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 *****************************************************************************/
25 #define _VLC_STREAM_H 1
32 * \defgroup stream Stream
34 * This will allow you to easily handle read/seek in demuxer modules.
39 * Possible commands to send to stream_Control() and stream_vaControl()
44 STREAM_CAN_SEEK, /**< arg1= vlc_bool_t * res=cannot fail*/
45 STREAM_CAN_FASTSEEK, /**< arg1= vlc_bool_t * res=cannot fail*/
48 STREAM_SET_POSITION, /**< arg1= int64_t res=can fail */
49 STREAM_GET_POSITION, /**< arg1= int64_t * res=cannot fail*/
51 STREAM_GET_SIZE, /**< arg1= int64_t * res=cannot fail (0 if no sense)*/
53 STREAM_GET_MTU, /**< arg1= int * res=cannot fail (0 if no sense)*/
55 /* Special for direct access control from demuxer.
56 * XXX: avoid using it by all means */
57 STREAM_CONTROL_ACCESS /* arg1= int i_access_query, args res: can fail
58 if access unreachable or access control answer */
68 block_t *(*pf_block) ( stream_t *, int i_size );
69 int (*pf_read) ( stream_t *, void *p_read, int i_read );
70 int (*pf_peek) ( stream_t *, uint8_t **pp_peek, int i_peek );
71 int (*pf_control)( stream_t *, int i_query, va_list );
72 void (*pf_destroy)( stream_t *);
76 /* UTF-16 and UTF-32 file reading */
79 vlc_bool_t b_little_endian;
83 * Try to read "i_read" bytes into a buffer pointed by "p_read". If
84 * "p_read" is NULL then data are skipped instead of read. The return
85 * value is the real numbers of bytes read/skip. If this value is less
86 * than i_read that means that it's the end of the stream.
88 static inline int stream_Read( stream_t *s, void *p_read, int i_read )
90 return s->pf_read( s, p_read, i_read );
94 * Store in pp_peek a pointer to the next "i_peek" bytes in the stream
95 * \return The real numbers of valid bytes, if it's less
96 * or equal to 0, *pp_peek is invalid.
97 * \note pp_peek is a pointer to internal buffer and it will be invalid as
98 * soons as other stream_* functions are called.
99 * \note Due to input limitation, it could be less than i_peek without meaning
100 * the end of the stream (but only when you have i_peek >=
101 * p_input->i_bufsize)
103 static inline int stream_Peek( stream_t *s, uint8_t **pp_peek, int i_peek )
105 return s->pf_peek( s, pp_peek, i_peek );
109 * Use to control the "stream_t *". Look at #stream_query_e for
110 * possible "i_query" value and format arguments. Return VLC_SUCCESS
111 * if ... succeed ;) and VLC_EGENERIC if failed or unimplemented
113 static inline int stream_vaControl( stream_t *s, int i_query, va_list args )
115 return s->pf_control( s, i_query, args );
121 static inline void stream_Delete( stream_t *s )
126 static inline int stream_Control( stream_t *s, int i_query, ... )
134 va_start( args, i_query );
135 i_result = s->pf_control( s, i_query, args );
141 * Get the current position in a stream
143 static inline int64_t stream_Tell( stream_t *s )
146 stream_Control( s, STREAM_GET_POSITION, &i_pos );
151 * Get the size of the stream.
153 static inline int64_t stream_Size( stream_t *s )
156 stream_Control( s, STREAM_GET_SIZE, &i_pos );
159 static inline int stream_MTU( stream_t *s )
162 stream_Control( s, STREAM_GET_MTU, &i_mtu );
165 static inline int stream_Seek( stream_t *s, int64_t i_pos )
167 return stream_Control( s, STREAM_SET_POSITION, i_pos );
171 * Read "i_size" bytes and store them in a block_t. If less than "i_size"
172 * bytes are available then return what is left and if nothing is availble,
175 static inline block_t *stream_Block( stream_t *s, int i_size )
177 if( i_size <= 0 ) return NULL;
181 return s->pf_block( s, i_size );
185 /* emulate block read */
186 block_t *p_bk = block_New( s, i_size );
189 p_bk->i_buffer = stream_Read( s, p_bk->p_buffer, i_size );
190 if( p_bk->i_buffer > 0 )
195 if( p_bk ) block_Release( p_bk );
200 VLC_EXPORT( char *, stream_ReadLine, ( stream_t * ) );
203 * Create a special stream and a demuxer, this allows chaining demuxers
205 #define stream_DemuxNew( a, b, c ) __stream_DemuxNew( VLC_OBJECT(a), b, c)
206 VLC_EXPORT( stream_t *,__stream_DemuxNew, ( vlc_object_t *p_obj, char *psz_demux, es_out_t *out ) );
207 VLC_EXPORT( void, stream_DemuxSend, ( stream_t *s, block_t *p_block ) );
208 VLC_EXPORT( void, stream_DemuxDelete,( stream_t *s ) );
211 #define stream_MemoryNew( a, b, c, d ) __stream_MemoryNew( VLC_OBJECT(a), b, c, d )
212 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 ) );
213 #define stream_UrlNew( a, b ) __stream_UrlNew( VLC_OBJECT(a), b )
214 VLC_EXPORT( stream_t *,__stream_UrlNew, (vlc_object_t *p_this, const char *psz_url ) );