/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"

typedef struct AVFormatContext AVFormatContext;

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);

/**
 * Like ffio_open_whitelist(), but additionally records @p avfc on the
 * underlying URLContext before it is connected, so protocols can use shared
 * per-format resource. Pass NULL for standalone use.
 */
int ffio_open_whitelist2(AVIOContext **s, const char *url, int flags,
                         const AVIOInterruptCB *int_cb, AVDictionary **options,
                         const char *whitelist, const char *blacklist,
                         AVFormatContext *avfc);

/**
 * 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: 2026-07-30 07:17

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		typedef struct AVFormatContext AVFormatContext;
27
28		extern const AVClass ff_avio_class;
29
30		typedef struct FFIOContext {
31		AVIOContext pub;
32		/**
33		* A callback that is used instead of short_seek_threshold.
34		*/
35		int (short_seek_get)(void opaque);
36
37		/**
38		* Threshold to favor readahead over seek.
39		*/
40		int short_seek_threshold;
41
42		enum AVIODataMarkerType current_type;
43		int64_t last_time;
44
45		/**
46		* max filesize, used to limit allocations
47		*/
48		int64_t maxsize;
49
50		/**
51		* Bytes read statistic
52		*/
53		int64_t bytes_read;
54
55		/**
56		* Bytes written statistic
57		*/
58		int64_t bytes_written;
59
60		/**
61		* seek statistic
62		*/
63		int seek_count;
64
65		/**
66		* writeout statistic
67		*/
68		int writeout_count;
69
70		/**
71		* Original buffer size
72		* used after probing to ensure seekback and to reset the buffer size
73		*/
74		int orig_buffer_size;
75
76		/**
77		* Written output size
78		* is updated each time a successful writeout ends up further position-wise
79		*/
80		int64_t written_output_size;
81		} FFIOContext;
82
83		static av_always_inline FFIOContext ffiocontext(AVIOContext ctx)
84	0	{
85	0	return (FFIOContext*)ctx;
86	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
87
88		void ffio_init_context(FFIOContext *s,
89		unsigned char *buffer,
90		int buffer_size,
91		int write_flag,
92		void *opaque,
93		int (read_packet)(void opaque, uint8_t *buf, int buf_size),
94		int (write_packet)(void opaque, const uint8_t *buf, int buf_size),
95		int64_t (seek)(void opaque, int64_t offset, int whence));
96
97		/**
98		* Wrap a buffer in an AVIOContext for reading.
99		*/
100		void ffio_init_read_context(FFIOContext s, const uint8_t buffer, int buffer_size);
101
102		/**
103		* Wrap a buffer in an AVIOContext for writing.
104		*/
105		void ffio_init_write_context(FFIOContext s, uint8_t buffer, int buffer_size);
106
107		/**
108		* Read size bytes from AVIOContext, returning a pointer.
109		* Note that the data pointed at by the returned pointer is only
110		* valid until the next call that references the same IO context.
111		* @param s IO context
112		* @param buf pointer to buffer into which to assemble the requested
113		* data if it is not available in contiguous addresses in the
114		* underlying buffer
115		* @param size number of bytes requested
116		* @param data address at which to store pointer: this will be a
117		* a direct pointer into the underlying buffer if the requested
118		* number of bytes are available at contiguous addresses, otherwise
119		* will be a copy of buf
120		* @return number of bytes read or AVERROR
121		*/
122		int ffio_read_indirect(AVIOContext s, unsigned char buf, int size, const unsigned char **data);
123
124		void ffio_fill(AVIOContext *s, int b, int64_t count);
125
126		static av_always_inline void ffio_wfourcc(AVIOContext pb, const uint8_t s)
127	0	{
128	0	avio_wl32(pb, MKTAG(s[0], s[1], s[2], s[3]));
129	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
130
131		/**
132		* Rewind the AVIOContext using the specified buffer containing the first buf_size bytes of the file.
