Add option to fix CD audio track offsets.

DiscImageChef.Core/Devices/Dumping/CompactDisc.cs

@@ -1311,6 +1311,48 @@ namespace DiscImageChef.Core.Devices.Dumping
                     Invoke("There will be thousand of errors between track 0 and track 1, that is normal and you can ignore them.");
             }
 
+            // Check offset
+            if(_fixOffset)
+            {
+                // TODO: Plextor raw reading
+                // TODO: HL-DT-ST raw reading
+                // TODO: VideoNow
+
+                if(tracks.All(t => t.TrackType != TrackType.Audio))
+                {
+                    // No audio tracks so no need to fix offset
+                    _dumpLog.WriteLine("No audio tracks, disabling offset fix.");
+                    UpdateStatus?.Invoke("No audio tracks, disabling offset fix.");
+
+                    _fixOffset = false;
+                }
+                else
+                {
+                    if(cdOffset is null)
+                    {
+                        _dumpLog.
+                            WriteLine("Drive read offset is unknown, disabling offset fix. Dump may not be correct.");
+
+                        UpdateStatus?.
+                            Invoke("Drive read offset is unknown, disabling offset fix. Dump may not be correct.");
+
+                        _fixOffset = false;
+                    }
+                    else
+                    {
+                        // TODO: Calculate offset in bytes
+
+                        _dumpLog.WriteLine("Disc write offset is unknown, dump may not be correct.");
+                        UpdateStatus?.Invoke("Disc write offset is unknown, dump may not be correct.");
+                    }
+                }
+            }
+            else if(tracks.Any(t => t.TrackType == TrackType.Audio))
+            {
+                _dumpLog.WriteLine("There are audio tracks and offset fixing is disabled, dump may not be correct.");
+                UpdateStatus?.Invoke("There are audio tracks and offset fixing is disabled, dump may not be correct.");
+            }
+
             mhddLog = new MhddLog(_outputPrefix + ".mhddlog.bin", _dev, blocks, blockSize, blocksToRead);
             ibgLog  = new IbgLog(_outputPrefix  + ".ibg", 0x0008);
 
@@ -1321,6 +1363,7 @@ namespace DiscImageChef.Core.Devices.Dumping
             timeSpeedStart   = DateTime.UtcNow;
             InitProgress?.Invoke();
 
+            // TODO: Apply offset
             for(long i = (long)_resume.NextBlock; i <= lastSector; i += blocksToRead)
             {
                 if(_aborted)

DiscImageChef.Core/Devices/Dumping/Dump.cs

@@ -33,6 +33,7 @@ namespace DiscImageChef.Core.Devices.Dumping
         readonly bool                       _stopOnError;
         bool                                _aborted;
         bool                                _dumpFirstTrackPregap;
+        bool                                _fixOffset;
         Resume                              _resume;
         Sidecar                             _sidecarClass;
         uint                                _skip;
@@ -61,7 +62,8 @@ namespace DiscImageChef.Core.Devices.Dumping
         public Dump(bool doResume, Device dev, string devicePath, IWritableImage outputPlugin, ushort retryPasses,
                     bool force, bool dumpRaw, bool persistent, bool stopOnError, Resume resume, DumpLog dumpLog,
                     Encoding encoding, string outputPrefix, string outputPath, Dictionary<string, string> formatOptions,
-                    CICMMetadataType preSidecar, uint skip, bool nometadata, bool notrim, bool dumpFirstTrackPregap)
+                    CICMMetadataType preSidecar, uint skip, bool nometadata, bool notrim, bool dumpFirstTrackPregap,
+                    bool fixOffset)
         {
             _doResume             = doResume;
             _dev                  = dev;
@@ -84,6 +86,7 @@ namespace DiscImageChef.Core.Devices.Dumping
             _notrim               = notrim;
             _dumpFirstTrackPregap = dumpFirstTrackPregap;
             _aborted              = false;
+            _fixOffset            = fixOffset;
         }
 
         /// <summary>Starts dumping with the stablished fields and autodetecting the device type</summary>

DiscImageChef.Gui/Forms/frmDump.xeto.cs

@@ -527,7 +527,7 @@ namespace DiscImageChef.Gui.Forms
                                chkStopOnError.Checked == true, _resume, dumpLog, encoding, _outputPrefix,
                                txtDestination.Text, parsedOptions, _sidecar, (uint)stpSkipped.Value,
                                chkExistingMetadata.Checked == false, chkTrim.Checked == false,
-                               chkTrack1Pregap.Checked     == true);
+                               chkTrack1Pregap.Checked     == true, true);
 
             new Thread(DoWork).Start();
         }

DiscImageChef/Commands/DumpMedia.cs

@@ -60,6 +60,7 @@ namespace DiscImageChef.Commands
         bool   _doResume = true;
         string _encodingName;
         bool   _firstTrackPregap;
+        bool   _fixOffset;
         bool   _force;
         bool   _noMetadata;
         bool   _noTrim;
@@ -91,6 +92,9 @@ namespace DiscImageChef.Commands
                 Options.Add("first-pregap", "Try to read first track pregap. Only applicable to CD/DDCD/GD.",
                             b => _firstTrackPregap = b != null);
 
+            Options.Add("fix-offset", "Fix audio tracks offset. Only applicable to CD/GD.",
+                        b => _fixOffset = b != null);
+
             Options.Add("force|f", "Continue dump whatever happens.", b => _force = b != null);
 
             Options.Add("format|t=",
@@ -339,7 +343,7 @@ namespace DiscImageChef.Commands
 
             var dumper = new Dump(_doResume, dev, _devicePath, outputFormat, _retryPasses, _force, false, _persistent,
                                   _stopOnError, resume, dumpLog, encoding, outputPrefix, _outputFile, parsedOptions,
-                                  sidecar, (uint)_skip, _noMetadata, _noTrim, _firstTrackPregap);
+                                  sidecar, (uint)_skip, _noMetadata, _noTrim, _firstTrackPregap, _fixOffset);
 
             dumper.UpdateStatus         += Progress.UpdateStatus;
             dumper.ErrorMessage         += Progress.ErrorMessage;