/* | |
* This file is part of FFmpeg. | |
* | |
* FFmpeg 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. | |
* | |
* FFmpeg 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 FFmpeg; if not, write to the Free Software | |
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
*/ | |
extern const AVClass ff_avio_class; | |
typedef struct FFIOContext { | |
AVIOContext pub; | |
/** | |
* A callback that is used instead of short_seek_threshold. | |
*/ | |
int (*short_seek_get)(void *opaque); | |
/** | |
* Threshold to favor readahead over seek. | |
*/ | |
int short_seek_threshold; | |
enum AVIODataMarkerType current_type; | |
int64_t last_time; | |
/** | |
* max filesize, used to limit allocations | |
*/ | |
int64_t maxsize; | |
/** | |
* Bytes read statistic | |
*/ | |
int64_t bytes_read; | |
/** | |
* Bytes written statistic | |
*/ | |
int64_t bytes_written; | |
/** | |
* seek statistic | |
*/ | |
int seek_count; | |
/** | |
* writeout statistic | |
*/ | |
int writeout_count; | |
/** | |
* Original buffer size | |
* used after probing to ensure seekback and to reset the buffer size | |
*/ | |
int orig_buffer_size; | |
/** | |
* Written output size | |
* is updated each time a successful writeout ends up further position-wise | |
*/ | |
int64_t written_output_size; | |
} FFIOContext; | |
static av_always_inline FFIOContext *ffiocontext(AVIOContext *ctx) | |
{ | |
return (FFIOContext*)ctx; | |
} | |
void ffio_init_context(FFIOContext *s, | |
unsigned char *buffer, | |
int buffer_size, | |
int write_flag, | |
void *opaque, | |
int (*read_packet)(void *opaque, uint8_t *buf, int buf_size), | |
int (*write_packet)(void *opaque, uint8_t *buf, int buf_size), | |
int64_t (*seek)(void *opaque, int64_t offset, int whence)); | |
/** | |
* Wrap a buffer in an AVIOContext for reading. | |
*/ | |
void ffio_init_read_context(FFIOContext *s, const uint8_t *buffer, int buffer_size); | |
/** | |
* Wrap a buffer in an AVIOContext for writing. | |
*/ | |
void ffio_init_write_context(FFIOContext *s, uint8_t *buffer, int buffer_size); | |
/** | |
* Read size bytes from AVIOContext, returning a pointer. | |
* Note that the data pointed at by the returned pointer is only | |
* valid until the next call that references the same IO context. | |
* @param s IO context | |
* @param buf pointer to buffer into which to assemble the requested | |
* data if it is not available in contiguous addresses in the | |
* underlying buffer | |
* @param size number of bytes requested | |
* @param data address at which to store pointer: this will be a | |
* a direct pointer into the underlying buffer if the requested | |
* number of bytes are available at contiguous addresses, otherwise | |
* will be a copy of buf | |
* @return number of bytes read or AVERROR | |
*/ | |
int ffio_read_indirect(AVIOContext *s, unsigned char *buf, int size, const unsigned char **data); | |
void ffio_fill(AVIOContext *s, int b, int64_t count); | |
static av_always_inline void ffio_wfourcc(AVIOContext *pb, const uint8_t *s) | |
{ | |
avio_wl32(pb, MKTAG(s[0], s[1], s[2], s[3])); | |
} | |
/** | |
* Rewind the AVIOContext using the specified buffer containing the first buf_size bytes of the file. | |
* Used after probing to avoid seeking. | |
* Joins buf and s->buffer, taking any overlap into consideration. | |
* @note s->buffer must overlap with buf or they can't be joined and the function fails | |
* | |
* @param s The read-only AVIOContext to rewind | |
* @param buf The probe buffer containing the first buf_size bytes of the file | |
* @param buf_size The size of buf | |
* @return >= 0 in case of success, a negative value corresponding to an | |
* AVERROR code in case of failure | |
*/ | |
int ffio_rewind_with_probe_data(AVIOContext *s, unsigned char **buf, int buf_size); | |
uint64_t ffio_read_varlen(AVIOContext *bc); | |
/** | |
* Read size bytes from AVIOContext into buf. | |
* Check that exactly size bytes have been read. | |
* @return number of bytes read or AVERROR | |
*/ | |
int ffio_read_size(AVIOContext *s, unsigned char *buf, int size); | |
/** | |
* Reallocate a given buffer for AVIOContext. | |
* | |
* @param s the AVIOContext to realloc. | |
* @param buf_size required new buffer size. | |
* @return 0 on success, a negative AVERROR on failure. | |
*/ | |
int ffio_realloc_buf(AVIOContext *s, int buf_size); | |
/** | |
* Ensures that the requested seekback buffer size will be available | |
* | |
* Will ensure that when reading sequentially up to buf_size, seeking | |
* within the current pos and pos+buf_size is possible. | |
* Once the stream position moves outside this window or another | |
