PeerStreamer

/*

 * copyright (c) 2001 Fabrice Bellard

 *

 * This file is part of Libav.

 *

 * Libav 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.

 *

 * Libav 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 Libav; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

 */

#ifndef AVFORMAT_AVIO_H

#define AVFORMAT_AVIO_H

/**

 * @file

 * Buffered I/O operations

 */

#include <stdint.h>

#include "libavutil/common.h"

#include "libavutil/log.h"

#include "libavformat/version.h"

#define AVIO_SEEKABLE_NORMAL 0x0001 /**< Seeking works like for a local file */

/**

 * Bytestream IO Context.

 * New fields can be added to the end with minor version bumps.

 * Removal, reordering and changes to existing fields require a major

 * version bump.

 * sizeof(AVIOContext) must not be used outside libav*.

 *

 * @note None of the function pointers in AVIOContext should be called

 *       directly, they should only be set by the client application

 *       when implementing custom I/O. Normally these are set to the

 *       function pointers specified in avio_alloc_context()

 */

typedef struct {

    unsigned char *buffer;  /**< Start of the buffer. */

    int buffer_size;        /**< Maximum buffer size */

    unsigned char *buf_ptr; /**< Current position in the buffer */

    unsigned char *buf_end; /**< End of the data, may be less than

                                 buffer+buffer_size if the read function returned

                                 less data than requested, e.g. for streams where

                                 no more data has been received yet. */

    void *opaque;           /**< A private pointer, passed to the read/write/seek/...

                                 functions. */

    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);

    int64_t pos;            /**< position in the file of the current buffer */

    int must_flush;         /**< true if the next seek should flush */

    int eof_reached;        /**< true if eof reached */

    int write_flag;         /**< true if open for writing */

#if FF_API_OLD_AVIO

    attribute_deprecated int is_streamed;

#endif

    int max_packet_size;

    unsigned long checksum;

    unsigned char *checksum_ptr;

    unsigned long (*update_checksum)(unsigned long checksum, const uint8_t *buf, unsigned int size);

    int error;              /**< contains the error code or 0 if no error happened */

    /**

     * Pause or resume playback for network streaming protocols - e.g. MMS.

     */

    int (*read_pause)(void *opaque, int pause);

    /**

     * Seek to a given timestamp in stream with the specified stream_index.

     * Needed for some network streaming protocols which don't support seeking

     * to byte position.

     */

    int64_t (*read_seek)(void *opaque, int stream_index,

                         int64_t timestamp, int flags);

    /**

     * A combination of AVIO_SEEKABLE_ flags or 0 when the stream is not seekable.

     */

    int seekable;

} AVIOContext;

/* unbuffered I/O */

#if FF_API_OLD_AVIO

/**

 * URL Context.

 * New fields can be added to the end with minor version bumps.

 * Removal, reordering and changes to existing fields require a major

 * version bump.

 * sizeof(URLContext) must not be used outside libav*.

 * @deprecated This struct will be made private

 */

typedef struct URLContext {

#if FF_API_URL_CLASS

    const AVClass *av_class; ///< information for av_log(). Set by url_open().

#endif

    struct URLProtocol *prot;

    int flags;

    int is_streamed;  /**< true if streamed (no seek possible), default = false */

    int max_packet_size;  /**< if non zero, the stream is packetized with this max packet size */

    void *priv_data;

    char *filename; /**< specified URL */

    int is_connected;

} URLContext;

#define URL_PROTOCOL_FLAG_NESTED_SCHEME 1 /*< The protocol name can be the first part of a nested protocol scheme */

/**

 * @deprecated This struct is to be made private. Use the higher-level

 *             AVIOContext-based API instead.

