Commit 164ef9f2 authored by François Cartegnie's avatar François Cartegnie 🤞

codecs: add ATSC A65 helpers

parent 8aef60e4
/*****************************************************************************
* atsc_a65.c : ATSC A65 decoding helpers
*****************************************************************************
* Copyright (C) 2016 - VideoLAN Authors
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*****************************************************************************/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <vlc_common.h>
#include <vlc_charset.h>
#include "atsc_a65.h"
enum
{
ATSC_A65_COMPRESSION_NONE = 0x00,
ATSC_A65_COMPRESSION_HUFFMAN_C4C5 = 0x01,
ATSC_A65_COMPRESSION_HUFFMAN_C6C7 = 0x02,
ATSC_A65_COMPRESSION_RESERVED_FIRST = 0x03,
ATSC_A65_COMPRESSION_RESERVED_LAST = 0xAF,
ATSC_A65_COMPRESSION_OTHER_FIRST = 0xB0,
ATSC_A65_COMPRESSION_OTHER_LAST = 0xFF,
};
enum
{
ATSC_A65_MODE_UNICODE_RANGE_START = 0x00, /* See reserved ranges */
ATSC_A65_MODE_UNICODE_RANGE_END = 0x33,
ATSC_A65_MODE_SCSU = 0x3E,
ATSC_A65_MODE_UNICODE_UTF16 = 0x3F,
ATSC_A65_MODE_TAIWAN_FIRST = 0x40,
ATSC_A65_MODE_TAIWAN_LAST = 0x41,
ATSC_A65_MODE_SOUTH_KOREA = 0x48,
ATSC_A65_MODE_OTHER_FIRST = 0xE0,
ATSC_A65_MODE_OTHER_LAST = 0xFE,
ATSC_A65_MODE_NOT_APPLICABLE = 0xFF,
};
const uint8_t ATSC_A65_MODE_RESERVED_RANGES[12] = {
/* start, end */
0x07, 0x08,
0x11, 0x1F,
0x28, 0x2F,
0x34, 0x3D,
0x42, 0x47,
0x49, 0xDF,
};
struct atsc_a65_handle_t
{
char *psz_lang;
vlc_iconv_t iconv16;
};
atsc_a65_handle_t *atsc_a65_handle_New( const char *psz_lang )
{
atsc_a65_handle_t *p_handle = malloc( sizeof(*p_handle) );
if( p_handle )
{
if( psz_lang && strlen(psz_lang) > 2 )
p_handle->psz_lang = strdup( psz_lang );
else
p_handle->psz_lang = NULL;
p_handle->iconv16 = NULL;
}
return p_handle;
}
void atsc_a65_handle_Release( atsc_a65_handle_t *p_handle )
{
if( p_handle->iconv16 )
vlc_iconv_close( p_handle->iconv16 );
free( p_handle->psz_lang );
free( p_handle );
}
static char *enlarge_to16( const uint8_t *p_src, size_t i_src, uint8_t i_prefix )
{
if( i_src == 0 )
return NULL;
char *psz_new = malloc( i_src * 2 + 1 );
if( psz_new )
{
memset( psz_new, i_prefix, i_src * 2 );
psz_new[ i_src * 2 ] = 0;
while( *p_src )
{
psz_new[1] = p_src[0];
p_src++;
psz_new += 2;
}
}
return psz_new;
}
static bool convert_encoding_set( atsc_a65_handle_t *p_handle,
const uint8_t *p_src, size_t i_src,
char **ppsz_merg, size_t *pi_mergmin1,
uint8_t i_mode )
{
char *psz_dest = *ppsz_merg;
size_t i_mergmin1 = *pi_mergmin1;
bool b_ret = true;
/* First exclude reserved ranges */
for( unsigned i=0; i<12; i+=2 )
{
if( i_mode >= ATSC_A65_MODE_RESERVED_RANGES[i] &&
i_mode <= ATSC_A65_MODE_RESERVED_RANGES[i+1] )
return false;
}
if( i_mode == ATSC_A65_MODE_UNICODE_RANGE_START ) /* Latin 1 */
{
char *psz_realloc = realloc( psz_dest, i_mergmin1 + i_src + 1 );
if( psz_realloc )
{