133		* Used after probing to avoid seeking.
134		* Joins buf and s->buffer, taking any overlap into consideration.
135		* @note s->buffer must overlap with buf or they can't be joined and the function fails
136		*
137		* @param s The read-only AVIOContext to rewind
138		* @param buf The probe buffer containing the first buf_size bytes of the file
139		* @param buf_size The size of buf
140		* @return >= 0 in case of success, a negative value corresponding to an
141		* AVERROR code in case of failure
142		*/
143		int ffio_rewind_with_probe_data(AVIOContext s, unsigned char *buf, int buf_size);
144
145		uint64_t ffio_read_varlen(AVIOContext *bc);
146
147		/**
148		* Read a unsigned integer coded as a variable number of up to eight
149		* little-endian bytes, where the MSB in a byte signals another byte
150		* must be read.
151		* All coded bytes are read, but values > UINT_MAX are truncated.
152		*/
153		unsigned int ffio_read_leb(AVIOContext *s);
154
155		void ffio_write_leb(AVIOContext *s, unsigned val);
156
157		/**
158		* Write a sequence of text lines, converting line endings.
159		* All input line endings (LF, CRLF, CR) are converted to the configured line ending.
160		* @param s The AVIOContext to write to
161		* @param buf The buffer to write
162		* @param size The size of the buffer, or <0 to use the full length of a null-terminated string
163		* @param ending The line ending sequence to convert to, or NULL for \n
164		*/
165		void ffio_write_lines(AVIOContext s, const unsigned char buf, int size,
166		const unsigned char *ending);
167
168		/**
169		* Read size bytes from AVIOContext into buf.
170		* Check that exactly size bytes have been read.
171		* @return number of bytes read or AVERROR
172		*/
173		int ffio_read_size(AVIOContext s, unsigned char buf, int size);
174
175		/**
176		* Reallocate a given buffer for AVIOContext.
177		*
178		* @param s the AVIOContext to realloc.
179		* @param buf_size required new buffer size.
180		* @return 0 on success, a negative AVERROR on failure.
181		*/
182		int ffio_realloc_buf(AVIOContext *s, int buf_size);
183
184		/**
185		* Ensures that the requested seekback buffer size will be available
186		*
187		* Will ensure that when reading sequentially up to buf_size, seeking
188		* within the current pos and pos+buf_size is possible.
189		* Once the stream position moves outside this window or another
190		* ffio_ensure_seekback call requests a buffer outside this window this
191		* guarantee is lost.
192		*/
193		int ffio_ensure_seekback(AVIOContext *s, int64_t buf_size);
194
195		int ffio_limit(AVIOContext *s, int size);
196
197		void ffio_init_checksum(AVIOContext *s,
198		unsigned long (update_checksum)(unsigned long c, const uint8_t p, unsigned int len),
199		unsigned long checksum);
200		unsigned long ffio_get_checksum(AVIOContext *s);
201		unsigned long ff_crc04C11DB7_update(unsigned long checksum, const uint8_t *buf,
202		unsigned int len);
203		unsigned long ff_crcEDB88320_update(unsigned long checksum, const uint8_t *buf,
204		unsigned int len);
205		unsigned long ff_crcA001_update(unsigned long checksum, const uint8_t *buf,
206		unsigned int len);
207
208		/**
209		* Open a write only packetized memory stream with a maximum packet
210		* size of 'max_packet_size'. The stream is stored in a memory buffer
211		* with a big-endian 4 byte header giving the packet size in bytes.
212		*
213		* @param s new IO context
214		* @param max_packet_size maximum packet size (must be > 0)
215		* @return zero if no error.
216		*/
217		int ffio_open_dyn_packet_buf(AVIOContext **s, int max_packet_size);
218
219		/**
220		* Return the URLContext associated with the AVIOContext
221		*
222		* @param s IO context
223		* @return pointer to URLContext or NULL.
224		*/
225		struct URLContext ffio_geturlcontext(AVIOContext s);