 */

typedef struct URLProtocol {

    const char *name;

    int (*url_open)(URLContext *h, const char *url, int flags);

    int (*url_read)(URLContext *h, unsigned char *buf, int size);

    int (*url_write)(URLContext *h, const unsigned char *buf, int size);

    int64_t (*url_seek)(URLContext *h, int64_t pos, int whence);

    int (*url_close)(URLContext *h);

    struct URLProtocol *next;

    int (*url_read_pause)(URLContext *h, int pause);

    int64_t (*url_read_seek)(URLContext *h, int stream_index,

                             int64_t timestamp, int flags);

    int (*url_get_file_handle)(URLContext *h);

    int priv_data_size;

    const AVClass *priv_data_class;

    int flags;

} URLProtocol;

typedef struct URLPollEntry {

    URLContext *handle;

    int events;

    int revents;

} URLPollEntry;

/* not implemented */

attribute_deprecated int url_poll(URLPollEntry *poll_table, int n, int timeout);

/**

 * @defgroup open_modes URL open modes

 * The flags argument to url_open and cosins must be one of the following

 * constants, optionally ORed with other flags.

 * @{

 */

#define URL_RDONLY 0  /**< read-only */

#define URL_WRONLY 1  /**< write-only */

#define URL_RDWR   2  /**< read-write */

/**

 * @}

 */

/**

 * Use non-blocking mode.

 * If this flag is set, operations on the context will return

 * AVERROR(EAGAIN) if they can not be performed immediately.

 * If this flag is not set, operations on the context will never return

 * AVERROR(EAGAIN).

 * Note that this flag does not affect the opening/connecting of the

 * context. Connecting a protocol will always block if necessary (e.g. on

 * network protocols) but never hang (e.g. on busy devices).

 * Warning: non-blocking protocols is work-in-progress; this flag may be

 * silently ignored.

 */

#define URL_FLAG_NONBLOCK 4

typedef int URLInterruptCB(void);

extern URLInterruptCB *url_interrupt_cb;

/**

 * @defgroup old_url_funcs Old url_* functions

 * @deprecated use the buffered API based on AVIOContext instead

 * @{

 */

attribute_deprecated int url_open_protocol (URLContext **puc, struct URLProtocol *up,

                                            const char *url, int flags);

attribute_deprecated int url_alloc(URLContext **h, const char *url, int flags);

attribute_deprecated int url_connect(URLContext *h);

attribute_deprecated int url_open(URLContext **h, const char *url, int flags);

attribute_deprecated int url_read(URLContext *h, unsigned char *buf, int size);

attribute_deprecated int url_read_complete(URLContext *h, unsigned char *buf, int size);

attribute_deprecated int url_write(URLContext *h, const unsigned char *buf, int size);

attribute_deprecated int64_t url_seek(URLContext *h, int64_t pos, int whence);

attribute_deprecated int url_close(URLContext *h);

attribute_deprecated int64_t url_filesize(URLContext *h);

attribute_deprecated int url_get_file_handle(URLContext *h);

attribute_deprecated int url_get_max_packet_size(URLContext *h);

attribute_deprecated void url_get_filename(URLContext *h, char *buf, int buf_size);

attribute_deprecated int av_url_read_pause(URLContext *h, int pause);

attribute_deprecated int64_t av_url_read_seek(URLContext *h, int stream_index,

                                              int64_t timestamp, int flags);

attribute_deprecated void url_set_interrupt_cb(int (*interrupt_cb)(void));

/**

 * If protocol is NULL, returns the first registered protocol,

 * if protocol is non-NULL, returns the next registered protocol after protocol,

 * or NULL if protocol is the last one.

 */

attribute_deprecated URLProtocol *av_protocol_next(URLProtocol *p);

/**

 * Register the URLProtocol protocol.

 *

 * @param size the size of the URLProtocol struct referenced

 */

attribute_deprecated int av_register_protocol2(URLProtocol *protocol, int size);

/**

 * @}

 */

typedef attribute_deprecated AVIOContext ByteIOContext;

attribute_deprecated int init_put_byte(AVIOContext *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));

attribute_deprecated AVIOContext *av_alloc_put_byte(

                  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));

/**

 * @defgroup old_avio_funcs Old put_/get_*() functions

 * @deprecated use the avio_ -prefixed functions instead.