psz_realloc[i_mergmin1 + i_src] = 0;
memcpy( &psz_realloc[i_mergmin1], p_src, i_src );
psz_dest = psz_realloc;
i_mergmin1 += i_src;
}
else return false;
}
else if( i_mode > ATSC_A65_MODE_UNICODE_RANGE_START && /* 8 range prefix + 8 */
i_mode <= ATSC_A65_MODE_UNICODE_RANGE_END )
{
if( !p_handle->iconv16 )
{
if ( !(p_handle->iconv16 = vlc_iconv_open("UTF-8", "UCS-2BE")) )
return false;
}
else if ( VLC_ICONV_ERR == vlc_iconv( p_handle->iconv16, NULL, NULL, NULL, NULL ) ) /* reset */
{
return false;
}
char *psz16 = enlarge_to16( p_src, i_src, i_mode ); /* Maybe we can skip and feed iconv 2 by 2 */
if( psz16 )
{
char *psz_realloc = realloc( psz_dest, i_mergmin1 + (4 * i_src) + 1 );
if( psz_realloc )
{
const char *p_inbuf = psz16;
char *p_outbuf = &psz_realloc[i_mergmin1];
size_t i_inbuf = i_src * 2;
size_t i_outbuf = i_src * 4;
b_ret = ( VLC_ICONV_ERR != vlc_iconv( p_handle->iconv16, &p_inbuf, &i_inbuf,
&p_outbuf, &i_outbuf ) );
psz_dest = psz_realloc;
i_mergmin1 += i_outbuf;
psz_dest[i_mergmin1] = 0;
}
free( psz16 );
}
else return false;
}
else
{
/* Unsupported encodings */
return false;
}
*ppsz_merg = psz_dest;
*pi_mergmin1 = i_mergmin1;
return b_ret;
}
#define BUF_ADVANCE(n) p_buffer += n; i_buffer -= n;
char * atsc_a65_Decode_multiple_string( atsc_a65_handle_t *p_handle, const uint8_t *p_buffer, size_t i_buffer )
{
char *psz_res = NULL;
size_t i_resmin1 = 0;
if( i_buffer < 1 )
return NULL;
uint8_t i_nb = p_buffer[0];
BUF_ADVANCE(1);
for( ; i_nb > 0; i_nb-- )
{
if( i_buffer < 4 )
goto error;
bool b_skip = ( p_handle->psz_lang && memcmp(p_buffer, p_handle->psz_lang, 3) );
BUF_ADVANCE(3);
uint8_t i_seg = p_buffer[0];
BUF_ADVANCE(1);
for( ; i_seg > 0; i_seg-- )
{
if( i_buffer < 3 )
goto error;
const uint8_t i_compression = p_buffer[0];
const uint8_t i_mode = p_buffer[1];
const uint8_t i_bytes = p_buffer[2];
BUF_ADVANCE(3);
if( i_buffer < i_bytes )
goto error;
if( i_compression != ATSC_A65_COMPRESSION_NONE ) // TBD
{
b_skip = true;
}
if( !b_skip )
{
(void) convert_encoding_set( p_handle, p_buffer, i_bytes,
&psz_res, &i_resmin1, i_mode );
}
BUF_ADVANCE(i_bytes);
}
}
return psz_res;
error:
free( psz_res );
return NULL;
}
#undef BUF_ADVANCE
/*****************************************************************************
* atsc_a65.h : ATSC A65 decoding helpers
*****************************************************************************
* Copyright (C) 2016 - VideoLAN Authors
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*****************************************************************************/
#ifndef VLC_ATSC_A65_H
#define VLC_ATSC_A65_H
typedef struct atsc_a65_handle_t atsc_a65_handle_t;
atsc_a65_handle_t *atsc_a65_handle_New( const char *psz_lang );
void atsc_a65_handle_Release( atsc_a65_handle_t * );
char * atsc_a65_Decode_multiple_string( atsc_a65_handle_t *, const uint8_t *, size_t );
#endif
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