226
227		/**
228		* Create and initialize a AVIOContext for accessing the
229		* resource referenced by the URLContext h.
230		* @note When the URLContext h has been opened in read+write mode, the
231		* AVIOContext can be used only for writing.
232		*
233		* @param s Used to return the pointer to the created AVIOContext.
234		* In case of failure the pointed to value is set to NULL.
235		* @return >= 0 in case of success, a negative value corresponding to an
236		* AVERROR code in case of failure
237		*/
238		int ffio_fdopen(AVIOContext *s, struct URLContext h);
239
240
241		/**
242		* Read url related dictionary options from the AVIOContext and write to the given dictionary
243		*/
244		int ffio_copy_url_options(AVIOContext* pb, AVDictionary** avio_opts);
245
246		/**
247		* Open a write-only fake memory stream. The written data is not stored
248		* anywhere - this is only used for measuring the amount of data
249		* written.
250		*
251		* @param s new IO context
252		* @return zero if no error.
253		*/
254		int ffio_open_null_buf(AVIOContext **s);
255
256		int ffio_open_whitelist(AVIOContext *s, const char url, int flags,
257		const AVIOInterruptCB int_cb, AVDictionary *options,
258		const char whitelist, const char blacklist);
259
260		/**
261		* Like ffio_open_whitelist(), but additionally records @p avfc on the
262		* underlying URLContext before it is connected, so protocols can use shared
263		* per-format resource. Pass NULL for standalone use.
264		*/
265		int ffio_open_whitelist2(AVIOContext *s, const char url, int flags,
266		const AVIOInterruptCB int_cb, AVDictionary *options,
267		const char whitelist, const char blacklist,
268		AVFormatContext *avfc);
269
270		/**
271		* Close a null buffer.
272		*
273		* @param s an IO context opened by ffio_open_null_buf
274		* @return the number of bytes written to the null buffer, negative on error
275		*/
276		int ffio_close_null_buf(AVIOContext *s);
277
278		/**
279		* Reset a dynamic buffer.
280		*
281		* Resets everything, but keeps the allocated buffer for later use.
282		*/
283		void ffio_reset_dyn_buf(AVIOContext *s);
284
285		/**
286		* Free a dynamic buffer.
287		*
288		* @param s a pointer to an IO context opened by avio_open_dyn_buf()
289		*/
290		void ffio_free_dyn_buf(AVIOContext **s);
291
292		struct AVBPrint;
293		/**
294		* Read a whole line of text from AVIOContext to an AVBPrint buffer overwriting
295		* its contents. Stop reading after reaching a \\r, a \\n, a \\r\\n, a \\0 or
296		* EOF. The line ending characters are NOT included in the buffer, but they
297		* are skipped on the input.
298		*
299		* @param s the read-only AVIOContext
300		* @param bp the AVBPrint buffer
301		* @return the length of the read line not including the line endings,
302		* negative on error, or if the buffer becomes truncated.
303		*/
304		int64_t ff_read_line_to_bprint_overwrite(AVIOContext s, struct AVBPrint bp);
305
306		/**
307		* Read a whole null-terminated string of text from AVIOContext to an AVBPrint
308		* buffer overwriting its contents. Stop reading after reaching the maximum
309		* length, a \\0 or EOF.
310		*
311		* @param s the read-only AVIOContext
312		* @param bp the AVBPrint buffer
313		* @param max_len the maximum length to be read from the AVIOContext.
314		* Negative (< 0) values signal that there is no known maximum
315		* length applicable. A maximum length of zero means that the
316		* AVIOContext is not touched, and the function returns
317		* with a read length of zero. In all cases the AVBprint
318		* is cleared.
319		* @return the length of the read string not including the terminating null,
320		* negative on error, or if the buffer becomes truncated.
321		*/
322		int64_t ff_read_string_to_bprint_overwrite(AVIOContext s, struct AVBPrint bp,
323		int64_t max_len);
324
325		#endif /* AVFORMAT_AVIO_INTERNAL_H */