 * @{

 */

attribute_deprecated int          get_buffer(AVIOContext *s, unsigned char *buf, int size);

attribute_deprecated int          get_partial_buffer(AVIOContext *s, unsigned char *buf, int size);

attribute_deprecated int          get_byte(AVIOContext *s);

attribute_deprecated unsigned int get_le16(AVIOContext *s);

attribute_deprecated unsigned int get_le24(AVIOContext *s);

attribute_deprecated unsigned int get_le32(AVIOContext *s);

attribute_deprecated uint64_t     get_le64(AVIOContext *s);

attribute_deprecated unsigned int get_be16(AVIOContext *s);

attribute_deprecated unsigned int get_be24(AVIOContext *s);

attribute_deprecated unsigned int get_be32(AVIOContext *s);

attribute_deprecated uint64_t     get_be64(AVIOContext *s);

attribute_deprecated void         put_byte(AVIOContext *s, int b);

attribute_deprecated void         put_nbyte(AVIOContext *s, int b, int count);

attribute_deprecated void         put_buffer(AVIOContext *s, const unsigned char *buf, int size);

attribute_deprecated void         put_le64(AVIOContext *s, uint64_t val);

attribute_deprecated void         put_be64(AVIOContext *s, uint64_t val);

attribute_deprecated void         put_le32(AVIOContext *s, unsigned int val);

attribute_deprecated void         put_be32(AVIOContext *s, unsigned int val);

attribute_deprecated void         put_le24(AVIOContext *s, unsigned int val);

attribute_deprecated void         put_be24(AVIOContext *s, unsigned int val);

attribute_deprecated void         put_le16(AVIOContext *s, unsigned int val);

attribute_deprecated void         put_be16(AVIOContext *s, unsigned int val);

attribute_deprecated void         put_tag(AVIOContext *s, const char *tag);

/**

 * @}

 */

attribute_deprecated int     av_url_read_fpause(AVIOContext *h,    int pause);

attribute_deprecated int64_t av_url_read_fseek (AVIOContext *h,    int stream_index,

                                                int64_t timestamp, int flags);

/**

 * @defgroup old_url_f_funcs Old url_f* functions

 * @deprecated use the avio_ -prefixed functions instead.

 * @{

 */

attribute_deprecated int url_fopen( AVIOContext **s, const char *url, int flags);

attribute_deprecated int url_fclose(AVIOContext *s);

attribute_deprecated int64_t url_fseek(AVIOContext *s, int64_t offset, int whence);

attribute_deprecated int url_fskip(AVIOContext *s, int64_t offset);

attribute_deprecated int64_t url_ftell(AVIOContext *s);

attribute_deprecated int64_t url_fsize(AVIOContext *s);

#define URL_EOF (-1)

attribute_deprecated int url_fgetc(AVIOContext *s);

attribute_deprecated int url_setbufsize(AVIOContext *s, int buf_size);

#ifdef __GNUC__

attribute_deprecated int url_fprintf(AVIOContext *s, const char *fmt, ...) __attribute__ ((__format__ (__printf__, 2, 3)));

#else

attribute_deprecated int url_fprintf(AVIOContext *s, const char *fmt, ...);

#endif

attribute_deprecated void put_flush_packet(AVIOContext *s);

attribute_deprecated int url_open_dyn_buf(AVIOContext **s);

attribute_deprecated int url_open_dyn_packet_buf(AVIOContext **s, int max_packet_size);

attribute_deprecated int url_close_dyn_buf(AVIOContext *s, uint8_t **pbuffer);

attribute_deprecated int url_fdopen(AVIOContext **s, URLContext *h);

/**

 * @}

 */

/**

 * @deprecated use AVIOContext.eof_reached

 */

attribute_deprecated int url_feof(AVIOContext *s);

attribute_deprecated int url_ferror(AVIOContext *s);

attribute_deprecated int udp_set_remote_url(URLContext *h, const char *uri);

attribute_deprecated int udp_get_local_port(URLContext *h);

attribute_deprecated void init_checksum(AVIOContext *s,

                   unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len),

                   unsigned long checksum);

attribute_deprecated unsigned long get_checksum(AVIOContext *s);

attribute_deprecated void put_strz(AVIOContext *s, const char *buf);

