/src/ffmpeg/libavformat/avio_internal.h

Source
/*
 * 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
 */

#ifndef AVFORMAT_AVIO_INTERNAL_H
#define AVFORMAT_AVIO_INTERNAL_H

#include "avio.h"

#include "libavutil/log.h"

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, const 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 a unsigned integer coded as a variable number of up to eight
 * little-endian bytes, where the MSB in a byte signals another byte
 * must be read.
 * All coded bytes are read, but values > UINT_MAX are truncated.
 */
unsigned int ffio_read_leb(AVIOContext *s);

void ffio_write_leb(AVIOContext *s, unsigned val);

/**
 * Write a sequence of text lines, converting line endings.
 * All input line endings (LF, CRLF, CR) are converted to the configured line ending.
 * @param s The AVIOContext to write to
 * @param buf The buffer to write
 * @param size The size of the buffer, or <0 to use the full length of a null-terminated string
 * @param ending The line ending sequence to convert to, or NULL for \n
 */
void ffio_write_lines(AVIOContext *s, const unsigned char *buf, int size,
                      const unsigned char *ending);

/**
 * 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);

/**
 * Return the URLContext associated with the AVIOContext
 *
 * @param s IO context
 * @return pointer to URLContext or NULL.
 */
struct URLContext *ffio_geturlcontext(AVIOContext *s);

/**
 * 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, struct URLContext *h);


/**
 * 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, negative on error
 */
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);

