF64(be64, 8, AV_RB64, AV_WB64)
00069 DEF (be32, 4, AV_RB32, AV_WB32)
00070 DEF (be24, 3, AV_RB24, AV_WB24)
00071 DEF (be16, 2, AV_RB16, AV_WB16)
00072 DEF (byte, 1, AV_RB8 , AV_WB8 )
00073
00074 #undef DEF
00075 #undef DEF64
00076 #undef DEF_T
00077
00078 #if HAVE_BIGENDIAN
00079 # define bytestream2_get_ne16 bytestream2_get_be16
00080 # define bytestream2_get_ne24 bytestream2_get_be24
00081 # define bytestream2_get_ne32 bytestream2_get_be32
00082 # define bytestream2_get_ne64 bytestream2_get_be64
00083 # define bytestream2_get_ne16u bytestream2_get_be16u
00084 # define bytestream2_get_ne24u bytestream2_get_be24u
00085 # define bytestream2_get_ne32u bytestream2_get_be32u
00086 # define bytestream2_get_ne64u bytestream2_get_be64u
00087 # define bytestream2_put_ne16 bytestream2_put_be16
00088 # define bytestream2_put_ne24 bytestream2_put_be24
00089 # define bytestream2_put_ne32 bytestream2_put_be32
00090 # define bytestream2_put_ne64 bytestream2_put_be64
00091 # define bytestream2_peek_ne16 bytestream2_peek_be16
00092 # define bytestream2_peek_ne24 bytestream2_peek_be24
00093 # define bytestream2_peek_ne32 bytestream2_peek_be32
00094 # define bytestream2_peek_ne64 bytestream2_peek_be64
00095 #else
00096 # define bytestream2_get_ne16 bytestream2_get_le16
00097 # define bytestream2_get_ne24 bytestream2_get_le24
00098 # define bytestream2_get_ne32 bytestream2_get_le32
00099 # define bytestream2_get_ne64 bytestream2_get_le64
00100 # define bytestream2_get_ne16u bytestream2_get_le16u
00101 # define bytestream2_get_ne24u bytestream2_get_le24u
00102 # define bytestream2_get_ne32u bytestream2_get_le32u
00103 # define bytestream2_get_ne64u bytestream2_get_le64u
00104 # define bytestream2_put_ne16 bytestream2_put_le16
00105 # define bytestream2_put_ne24 bytestream2_put_le24
00106 # define bytestream2_put_ne32 bytestream2_put_le32
00107 # define bytestream2_put_ne64 bytestream2_put_le64
00108 # define bytestream2_peek_ne16 bytestream2_peek_le16
00109 # define bytestream2_peek_ne24 bytestream2_peek_le24
00110 # define bytestream2_peek_ne32 bytestream2_peek_le32
00111 # define bytestream2_peek_ne64 bytestream2_peek_le64
00112 #endif
00113
00114 static av_always_inline void bytestream2_init(GetByteContext *g,
00115 const uint8_t *buf, int buf_size)
00116 {
00117 g->buffer = buf;
00118 g->buffer_start = buf;
00119 g->buffer_end = buf + buf_size;
00120 }
00121
00122 static av_always_inline unsigned int bytestream2_get_bytes_left(GetByteContext *g)
00123 {
00124 return g->buffer_end - g->buffer;
00125 }
00126
00127 static av_always_inline void bytestream2_skip(GetByteContext *g,
00128 unsigned int size)
00129 {
00130 g->buffer += FFMIN(g->buffer_end - g->buffer, size);
00131 }
00132
00133 static av_always_inline int bytestream2_tell(GetByteContext *g)
00134 {
00135 return (int)(g->buffer - g->buffer_start);
00136 }
00137
00138 static av_always_inline int bytestream2_seek(GetByteContext *g, int offset,
00139 int whence)
00140 {
00141 switch (whence) {
00142 case SEEK_CUR:
00143 offset = av_clip(offset, -(g->buffer - g->buffer_start),
00144 g->buffer_end - g->buffer);
00145 g->buffer += offset;
00146 break;
00147 case SEEK_END:
00148 offset = av_clip(offset, -(g->buffer_end - g->buffer_start), 0);
00149 g->buffer = g->buffer_end + offset;
00150 break;
00151 case SEEK_SET:
00152 offset = av_clip(offset, 0, g->buffer_end - g->buffer_start);
00153 g->buffer = g->buffer_start + offset;
00154 break;
00155 default:
00156 return AVERROR(EINVAL);
00157 }
00158 return bytestream2_tell(g);
00159 }
00160
00161 static av_always_inline unsigned int bytestream2_get_buffer(GetByteContext *g,
00162 uint8_t *dst,
00163 unsigned int size)
00164 {
00165 int size2 = FFMIN(g->buffer_end - g->buffer, size);
00166 memcpy(dst, g->buffer, size2);
00167 g->buffer += size2;
00168 return size2;
00169 }
00170
00171 static av_always_inline unsigned int bytestream_get_buffer(const uint8_t **b, uint8_t *dst, unsigned int size)
00172 {
00173 memcpy(dst, *b, size);
00174 (*b) += size;
00175 return size;
00176 }
00177
00178 static av_always_inline void bytestream_put_buffer(uint8_t **b, const uint8_t *src, unsigned int size)
00179 {
00180 memcpy(*b, src, size);
00181 (*b) += size;
00182 }
00183
00184 #endif