1 /*****************************************************************************
2 * vlc_stream.h: Stream (between access and demux) descriptor and methods
3 *****************************************************************************
4 * Copyright (C) 1999-2004 the VideoLAN team
7 * Authors: Laurent Aimar <fenrir@via.ecp.fr>
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.
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.
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 *****************************************************************************/
24 #if !defined( __LIBVLC__ )
25 #error You are not libvlc or one of its plugins. You cannot include this file
29 #define _VLC_STREAM_H 1
31 #include <vlc_block.h>
38 * \defgroup stream Stream
40 * This will allow you to easily handle read/seek in demuxer modules.
45 * Possible commands to send to stream_Control() and stream_vaControl()
50 STREAM_CAN_SEEK, /**< arg1= vlc_bool_t * res=cannot fail*/
51 STREAM_CAN_FASTSEEK, /**< arg1= vlc_bool_t * res=cannot fail*/
54 STREAM_SET_POSITION, /**< arg1= int64_t res=can fail */
55 STREAM_GET_POSITION, /**< arg1= int64_t * res=cannot fail*/
57 STREAM_GET_SIZE, /**< arg1= int64_t * res=cannot fail (0 if no sense)*/
59 STREAM_GET_MTU, /**< arg1= int * res=cannot fail (0 if no sense)*/
61 /* Special for direct access control from demuxer.
62 * XXX: avoid using it by all means */
63 STREAM_CONTROL_ACCESS /* arg1= int i_access_query, args res: can fail
64 if access unreachable or access control answer */
74 block_t *(*pf_block) ( stream_t *, int i_size );
75 int (*pf_read) ( stream_t *, void *p_read, int i_read );
76 int (*pf_peek) ( stream_t *, uint8_t **pp_peek, int i_peek );
77 int (*pf_control)( stream_t *, int i_query, va_list );
78 void (*pf_destroy)( stream_t *);
82 /* UTF-16 and UTF-32 file reading */
85 vlc_bool_t b_little_endian;
89 * Try to read "i_read" bytes into a buffer pointed by "p_read". If
90 * "p_read" is NULL then data are skipped instead of read. The return
91 * value is the real numbers of bytes read/skip. If this value is less
92 * than i_read that means that it's the end of the stream.
94 static inline int stream_Read( stream_t *s, void *p_read, int i_read )
96 return s->pf_read( s, p_read, i_read );
100 * Store in pp_peek a pointer to the next "i_peek" bytes in the stream
101 * \return The real numbers of valid bytes, if it's less
102 * or equal to 0, *pp_peek is invalid.
103 * \note pp_peek is a pointer to internal buffer and it will be invalid as
104 * soons as other stream_* functions are called.
105 * \note Due to input limitation, it could be less than i_peek without meaning
106 * the end of the stream (but only when you have i_peek >=
107 * p_input->i_bufsize)
109 static inline int stream_Peek( stream_t *s, uint8_t **pp_peek, int i_peek )
111 return s->pf_peek( s, pp_peek, i_peek );
115 * Use to control the "stream_t *". Look at #stream_query_e for
116 * possible "i_query" value and format arguments. Return VLC_SUCCESS
117 * if ... succeed ;) and VLC_EGENERIC if failed or unimplemented
119 static inline int stream_vaControl( stream_t *s, int i_query, va_list args )
121 return s->pf_control( s, i_query, args );
127 static inline void stream_Delete( stream_t *s )
132 static inline int stream_Control( stream_t *s, int i_query, ... )
140 va_start( args, i_query );
141 i_result = s->pf_control( s, i_query, args );
147 * Get the current position in a stream
149 static inline int64_t stream_Tell( stream_t *s )
152 stream_Control( s, STREAM_GET_POSITION, &i_pos );
157 * Get the size of the stream.
159 static inline int64_t stream_Size( stream_t *s )
162 stream_Control( s, STREAM_GET_SIZE, &i_pos );
165 static inline int stream_MTU( stream_t *s )
168 stream_Control( s, STREAM_GET_MTU, &i_mtu );
171 static inline int stream_Seek( stream_t *s, int64_t i_pos )
173 return stream_Control( s, STREAM_SET_POSITION, i_pos );
177 * Read "i_size" bytes and store them in a block_t. If less than "i_size"
178 * bytes are available then return what is left and if nothing is availble,
181 static inline block_t *stream_Block( stream_t *s, int i_size )
183 if( i_size <= 0 ) return NULL;
187 return s->pf_block( s, i_size );
191 /* emulate block read */
192 block_t *p_bk = block_New( s, i_size );
195 p_bk->i_buffer = stream_Read( s, p_bk->p_buffer, i_size );
196 if( p_bk->i_buffer > 0 )
201 if( p_bk ) block_Release( p_bk );
206 VLC_EXPORT( char *, stream_ReadLine, ( stream_t * ) );
209 * Create a special stream and a demuxer, this allows chaining demuxers
211 #define stream_DemuxNew( a, b, c ) __stream_DemuxNew( VLC_OBJECT(a), b, c)
212 VLC_EXPORT( stream_t *,__stream_DemuxNew, ( vlc_object_t *p_obj, const char *psz_demux, es_out_t *out ) );
213 VLC_EXPORT( void, stream_DemuxSend, ( stream_t *s, block_t *p_block ) );
214 VLC_EXPORT( void, stream_DemuxDelete,( stream_t *s ) );
217 #define stream_MemoryNew( a, b, c, d ) __stream_MemoryNew( VLC_OBJECT(a), b, c, d )
218 VLC_EXPORT( stream_t *,__stream_MemoryNew, (vlc_object_t *p_obj, uint8_t *p_buffer, int64_t i_size, vlc_bool_t i_preserve_memory ) );
219 #define stream_UrlNew( a, b ) __stream_UrlNew( VLC_OBJECT(a), b )
220 VLC_EXPORT( stream_t *,__stream_UrlNew, (vlc_object_t *p_this, const char *psz_url ) );