Hi list,
  Here's an updated version of nav_notes.  It has more information
on the DSI but I don't know how to verify it.
  The last 4 links are 3 DVD related patents and a paper.
  
  Yuqing
  
	
	DVD navigation packets
        --------------------------

  0.  Introduction
  1.  PCI structure
  2.  DSI structure
  3.  To do
  4.  Acknowledgements
  5.  Reference

0.  Introduction

  Navigation packet is the last big chunk of information
that we needed to implement a fully functional DVD player
(I hate to make absolute comments but this time I can't
help making an exception.).  The information presented
in this document is based on the vobdump program published by
Eric Smith in 1999.  What I did was reading the program
and gathering information on the internet to make sense
out of the program.
  Navigation packets are PES packets with a stream id 0xbf, i.e.
private stream 2.  It's made up of PCI, Presentation Control Information
and DSI, Data Search Information.

   0      6         7                  0x3d4+0x6 0x3d4+0xb 0x3d4+0xc
   +------+---------+----------------------+------+---------+-----------------+
   |Packet|Substream|        PCI           |Packet|Substream|       DSI       |
   |Header|  ID     |        Data          |Header|   ID    |       Data      |
   +------+---------+----------------------+------+---------+-----------------+

  The packet head is just a PES packet header, a packet start code, a stream id
and a packet length.  The first packet lenght is 0x3d4, the length of the PCI data
plus one.  The second packet length is 0x3fa, the length of DSI data plus one.
The substream id for PCI packet is 0x00 and 0x01 for DSI.

1.  PCI structure

  Here's the PCI data structure in C syntax:

{
  pci_gi: // PCI general information
  {
	nv_pck_lbn 	: 32;  // block length
	vobu_cat 	: 16;  // vobu category
	reserved 	: 16;
	vobu_uop_ctl 	: 32;  // user operation
	vobu_s_ptm	: 32;  // vobu start time in 90KHz system clock unit
	vobu_e_ptm	: 32;  // vobu end time
	vobu_sl_e_ptm	: 32;  // sequence end termiation time
	e_eltm		: 32;  // cell elapse time
	vobu_isrc[32]	: 32 * 8;
   } 

   nsml_agli_dsta:  // Non-seamless playback
   {
	nsml_agl_c_dsta[9]	: 32 * 9;  // destination address of Angle Cell #
   }
  
   hli_gi:
   {
	reserved	: 14;
	hli_ss		: 2;
	hli_s_ptm	: 32; // highlight start time
	hli_e_ptm	: 32; // highlight end time
	btn_sl_e_ptm	: 32; // button select end time
	reserved	: 2;
	btngr_ns	: 2;  // number of buttons groups
	
	reserved	: 1;
	btngr0_dsp_ty	: 3;
	reserved	: 1;
	btngr1_dsp_ty	: 3;
	reserved	: 1;
	btngr2_dsp_ty	: 3;
	
	btn_ofn		: 8;
	reserved	: 2;
	btn_ns		: 6;  // number of buttons
	reserved	: 2;
	nsl_btn_ns	: 6;
	reserved 	: 8;
	
	reserved 	: 2;
	fosl_btnn	: 6; // auto selected button number
	
	reserved 	: 2;
	foac_btnn	: 6; // auto action button number

	btn_coli_0_sl	: 32;
	btn_coli_0_ac	: 32;
	btn_coli_1_sl	: 32;
	btn_coli_1_ac	: 32;
	btn_coli_2_sl	: 32;
	btn_coli_2_ac	: 32;
  }
  
  buttons:
  {
  	for (i = 0; i < btngr_ns; i++) {
		for (j = 0; j < 36 / btngr_ns; j++) {
			if (j < btn_ns) {
				button();
			} else {
				18 bytes of 0x00;
			}
		}
	}
  }
 
  for (i = 0; i < 17; i++) {
	pci_reci();
  }

  unknown	: 8;
}

  pci_reci() {
	unknown		:1;
	unknown		:7;

	unknown		:2;
	unknown		:6;

	unknown		:2;
	unknown		:6;

	unknown		:2;
	unknown		:6;

	unknown		:2;
	unknown		:6;

	unknown		:2;
	unknown		:6;

	unknown		:4;
	unknown		:4;

	unknown		:4;
	unknown		:4;

	unknown		:4;
	unknown		:4;

	unknown		:4;
	unknown		:4;
  }

  button() {
	btn_coln	: 2; // button color number, selects wich btn_coli apply
	x_start		: 10;
	reserved	: 2;
	x_end		: 10;
	