/** @note unlike fgets, the EOL character is not returned and a whole

    line is parsed. return NULL if first char read was EOF */

attribute_deprecated char *url_fgets(AVIOContext *s, char *buf, int buf_size);

/**

 * @deprecated use avio_get_str instead

 */

attribute_deprecated char *get_strz(AVIOContext *s, char *buf, int maxlen);

/**

 * @deprecated Use AVIOContext.seekable field directly.

 */

attribute_deprecated static inline int url_is_streamed(AVIOContext *s)

{

    return !s->seekable;

}

attribute_deprecated URLContext *url_fileno(AVIOContext *s);

/**

 * @deprecated use AVIOContext.max_packet_size directly.

 */

attribute_deprecated int url_fget_max_packet_size(AVIOContext *s);

attribute_deprecated int url_open_buf(AVIOContext **s, uint8_t *buf, int buf_size, int flags);

/** return the written or read size */

attribute_deprecated int url_close_buf(AVIOContext *s);

#endif // FF_API_OLD_AVIO

/**

 * Return a non-zero value if the resource indicated by url

 * exists, 0 otherwise.

 */

int url_exist(const char *url);

/**

 * The callback is called in blocking functions to test regulary if

 * asynchronous interruption is needed. AVERROR_EXIT is returned

 * in this case by the interrupted function. 'NULL' means no interrupt

 * callback is given.

 */

void avio_set_interrupt_cb(int (*interrupt_cb)(void));

#if FF_API_REGISTER_PROTOCOL

extern URLProtocol *first_protocol;

#endif

#if FF_API_REGISTER_PROTOCOL

/**

 * @deprecated Use av_register_protocol() instead.

 */

attribute_deprecated int register_protocol(URLProtocol *protocol);

/**

 * @deprecated Use av_register_protocol2() instead.

 */

attribute_deprecated int av_register_protocol(URLProtocol *protocol);

#endif

/**

 * Allocate and initialize an AVIOContext for buffered I/O. It must be later

 * freed with av_free().

 *

 * @param buffer Memory block for input/output operations via AVIOContext.

 * @param buffer_size The buffer size is very important for performance.

 *        For protocols with fixed blocksize it should be set to this blocksize.

 *        For others a typical size is a cache page, e.g. 4kb.

 * @param write_flag Set to 1 if the buffer should be writable, 0 otherwise.

 * @param opaque An opaque pointer to user-specific data.

 * @param read_packet  A function for refilling the buffer, may be NULL.

 * @param write_packet A function for writing the buffer contents, may be NULL.

 * @param seek A function for seeking to specified byte position, may be NULL.

 *

 * @return Allocated AVIOContext or NULL on failure.

 */

AVIOContext *avio_alloc_context(

                  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));

void avio_w8(AVIOContext *s, int b);

void avio_write(AVIOContext *s, const unsigned char *buf, int size);

void avio_wl64(AVIOContext *s, uint64_t val);

void avio_wb64(AVIOContext *s, uint64_t val);

void avio_wl32(AVIOContext *s, unsigned int val);

void avio_wb32(AVIOContext *s, unsigned int val);

void avio_wl24(AVIOContext *s, unsigned int val);

void avio_wb24(AVIOContext *s, unsigned int val);

void avio_wl16(AVIOContext *s, unsigned int val);

void avio_wb16(AVIOContext *s, unsigned int val);

/**

 * Write a NULL-terminated string.

 * @return number of bytes written.

 */

int avio_put_str(AVIOContext *s, const char *str);

/**

 * Convert an UTF-8 string to UTF-16LE and write it.

 * @return number of bytes written.

