1/* 2 * 3 * This file is part of Libav. 4 * 5 * Libav is free software; you can redistribute it and/or 6 * modify it under the terms of the GNU Lesser General Public 7 * License as published by the Free Software Foundation; either 8 * version 2.1 of the License, or (at your option) any later version. 9 * 10 * Libav is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 * Lesser General Public License for more details. 14 * 15 * You should have received a copy of the GNU Lesser General Public 16 * License along with Libav; if not, write to the Free Software 17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 18 */ 19 20#ifndef AVFORMAT_AVIO_INTERNAL_H 21#define AVFORMAT_AVIO_INTERNAL_H 22 23#include "avio.h" 24#include "url.h" 25 26#include "libavutil/log.h" 27 28extern const AVClass ffio_url_class; 29 30int ffio_init_context(AVIOContext *s, 31 unsigned char *buffer, 32 int buffer_size, 33 int write_flag, 34 void *opaque, 35 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size), 36 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size), 37 int64_t (*seek)(void *opaque, int64_t offset, int whence)); 38 39 40/** 41 * Read size bytes from AVIOContext into buf. 42 * This reads at most 1 packet. If that is not enough fewer bytes will be 43 * returned. 44 * @return number of bytes read or AVERROR 45 */ 46int ffio_read_partial(AVIOContext *s, unsigned char *buf, int size); 47 48void ffio_fill(AVIOContext *s, int b, int count); 49 50static av_always_inline void ffio_wfourcc(AVIOContext *pb, const uint8_t *s) 51{ 52 avio_wl32(pb, MKTAG(s[0], s[1], s[2], s[3])); 53} 54 55/** 56 * Rewind the AVIOContext using the specified buffer containing the first buf_size bytes of the file. 57 * Used after probing to avoid seeking. 58 * Joins buf and s->buffer, taking any overlap into consideration. 59 * @note s->buffer must overlap with buf or they can't be joined and the function fails 60 * 61 * @param s The read-only AVIOContext to rewind 62 * @param buf The probe buffer containing the first buf_size bytes of the file 63 * @param buf_size The size of buf 64 * @return 0 in case of success, a negative value corresponding to an 65 * AVERROR code in case of failure 66 */ 67int ffio_rewind_with_probe_data(AVIOContext *s, unsigned char *buf, int buf_size); 68 69uint64_t ffio_read_varlen(AVIOContext *bc); 70 71/** @warning must be called before any I/O */ 72int ffio_set_buf_size(AVIOContext *s, int buf_size); 73 74void ffio_init_checksum(AVIOContext *s, 75 unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len), 76 unsigned long checksum); 77unsigned long ffio_get_checksum(AVIOContext *s); 78unsigned long ff_crc04C11DB7_update(unsigned long checksum, const uint8_t *buf, 79 unsigned int len); 80 81/** 82 * Open a write only packetized memory stream with a maximum packet 83 * size of 'max_packet_size'. The stream is stored in a memory buffer 84 * with a big endian 4 byte header giving the packet size in bytes. 85 * 86 * @param s new IO context 87 * @param max_packet_size maximum packet size (must be > 0) 88 * @return zero if no error. 89 */ 90int ffio_open_dyn_packet_buf(AVIOContext **s, int max_packet_size); 91 92/** 93 * Create and initialize a AVIOContext for accessing the 94 * resource referenced by the URLContext h. 95 * @note When the URLContext h has been opened in read+write mode, the 96 * AVIOContext can be used only for writing. 97 * 98 * @param s Used to return the pointer to the created AVIOContext. 99 * In case of failure the pointed to value is set to NULL. 100 * @return 0 in case of success, a negative value corresponding to an 101 * AVERROR code in case of failure 102 */ 103int ffio_fdopen(AVIOContext **s, URLContext *h); 104 105#endif /* AVFORMAT_AVIO_INTERNAL_H */ 106