* ffio_ensure_seekback call requests a buffer outside this window this | |
* guarantee is lost. | |
*/ | |
int ffio_ensure_seekback(AVIOContext *s, int64_t buf_size); | |
int ffio_limit(AVIOContext *s, int size); | |
void ffio_init_checksum(AVIOContext *s, | |
unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len), | |
unsigned long checksum); | |
unsigned long ffio_get_checksum(AVIOContext *s); | |
unsigned long ff_crc04C11DB7_update(unsigned long checksum, const uint8_t *buf, | |
unsigned int len); | |
unsigned long ff_crcEDB88320_update(unsigned long checksum, const uint8_t *buf, | |
unsigned int len); | |
unsigned long ff_crcA001_update(unsigned long checksum, const uint8_t *buf, | |
unsigned int len); | |
/** | |
* Open a write only packetized memory stream with a maximum packet | |
* size of 'max_packet_size'. The stream is stored in a memory buffer | |
* with a big-endian 4 byte header giving the packet size in bytes. | |
* | |
* @param s new IO context | |
* @param max_packet_size maximum packet size (must be > 0) | |
* @return zero if no error. | |
*/ | |
int ffio_open_dyn_packet_buf(AVIOContext **s, int max_packet_size); | |
/** | |
* Create and initialize a AVIOContext for accessing the | |
* resource referenced by the URLContext h. | |
* @note When the URLContext h has been opened in read+write mode, the | |
* AVIOContext can be used only for writing. | |
* | |
* @param s Used to return the pointer to the created AVIOContext. | |
* In case of failure the pointed to value is set to NULL. | |
* @return >= 0 in case of success, a negative value corresponding to an | |
* AVERROR code in case of failure | |
*/ | |
int ffio_fdopen(AVIOContext **s, URLContext *h); | |
/** | |
* Return the URLContext associated with the AVIOContext | |
* | |
* @param s IO context | |
* @return pointer to URLContext or NULL. | |
*/ | |
URLContext *ffio_geturlcontext(AVIOContext *s); | |
/** | |
* Read url related dictionary options from the AVIOContext and write to the given dictionary | |
*/ | |
int ffio_copy_url_options(AVIOContext* pb, AVDictionary** avio_opts); | |
/** | |
* Open a write-only fake memory stream. The written data is not stored | |
* anywhere - this is only used for measuring the amount of data | |
* written. | |
* | |
* @param s new IO context | |
* @return zero if no error. | |
*/ | |
int ffio_open_null_buf(AVIOContext **s); | |
int ffio_open_whitelist(AVIOContext **s, const char *url, int flags, | |
const AVIOInterruptCB *int_cb, AVDictionary **options, | |
const char *whitelist, const char *blacklist); | |
/** | |
* Close a null buffer. | |
* | |
* @param s an IO context opened by ffio_open_null_buf | |
* @return the number of bytes written to the null buffer | |
*/ | |
int ffio_close_null_buf(AVIOContext *s); | |
/** | |
* Reset a dynamic buffer. | |
* | |
* Resets everything, but keeps the allocated buffer for later use. | |
*/ | |
void ffio_reset_dyn_buf(AVIOContext *s); | |
/** | |
* Free a dynamic buffer. | |
* | |
* @param s a pointer to an IO context opened by avio_open_dyn_buf() | |
*/ | |
void ffio_free_dyn_buf(AVIOContext **s); | |
struct AVBPrint; | |
/** | |
* Read a whole line of text from AVIOContext to an AVBPrint buffer overwriting | |
* its contents. Stop reading after reaching a \\r, a \\n, a \\r\\n, a \\0 or | |
* EOF. The line ending characters are NOT included in the buffer, but they | |
* are skipped on the input. | |
* | |
* @param s the read-only AVIOContext | |
* @param bp the AVBPrint buffer | |
* @return the length of the read line not including the line endings, | |
* negative on error, or if the buffer becomes truncated. | |
*/ | |
int64_t ff_read_line_to_bprint_overwrite(AVIOContext *s, struct AVBPrint *bp); | |
/** | |
* Read a whole null-terminated string of text from AVIOContext to an AVBPrint | |
* buffer overwriting its contents. Stop reading after reaching the maximum | |
* length, a \\0 or EOF. | |
* | |
* @param s the read-only AVIOContext | |
* @param bp the AVBPrint buffer | |
* @param max_len the maximum length to be read from the AVIOContext. | |
* Negative (< 0) values signal that there is no known maximum | |
* length applicable. A maximum length of zero means that the | |
* AVIOContext is not touched, and the function returns | |
* with a read length of zero. In all cases the AVBprint | |
* is cleared. | |
* @return the length of the read string not including the terminating null, | |
* negative on error, or if the buffer becomes truncated. | |
*/ | |
int64_t ff_read_string_to_bprint_overwrite(AVIOContext *s, struct AVBPrint *bp, | |
int64_t max_len); | |