 */

int avio_put_str16le(AVIOContext *s, const char *str);

/**

 * Passing this as the "whence" parameter to a seek function causes it to

 * return the filesize without seeking anywhere. Supporting this is optional.

 * If it is not supported then the seek function will return <0.

 */

#define AVSEEK_SIZE 0x10000

/**

 * Oring this flag as into the "whence" parameter to a seek function causes it to

 * seek by any means (like reopening and linear reading) or other normally unreasonble

 * means that can be extreemly slow.

 * This may be ignored by the seek code.

 */

#define AVSEEK_FORCE 0x20000

/**

 * fseek() equivalent for AVIOContext.

 * @return new position or AVERROR.

 */

int64_t avio_seek(AVIOContext *s, int64_t offset, int whence);

/**

 * Skip given number of bytes forward

 * @return new position or AVERROR.

 */

static av_always_inline int64_t avio_skip(AVIOContext *s, int64_t offset)

{

    return avio_seek(s, offset, SEEK_CUR);

}

/**

 * ftell() equivalent for AVIOContext.

 * @return position or AVERROR.

 */

static av_always_inline int64_t avio_tell(AVIOContext *s)

{

    return avio_seek(s, 0, SEEK_CUR);

}

/**

 * Get the filesize.

 * @return filesize or AVERROR

 */

int64_t avio_size(AVIOContext *s);

/** @warning currently size is limited */

#ifdef __GNUC__

int avio_printf(AVIOContext *s, const char *fmt, ...) __attribute__ ((__format__ (__printf__, 2, 3)));

#else

int avio_printf(AVIOContext *s, const char *fmt, ...);

#endif

void avio_flush(AVIOContext *s);

/**

 * Read size bytes from AVIOContext into buf.

 * @return number of bytes read or AVERROR

 */

int avio_read(AVIOContext *s, unsigned char *buf, int size);

/**

 * @defgroup avio_read Functions for reading from AVIOContext.

 * @{

 *

 * @note return 0 if EOF, so you cannot use it if EOF handling is

 *       necessary

 */

int          avio_r8  (AVIOContext *s);

unsigned int avio_rl16(AVIOContext *s);

unsigned int avio_rl24(AVIOContext *s);

unsigned int avio_rl32(AVIOContext *s);

uint64_t     avio_rl64(AVIOContext *s);

unsigned int avio_rb16(AVIOContext *s);

unsigned int avio_rb24(AVIOContext *s);

unsigned int avio_rb32(AVIOContext *s);

uint64_t     avio_rb64(AVIOContext *s);

/**

 * @}

 */

/**

 * Read a string from pb into buf. The reading will terminate when either

 * a NULL character was encountered, maxlen bytes have been read, or nothing

 * more can be read from pb. The result is guaranteed to be NULL-terminated, it

 * will be truncated if buf is too small.

 * Note that the string is not interpreted or validated in any way, it

 * might get truncated in the middle of a sequence for multi-byte encodings.

 *

 * @return number of bytes read (is always <= maxlen).

 * If reading ends on EOF or error, the return value will be one more than

 * bytes actually read.

 */

int avio_get_str(AVIOContext *pb, int maxlen, char *buf, int buflen);

/**

 * Read a UTF-16 string from pb and convert it to UTF-8.

 * The reading will terminate when either a null or invalid character was

 * encountered or maxlen bytes have been read.

 * @return number of bytes read (is always <= maxlen)

 */

int avio_get_str16le(AVIOContext *pb, int maxlen, char *buf, int buflen);

int avio_get_str16be(AVIOContext *pb, int maxlen, char *buf, int buflen);

#if FF_API_URL_RESETBUF

/** Reset the buffer for reading or writing.

 * @note Will drop any data currently in the buffer without transmitting it.

 * @param flags URL_RDONLY to set up the buffer for reading, or URL_WRONLY

 *        to set up the buffer for writing. */

int url_resetbuf(AVIOContext *s, int flags);

#endif

/**

 * @defgroup open_modes URL open modes

 * The flags argument to avio_open must be one of the following

 * constants, optionally ORed with other flags.

