/*****************************************************************************
* vlc_block.h: Data blocks management functions
*****************************************************************************
* Copyright (C) 2003 the VideoLAN team
* $Id$
*
* Authors: Laurent Aimar <fenrir@via.ecp.fr>
*
* 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., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
*****************************************************************************/
#ifndef VLC_BLOCK_H
#define VLC_BLOCK_H 1
/**
* \file
* This file implements functions and structures to handle blocks of data in vlc
*
*/
/****************************************************************************
* block:
****************************************************************************
* - block_sys_t is opaque and thus block_t->p_sys is PRIVATE
* - i_flags may not always be set (ie could be 0, even for a key frame
* it depends where you receive the buffer (before/after a packetizer
* and the demux/packetizer implementations.
* - i_dts/i_pts could be 0, it means no pts
* - i_length: length in microseond of the packet, can be null except in the
* sout where it is mandatory.
* - i_rate 0 or a valid input rate, look at vlc_input.h
*
* - i_buffer number of valid data pointed by p_buffer
* you can freely decrease it but never increase it yourself
* (use block_Realloc)
* - p_buffer: pointer over datas. You should never overwrite it, you can
* only incremment it to skip datas, in others cases use block_Realloc
* (don't duplicate yourself in a bigger buffer, block_Realloc is
* optimised for prehader/postdatas increase)
****************************************************************************/
typedef struct block_sys_t block_sys_t;
/** The content doesn't follow the last block, or is probably broken */
#define BLOCK_FLAG_DISCONTINUITY 0x0001
/** Intra frame */
#define BLOCK_FLAG_TYPE_I 0x0002
/** Inter frame with backward reference only */
#define BLOCK_FLAG_TYPE_P 0x0004
/** Inter frame with backward and forward reference */
#define BLOCK_FLAG_TYPE_B 0x0008
/** For inter frame when you don't know the real type */
#define BLOCK_FLAG_TYPE_PB 0x0010
/** Warn that this block is a header one */
#define BLOCK_FLAG_HEADER 0x0020
/** This is the last block of the frame */
#define BLOCK_FLAG_END_OF_FRAME 0x0040
/** This is not a key frame for bitrate shaping */
#define BLOCK_FLAG_NO_KEYFRAME 0x0080
/** This block contains the last part of a sequence */
#define BLOCK_FLAG_END_OF_SEQUENCE 0x0100
/** This block contains a clock reference */
#define BLOCK_FLAG_CLOCK 0x0200
/** This block is scrambled */
#define BLOCK_FLAG_SCRAMBLED 0x0400
/** This block has to be decoded but not be displayed */
#define BLOCK_FLAG_PREROLL 0x0800
/** This block is corrupted and/or there is data loss */
#define BLOCK_FLAG_CORRUPTED 0x1000
#define BLOCK_FLAG_PRIVATE_MASK 0xffff0000
#define BLOCK_FLAG_PRIVATE_SHIFT 16
typedef void (*block_free_t) (block_t *);
struct block_t
{
block_t *p_next;
block_t *p_prev;
uint32_t i_flags;
mtime_t i_pts;
mtime_t i_dts;
mtime_t i_length;
int i_samples; /* Used for audio */
int i_rate;
size_t i_buffer;
uint8_t *p_buffer;
/* Rudimentary support for overloading block (de)allocation. */
block_free_t pf_release;
};
/****************************************************************************
* Blocks functions:
****************************************************************************
* - block_Alloc : create a new block with the requested size ( >= 0 ), return
* NULL for failure.
* - block_Release : release a block allocated with block_Alloc.
* - block_Realloc : realloc a block,
* i_pre: how many bytes to insert before body if > 0, else how many
* bytes of body to skip (the latter can be done without using
* block_Realloc i_buffer -= -i_pre, p_buffer += -i_pre as i_pre < 0)
* i_body (>= 0): the final size of the body (decreasing it can directly
* be done with i_buffer = i_body).
* with preheader and or body (increase
* and decrease are supported). Use it as it is optimised.
* - block_Duplicate : create a copy of a block.
