help with VMGM_VOBU_ADMAP

[brawler]

im tring to figure out how to access the values for VMGM_VOBU_ADMAP. when i open up the file VIDEO_TS.IFO i can locate offset 00DC fine and get the value for that but i dont know how to access all the information for VMGM_VOBU_ADMAP. can someone explain how i would access these values? what offsets should i be looking at?

[mpucoder]

Location 0x0dc is a 4-byte pointer, it contains the sector number within the ifo file where the table begins. Each sector is 2048 (0x800) bytes long. The first double word of the table is the last byte offset of the table, ie the length-1. The double words after that are the sector numbers of each VOBU (NAV pack), with sector 00000000 being the start of video_ts.vob

[brawler]

at offset 0DCh my byte values are:
byte1 == 00
byte2 == 00
byte3 == 00
byte4 == 08

byte4 contains the only value other than zero, so this must contain the sector number you were referring to. with a dec value of 8 where exactly do i look next for the beggining of the table?

im attaching the VIDEO_TS.IFO file im using just in case you may want to take a look at it.

EDIT: removed attatchment - DaveEL

[mpucoder]

The attachment won't get approved, but that doesn't matter. As you surmised, you want sector 8 (all values in DVDs are little-endian). Since the sector size is 0x800 you want to look at 8*0x800, or 0x4000.
More info about DVD structure is at http://mpucoder.kewlhair.com/DVD/

[brawler]

thanks mpucoder. that information was very benificial.