 * @{

 */

#define AVIO_RDONLY 0  /**< read-only */

#define AVIO_WRONLY 1  /**< write-only */

#define AVIO_RDWR   2  /**< read-write */

/**

 * @}

 */

/**

 * Use non-blocking mode.

 * If this flag is set, operations on the context will return

 * AVERROR(EAGAIN) if they can not be performed immediately.

 * If this flag is not set, operations on the context will never return

 * AVERROR(EAGAIN).

 * Note that this flag does not affect the opening/connecting of the

 * context. Connecting a protocol will always block if necessary (e.g. on

 * network protocols) but never hang (e.g. on busy devices).

 * Warning: non-blocking protocols is work-in-progress; this flag may be

 * silently ignored.

 */

#define AVIO_FLAG_NONBLOCK 4

/**

 * Create and initialize a AVIOContext for accessing the

 * resource indicated by url.

 * @note When the resource indicated by url 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.

 * @param flags flags which control how the resource indicated by url

 * is to be opened

 * @return 0 in case of success, a negative value corresponding to an

 * AVERROR code in case of failure

 */

int avio_open(AVIOContext **s, const char *url, int flags);

/**

 * Close the resource accessed by the AVIOContext s and free it.

 * This function can only be used if s was opened by avio_open().

 *

 * @return 0 on success, an AVERROR < 0 on error.

 */

int avio_close(AVIOContext *s);

/**

 * Open a write only memory stream.

 *

 * @param s new IO context

 * @return zero if no error.

 */

int avio_open_dyn_buf(AVIOContext **s);

/**

 * Return the written size and a pointer to the buffer. The buffer

 * must be freed with av_free().

 * Padding of FF_INPUT_BUFFER_PADDING_SIZE is added to the buffer.

 *

 * @param s IO context

 * @param pbuffer pointer to a byte buffer

 * @return the length of the byte buffer

 */

int avio_close_dyn_buf(AVIOContext *s, uint8_t **pbuffer);

#if FF_API_UDP_GET_FILE

int udp_get_file_handle(URLContext *h);

#endif

/**

 * Iterate through names of available protocols.

 *

 * @param opaque A private pointer representing current protocol.

 *        It must be a pointer to NULL on first iteration and will

 *        be updated by successive calls to avio_enum_protocols.

 * @param output If set to 1, iterate over output protocols,

 *               otherwise over input protocols.

 *

 * @return A static string containing the name of current protocol or NULL

 */

const char *avio_enum_protocols(void **opaque, int output);

/**

 * Pause and resume playing - only meaningful if using a network streaming

 * protocol (e.g. MMS).

 * @param pause 1 for pause, 0 for resume

 */

int     avio_pause(AVIOContext *h, int pause);

/**

 * Seek to a given timestamp relative to some component stream.

 * Only meaningful if using a network streaming protocol (e.g. MMS.).

 * @param stream_index The stream index that the timestamp is relative to.

 *        If stream_index is (-1) the timestamp should be in AV_TIME_BASE

 *        units from the beginning of the presentation.

 *        If a stream_index >= 0 is used and the protocol does not support

 *        seeking based on component streams, the call will fail with ENOTSUP.

 * @param timestamp timestamp in AVStream.time_base units

 *        or if there is no stream specified then in AV_TIME_BASE units.

 * @param flags Optional combination of AVSEEK_FLAG_BACKWARD, AVSEEK_FLAG_BYTE

 *        and AVSEEK_FLAG_ANY. The protocol may silently ignore

 *        AVSEEK_FLAG_BACKWARD and AVSEEK_FLAG_ANY, but AVSEEK_FLAG_BYTE will

 *        fail with ENOTSUP if used and not supported.

 * @return >= 0 on success

 * @see AVInputFormat::read_seek

 */

int64_t avio_seek_time(AVIOContext *h, int stream_index,

                       int64_t timestamp, int flags);

#endif /* AVFORMAT_AVIO_H */