DVD-Video 解谜 - NAV pack - DSI packet

Offset			Label	size	Content
Sector	Packet	Table
400	---	---	---	4	00 00 01 bf | Private Stream 2 header
404	---	---	---	2	03 fa | length
406	---	---	---	1	01 | substream ID, 01=DSI
407	000	DSI_GI 00	nv_pck_scr	4	system clock reference
40b	004	DSI_GI 04	nv_pck_lbn	4	Logical Block Number (sector) of this block
40f	008	DSI_GI 08	vobu_ea	4	VOBU end address | relative offset to last sector of VOBU
413	00c	DSI_GI 0c	vobu_1stref_ea	4	first reference frame end block, relative | used for fast playing
417	010	DSI_GI 10	vobu_2ndref_ea	4	second reference frame end block, relative | used for fast playing
41b	014	DSI_GI 14	vobu_3rdref_ea	4	third reference frame end block, relative | used for fast playing
41f	018	DSI_GI 18	vobu_vob_idn	2	VOB number
421	01a	DSI_GI 1a	reserved	1	00
422	01b	DSI_GI 1b	vobu_c_idn	1	CELL number within VOB
423	01c	DSI_GI 1c	c_eltm	4	cell elapsed time, BCD, hh:mm:ss:ff with bits 7&6 of frame (last) byte indicating frame rate 11 = 30 fps, 10 = illegal, 01 = 25 fps, 00 = illegal
427	020	SML_PBI 00	ilvu	2	Interleaved Unit flags
429	022	SML_PBI 02	ilvu_ea	4	ILVU end address | relative offset to the last sector within this ILVU for this angle or scene. 00 00 00 00 for PREU and non-interleaved blocks
42d	026	SML_PBI 06	nxt_ilvu_sa	4	relative offset to the next ILVU block (not VOBU) for this angle or scene. 00 00 00 00 for PREU and non-interleaved blocks ff ff ff ff for the last interleaved block, indicating the end of interleaving
431	02a	SML_PBI 0a	nxt_ilvu_sz	2	size of the next ILVU block for this angle or scene. 00 00 for PREU and non-interleaved blocks ff ff for the last interleaved block, indicating the end of interleaving
433	02c	SML_PBI 0c	vob_v_s_ptm	4	PTM of first video frame in first GOP of VOB
437	030	SML_PBI 10	vob_v_e_ptm	4	PTM of last video frame in last GOP of VOB
43b	034	SML_PBI 14	vob_a_stp_ptm1[0]	4	PTM of first audio gap in stream 0
43f	038	SML_PBI 18	vob_a_stp_ptm2[0]	4	PTM of second audio gap in stream 0
:	:	:	:	:	:
473	0a4	SML_PBI 84	vob_a_stp_ptm1[7]	4	PTM of first audio gap in stream 7
477	0a8	SML_PBI 88	vob_a_stp_ptm2[7]	4	PTM of second audio gap in stream 7
47b	03c	SML_PBI 1c	vob_a_gap_len1[0]	4	duration, in 90KHz clocks, of first audio gap in stream 0
47f	040	SML_PBI 20	vob_a_gap_len2[0]	4	duration, in 90KHz clocks, of second audio gap in stream 0
:	:	:	:	:	:
4b3	0ac	SML_PBI 8c	vob_a_gap_len1[7]	4	duration, in 90KHz clocks, of first audio gap in stream 7
4b7	0b0	SML_PBI 90	vob_a_gap_len2[7]	4	duration, in 90KHz clocks, of second audio gap in stream 7
4bb	0b4	SML_AGLI 00	sml_agl_c1_dsta	4	seamless angle 1 relative offset to NEXT ILVU the msb (bit 31) is used to denote the direction, 0=forward, 1=backward 00 00 00 00 indicates the angle does not exist 7f ff ff ff indicates no more video for this angle
4bf	0b8	SML_AGLI 04	sml_agl_c1_sz	2	seamless angle 1 ILVU size in sectors
:	:	:	:	:	:
4eb	0e4	SML_AGLI 30	sml_agl_c9_dsta	4	seamless angle 9 relative offset to NEXT ILVU
4ef	0e8	SML_AGLI 34	sml_agl_c9_sz	2	seamless angle 9 ILVU size in sectors
4f1	0ea	VOBU_SRI 00	sri_nvwv	4	offset to the next VOBU with video this pointer is always forward bit 31 is set since there is video bf ff ff ff indicates no following VOBU contains video
4f5	0ee	VOBU_SRI 04	sri_fwda240	4	offset to VOBU 120, 60, 30, 10, 7.5, 7.0, 6.5, 6.0, 5.5, 5.0, 4.5, 4.0, 3.5, 3.0, 2.5, 2.0, 1.5, 1.0, 0.5 seconds forward. this pointer is always forward bit 31 is set if the referenced VOBU contains video bit 30 is set to indicate one or more VOBU are present between this reference and the reference closer to the current VOBU. 3f ff ff ff indicates no VOBU within the cell for this span labels refer to the nominal VOBU span, which will be correct for .5 second VOBUs only.