#endif /* AVFORMAT_AVIO_INTERNAL_H */

Coverage Report

Created: 2026-01-25 07:18

Line	Count	Source
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
24		#include "libavutil/log.h"
25
26		extern const AVClass ff_avio_class;
27
28		typedef struct FFIOContext {
29		AVIOContext pub;
30		/**
31		* A callback that is used instead of short_seek_threshold.
32		*/
33		int (short_seek_get)(void opaque);
34
35		/**
36		* Threshold to favor readahead over seek.
37		*/
38		int short_seek_threshold;
39
40		enum AVIODataMarkerType current_type;
41		int64_t last_time;
42
43		/**
44		* max filesize, used to limit allocations
45		*/
46		int64_t maxsize;
47
48		/**
49		* Bytes read statistic
50		*/
51		int64_t bytes_read;
52
53		/**
54		* Bytes written statistic
55		*/
56		int64_t bytes_written;
57
58		/**
59		* seek statistic
60		*/
61		int seek_count;
62
63		/**
64		* writeout statistic
65		*/
66		int writeout_count;
67
68		/**
69		* Original buffer size
70		* used after probing to ensure seekback and to reset the buffer size
71		*/
72		int orig_buffer_size;
73
74		/**
75		* Written output size
76		* is updated each time a successful writeout ends up further position-wise
77		*/
78		int64_t written_output_size;
79		} FFIOContext;
80
81		static av_always_inline FFIOContext ffiocontext(AVIOContext ctx)
82	0	{
83	0	return (FFIOContext*)ctx;
84	0	} Unexecuted instantiation: demux.c:ffiocontext Unexecuted instantiation: demux_utils.c:ffiocontext Unexecuted instantiation: format.c:ffiocontext Unexecuted instantiation: id3v2.c:ffiocontext Unexecuted instantiation: options.c:ffiocontext Unexecuted instantiation: seek.c:ffiocontext Unexecuted instantiation: utils.c:ffiocontext Unexecuted instantiation: avio.c:ffiocontext Unexecuted instantiation: aviobuf.c:ffiocontext
85
86		void ffio_init_context(FFIOContext *s,
87		unsigned char *buffer,
88		int buffer_size,
89		int write_flag,
90		void *opaque,
91		int (read_packet)(void opaque, uint8_t *buf, int buf_size),
92		int (write_packet)(void opaque, const uint8_t *buf, int buf_size),
93		int64_t (seek)(void opaque, int64_t offset, int whence));
94
95		/**
96		* Wrap a buffer in an AVIOContext for reading.
97		*/
98		void ffio_init_read_context(FFIOContext s, const uint8_t buffer, int buffer_size);
99
100		/**
101		* Wrap a buffer in an AVIOContext for writing.
102		*/
103		void ffio_init_write_context(FFIOContext s, uint8_t buffer, int buffer_size);
104
105		/**
106		* Read size bytes from AVIOContext, returning a pointer.
107		* Note that the data pointed at by the returned pointer is only
108		* valid until the next call that references the same IO context.
109		* @param s IO context
110		* @param buf pointer to buffer into which to assemble the requested
111		* data if it is not available in contiguous addresses in the
112		* underlying buffer
113		* @param size number of bytes requested
114		* @param data address at which to store pointer: this will be a
115		* a direct pointer into the underlying buffer if the requested
116		* number of bytes are available at contiguous addresses, otherwise
117		* will be a copy of buf
118		* @return number of bytes read or AVERROR
119		*/
120		int ffio_read_indirect(AVIOContext s, unsigned char buf, int size, const unsigned char **data);
121
122		void ffio_fill(AVIOContext *s, int b, int64_t count);
123
124		static av_always_inline void ffio_wfourcc(AVIOContext pb, const uint8_t s)
125	0	{
126	0	avio_wl32(pb, MKTAG(s[0], s[1], s[2], s[3]));
127	0	} Unexecuted instantiation: demux.c:ffio_wfourcc Unexecuted instantiation: demux_utils.c:ffio_wfourcc Unexecuted instantiation: format.c:ffio_wfourcc Unexecuted instantiation: id3v2.c:ffio_wfourcc Unexecuted instantiation: options.c:ffio_wfourcc Unexecuted instantiation: seek.c:ffio_wfourcc Unexecuted instantiation: utils.c:ffio_wfourcc Unexecuted instantiation: avio.c:ffio_wfourcc Unexecuted instantiation: aviobuf.c:ffio_wfourcc
128
129		/**
130		* Rewind the AVIOContext using the specified buffer containing the first buf_size bytes of the file.
131		* Used after probing to avoid seeking.
132		* Joins buf and s->buffer, taking any overlap into consideration.
133		* @note s->buffer must overlap with buf or they can't be joined and the function fails
134		*
135		* @param s The read-only AVIOContext to rewind
136		* @param buf The probe buffer containing the first buf_size bytes of the file
137		* @param buf_size The size of buf
138		* @return >= 0 in case of success, a negative value corresponding to an
139		* AVERROR code in case of failure
140		*/
141		int ffio_rewind_with_probe_data(AVIOContext s, unsigned char *buf, int buf_size);
142
143		uint64_t ffio_read_varlen(AVIOContext *bc);
144
145		/**
146		* Read a unsigned integer coded as a variable number of up to eight
147		* little-endian bytes, where the MSB in a byte signals another byte
148		* must be read.
149		* All coded bytes are read, but values > UINT_MAX are truncated.
150		*/
151		unsigned int ffio_read_leb(AVIOContext *s);
152
153		void ffio_write_leb(AVIOContext *s, unsigned val);
154
155		/**
156		* Write a sequence of text lines, converting line endings.
157		* All input line endings (LF, CRLF, CR) are converted to the configured line ending.
158		* @param s The AVIOContext to write to
159		* @param buf The buffer to write
160		* @param size The size of the buffer, or <0 to use the full length of a null-terminated string
161		* @param ending The line ending sequence to convert to, or NULL for \n
162		*/
163		void ffio_write_lines(AVIOContext s, const unsigned char buf, int size,
164		const unsigned char *ending);
165
166		/**
167		* Read size bytes from AVIOContext into buf.