****************************************************************************/
VLC_EXPORT( void, block_Init, ( block_t *, void *, size_t ) );
VLC_EXPORT( block_t *, block_Alloc, ( size_t ) );
VLC_EXPORT( block_t *, block_Realloc, ( block_t *, ssize_t i_pre, size_t i_body ) );
#define block_New( dummy, size ) block_Alloc(size)
static inline block_t *block_Duplicate( block_t *p_block )
{
block_t *p_dup = block_Alloc( p_block->i_buffer );
if( p_dup == NULL )
return NULL;
p_dup->i_dts = p_block->i_dts;
p_dup->i_pts = p_block->i_pts;
p_dup->i_flags = p_block->i_flags;
p_dup->i_length = p_block->i_length;
p_dup->i_rate = p_block->i_rate;
p_dup->i_samples = p_block->i_samples;
memcpy( p_dup->p_buffer, p_block->p_buffer, p_block->i_buffer );
return p_dup;
}
static inline void block_Release( block_t *p_block )
{
p_block->pf_release( p_block );
}
VLC_EXPORT( block_t *, block_mmap_Alloc, (void *addr, size_t length) );
VLC_EXPORT( block_t *, block_File, (int fd) );
/****************************************************************************
* Chains of blocks functions helper
****************************************************************************
* - block_ChainAppend : append a block to the last block of a chain. Try to
* avoid using with a lot of data as it's really slow, prefer
* block_ChainLastAppend
* - block_ChainLastAppend : use a pointer over a pointer to the next blocks,
* and update it.
* - block_ChainRelease : release a chain of block
* - block_ChainExtract : extract data from a chain, return real bytes counts
* - block_ChainGather : gather a chain, free it and return one block.
****************************************************************************/
static inline void block_ChainAppend( block_t **pp_list, block_t *p_block )
{
if( *pp_list == NULL )
{
*pp_list = p_block;
}
else
{
block_t *p = *pp_list;
while( p->p_next ) p = p->p_next;
p->p_next = p_block;
}
}
static inline void block_ChainLastAppend( block_t ***ppp_last, block_t *p_block )
{
block_t *p_last = p_block;
**ppp_last = p_block;
while( p_last->p_next ) p_last = p_last->p_next;
*ppp_last = &p_last->p_next;
}
static inline void block_ChainRelease( block_t *p_block )
{
while( p_block )
{
block_t *p_next = p_block->p_next;
block_Release( p_block );
p_block = p_next;
}
}
static size_t block_ChainExtract( block_t *p_list, void *p_data, size_t i_max )
{
size_t i_total = 0;
uint8_t *p = (uint8_t*)p_data;
while( p_list && i_max )
{
size_t i_copy = __MIN( i_max, p_list->i_buffer );
memcpy( p, p_list->p_buffer, i_copy );
i_max -= i_copy;
i_total += i_copy;
p += i_copy;
p_list = p_list->p_next;
}
return i_total;
}
static inline block_t *block_ChainGather( block_t *p_list )
{
size_t i_total = 0;
mtime_t i_length = 0;
block_t *b, *g;
if( p_list->p_next == NULL )
return p_list; /* Already gathered */
for( b = p_list; b != NULL; b = b->p_next )
{
i_total += b->i_buffer;
i_length += b->i_length;
}
g = block_Alloc( i_total );
block_ChainExtract( p_list, g->p_buffer, g->i_buffer );
g->i_flags = p_list->i_flags;
g->i_pts = p_list->i_pts;
g->i_dts = p_list->i_dts;
g->i_length = i_length;
/* free p_list */
block_ChainRelease( p_list );
return g;
}
/****************************************************************************
* Fifos of blocks.
****************************************************************************
* - block_FifoNew : create and init a new fifo
* - block_FifoRelease : destroy a fifo and free all blocks in it.
* - block_FifoEmpty : free all blocks in a fifo
* - block_FifoPut : put a block
* - block_FifoGet : get a packet from the fifo (and wait if it is empty)
* - block_FifoShow : show the first packet of the fifo (and wait if
* needed), be carefull, you can use it ONLY if you are sure to be the
* only one getting data from the fifo.
* - block_FifoCount : how many packets are waiting in the fifo
* - block_FifoSize : how many cumulated bytes are waiting in the fifo
* - block_FifoWake : wake ups a thread with block_FifoGet() = NULL
* (this is used to wakeup a thread when there is no data to queue)
****************************************************************************/
VLC_EXPORT( block_fifo_t *, block_FifoNew, ( void ) );
VLC_EXPORT( void, block_FifoRelease, ( block_fifo_t * ) );
VLC_EXPORT( void, block_FifoEmpty, ( block_fifo_t * ) );
VLC_EXPORT( size_t, block_FifoPut, ( block_fifo_t *, block_t * ) );
VLC_EXPORT( void, block_FifoWake, ( block_fifo_t * ) );
VLC_EXPORT( block_t *, block_FifoGet, ( block_fifo_t * ) );
VLC_EXPORT( block_t *, block_FifoShow, ( block_fifo_t * ) );
VLC_EXPORT( size_t, block_FifoSize, ( const block_fifo_t *p_fifo ) );
VLC_EXPORT( size_t, block_FifoCount, ( const block_fifo_t *p_fifo ) );
#endif /* VLC_BLOCK_H */
