/***************************************************************************** * vlc_stream.h: Stream (between access and demux) descriptor and methods ***************************************************************************** * Copyright (C) 1999-2004 the VideoLAN team * $Id$ * * Authors: Laurent Aimar * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program 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 General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA. *****************************************************************************/ #ifndef _VLC_STREAM_H #define _VLC_STREAM_H 1 # ifdef __cplusplus extern "C" { # endif /** * \defgroup stream Stream * * This will allow you to easily handle read/seek in demuxer modules. * @{ */ /** * Possible commands to send to stream_Control() and stream_vaControl() */ enum stream_query_e { /* capabilities */ STREAM_CAN_SEEK, /**< arg1= vlc_bool_t * res=cannot fail*/ STREAM_CAN_FASTSEEK, /**< arg1= vlc_bool_t * res=cannot fail*/ /* */ STREAM_SET_POSITION, /**< arg1= int64_t res=can fail */ STREAM_GET_POSITION, /**< arg1= int64_t * res=cannot fail*/ STREAM_GET_SIZE, /**< arg1= int64_t * res=cannot fail (0 if no sense)*/ STREAM_GET_MTU, /**< arg1= int * res=cannot fail (0 if no sense)*/ /* Special for direct access control from demuxer. * XXX: avoid using it by all means */ STREAM_CONTROL_ACCESS /* arg1= int i_access_query, args res: can fail if access unreachable or access control answer */ }; /** * stream_t definition */ struct stream_t { VLC_COMMON_MEMBERS block_t *(*pf_block) ( stream_t *, int i_size ); int (*pf_read) ( stream_t *, void *p_read, int i_read ); int (*pf_peek) ( stream_t *, uint8_t **pp_peek, int i_peek ); int (*pf_control)( stream_t *, int i_query, va_list ); void (*pf_destroy)( stream_t *); stream_sys_t *p_sys; /* UTF-16 and UTF-32 file reading */ vlc_iconv_t conv; int i_char_width; vlc_bool_t b_little_endian; }; /** * Try to read "i_read" bytes into a buffer pointed by "p_read". If * "p_read" is NULL then data are skipped instead of read. The return * value is the real numbers of bytes read/skip. If this value is less * than i_read that means that it's the end of the stream. */ static inline int stream_Read( stream_t *s, void *p_read, int i_read ) { return s->pf_read( s, p_read, i_read ); } /** * Store in pp_peek a pointer to the next "i_peek" bytes in the stream * \return The real numbers of valid bytes, if it's less * or equal to 0, *pp_peek is invalid. * \note pp_peek is a pointer to internal buffer and it will be invalid as * soons as other stream_* functions are called. * \note Due to input limitation, it could be less than i_peek without meaning * the end of the stream (but only when you have i_peek >= * p_input->i_bufsize) */ static inline int stream_Peek( stream_t *s, uint8_t **pp_peek, int i_peek ) { return s->pf_peek( s, pp_peek, i_peek ); } /** * Use to control the "stream_t *". Look at #stream_query_e for * possible "i_query" value and format arguments. Return VLC_SUCCESS * if ... succeed ;) and VLC_EGENERIC if failed or unimplemented */ static inline int stream_vaControl( stream_t *s, int i_query, va_list args ) { return s->pf_control( s, i_query, args ); } /** * Destroy a stream */ static inline void stream_Delete( stream_t *s ) { s->pf_destroy( s ); } static inline int stream_Control( stream_t *s, int i_query, ... ) { va_list args; int i_result; if ( s == NULL ) return VLC_EGENERIC; va_start( args, i_query ); i_result = s->pf_control( s, i_query, args ); va_end( args ); return i_result; } /** * Get the current position in a stream */ static inline int64_t stream_Tell( stream_t *s ) { int64_t i_pos; stream_Control( s, STREAM_GET_POSITION, &i_pos ); return i_pos; } /** * Get the size of the stream. */ static inline int64_t stream_Size( stream_t *s ) { int64_t i_pos; stream_Control( s, STREAM_GET_SIZE, &i_pos ); return i_pos; } static inline int stream_MTU( stream_t *s ) { int i_mtu; stream_Control( s, STREAM_GET_MTU, &i_mtu ); return i_mtu; } static inline int stream_Seek( stream_t *s, int64_t i_pos ) { return stream_Control( s, STREAM_SET_POSITION, i_pos ); } /** * Read "i_size" bytes and store them in a block_t. If less than "i_size" * bytes are available then return what is left and if nothing is availble, * return NULL. */ static inline block_t *stream_Block( stream_t *s, int i_size ) { if( i_size <= 0 ) return NULL; if( s->pf_block ) { return s->pf_block( s, i_size ); } else { /* emulate block read */ block_t *p_bk = block_New( s, i_size ); if( p_bk ) { p_bk->i_buffer = stream_Read( s, p_bk->p_buffer, i_size ); if( p_bk->i_buffer > 0 ) { return p_bk; } } if( p_bk ) block_Release( p_bk ); return NULL; } } VLC_EXPORT( char *, stream_ReadLine, ( stream_t * ) ); /** * Create a special stream and a demuxer, this allows chaining demuxers */ #define stream_DemuxNew( a, b, c ) __stream_DemuxNew( VLC_OBJECT(a), b, c) VLC_EXPORT( stream_t *,__stream_DemuxNew, ( vlc_object_t *p_obj, char *psz_demux, es_out_t *out ) ); VLC_EXPORT( void, stream_DemuxSend, ( stream_t *s, block_t *p_block ) ); VLC_EXPORT( void, stream_DemuxDelete,( stream_t *s ) ); #define stream_MemoryNew( a, b, c, d ) __stream_MemoryNew( VLC_OBJECT(a), b, c, d ) 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 ) ); #define stream_UrlNew( a, b ) __stream_UrlNew( VLC_OBJECT(a), b ) VLC_EXPORT( stream_t *,__stream_UrlNew, (vlc_object_t *p_this, const char *psz_url ) ); /** * @} */ # ifdef __cplusplus } # endif #endif