* vlc_block_helper.h: Helper functions for data blocks management.
*****************************************************************************
* Copyright (C) 2003 VideoLAN
- * $Id: vlc_block_helper.h,v 1.5 2003/11/16 21:07:30 gbazin Exp $
+ * $Id: vlc_block_helper.h,v 1.6 2003/12/06 23:25:23 gbazin Exp $
*
* Authors: Gildas Bazin <gbazin@netcourrier.com>
*
return VLC_SUCCESS;
}
+static inline int block_FindStartcodeFromOffset(
+ block_bytestream_t *p_bytestream, int *pi_offset,
+ uint8_t *p_startcode, int i_startcode_length )
+{
+ block_t *p_block, *p_block_backup = 0;
+ int i_size, i_offset, i_offset_backup = 0;
+ int i_caller_offset_backup = 0, i_match;
+
+ /* Find the right place */
+ i_size = *pi_offset + p_bytestream->i_offset;
+ for( p_block = p_bytestream->p_block;
+ p_block != NULL; p_block = p_block->p_next )
+ {
+ i_size -= p_block->i_buffer;
+ if( i_size < 0 ) break;
+ }
+
+ if( i_size >= 0 )
+ {
+ /* Not enough data, bail out */
+ return VLC_EGENERIC;
+ }
+
+ /* Begin the search.
+ * We first look for an occurence of the 1st startcode byte and
+ * if found, we do a more thorough check. */
+ i_size = p_block->i_buffer + i_size;
+ *pi_offset -= i_size;
+ i_match = 0;
+ for( ; p_block != NULL; p_block = p_block->p_next )
+ {
+ for( i_offset = i_size; i_offset < p_block->i_buffer; i_offset++ )
+ {
+ if( p_block->p_buffer[i_offset] == p_startcode[i_match] )
+ {
+ if( !i_match )
+ {
+ p_block_backup = p_block;
+ i_offset_backup = i_offset;
+ i_caller_offset_backup = *pi_offset;
+ }
+
+ if( i_match + 1 == i_startcode_length )
+ {
+ /* We have it */
+ *pi_offset += i_offset - i_match;
+ return VLC_SUCCESS;
+ }
+
+ i_match++;
+ }
+ else if ( i_match )
+ {
+ /* False positive */
+ p_block = p_block_backup;
+ i_offset = i_offset_backup;
+ *pi_offset = i_caller_offset_backup;
+ i_match = 0;
+ }
+
+ }
+ i_size = 0;
+ *pi_offset += i_offset;
+ }
+
+ return VLC_EGENERIC;
+}
+
#endif /* VLC_BLOCK_HELPER_H */