PeerStreamer

/*

 * copyright (c) 2001 Fabrice Bellard

 *

 * 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_H

#define AVFORMAT_AVIO_H

/**

 * @file

 * unbuffered I/O operations

 *

 * @warning This file has to be considered an internal but installed

 * header, so it should not be directly included in your projects.

 */

#include <stdint.h>

#include "libavutil/common.h"

#include "libavutil/log.h"

#include "libavformat/version.h"

/* unbuffered I/O */

/**

 * 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*.

 */

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;

typedef struct URLPollEntry {

    URLContext *handle;

    int events;

    int revents;

} URLPollEntry;

#define URL_RDONLY 0

#define URL_WRONLY 1

#define URL_RDWR   2

typedef int URLInterruptCB(void);

/**

 * Create a URLContext for accessing to the resource indicated by

 * url, and open it using the URLProtocol up.

 *

 * @param puc pointer to the location where, in case of success, the

 * function puts the pointer to the created URLContext

 * @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 url_open_protocol (URLContext **puc, struct URLProtocol *up,

                       const char *url, int flags);

/**

 * Create a URLContext for accessing to the resource indicated by

 * url, but do not initiate the connection yet.

 *

 * @param puc pointer to the location where, in case of success, the

 * function puts the pointer to the created URLContext

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

/**

 * Connect an URLContext that has been allocated by url_alloc

 */

int url_connect(URLContext *h);

/**

 * Create an URLContext for accessing to the resource indicated by

 * url, and open it.

 *

 * @param puc pointer to the location where, in case of success, the

 * function puts the pointer to the created URLContext

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

/**

 * Read up to size bytes from the resource accessed by h, and store

 * the read bytes in buf.

 *

 * @return The number of bytes actually read, or a negative value

 * corresponding to an AVERROR code in case of error. A value of zero

 * indicates that it is not possible to read more from the accessed

 * resource (except if the value of the size argument is also zero).

 */

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

/**

 * Read as many bytes as possible (up to size), calling the

 * read function multiple times if necessary.

 * Will also retry if the read function returns AVERROR(EAGAIN).

 * This makes special short-read handling in applications

 * unnecessary, if the return value is < size then it is

 * certain there was either an error or the end of file was reached.

 */

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

/**

 * Write size bytes from buf to the resource accessed by h.

 *

 * @return the number of bytes actually written, or a negative value

 * corresponding to an AVERROR code in case of failure

 */

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

/**

 * 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

/**

 * Change the position that will be used by the next read/write

 * operation on the resource accessed by h.

 *

 * @param pos specifies the new position to set

 * @param whence specifies how pos should be interpreted, it must be

 * one of SEEK_SET (seek from the beginning), SEEK_CUR (seek from the

 * current position), SEEK_END (seek from the end), or AVSEEK_SIZE

 * (return the filesize of the requested resource, pos is ignored).

 * @return a negative value corresponding to an AVERROR code in case

 * of failure, or the resulting file position, measured in bytes from

 * the beginning of the file. You can use this feature together with

 * SEEK_CUR to read the current file position.

 */

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

/**

 * Close the resource accessed by the URLContext h, and free the

 * memory used by it.

 *

 * @return a negative value if an error condition occurred, 0

 * otherwise

 */

int url_close(URLContext *h);

/**

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

 * exists, 0 otherwise.

 */

int url_exist(const char *url);

/**

 * Return the filesize of the resource accessed by h, AVERROR(ENOSYS)

 * if the operation is not supported by h, or another negative value

 * corresponding to an AVERROR error code in case of failure.

 */

int64_t url_filesize(URLContext *h);

/**

 * Return the file descriptor associated with this URL. For RTP, this

 * will return only the RTP file descriptor, not the RTCP file descriptor.

 *

 * @return the file descriptor associated with this URL, or <0 on error.

 */

int url_get_file_handle(URLContext *h);

/**

 * Return the maximum packet size associated to packetized file

 * handle. If the file is not packetized (stream like HTTP or file on

 * disk), then 0 is returned.

 *

 * @param h file handle

 * @return maximum packet size in bytes

 */

int url_get_max_packet_size(URLContext *h);

/**

 * Copy the filename of the resource accessed by h to buf.

 *

 * @param buf_size size in bytes of buf

 */

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

/**

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

 * asynchronous interruption is needed. AVERROR(EINTR) is returned

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

 * callback is given.

 */

void url_set_interrupt_cb(URLInterruptCB *interrupt_cb);

/* not implemented */

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

/**

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

 * protocol (e.g. MMS).

 * @param pause 1 for pause, 0 for resume

 */

int av_url_read_pause(URLContext *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 av_url_read_seek(URLContext *h, int stream_index,

                         int64_t timestamp, int flags);

/**

 * 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

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;

} URLProtocol;

#if FF_API_REGISTER_PROTOCOL

extern URLProtocol *first_protocol;

#endif

extern URLInterruptCB *url_interrupt_cb;

/**

 * 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.

 */

URLProtocol *av_protocol_next(URLProtocol *p);

#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

/**

 * Register the URLProtocol protocol.

 *

 * @param size the size of the URLProtocol struct referenced

 */

int av_register_protocol2(URLProtocol *protocol, int size);

/**

 * 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(ByteIOContext) must not be used outside libav*.

