 /*****************************************************************************
  * vlc_block.h: Data blocks management functions
  *****************************************************************************
  * Copyright (C) 2003 the VideoLAN team
  * $Id: ce8d8e4d4dd24191613e0bb3a32e3755a7832f2d $
  *
  * 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 VLC_TS_INVALID, it means no pts/dts
  * - 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 preheader/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
 /** This block contains an interlaced picture with top field first */
 #define BLOCK_FLAG_TOP_FIELD_FIRST 0x2000
 /** This block contains an interlaced picture with bottom field first */
 #define BLOCK_FLAG_BOTTOM_FIELD_FIRST 0x4000
 
 /** This block contains an interlaced picture */
 #define BLOCK_FLAG_INTERLACED_MASK \
     (BLOCK_FLAG_TOP_FIELD_FIRST|BLOCK_FLAG_BOTTOM_FIELD_FIRST)
 
 #define BLOCK_FLAG_TYPE_MASK \
     (BLOCK_FLAG_TYPE_I|BLOCK_FLAG_TYPE_P|BLOCK_FLAG_TYPE_B|BLOCK_FLAG_TYPE_PB)
 
 /* These are for input core private usage only */
 #define BLOCK_FLAG_CORE_PRIVATE_MASK  0x00ff0000
 #define BLOCK_FLAG_CORE_PRIVATE_SHIFT 16
 
 /* These are for module private usage only */
 #define BLOCK_FLAG_PRIVATE_MASK  0xff000000
 #define BLOCK_FLAG_PRIVATE_SHIFT 24
 
 typedef void (*block_free_t) (block_t *);
 
 struct block_t
 {
     block_t     *p_next;
 
     uint32_t    i_flags;
 
     mtime_t     i_pts;
     mtime_t     i_dts;
     mtime_t     i_length;
 
     unsigned    i_nb_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_API void block_Init( block_t *, void *, size_t );
 VLC_API block_t * block_Alloc( size_t ) VLC_USED;
 VLC_API block_t * block_Realloc( block_t *, ssize_t i_pre, size_t i_body ) VLC_USED;
 
 #define block_New( dummy, size ) block_Alloc(size)
 
 VLC_USED
 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_nb_samples = p_block->i_nb_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_API block_t * block_heap_Alloc(void *, void *, size_t) VLC_USED;
 VLC_API block_t * block_mmap_Alloc(void *addr, size_t length) VLC_USED;
 VLC_API block_t * block_File(int fd) VLC_USED;
 
 static inline void block_Cleanup (void *block)
 {
     block_Release ((block_t *)block);
 }
 #define block_cleanup_push( block ) vlc_cleanup_push (block_Cleanup, block)
 
 /****************************************************************************
  * 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, p_block can be NULL
  * - 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 void block_ChainProperties( block_t *p_list, int *pi_count, size_t *pi_size, mtime_t *pi_length )
 {
     size_t i_size = 0;
     mtime_t i_length = 0;
     int i_count = 0;
 
     while( p_list )
     {
         i_size += p_list->i_buffer;
         i_length += p_list->i_length;
         i_count++;
 
         p_list = p_list->p_next;
     }
 
     if( pi_size )
         *pi_size = i_size;
     if( pi_length )
         *pi_length = i_length;
     if( pi_count )
         *pi_count = i_count;
 }
 
 static inline block_t *block_ChainGather( block_t *p_list )
 {
     size_t  i_total = 0;
     mtime_t i_length = 0;
     block_t *g;
 
     if( p_list->p_next == NULL )
         return p_list;  /* Already gathered */
 
     block_ChainProperties( p_list, NULL, &i_total, &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_FifoPace : wait for a fifo to drain to a specified number of packets or total data size
  * - 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_FifoWake : wake ups a thread with block_FifoGet() = NULL
  *   (this is used to wakeup a thread when there is no data to queue)
  *
  * block_FifoGet and block_FifoShow are cancellation points.
  ****************************************************************************/
 
 VLC_API block_fifo_t * block_FifoNew( void ) VLC_USED;
 VLC_API void block_FifoRelease( block_fifo_t * );
 VLC_API void block_FifoPace( block_fifo_t *fifo, size_t max_depth, size_t max_size );
 VLC_API void block_FifoEmpty( block_fifo_t * );
 VLC_API size_t block_FifoPut( block_fifo_t *, block_t * );
 VLC_API void block_FifoWake( block_fifo_t * );
 VLC_API block_t * block_FifoGet( block_fifo_t * ) VLC_USED;
 VLC_API block_t * block_FifoShow( block_fifo_t * );
 size_t block_FifoSize( const block_fifo_t *p_fifo ) VLC_USED;
 VLC_API size_t block_FifoCount( const block_fifo_t *p_fifo ) VLC_USED;
 
 #endif /* VLC_BLOCK_H */
