* parse.c: Philips OGT (SVCD subtitle) packet parser
*****************************************************************************
* Copyright (C) 2003, 2004 VideoLAN
- * $Id: cvd_parse.c,v 1.6 2004/01/04 04:56:21 rocky Exp $
+ * $Id: cvd_parse.c,v 1.7 2004/01/04 16:51:59 rocky Exp $
*
* Authors: Rocky Bernstein
* based on code from:
origin. Thus, this is the result of reading some code whose
correctness is not known and some experimentation.
- CVD subtitles are different in severl ways from SVCD OGT subtitles.
- First, the image comes first and the metadata is at the end. So
- that the metadata can be found easily, the subtitle packet starts
- with two bytes (everything is big-endian again) that give the total
- size of the subtitle data and the offset to the metadata - i.e. size
- of the image data plus the four bytes at the beginning.
+ CVD subtitles are different in several ways from SVCD OGT subtitles.
+ Image comes first and metadata is at the end. So that the metadata
+ can be found easily, the subtitle packet starts with two bytes
+ (everything is big-endian again) that give the total size of the
+ subtitle data and the offset to the metadata - i.e. size of the
+ image data plus the four bytes at the beginning.
Image data comes interlaced is run-length encoded. Each field is a
four-bit nibble. Each nibble contains a two-bit repeat count and a
that the fill-line complete case above is not as described and the
zero repeat count means fill line. The sample code never produces
this, so it may be untested.
-
- The metadata section does not follow a fixed pattern, every
- metadata item consists of a tag byte followed by parameters. In all
- cases known, the block (including the tag byte) is exactly four
- bytes in length. Read the code for the rest.
*/
void E_(ParseHeader)( decoder_t *p_dec, uint8_t *p_buffer, block_t *p_block )
}
+#define ExtractXY(x, y) \
+ x = ((p[1]&0x0f)<<6) + (p[2]>>2); \
+ y = ((p[2]&0x03)<<8) + p[3];
+
+
+/*
+ We parse the metadata information here.
+
+ Although metadata information does not have to come in a fixed field
+ order, every metadata field consists of a tag byte followed by
+ parameters. In all cases known, the size including tag byte is
+ exactly four bytes in length.
+*/
+
void E_(ParseMetaInfo)( decoder_t *p_dec )
{
/* last packet in subtitle block. */
switch ( p[0] ) {
- case 0x04: /* Display duration in 1/90000ths of a second */
+ case 0x04: /* subtitle duration in 1/90000ths of a second */
p_sys->i_duration = (p[1]<<16) + (p[2]<<8) + p[3];
"subtitle display duration %u", p_sys->i_duration);
break;
- case 0x0c: /* Unknown */
+ case 0x0c: /* unknown */
dbg_print( DECODE_DBG_PACKET,
"subtitle command unknown 0x%0x 0x%0x 0x%0x 0x%0x\n",
p[0], p[1], p[2], p[3]);
break;
- case 0x17: /* Position */
- p_sys->i_x_start = ((p[1]&0x0f)<<6) + (p[2]>>2);
- p_sys->i_y_start = ((p[2]&0x03)<<8) + p[3];
- dbg_print( DECODE_DBG_PACKET,
- "start position (%d,%d): %.2x %.2x %.2x",
- p_sys->i_x_start, p_sys->i_y_start,
- p[1], p[2], p[3] );
+ case 0x17: /* coordinates of subtitle upper left x, y position */
+ ExtractXY(p_sys->i_x_start, p_sys->i_y_start);
break;
- case 0x1f: /* Coordinates of the image bottom right */
+ case 0x1f: /* coordinates of subtitle bottom right x, y position */
{
- int lastx = ((p[1]&0x0f)<<6) + (p[2]>>2);
- int lasty = ((p[2]&0x03)<<8) + p[3];
+ int lastx;
+ int lasty;
+ ExtractXY(lastx, lasty);
p_sys->i_width = lastx - p_sys->i_x_start + 1;
p_sys->i_height = lasty - p_sys->i_y_start + 1;
dbg_print( DECODE_DBG_PACKET,
p_sys->p_palette[3].s.t = p[2] >> 4;
dbg_print( DECODE_DBG_PACKET,
- "transparancy for primary palette 0..3: "
+ "transparency for primary palette 0..3: "
"0x%0x 0x%0x 0x%0x 0x%0x",
p_sys->p_palette[0].s.t,
p_sys->p_palette[1].s.t,
p_sys->p_palette_highlight[3].s.t = p[1] >> 4;
dbg_print( DECODE_DBG_PACKET,
- "transparancy for primary palette 0..3: "
+ "transparency for primary palette 0..3: "
"0x%0x 0x%0x 0x%0x 0x%0x",
p_sys->p_palette_highlight[0].s.t,
p_sys->p_palette_highlight[1].s.t,
break;
case 0x47:
- /* offset to first field data, we correct to make it relative
- to comp_image_offset (usually 4) */
+ /* offset to start of even rows of interlaced image, we correct
+ to make it relative to comp_image_offset (usually 4) */
p_sys->first_field_offset =
(p[2] << 8) + p[3] - p_sys->comp_image_offset;
dbg_print( DECODE_DBG_PACKET,
break;
case 0x4f:
- /* offset to second field data, we correct to make it relative to
- comp_image_offset (usually 4) */
+ /* offset to start of odd rows of interlaced image, we correct
+ to make it relative to comp_image_offset (usually 4) */
p_sys->second_field_offset =
(p[2] << 8) + p[3] - p_sys->comp_image_offset;
dbg_print( DECODE_DBG_PACKET,
p_spu->i_height = p_sys->i_height;
p_spu->i_start = p_sys->i_pts;
- p_spu->i_stop = p_sys->i_pts + (p_sys->i_duration * 5);
+ p_spu->i_stop = p_sys->i_pts + (p_sys->i_duration);
p_spu->p_sys->b_crop = VLC_FALSE;
p_spu->p_sys->i_debug = p_sys->i_debug;
}
#endif /*HAVE_LIBPNG*/
-
VCDInlinePalette( p_dest, p_sys, i_height, i_width );
/* The video is automatically scaled. However subtitle bitmaps
projects / vlc / blobdiff