summaryrefslogtreecommitdiff
path: root/libavcodec/bytestream.h
blob: 0f89558e3d29465058a94fdb5d92092c8a69f85d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
/*
 * Bytestream functions
 * copyright (c) 2006 Baptiste Coudurier <baptiste.coudurier@free.fr>
 * Copyright (c) 2012 Aneesh Dogra (lionaneesh) <lionaneesh@gmail.com>
 *
 * 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 <stdint.h>
#include <string.h>

#include "libavutil/common.h"
#include "libavutil/intreadwrite.h"

typedef struct GetByteContext {
    const uint8_t *buffer, *buffer_end, *buffer_start;
} GetByteContext;

typedef struct PutByteContext {
    uint8_t *buffer, *buffer_end, *buffer_start;
    int eof;
} PutByteContext;

#define DEF(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 void bytestream2_put_ ## name ## u(PutByteContext *p,  \
                                                           const type value)   \
{                                                                              \
    bytestream_put_ ## name(&p->buffer, value);                                \
}                                                                              \
static av_always_inline void bytestream2_put_ ## name(PutByteContext *p,       \
                                                      const type value)        \
{                                                                              \
    if (!p->eof && (p->buffer_end - p->buffer >= bytes)) {                     \
        write(p->buffer, value);                                               \
        p->buffer += bytes;                                                    \
    } else                                                                     \
        p->eof = 1;                                                            \
}                                                                              \
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);                                                    \
}

DEF(uint64_t,     le64, 8, AV_RL64, AV_WL64)
DEF(unsigned int, le32, 4, AV_RL32, AV_WL32)
DEF(unsigned int, le24, 3, AV_RL24, AV_WL24)
DEF(unsigned int, le16, 2, AV_RL16, AV_WL16)
DEF(uint64_t,     be64, 8, AV_RB64, AV_WB64)
DEF(unsigned int, be32, 4, AV_RB32, AV_WB32)
DEF(unsigned int, be24, 3, AV_RB24, AV_WB24)
DEF(unsigned int, be16, 2, AV_RB16, AV_WB16)
DEF(unsigned int, byte, 1, AV_RB8 , AV_WB8)

#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 void bytestream2_init_writer(PutByteContext *p,
                                                     uint8_t *buf,
                                                     int buf_size)
{
    p->buffer       = buf;
    p->buffer_start = buf;
    p->buffer_end   = buf + buf_size;
    p->eof          = 0;
}

static av_always_inline unsigned int bytestream2_get_bytes_left(GetByteContext *g)
{
    return g->buffer_end - g->buffer;
}

static av_always_inline unsigned int bytestream2_get_bytes_left_p(PutByteContext *p)
{
    return p->buffer_end - p->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 void bytestream2_skipu(GetByteContext *g,
                                               unsigned int size)
{
    g->buffer += size;
}

static av_always_inline void bytestream2_skip_p(PutByteContext *p,
                                                unsigned int size)
{
    int size2;
    if (p->eof)
        return;
    size2 = FFMIN(p->buffer_end - p->buffer, size);
    if (size2 != size)
        p->eof = 1;
    p->buffer += size2;
}

static av_always_inline int bytestream2_tell(GetByteContext *g)
{
    return (int)(g->buffer - g->buffer_start);
}

static av_always_inline int bytestream2_tell_p(PutByteContext *p)
{
    return (int)(p->buffer - p->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 int bytestream2_seek_p(PutByteContext *p,
                                               int offset,
                                               int whence)
{
    p->eof = 0;
    switch (whence) {
    case SEEK_CUR:
        if (p->buffer_end - p->buffer < offset)
            p->eof = 1;
        offset     = av_clip(offset, -(p->buffer - p->buffer_start),
                             p->buffer_end - p->buffer);
        p->buffer += offset;
        break;
    case SEEK_END:
        if (offset > 0)
            p->eof = 1;
        offset    = av_clip(offset, -(p->buffer_end - p->buffer_start), 0);
        p->buffer = p->buffer_end + offset;
        break;
    case SEEK_SET:
        if (p->buffer_end - p->buffer_start < offset)
            p->eof = 1;
        offset    = av_clip(offset, 0, p->buffer_end - p->buffer_start);
        p->buffer = p->buffer_start + offset;
        break;
    default:
        return AVERROR(EINVAL);
    }
    return bytestream2_tell_p(p);
}

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 bytestream2_get_bufferu(GetByteContext *g,
                                                             uint8_t *dst,
                                                             unsigned int size)
{
    memcpy(dst, g->buffer, size);
    g->buffer += size;
    return size;
}

static av_always_inline unsigned int bytestream2_put_buffer(PutByteContext *p,
                                                            const uint8_t *src,
                                                            unsigned int size)
{
    int size2;
    if (p->eof)
        return 0;
    size2 = FFMIN(p->buffer_end - p->buffer, size);
    if (size2 != size)
        p->eof = 1;
    memcpy(p->buffer, src, size2);
    p->buffer += size2;
    return size2;
}

static av_always_inline unsigned int bytestream2_put_bufferu(PutByteContext *p,
                                                             const uint8_t *src,
                                                             unsigned int size)
{
    memcpy(p->buffer, src, size);
    p->buffer += size;
    return size;
}

static av_always_inline void bytestream2_set_buffer(PutByteContext *p,
                                                    const uint8_t c,
                                                    unsigned int size)
{
    int size2;
    if (p->eof)
        return;
    size2 = FFMIN(p->buffer_end - p->buffer, size);
    if (size2 != size)
        p->eof = 1;
    memset(p->buffer, c, size2);
    p->buffer += size2;
}

static av_always_inline void bytestream2_set_bufferu(PutByteContext *p,
                                                     const uint8_t c,
                                                     unsigned int size)
{
    memset(p->buffer, c, size);
    p->buffer += size;
}

static av_always_inline unsigned int bytestream2_get_eof(PutByteContext *p)
{
    return p->eof;
}

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 */