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     bool        b_error;
  56
  57     /* Module properties for stream filter */
  58     module_t    *p_module;
  59
  60     /* Real or virtual path (it can only be changed during stream_t opening) */
  61     char        *psz_path;
  62
  63     /* Stream source for stream filter */
  64     stream_t *p_source;
  65
  66     /* */
  67     int      (*pf_read)   ( stream_t *, void *p_read, unsigned int i_read );
  68     int      (*pf_peek)   ( stream_t *, const uint8_t **pp_peek, unsigned int i_peek );
  69     int      (*pf_control)( stream_t *, int i_query, va_list );
  70
  71     /* */
  72     void     (*pf_destroy)( stream_t *);
  73
  74     /* Private data for module */
  75     stream_sys_t *p_sys;
  76
  77     /* Text reader state */
  78     stream_text_t *p_text;
  79
  80     /* Weak link to parent input */
  81     input_thread_t *p_input;
  82 };
  83
  84 /**
  85  * Possible commands to send to stream_Control() and stream_vaControl()
  86  */
  87 enum stream_query_e
  88 {
  89     /* capabilities */
  90     STREAM_CAN_SEEK,            /**< arg1= bool *   res=cannot fail*/
  91     STREAM_CAN_FASTSEEK,        /**< arg1= bool *   res=cannot fail*/
  92
  93     /* */
  94     STREAM_SET_POSITION,        /**< arg1= uint64_t       res=can fail  */
  95     STREAM_GET_POSITION,        /**< arg1= uint64_t *     res=cannot fail*/
  96
  97     STREAM_GET_SIZE,            /**< arg1= uint64_t *     res=cannot fail (0 if no sense)*/
  98
  99     /* Special for direct access control from demuxer.
 100      * XXX: avoid using it by all means */
 101     STREAM_CONTROL_ACCESS,  /* arg1= int i_access_query, args   res: can fail
 102                              if access unreachable or access control answer */
 103
 104     /* You should update size of source if any and then update size
 105      * FIXME find a way to avoid it */
 106     STREAM_UPDATE_SIZE,
 107
 108     /* */
 109     STREAM_GET_CONTENT_TYPE,    /**< arg1= char **         res=can fail */
 110
 111     /* XXX only data read through stream_Read/Block will be recorded */
 112     STREAM_SET_RECORD_STATE,     /**< arg1=bool, arg2=const char *psz_ext (if arg1 is true)  res=can fail */
 113 };
 114
 115 VLC_EXPORT( int, stream_Read, ( stream_t *s, void *p_read, int i_read ) );
 116 VLC_EXPORT( int, stream_Peek, ( stream_t *s, const uint8_t **pp_peek, int i_peek ) );
 117 VLC_EXPORT( int, stream_vaControl, ( stream_t *s, int i_query, va_list args ) );
 118 VLC_EXPORT( void, stream_Delete, ( stream_t *s ) );
 119 VLC_EXPORT( int, stream_Control, ( stream_t *s, int i_query, ... ) );
 120 VLC_EXPORT( block_t *, stream_Block, ( stream_t *s, int i_size ) );
 121 VLC_EXPORT( char *, stream_ReadLine, ( stream_t * ) );
 122
 123 /**
 124  * Get the current position in a stream
 125  */
 126 static inline int64_t stream_Tell( stream_t *s )
 127 {
 128     uint64_t i_pos;
 129     stream_Control( s, STREAM_GET_POSITION, &i_pos );
 130     if( i_pos >> 62 )
 131         return (int64_t)1 << 62;
 132     return i_pos;
 133 }
 134
 135 /**
 136  * Get the size of the stream.
 137  */
 138 static inline int64_t stream_Size( stream_t *s )
 139 {
 140     uint64_t i_pos;
 141     stream_Control( s, STREAM_GET_SIZE, &i_pos );
 142     if( i_pos >> 62 )
 143         return (int64_t)1 << 62;
 144     return i_pos;
 145 }
 146
 147 static inline int stream_Seek( stream_t *s, uint64_t i_pos )
 148 {
 149     return stream_Control( s, STREAM_SET_POSITION, i_pos );
 150 }
 151
 152 /**
 153  * Get the Content-Type of a stream, or NULL if unknown.
 154  * Result must be free()'d.
 155  */
 156 static inline char *stream_ContentType( stream_t *s )
 157 {
 158     char *res;
 159     if( stream_Control( s, STREAM_GET_CONTENT_TYPE, &res ) )
 160         return NULL;
 161     return res;
 162 }
 163
 164 /**
 165  * Create a special stream and a demuxer, this allows chaining demuxers
 166  * You must delete it using stream_Delete.
 167  */
 168 VLC_EXPORT( stream_t *, stream_DemuxNew, ( demux_t *p_demux, const char *psz_demux, es_out_t *out ) );
 169
 170 /**
 171  * Send data to a stream_t handle created by stream_DemuxNew.
 172  */
 173 VLC_EXPORT( void,      stream_DemuxSend,  ( stream_t *s, block_t *p_block ) );
 174
 175 /**
 176  * Create a stream_t reading from memory.
 177  * You must delete it using stream_Delete.
 178  */
 179 #define stream_MemoryNew( a, b, c, d ) __stream_MemoryNew( VLC_OBJECT(a), b, c, d )
 180 VLC_EXPORT( stream_t *,__stream_MemoryNew, (vlc_object_t *p_obj, uint8_t *p_buffer, uint64_t i_size, bool b_preserve_memory ) );
 181
 182 /**
 183  * Create a stream_t reading from an URL.
 184  * You must delete it using stream_Delete.
 185  */
 186 #define stream_UrlNew( a, b ) __stream_UrlNew( VLC_OBJECT(a), b )
 187 VLC_EXPORT( stream_t *,__stream_UrlNew, (vlc_object_t *p_this, const char *psz_url ) );
 188
 189 /**
 190  * Try to add a stream filter to an open stream.
 191  * @return New stream to use, or NULL if the filter could not be added.
 192  **/
 193 VLC_EXPORT( stream_t*, stream_FilterNew, ( stream_t *p_source, const char *psz_stream_filter ) );
 194 /**
 195  * @}
 196  */
 197
 198 # ifdef __cplusplus
 199 }
 200 # endif
 201
 202 #endif