DVD programming question

[William Johnston]

Hi.

I wrote a DVD parser in Visual C# 2005 and I am not getting accurate log file results.

The parser simply extracts bytes based on a beginning and ending offset from an XML file. The beginning and ending offsets are from a log file produced from a commercial DVD Extractor program.

When the extracted VOB file is created, the new log file does not show accurate information.

The original log file segment is below:

[00:00:00:00 0 11 1
00:00:00:15 59 11 1
00:00:01:00 127 11 1
00:00:00:00 196 12 1
00:00:00:15 345 12 1
00:00:00:00 516 13 1
...]

The XML node is below:

<LogFileInfo TitleNumber="11" BegOffset="0" EndOffset="401408">G:\DVD\SwitchOver output\...\VIDEO_TS\VIDEO_TS.vob</LogFileInfo>

The log file offset value is in multiples of blocks of 2048 bytes.

192 blocks * 2048 bytes/block = 401408 bytes

The newly created log file is below:

[00:00:00:00 0 11 1
00:00:00:15 51 11 1
00:00:01:00 105 11 1
00:00:00:00 159 12 1
00:00:00:15]
Why is the beginning offset of title number 12 present in this log file? (offset 196 should start title number 12, not offset 159!)

The file IO code segment is as follows:

while (true)
{
byte[] bytes = GetBytesFromFile(fs1, r1, begOffset, endOffset, bytesRead, length);

bytesRead += bytes.Length;

// Write bytes to file
if (bytes != null) StoreBytes(bytes);

//reached end of file
if (bytes == null || bytesRead == length)
{
Console.WriteLine("reached end of reading.");
break;
}
...
}

Your help would be appreciated.

Thanks,
William Johnston