	auto_action_mode	: 2;
	y_start		: 10;
	resereve	: 2;
	y_end		10;

	reserved	: 2;
	up		: 6; // up button number, self if non
	reserved	: 2;
	down		: 6;
	reserved	: 2;
	left		: 6;
	reserved	: 2;
	right		: 6;

	btn_command	: 8 * 8;
   }
  
   The highlight times, hli_s_ptm, hli_e_ptm and btn_sl_e_ptm,
satisfy the following constraints:
   + hli_s_ptm < btn_sl_e_ptm <= hli_e_ptm
   + hli_s_ptm = PTS of the SPU that associats with it
   + hli_e_ptm 	= start time the DCSQ, where an STP_DSP command exists.
	  	= PTS of the next SPU, if there is no STP_DSP command in the SPU.
		= 0xffffffff, in case of a still frame(e.g. menu file) 
The 32-bit btn_coli_i_sl has the following structure:
   bit31                     bit0
     0xc1 c2 c3 c4 b1 b2 b3 b4
Each of the cx and bx is 4 bits.  c1 and b1 are 
the color index and blend factor when the system time is
after the hli_e_ptm time.  c2 and b2 are the
color index and blend factor when the system time is between
btn_sl_e_ptm and hli_e_ptm or exactly at one of them.
c3 and b3 are the color index and blend factor
when the system time is between hli_s_ptm and bts_sl_e_ptm.
c4 and b4 are used when hli is disabled.
The box defined in each button tells the SPU decoder
the hli color should be used when decoding the spu data.
Detailed description about the highlighting is given
in the Zoran 36710 chip manual.

Buttons are categorized in to groups.
There can be 3 groups of buttons correspond
to different aspect ratios, i.e. wide screan, letter box and pan & scan.
fosl_btnn defines the auto selected button.  This is
how the white rabit appears in the Maxtrix.
foac_btnn defines the auto action button.

2.  DSI structure
   DSI structure in C syntax
{
   dsi_gi:  //DSI general information
   {
	nv_pck_scr	: 32;  // system clock reference
	nv_pck_lbn	: 32;  // start address of the NV pack
	vobu_ea		: 32;  // End Address for VOB
	vobu_1stref_ea	: 32;
	vobu_2ndref_ea	: 32;
	vobu_3rdref_ea	: 32;
	vobu_vob_idn	: 16; // vob id
	reserved	: 8;
	vobu_c_idn	: 8;	// cell id
	c_eltm		: 32;
  }

  sml_pbi: // Seamless playback information
  {
	ilvu		: 16; // Interleaved Unit Flag ??
	ilvu_ea		: 32; // ??
	nt_ilvu_sa	: 32; // ??
	u_end		: 16; // Unit END flag ??
	unknown		: 32;
	unknown		: 32;

	for (i = 0; i < 8; i++) {
		vob_a_stp_ptm1	: 32; // ??
		vob_a_stp_ptm2	: 32; // ??
		vob_a_gap_len1	: 32; // ??
		vob_a_gap_len2	: 32; // ??
	}
  }

  sml_agli: // Angle information for seamless
  {
 	for (i = 0; i < 9; i++) {
		sml_agl_a	: 32;  // address of destination ILVU
		size		: 16;  // size of destination ILVU
	}
  }

  vobu_sri: // VOB unit search information
  {
	for (i = 0; i < 42; i++) {
		unknown		: 32;
	}
  }

  synci: // Synchronous information
  {
	for (i = 0; i < 8; i++) {
		a_synca		: 16; // ??
	}
	for (i = 0; i < 32; i++) {
		sp_synca	: 32; // ??
	}
  }

  Reserved: 
       for (i = 0; i < 471; i++) {
        	unknown		: 8;
       }
}

3.  ToDo

   Fill in the missing info in the DSI data.

4.  Acknowledgements

   Thanks to Eric Smith for publishing vobdump in GPL.

5.  Reference

    vobdump by Eric Smith <eric@brouhaha.com>, original vobdump can be found
	at http://www.brouhaha.com/~/eric/video/dvd/development
    Zoran 37610 manual
    L64021 manual
    DVD Technical Notes by Chad Fogg at http://www.mpeg.org/MPEG/DVD
    http://swpat.ffii.org/vreji/pikta/txt/ep/0847/199/
    http://swpat.ffii.org/vreji/pikta/txt/ep/0847/195/
    http://swpat.ffii.org/vreji/pikta/txt/ep/0737/980/
    http://www.eetasia.com/ARTICLES/1999JAN/1999JAN01_ID_DSP_MSD_EMS_TA.PDF