include/vlc_stream.h

   1 /*****************************************************************************
   2  * vlc_stream.h: Stream (between access and demux) descriptor and methods
   3  *****************************************************************************
   4  * Copyright (C) 1999-2004 the VideoLAN team
   5  * $Id$
   6  *
   7  * Authors: Laurent Aimar <fenrir@via.ecp.fr>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  22  *****************************************************************************/
  23
  24 #ifndef VLC_STREAM_H
  25 #define VLC_STREAM_H 1
  26
  27 #include <vlc_block.h>
  28
  29 /**
  30  * \file
  31  * This file defines structures and functions for stream (between access and demux) descriptor in vlc
  32  */
  33
  34 # ifdef __cplusplus
  35 extern "C" {
  36 # endif
  37
  38 /**
  39  * \defgroup stream Stream
  40  *
  41  *  This will allow you to easily handle read/seek in demuxer modules.
  42  * @{
  43  */
  44
  45 /* Opaque definition for text reader context */
  46 typedef struct stream_text_t stream_text_t;
  47
  48 /**
  49  * stream_t definition
  50  */
  51
  52 struct stream_t
  53 {
  54     VLC_COMMON_MEMBERS
  55
  56     /* Module properties for stream filter */
  57     module_t    *p_module;
  58
  59     /* Stream source for stream filter */
  60     stream_t *p_source;
  61
  62     /* */
  63     int      (*pf_read)   ( stream_t *, void *p_read, unsigned int i_read );
  64     int      (*pf_peek)   ( stream_t *, const uint8_t **pp_peek, unsigned int i_peek );
  65     int      (*pf_control)( stream_t *, int i_query, va_list );
  66
  67     /* */
  68     void     (*pf_destroy)( stream_t *);
  69
  70     /* Private data for module */
  71     stream_sys_t *p_sys;
  72
  73     /* Text reader state */
  74     stream_text_t *p_text;
  75 };
  76
  77 /**
  78  * Possible commands to send to stream_Control() and stream_vaControl()
  79  */
  80 enum stream_query_e
  81 {
  82     /* capabilities */
  83     STREAM_CAN_SEEK,            /**< arg1= bool *   res=cannot fail*/
  84     STREAM_CAN_FASTSEEK,        /**< arg1= bool *   res=cannot fail*/
  85
  86     /* */
  87     STREAM_SET_POSITION,        /**< arg1= int64_t        res=can fail  */
  88     STREAM_GET_POSITION,        /**< arg1= int64_t *      res=cannot fail*/
  89
  90     STREAM_GET_SIZE,            /**< arg1= int64_t *      res=cannot fail (0 if no sense)*/
  91
  92     STREAM_GET_MTU,             /**< arg1= int *          res=cannot fail (0 if no sense)*/
  93
  94     /* Special for direct access control from demuxer.
  95      * XXX: avoid using it by all means */
  96     STREAM_CONTROL_ACCESS,  /* arg1= int i_access_query, args   res: can fail
  97                              if access unreachable or access control answer */
  98
  99     /* You should update size of source if any and then update size
 100      * FIXME find a way to avoid it */
 101     STREAM_UPDATE_SIZE,
 102
 103     /* */
 104     STREAM_GET_CONTENT_TYPE,    /**< arg1= char **         res=can fail */
 105
 106     /* XXX only data read through stream_Read/Block will be recorded */
 107     STREAM_SET_RECORD_STATE,     /**< arg1=bool, arg2=const char *psz_ext (if arg1 is true)  res=can fail */
 108 };
 109
 110 VLC_EXPORT( int, stream_Read, ( stream_t *s, void *p_read, int i_read ) );
 111 VLC_EXPORT( int, stream_Peek, ( stream_t *s, const uint8_t **pp_peek, int i_peek ) );
 112 VLC_EXPORT( int, stream_vaControl, ( stream_t *s, int i_query, va_list args ) );
 113 VLC_EXPORT( void, stream_Delete, ( stream_t *s ) );
 114 VLC_EXPORT( int, stream_Control, ( stream_t *s, int i_query, ... ) );
 115 VLC_EXPORT( block_t *, stream_Block, ( stream_t *s, int i_size ) );
 116 VLC_EXPORT( char *, stream_ReadLine, ( stream_t * ) );
 117
 118 /**
 119  * Get the current position in a stream
 120  */
 121 static inline int64_t stream_Tell( stream_t *s )
 122 {
 123     int64_t i_pos;
 124     stream_Control( s, STREAM_GET_POSITION, &i_pos );
 125     return i_pos;
 126 }
 127
 128 /**
 129  * Get the size of the stream.
 130  */
 131 static inline int64_t stream_Size( stream_t *s )
 132 {
 133     int64_t i_pos;
 134     stream_Control( s, STREAM_GET_SIZE, &i_pos );
 135     return i_pos;
 136 }
 137
 138 static inline int stream_MTU( stream_t *s )
 139 {
 140     int i_mtu;
 141     stream_Control( s, STREAM_GET_MTU, &i_mtu );
 142     return i_mtu;
 143 }
 144
 145 static inline int stream_Seek( stream_t *s, int64_t i_pos )
 146 {
 147     return stream_Control( s, STREAM_SET_POSITION, i_pos );
 148 }
 149
 150 /**
 151  * Get the Content-Type of a stream, or NULL if unknown.
 152  * Result must be free()'d.
 153  */
 154 static inline char *stream_ContentType( stream_t *s )
 155 {
 156     char *res;
 157     if( stream_Control( s, STREAM_GET_CONTENT_TYPE, &res ) )
 158         return NULL;
 159     return res;
 160 }
 161
 162 /**
 163  * Create a special stream and a demuxer, this allows chaining demuxers
 164  * You must delete it using stream_Delete.
 165  */
 166 #define stream_DemuxNew( a, b, c ) __stream_DemuxNew( VLC_OBJECT(a), b, c)
 167 VLC_EXPORT( stream_t *,__stream_DemuxNew, ( vlc_object_t *p_obj, const char *psz_demux, es_out_t *out ) );
 168 /**
 169  * Send data to a stream_t handle created by stream_DemuxNew.
 170  */
 171 VLC_EXPORT( void,      stream_DemuxSend,  ( stream_t *s, block_t *p_block ) );
 172
 173 /**
 174  * Create a stream_t reading from memory.
 175  * You must delete it using stream_Delete.
 176  */
 177 #define stream_MemoryNew( a, b, c, d ) __stream_MemoryNew( VLC_OBJECT(a), b, c, d )
 178 VLC_EXPORT( stream_t *,__stream_MemoryNew, (vlc_object_t *p_obj, uint8_t *p_buffer, int64_t i_size, bool b_preserve_memory ) );
 179
 180 /**
 181  * Create a stream_t reading from an URL.
 182  * You must delete it using stream_Delete.
 183  */
 184 #define stream_UrlNew( a, b ) __stream_UrlNew( VLC_OBJECT(a), b )
 185 VLC_EXPORT( stream_t *,__stream_UrlNew, (vlc_object_t *p_this, const char *psz_url ) );
 186
 187 /**
 188  * @}
 189  */
 190
 191 # ifdef __cplusplus
 192 }
 193 # endif
 194
 195 #endif