blob: fdb323c8f1e5e3b9221ab52215fd0128bc34e5b6
| 1 | /* |
| 2 | * This file is part of FFmpeg. |
| 3 | * |
| 4 | * FFmpeg is free software; you can redistribute it and/or |
| 5 | * modify it under the terms of the GNU Lesser General Public |
| 6 | * License as published by the Free Software Foundation; either |
| 7 | * version 2.1 of the License, or (at your option) any later version. |
| 8 | * |
| 9 | * FFmpeg is distributed in the hope that it will be useful, |
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 12 | * Lesser General Public License for more details. |
| 13 | * |
| 14 | * You should have received a copy of the GNU Lesser General Public |
| 15 | * License along with FFmpeg; if not, write to the Free Software |
| 16 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 17 | */ |
| 18 | |
| 19 | #ifndef AVFORMAT_AVIO_INTERNAL_H |
| 20 | #define AVFORMAT_AVIO_INTERNAL_H |
| 21 | |
| 22 | #include "avio.h" |
| 23 | #include "url.h" |
| 24 | |
| 25 | #include "libavutil/log.h" |
| 26 | |
| 27 | extern const AVClass ff_avio_class; |
| 28 | |
| 29 | int ffio_init_context(AVIOContext *s, |
| 30 | unsigned char *buffer, |
| 31 | int buffer_size, |
| 32 | int write_flag, |
| 33 | void *opaque, |
| 34 | int (*read_packet)(void *opaque, uint8_t *buf, int buf_size), |
| 35 | int (*write_packet)(void *opaque, uint8_t *buf, int buf_size), |
| 36 | int64_t (*seek)(void *opaque, int64_t offset, int whence)); |
| 37 | |
| 38 | |
| 39 | /** |
| 40 | * Read size bytes from AVIOContext, returning a pointer. |
| 41 | * Note that the data pointed at by the returned pointer is only |
| 42 | * valid until the next call that references the same IO context. |
| 43 | * @param s IO context |
| 44 | * @param buf pointer to buffer into which to assemble the requested |
| 45 | * data if it is not available in contiguous addresses in the |
| 46 | * underlying buffer |
| 47 | * @param size number of bytes requested |
| 48 | * @param data address at which to store pointer: this will be a |
| 49 | * a direct pointer into the underlying buffer if the requested |
| 50 | * number of bytes are available at contiguous addresses, otherwise |
| 51 | * will be a copy of buf |
| 52 | * @return number of bytes read or AVERROR |
| 53 | */ |
| 54 | int ffio_read_indirect(AVIOContext *s, unsigned char *buf, int size, const unsigned char **data); |
| 55 | |
| 56 | /** |
| 57 | * Read size bytes from AVIOContext into buf. |
| 58 | * This reads at most 1 packet. If that is not enough fewer bytes will be |
| 59 | * returned. |
| 60 | * @return number of bytes read or AVERROR |
| 61 | */ |
| 62 | int ffio_read_partial(AVIOContext *s, unsigned char *buf, int size); |
| 63 | |
| 64 | void ffio_fill(AVIOContext *s, int b, int count); |
| 65 | |
| 66 | static av_always_inline void ffio_wfourcc(AVIOContext *pb, const uint8_t *s) |
| 67 | { |
| 68 | avio_wl32(pb, MKTAG(s[0], s[1], s[2], s[3])); |
| 69 | } |
| 70 | |
| 71 | /** |
| 72 | * Rewind the AVIOContext using the specified buffer containing the first buf_size bytes of the file. |
| 73 | * Used after probing to avoid seeking. |
| 74 | * Joins buf and s->buffer, taking any overlap into consideration. |
| 75 | * @note s->buffer must overlap with buf or they can't be joined and the function fails |
| 76 | * |
| 77 | * @param s The read-only AVIOContext to rewind |
| 78 | * @param buf The probe buffer containing the first buf_size bytes of the file |
| 79 | * @param buf_size The size of buf |
| 80 | * @return >= 0 in case of success, a negative value corresponding to an |
| 81 | * AVERROR code in case of failure |
| 82 | */ |
| 83 | int ffio_rewind_with_probe_data(AVIOContext *s, unsigned char **buf, int buf_size); |
| 84 | |
