/*
  * 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 libavformat/avio.h
  * 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"
 

 /* 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*.

  */

 struct URLContext {

 #if LIBAVFORMAT_VERSION_MAJOR >= 53
     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 filename */

 };
 
 typedef struct URLContext 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);
 

 int url_open_protocol (URLContext **puc, struct URLProtocol *up,
                        const char *filename, int flags);

 int url_open(URLContext **h, const char *filename, int flags);
 int url_read(URLContext *h, unsigned char *buf, int size);
 int url_write(URLContext *h, unsigned char *buf, int size);

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

 int url_close(URLContext *h);
 int url_exist(const char *filename);

 int64_t url_filesize(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);

 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);

 /**

  * 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
 

 typedef struct URLProtocol {
     const char *name;
     int (*url_open)(URLContext *h, const char *filename, int flags);
     int (*url_read)(URLContext *h, unsigned char *buf, int size);
     int (*url_write)(URLContext *h, 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);

 } URLProtocol;
 

 #if LIBAVFORMAT_VERSION_MAJOR < 53

 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 LIBAVFORMAT_VERSION_MAJOR < 53
 /**
  * @deprecated Use av_register_protocol() instead.
  */
 attribute_deprecated int register_protocol(URLProtocol *protocol);
 #endif
 
 int av_register_protocol(URLProtocol *protocol);

 /**
  * 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_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
  */

 void url_fskip(ByteIOContext *s, int64_t offset);

 
 /**
  * ftell() equivalent for ByteIOContext.
  * @return position or AVERROR.
  */

 int64_t url_ftell(ByteIOContext *s);

 
 /**
  * Gets 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);
 

 
 /**
  * Reads size bytes from ByteIOContext into buf.
  * @returns number of bytes read or AVERROR
  */

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

 
 /**
  * Reads size bytes from ByteIOContext into buf.

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

  * returned.
  * @returns 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;
 }
 

 /** @note when opened as read/write, the buffers are only used for

     writing */

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

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

 int url_setbufsize(ByteIOContext *s, int buf_size);

 /** 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);

 /** @note when opened as read/write, the buffers are only used for

     writing */

 int url_fopen(ByteIOContext **s, const char *filename, 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().
  * @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);
 int udp_get_file_handle(URLContext *h);
 

 #endif /* AVFORMAT_AVIO_H */