 */

typedef struct {

    unsigned char *buffer;

    int buffer_size;

    unsigned char *buf_ptr, *buf_end;

    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);

    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 */

    int is_streamed;

    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

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

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

                         int64_t timestamp, int flags);

} ByteIOContext;

int init_put_byte(ByteIOContext *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));

ByteIOContext *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));

void put_byte(ByteIOContext *s, int b);

void put_nbyte(ByteIOContext *s, int b, int count);

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

void put_le64(ByteIOContext *s, uint64_t val);

void put_be64(ByteIOContext *s, uint64_t val);

void put_le32(ByteIOContext *s, unsigned int val);

void put_be32(ByteIOContext *s, unsigned int val);

void put_le24(ByteIOContext *s, unsigned int val);

void put_be24(ByteIOContext *s, unsigned int val);

void put_le16(ByteIOContext *s, unsigned int val);

void put_be16(ByteIOContext *s, unsigned int val);

void put_tag(ByteIOContext *s, const char *tag);

void put_strz(ByteIOContext *s, const char *buf);

/**

 * fseek() equivalent for ByteIOContext.

 * @return new position or AVERROR.

 */

int64_t url_fseek(ByteIOContext *s, int64_t offset, int whence);

/**

 * Skip given number of bytes forward.

 * @param offset number of bytes

 * @return 0 on success, <0 on error

 */

int url_fskip(ByteIOContext *s, int64_t offset);

/**

 * ftell() equivalent for ByteIOContext.

 * @return position or AVERROR.

 */

int64_t url_ftell(ByteIOContext *s);

/**

 * Get the filesize.

 * @return filesize or AVERROR

 */

int64_t url_fsize(ByteIOContext *s);

/**

 * feof() equivalent for ByteIOContext.

 * @return non zero if and only if end of file

 */

int url_feof(ByteIOContext *s);

int url_ferror(ByteIOContext *s);

int av_url_read_fpause(ByteIOContext *h, int pause);

int64_t av_url_read_fseek(ByteIOContext *h, int stream_index,

                          int64_t timestamp, int flags);

#define URL_EOF (-1)

/** @note return URL_EOF (-1) if EOF */

int url_fgetc(ByteIOContext *s);

/** @warning currently size is limited */

#ifdef __GNUC__

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

#else

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

#endif

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

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

char *url_fgets(ByteIOContext *s, char *buf, int buf_size);

void put_flush_packet(ByteIOContext *s);

/**

 * Read size bytes from ByteIOContext into buf.

 * @return number of bytes read or AVERROR

 */

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

/**

 * Read size bytes from ByteIOContext into buf.

 * This reads at most 1 packet. If that is not enough fewer bytes will be

 * returned.

 * @return number of bytes read or AVERROR

 */

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

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

    necessary */

int get_byte(ByteIOContext *s);

unsigned int get_le24(ByteIOContext *s);

unsigned int get_le32(ByteIOContext *s);

uint64_t get_le64(ByteIOContext *s);

unsigned int get_le16(ByteIOContext *s);

char *get_strz(ByteIOContext *s, char *buf, int maxlen);

unsigned int get_be16(ByteIOContext *s);

unsigned int get_be24(ByteIOContext *s);

unsigned int get_be32(ByteIOContext *s);

uint64_t get_be64(ByteIOContext *s);

uint64_t ff_get_v(ByteIOContext *bc);

static inline int url_is_streamed(ByteIOContext *s)

{

    return s->is_streamed;

}

/**

 * Create and initialize a ByteIOContext for accessing the

 * resource referenced by the URLContext h.

 * @note When the URLContext h has been opened in read+write mode, the

 * ByteIOContext can be used only for writing.

 *

 * @param s Used to return the pointer to the created ByteIOContext.

 * 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 url_fdopen(ByteIOContext **s, URLContext *h);

/** @warning must be called before any I/O */

int url_setbufsize(ByteIOContext *s, int buf_size);

#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(ByteIOContext *s, int flags);

#endif

/**

 * Rewind the ByteIOContext 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

 * @note This function is NOT part of the public API

 *

 * @param s The read-only ByteIOContext 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 ff_rewind_with_probe_data(ByteIOContext *s, unsigned char *buf, int buf_size);

/**

 * Create and initialize a ByteIOContext for accessing the

 * resource indicated by url.

 * @note When the resource indicated by url has been opened in

 * read+write mode, the ByteIOContext can be used only for writing.

 *

 * @param s Used to return the pointer to the created ByteIOContext.

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

int url_fclose(ByteIOContext *s);

URLContext *url_fileno(ByteIOContext *s);

/**

 * Return the maximum packet size associated to packetized buffered file

 * handle. If the file is not packetized (stream like http or file on

 * disk), then 0 is returned.

 *

 * @param s buffered file handle

 * @return maximum packet size in bytes

 */

int url_fget_max_packet_size(ByteIOContext *s);

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

/** return the written or read size */

int url_close_buf(ByteIOContext *s);

/**

 * Open a write only memory stream.

 *

 * @param s new IO context

 * @return zero if no error.

 */

int url_open_dyn_buf(ByteIOContext **s);

/**

 * 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 url_open_dyn_packet_buf(ByteIOContext **s, int max_packet_size);

/**

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

 * must be freed with av_free(). If the buffer is opened with

 * url_open_dyn_buf, then padding of FF_INPUT_BUFFER_PADDING_SIZE is

 * added; if opened with url_open_dyn_packet_buf, no padding is added.

 *

 * @param s IO context

 * @param pbuffer pointer to a byte buffer

 * @return the length of the byte buffer

 */

int url_close_dyn_buf(ByteIOContext *s, uint8_t **pbuffer);

unsigned long ff_crc04C11DB7_update(unsigned long checksum, const uint8_t *buf,

                                    unsigned int len);

unsigned long get_checksum(ByteIOContext *s);

void init_checksum(ByteIOContext *s,

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

                   unsigned long checksum);

/* udp.c */

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

int udp_get_local_port(URLContext *h);

#if FF_API_UDP_GET_FILE

int udp_get_file_handle(URLContext *h);

#endif

#endif /* AVFORMAT_AVIO_H */