4f9	0f2	VOBU_SRI 08	sri_fwda120	4
4fd	0f6	VOBU_SRI 0c	sri_fwda60	4
501	0fa	VOBU_SRI 10	sri_fwda20	4
505	0fe	VOBU_SRI 14	sri_fwda15	4
:	:	:	:	:
53d	13a	VOBU_SRI 4c	sri_fwda1	4
541	13e	VOBU_SRI 50	sri_nv	4	offset to the next VOBU this pointer is always forward bit 31 is set if the next VOBU contains video 3f ff ff ff indicates there is no VOBU following this
545	142	VOBU_SRI 54	sri_pv	4	offset to the previous VOBU this pointer is always backward bit 31 is set if the previous VOBU contains video 3f ff ff ff indicates there is no VOBU preceeding this
549	146	VOBU_SRI 58	sri_bwda1	4	offset to VOBU 120, 60, 30, 10, 7.5, 7.0, 6.5, 6.0, 5.5, 5.0, 4.5, 4.0, 3.5, 3.0, 2.5, 2.0, 1.5, 1.0, 0.5 seconds preceeding. this pointer is always backward bit 31 is set if the referenced VOBU contains video bit 30 is set to indicate one or more VOBU are present between this reference and the reference closer to the current VOBU. 3f ff ff ff indicates no VOBU within the cell for this span labels refer to the nominal VOBU span, which will be correct for .5 second VOBUs only.
:	:	:	:	:
581	17e	VOBU_SRI 90	sri_bwda15	4
585	182	VOBU_SRI 94	sri_bwda20	4
589	186	VOBU_SRI 98	sri_bwda60	4
58d	18a	VOBU_SRI 9c	sri_bwda120	4
591	18e	VOBU_SRI a0	sri_bwda240	4
595	182	VOBU_SRI a4	sri_pvwv	4	offset to the previous VOBU with video this pointer is always backward bit 31 is set since there is video bf ff ff ff indicates no preceeding VOBU contains video
599	192	SYNCI 00	a_synca[0:7]	8*2	relative offset to 1st audio packet for this VOBU the msb (bit 15) is used to denote the direction, 0=forward, 1=backward 00 00 indicates this audio stream does not exist 3f ff indicates no more audio for this stream
5a9	1a2	SYNCI 10	sp_synca[0:31]	32*4	relative offset to VOBU (NAV pack) containing subpicture data for this VOBU the msb (bit 31) is used to denote the direction, 0=forward, 1=backward note: forward references are not used for subpictures, if the direction bit == 0 the offset should be 0x7fffffff 00 00 00 00 indicates this subpicture stream does not exist 7f ff ff ff indicates the next subpicture data, if any, is contained within this or a later VOBU
629	222	reserved

Only 4 of the bits of the ILVU flag word are used, the top 4 of the first byte. They are:
bit 15	PREU flag	set during the last 3 VOBU preceeding an interleaved block. note: the 3rd preceeding has the Unit_Start bit set for a value of a0, the 2nd preceeding has only the PREU bit set for a value of 80, and the 1st preceeding has the Unit_End bit set for a value of 90
bit 14	ILVU flag	set for all VOBU in an interleaved block
bit 13	Unit_Start flag	set for the first VOBU for a given angle or scene within a ILVU, or the first VOBU in the preparation (PREU) sequence
bit 12	Unit_End flag	set for the last VOBU for a given angle or scene within a ILVU, or the last VOBU in the preparation (PREU) sequence