| 85 | uint64_t ffio_read_varlen(AVIOContext *bc); |
| 86 | |
| 87 | /** |
| 88 | * Read size bytes from AVIOContext into buf. |
| 89 | * Check that exactly size bytes have been read. |
| 90 | * @return number of bytes read or AVERROR |
| 91 | */ |
| 92 | int ffio_read_size(AVIOContext *s, unsigned char *buf, int size); |
| 93 | |
| 94 | /** @warning must be called before any I/O */ |
| 95 | int ffio_set_buf_size(AVIOContext *s, int buf_size); |
| 96 | |
| 97 | /** |
| 98 | * Ensures that the requested seekback buffer size will be available |
| 99 | * |
| 100 | * Will ensure that when reading sequentially up to buf_size, seeking |
| 101 | * within the current pos and pos+buf_size is possible. |
| 102 | * Once the stream position moves outside this window this guarantee is lost. |
| 103 | */ |
| 104 | int ffio_ensure_seekback(AVIOContext *s, int64_t buf_size); |
| 105 | |
| 106 | int ffio_limit(AVIOContext *s, int size); |
| 107 | |
| 108 | void ffio_init_checksum(AVIOContext *s, |
| 109 | unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len), |
| 110 | unsigned long checksum); |
| 111 | unsigned long ffio_get_checksum(AVIOContext *s); |
| 112 | unsigned long ff_crc04C11DB7_update(unsigned long checksum, const uint8_t *buf, |
| 113 | unsigned int len); |
| 114 | unsigned long ff_crcEDB88320_update(unsigned long checksum, const uint8_t *buf, |
| 115 | unsigned int len); |
| 116 | unsigned long ff_crcA001_update(unsigned long checksum, const uint8_t *buf, |
| 117 | unsigned int len); |
| 118 | |
| 119 | /** |
| 120 | * Open a write only packetized memory stream with a maximum packet |
| 121 | * size of 'max_packet_size'. The stream is stored in a memory buffer |
| 122 | * with a big-endian 4 byte header giving the packet size in bytes. |
| 123 | * |
| 124 | * @param s new IO context |
| 125 | * @param max_packet_size maximum packet size (must be > 0) |
| 126 | * @return zero if no error. |
| 127 | */ |
| 128 | int ffio_open_dyn_packet_buf(AVIOContext **s, int max_packet_size); |
| 129 | |
| 130 | /** |
| 131 | * Create and initialize a AVIOContext for accessing the |
| 132 | * resource referenced by the URLContext h. |
| 133 | * @note When the URLContext h has been opened in read+write mode, the |
| 134 | * AVIOContext can be used only for writing. |
| 135 | * |
| 136 | * @param s Used to return the pointer to the created AVIOContext. |
| 137 | * In case of failure the pointed to value is set to NULL. |
| 138 | * @return >= 0 in case of success, a negative value corresponding to an |
| 139 | * AVERROR code in case of failure |
| 140 | */ |
| 141 | int ffio_fdopen(AVIOContext **s, URLContext *h); |
| 142 | |
| 143 | /** |
| 144 | * Open a write-only fake memory stream. The written data is not stored |
| 145 | * anywhere - this is only used for measuring the amount of data |
| 146 | * written. |
| 147 | * |
| 148 | * @param s new IO context |
| 149 | * @return zero if no error. |
| 150 | */ |
| 151 | int ffio_open_null_buf(AVIOContext **s); |
| 152 | |
| 153 | int ffio_open_whitelist(AVIOContext **s, const char *url, int flags, |
| 154 | const AVIOInterruptCB *int_cb, AVDictionary **options, |
| 155 | const char *whitelist, const char *blacklist); |
| 156 | |
| 157 | /** |
| 158 | * Close a null buffer. |
| 159 | * |
| 160 | * @param s an IO context opened by ffio_open_null_buf |
| 161 | * @return the number of bytes written to the null buffer |
| 162 | */ |
| 163 | int ffio_close_null_buf(AVIOContext *s); |
| 164 | |
| 165 | /** |
| 166 | * Free a dynamic buffer. |
| 167 | * |
| 168 | * @param s a pointer to an IO context opened by avio_open_dyn_buf() |
| 169 | */ |
| 170 | void ffio_free_dyn_buf(AVIOContext **s); |
| 171 | |
| 172 | #endif /* AVFORMAT_AVIO_INTERNAL_H */ |
| 173 |