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Fix offset calculation when data can be read scrambled.

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This commit is contained in:
Natalia Portillo
2020-01-06 23:20:10 +00:00
parent eff08a571d
commit 0380b6f986
1 changed files with 54 additions and 42 deletions
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96
DiscImageChef.Core/Media/Info/CompactDisc.cs
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@@ -34,12 +34,13 @@ namespace DiscImageChef.Core.Media.Info
{
byte[] cmdBuf;
bool sense;
ulong minute;
ulong second;
ulong frame;
ulong remainder;
int minute;
int second;
int frame;
byte[] sectorSync;
byte[] tmpBuf;
int lba;
int diff;
Track dataTrack = default;
Track audioTrack = default;
bool offsetFound = false;
@@ -55,32 +56,10 @@ namespace DiscImageChef.Core.Media.Info
if(dataTrack.TrackSequence != 0)
{
dataTrack.TrackStartSector += 151;
// Calculate MSF
minute = dataTrack.TrackStartSector / 4500;
second = (dataTrack.TrackStartSector - (minute * 4500)) / 75;
frame = dataTrack.TrackStartSector - (minute * 4500) - (second * 75);
dataTrack.TrackStartSector -= 151;
// Convert to BCD
remainder = minute % 10;
minute = ((minute / 10) * 16) + remainder;
remainder = second % 10;
second = ((second / 10) * 16) + remainder;
remainder = frame % 10;
frame = ((frame / 10) * 16) + remainder;
// Scramble M and S
minute ^= 0x01;
second ^= 0x80;
// Build sync
sectorSync = new byte[]
{
0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x00, (byte)minute,
(byte)second, (byte)frame
0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x00
};
tmpBuf = new byte[sectorSync.Length];
@@ -103,7 +82,23 @@ namespace DiscImageChef.Core.Media.Info
if(!tmpBuf.SequenceEqual(sectorSync))
continue;
combinedOffset = i - 2352;
// De-scramble M and S
minute = cmdBuf[i + 12] ^ 0x01;
second = cmdBuf[i + 13] ^ 0x80;
frame = cmdBuf[i + 14];
// Convert to binary
minute = ((minute / 16) * 10) + (minute & 0x0F);
second = ((second / 16) * 10) + (second & 0x0F);
frame = ((frame / 16) * 10) + (frame & 0x0F);
// Calculate the first found LBA
lba = ((minute * 60 * 75) + (second * 75) + frame) - 150;
// Calculate the difference between the found LBA and the requested one
diff = (int)dataTrack.TrackStartSector - lba;
combinedOffset = i + (2352 * diff);
offsetFound = true;
break;
@@ -111,10 +106,11 @@ namespace DiscImageChef.Core.Media.Info
}
}
if(debug ||
dbDev?.ATAPI?.RemovableMedias?.Any(d => d.CanReadCdScrambled == true) == true ||
dbDev?.SCSI?.RemovableMedias?.Any(d => d.CanReadCdScrambled == true) == true ||
dev.Manufacturer.ToLowerInvariant() == "hl-dt-st")
if(!offsetFound &&
(debug || dbDev?.ATAPI?.RemovableMedias?.Any(d => d.CanReadCdScrambled == true) == true ||
dbDev?.SCSI?.RemovableMedias?.Any(d => d.CanReadCdScrambled == true) == true ||
dev.Manufacturer.ToLowerInvariant() ==
"hl-dt-st"))
{
sense = dev.ReadCd(out cmdBuf, out _, (uint)dataTrack.TrackStartSector, sectorSize, 3,
MmcSectorTypes.Cdda, false, false, false, MmcHeaderCodes.None, true,
@@ -130,7 +126,23 @@ namespace DiscImageChef.Core.Media.Info
if(!tmpBuf.SequenceEqual(sectorSync))
continue;
combinedOffset = i - 2352;
// De-scramble M and S
minute = cmdBuf[i + 12] ^ 0x01;
second = cmdBuf[i + 13] ^ 0x80;
frame = cmdBuf[i + 14];
// Convert to binary
minute = ((minute / 16) * 10) + (minute & 0x0F);
second = ((second / 16) * 10) + (second & 0x0F);
frame = ((frame / 16) * 10) + (frame & 0x0F);
// Calculate the first found LBA
lba = ((minute * 60 * 75) + (second * 75) + frame) - 150;
// Calculate the difference between the found LBA and the requested one
diff = (int)dataTrack.TrackStartSector - lba;
combinedOffset = i + (2352 * diff);
offsetFound = true;
break;
@@ -172,19 +184,19 @@ namespace DiscImageChef.Core.Media.Info
dataTrack.TrackEndSector += 150;
// Calculate MSF
minute = dataTrack.TrackEndSector / 4500;
second = (dataTrack.TrackEndSector - (minute * 4500)) / 75;
frame = dataTrack.TrackEndSector - (minute * 4500) - (second * 75);
minute = (int)dataTrack.TrackEndSector / 4500;
second = ((int)dataTrack.TrackEndSector - (minute * 4500)) / 75;
frame = (int)dataTrack.TrackEndSector - (minute * 4500) - (second * 75);
dataTrack.TrackEndSector -= 150;
// Convert to BCD
remainder = minute % 10;
minute = ((minute / 10) * 16) + remainder;
remainder = second % 10;
second = ((second / 10) * 16) + remainder;
remainder = frame % 10;
frame = ((frame / 10) * 16) + remainder;
minute = ((minute / 10) << 4) + (minute % 10);
;
second = ((second / 10) << 4) + (second % 10);
;
frame = ((frame / 10) << 4) + (frame % 10);
;
// Scramble M and S
minute ^= 0x01;