168		* Check that exactly size bytes have been read.
169		* @return number of bytes read or AVERROR
170		*/
171		int ffio_read_size(AVIOContext s, unsigned char buf, int size);
172
173		/**
174		* Reallocate a given buffer for AVIOContext.
175		*
176		* @param s the AVIOContext to realloc.
177		* @param buf_size required new buffer size.
178		* @return 0 on success, a negative AVERROR on failure.
179		*/
180		int ffio_realloc_buf(AVIOContext *s, int buf_size);
181
182		/**
183		* Ensures that the requested seekback buffer size will be available
184		*
185		* Will ensure that when reading sequentially up to buf_size, seeking
186		* within the current pos and pos+buf_size is possible.
187		* Once the stream position moves outside this window or another
188		* ffio_ensure_seekback call requests a buffer outside this window this
189		* guarantee is lost.
190		*/
191		int ffio_ensure_seekback(AVIOContext *s, int64_t buf_size);
192
193		int ffio_limit(AVIOContext *s, int size);
194
195		void ffio_init_checksum(AVIOContext *s,
196		unsigned long (update_checksum)(unsigned long c, const uint8_t p, unsigned int len),
197		unsigned long checksum);
198		unsigned long ffio_get_checksum(AVIOContext *s);
199		unsigned long ff_crc04C11DB7_update(unsigned long checksum, const uint8_t *buf,
200		unsigned int len);
201		unsigned long ff_crcEDB88320_update(unsigned long checksum, const uint8_t *buf,
202		unsigned int len);
203		unsigned long ff_crcA001_update(unsigned long checksum, const uint8_t *buf,
204		unsigned int len);
205
206		/**
207		* Open a write only packetized memory stream with a maximum packet
208		* size of 'max_packet_size'. The stream is stored in a memory buffer
209		* with a big-endian 4 byte header giving the packet size in bytes.
210		*
211		* @param s new IO context
212		* @param max_packet_size maximum packet size (must be > 0)
213		* @return zero if no error.
214		*/
215		int ffio_open_dyn_packet_buf(AVIOContext **s, int max_packet_size);
216
217		/**
218		* Return the URLContext associated with the AVIOContext
219		*
220		* @param s IO context
221		* @return pointer to URLContext or NULL.
222		*/
223		struct URLContext ffio_geturlcontext(AVIOContext s);
224
225		/**
226		* Create and initialize a AVIOContext for accessing the
227		* resource referenced by the URLContext h.
228		* @note When the URLContext h has been opened in read+write mode, the
229		* AVIOContext can be used only for writing.
230		*
231		* @param s Used to return the pointer to the created AVIOContext.
232		* In case of failure the pointed to value is set to NULL.
233		* @return >= 0 in case of success, a negative value corresponding to an
234		* AVERROR code in case of failure
235		*/
236		int ffio_fdopen(AVIOContext *s, struct URLContext h);
237
238
239		/**
240		* Read url related dictionary options from the AVIOContext and write to the given dictionary
241		*/
242		int ffio_copy_url_options(AVIOContext* pb, AVDictionary** avio_opts);
243
244		/**
245		* Open a write-only fake memory stream. The written data is not stored
246		* anywhere - this is only used for measuring the amount of data
247		* written.
248		*
249		* @param s new IO context
250		* @return zero if no error.
251		*/
252		int ffio_open_null_buf(AVIOContext **s);
253
254		int ffio_open_whitelist(AVIOContext *s, const char url, int flags,
255		const AVIOInterruptCB int_cb, AVDictionary *options,
256		const char whitelist, const char blacklist);
257
258		/**
259		* Close a null buffer.
260		*
261		* @param s an IO context opened by ffio_open_null_buf
262		* @return the number of bytes written to the null buffer, negative on error
263		*/
264		int ffio_close_null_buf(AVIOContext *s);
265
266		/**
267		* Reset a dynamic buffer.
268		*
269		* Resets everything, but keeps the allocated buffer for later use.
270		*/
271		void ffio_reset_dyn_buf(AVIOContext *s);
272
273		/**
274		* Free a dynamic buffer.
275		*
276		* @param s a pointer to an IO context opened by avio_open_dyn_buf()
277		*/
278		void ffio_free_dyn_buf(AVIOContext **s);
279
280		struct AVBPrint;
281		/**
282		* Read a whole line of text from AVIOContext to an AVBPrint buffer overwriting
283		* its contents. Stop reading after reaching a \\r, a \\n, a \\r\\n, a \\0 or
284		* EOF. The line ending characters are NOT included in the buffer, but they
285		* are skipped on the input.
286		*
287		* @param s the read-only AVIOContext
288		* @param bp the AVBPrint buffer
289		* @return the length of the read line not including the line endings,
290		* negative on error, or if the buffer becomes truncated.
291		*/
292		int64_t ff_read_line_to_bprint_overwrite(AVIOContext s, struct AVBPrint bp);
293
294		/**
295		* Read a whole null-terminated string of text from AVIOContext to an AVBPrint
296		* buffer overwriting its contents. Stop reading after reaching the maximum
297		* length, a \\0 or EOF.
298		*
299		* @param s the read-only AVIOContext
300		* @param bp the AVBPrint buffer
301		* @param max_len the maximum length to be read from the AVIOContext.
302		* Negative (< 0) values signal that there is no known maximum
303		* length applicable. A maximum length of zero means that the
304		* AVIOContext is not touched, and the function returns
305		* with a read length of zero. In all cases the AVBprint
306		* is cleared.
307		* @return the length of the read string not including the terminating null,
308		* negative on error, or if the buffer becomes truncated.
309		*/
310		int64_t ff_read_string_to_bprint_overwrite(AVIOContext s, struct AVBPrint bp,
311		int64_t max_len);
312
313		#endif /* AVFORMAT_AVIO_INTERNAL_H */