www.pudn.com > p264decoder.zip > vlc.c
/*****************************************************************************
* vlc.c: VLC lookup table generation.
*****************************************************************************
* Copyright (C) 2003 Laurent Aimar
* $Id: vlc.c,v 1.1 2004/06/03 19:27:07 fenrir Exp $
*
* 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.
*****************************************************************************/
#include
#include
//#include
#include "stdint.h"
#include "core/core.h"
#include "core/vlc.h"
#include "vlc.h"
static int vlc_table_realloc( p264_vlc_table_t *table, int i_size )
{
int i_index;
i_index = table->i_lookup;
table->i_lookup += i_size;
table->lookup = p264_realloc( table->lookup, sizeof( vlc_lookup_t ) * table->i_lookup );
return( i_index );
}
static int vlc_table_create_part( p264_vlc_table_t *table, const vlc_t *vlc, int i_lookup_bits, int i_nb_vlc, int i_prefix_code, int i_prefix_length )
{
int i;
int i_nb_lookup;
vlc_lookup_t *lookup;
int i_table_index;
i_nb_lookup = 1 << i_lookup_bits;
i_table_index = vlc_table_realloc( table, i_nb_lookup );
lookup = &table->lookup[i_table_index];
for( i = 0; i < i_nb_lookup; i++ )
{
lookup[i].i_value = -1;
lookup[i].i_size = 0;
}
for( i = 0; i < i_nb_vlc; i++ )
{
int i_bits;
if( vlc[i].i_size <= 0 )
{
continue;
}
i_bits = vlc[i].i_size - i_prefix_length;
if( i_bits > 0 && ( vlc[i].i_bits >> i_bits ) == i_prefix_code )
{
if( i_bits <= i_lookup_bits )
{
int i_lookup_index;
int nb;
i_lookup_index = ( vlc[i].i_bits << ( i_lookup_bits - i_bits ) )%i_nb_lookup;
nb = 1 << ( i_lookup_bits - i_bits );
for( nb = 0; nb < (1 << ( i_lookup_bits - i_bits)); nb++ )
{
lookup[i_lookup_index].i_value = i; /* vlc[i].i_value; */
lookup[i_lookup_index].i_size = i_bits;
i_lookup_index++;
}
}
else
{
int i_bits_max;
int i_lookup_index;
/* need another table */
i_lookup_index = ( vlc[i].i_bits >> (i_bits - i_lookup_bits ) )%i_nb_lookup;
i_bits_max = -lookup[i_lookup_index].i_size;
if( i_bits_max < i_bits - i_lookup_bits )
{
i_bits_max = i_bits - i_lookup_bits;
}
lookup[i_lookup_index].i_size = -i_bits_max;
}
}
}
/* create other level table */
for( i = 0; i < i_nb_lookup; i++ )
{
if( lookup[i].i_size < 0 )
{
int i_bits;
int i_index;
i_bits = -lookup[i].i_size;
if( i_bits > i_lookup_bits )
{
lookup[i].i_size = -i_lookup_bits;
i_bits = i_lookup_bits;
}
i_index = vlc_table_create_part( table, vlc, i_bits, i_nb_vlc,
(i_prefix_code << i_lookup_bits)|i,
i_lookup_bits+i_prefix_length );
lookup = &table->lookup[i_table_index]; // reallocated
lookup[i].i_value = i_index;
}
}
return( i_table_index );
}
p264_vlc_table_t *p264_vlc_table_lookup_new( const vlc_t *vlc, int i_vlc, int i_lookup_bits )
{
p264_vlc_table_t *table = p264_malloc( sizeof( p264_vlc_table_t ) );
table->i_lookup_bits = i_lookup_bits;
table->i_lookup = 0;
table->lookup = NULL;
vlc_table_create_part( table, vlc, i_lookup_bits, i_vlc, 0, 0 );
return table;
}
void p264_vlc_table_lookup_delete( p264_vlc_table_t *table )
{
p264_free( table->lookup );
p264_free( table );
}
#if 0
void p264_vlc_table_lookup_print( p264_vlc_table_t *table )
{
int idx;
fprintf( stderr, " " );
for( idx = 0; idx < table->i_lookup; idx++ )
{
if( table->lookup[idx].i_value == -1 )
{
fprintf( stderr, " MKVLCLU( -1, 0 )," );
}
else
{
fprintf( stderr, " MKVLCLU( 0x%.3x, % 2d ),", table->lookup[idx].i_value, table->lookup[idx].i_size );
}
if( (idx+1)%4 == 0 && idx < table->i_lookup - 1)
{
fprintf( stderr, "\n " );
}
}
fprintf( stderr, "\n" );
}
int main(void)
{
int i;
p264_vlc_table_t *table;
printf( "typedef struct\n int i_value;\n int i_size;\n} vlc_lookup_t;\n\n#define MKVLCLU(a,b) { .i_value=a, .i_size=b}" );
/* create vlc entry table and then vlc_lookup_t table */
/* p264_coeff_token */
fprintf( stderr, "static const vlc_lookup_t p264_coeff_token_lookup[5][]=\n{\n" );
for( i = 0; i < 5; i++ )
{
fprintf( stderr, " {\n" );
table = p264_vlc_table_lookup_new( p264_coeff_token[i], 17*4, 6 );
p264_vlc_table_lookup_print( table );
p264_vlc_table_lookup_delete( table );
fprintf( stderr, " },\n" );
}
fprintf( stderr, "};\n" );
#if 0
vlce = convert_vlc_to_vlce( p264_level_prefix, 16 );
do_vlc_table_create( vlce, 16, "p264_level_prefix_lookup", 8 );
free( vlce );
for( i_table = 0; i_table < 15; i_table++ )
{
char name[512];
vlce = convert_vlc_to_vlce( p264_total_zeros[i_table], 16 );
sprintf( name, "p264_total_zeros_%d", i_table );
do_vlc_table_create( vlce, 16, name, 6 );
free( vlce );
}
for( i_table = 0; i_table < 3; i_table++ )
{
char name[512];
vlce = convert_vlc_to_vlce( p264_total_zeros_dc[i_table], 4 );
sprintf( name, "p264_total_zeros_dc_%d", i_table );
do_vlc_table_create( vlce, 4, name, 3 );
free( vlce );
}
for( i_table = 0; i_table < 7; i_table++ )
{
char name[512];
vlce = convert_vlc_to_vlce( p264_run_before[i_table], 15 );
sprintf( name, "p264_run_before_%d", i_table );
do_vlc_table_create( vlce, 15, name, 6 );
free( vlce );
}
#endif
return 0;
}
#endif