[vlc-devel] [vlc-commits] demux: mp4: handle in sample text encoding (fix #11137)

[Rémi Denis-Courmont]

Le jeudi 3 avril 2014, 19:48:55 Francois Cartegnie a écrit :
> vlc | branch: master | Francois Cartegnie <fcvlcdev at free.fr> | Thu Apr  3
> 18:14:57 2014 +0200| [c3c6e9b81d34ab970ccc9bb22f960558acb31cb8] |
> committer: Francois Cartegnie
> 
> demux: mp4: handle in sample text encoding (fix #11137)
> 
> > http://git.videolan.org/gitweb.cgi/vlc.git/?a=commit;h=c3c6e9b81d34ab970cc
> > c9bb22f960558acb31cb8
> ---
> 
>  modules/codec/substx3g.c |   24 ++++++++++++++++--------
>  modules/demux/mp4/mp4.c  |    1 -
>  2 files changed, 16 insertions(+), 9 deletions(-)
> 
> diff --git a/modules/codec/substx3g.c b/modules/codec/substx3g.c
> index 4d26b9c..a735f45 100644
> --- a/modules/codec/substx3g.c
> +++ b/modules/codec/substx3g.c
> @@ -26,6 +26,7 @@
>  #include <vlc_plugin.h>
>  #include <vlc_codec.h>
>  #include <vlc_sout.h>
> +#include <vlc_charset.h>
> 
>  #include "substext.h"
> 
> @@ -255,14 +256,21 @@ static subpicture_t *Decode( decoder_t *p_dec, block_t
> **pp_block ) uint8_t *p_buf = p_block->p_buffer;
> 
>      /* Read our raw string and create the styled segment for HTML */
> -    uint16_t i_psz_length = GetWBE( p_buf );
> -    char *psz_subtitle = malloc( i_psz_length + 1 );
> +    uint16_t i_psz_bytelength = GetWBE( p_buf );
> +    const uint8_t *p_pszstart = p_block->p_buffer + sizeof(uint16_t);
> +    char *psz_subtitle;
> +    if ( i_psz_bytelength > 2 &&
> +         ( !memcmp( p_pszstart, "\xFE\xFF", 2 ) || !memcmp( p_pszstart,
> "\xFF\xFE", 2 ) ) +       )
> +        psz_subtitle = FromCharset( "UTF-16", p_pszstart, i_psz_bytelength
> ); +    else
> +        psz_subtitle = malloc( i_psz_bytelength + 1 );
>      if ( !psz_subtitle ) return NULL;
> -    memcpy( psz_subtitle, p_block->p_buffer + sizeof(uint16_t),
> i_psz_length ); -    psz_subtitle[ i_psz_length ] = '\0';
> -    p_buf += i_psz_length + sizeof(uint16_t);
> +    memcpy( psz_subtitle, p_pszstart, i_psz_bytelength );

As pointed out on IRC, this makes no sense, not to mention that it will 
overflow the heap on ASCII characters.

> +    psz_subtitle[ i_psz_bytelength ] = '\0';

FromCharset() already nul-terminates. But this code makes no sense anyway.

> +    p_buf += i_psz_bytelength + sizeof(uint16_t);
> 
> -    for( uint16_t i=0; i < i_psz_length; i++ )
> +    for( uint16_t i=0; i < i_psz_bytelength; i++ )
>       if ( psz_subtitle[i] == '\r' ) psz_subtitle[i] = '\n';
> 
>      segment_t *p_segment = calloc( 1, sizeof(segment_t) );
> @@ -317,8 +325,8 @@ static subpicture_t *Decode( decoder_t *p_dec, block_t
> **pp_block ) while( i_cur_record++ < i_nbrecords )
>              {
>                  if ( (size_t)(p_buf - p_block->p_buffer) < 12 ) break;
> -                uint16_t i_start = __MIN( GetWBE(p_buf), i_psz_length - 1
> ); -                uint16_t i_end =  __MIN( GetWBE(p_buf + 2),
> i_psz_length - 1 ); +                uint16_t i_start = __MIN(
> GetWBE(p_buf), i_psz_bytelength - 1 ); +                uint16_t i_end = 
> __MIN( GetWBE(p_buf + 2), i_psz_bytelength - 1 );
> 
>                  segment_style_t style;
>                  style.i_flags = ConvertFlags( p_buf[6] );
> diff --git a/modules/demux/mp4/mp4.c b/modules/demux/mp4/mp4.c
> index e63a3f0..de1d749 100644
> --- a/modules/demux/mp4/mp4.c
> +++ b/modules/demux/mp4/mp4.c
> @@ -2001,7 +2001,6 @@ static int TrackCreateES( demux_t *p_demux,
> mp4_track_t *p_track, }
>                  p_track->fmt.subs.p_style = p_style;
>              }
> -            /* FIXME: Not true, could be UTF-16 with a Byte Order Mark
> (0xfeff) */ /* FIXME UTF-8 doesn't work here ? */
>              if( p_track->b_mac_encoding )
>                  p_track->fmt.subs.psz_encoding = strdup( "MAC" );
> 
> _______________________________________________
> vlc-commits mailing list
> vlc-commits at videolan.org
> https://mailman.videolan.org/listinfo/vlc-commits

-- 
Rémi Denis-Courmont
http://www.remlab.net/