BizHawk/BizHawk.Emulation.DiscSystem/TOC/TOCRaw.cs

120 lines
4.2 KiB
C#

using System;
using System.Text;
using System.Collections.Generic;
namespace BizHawk.Emulation.DiscSystem
{
/// <summary>
/// Represents our best guess at what a disc drive firmware will receive by reading the TOC from the lead-in track, modeled after CCD contents and mednafen/PSX needs.
/// </summary>
public class DiscTOCRaw
{
/// <summary>
/// Synthesizes the TOC from a set of raw entries.
/// When a disc drive firmware reads the lead-in area, it builds this TOC from finding ADR=1 (mode=1) sectors in the Q subchannel of the lead-in area.
/// I don't think this lead-in area Q subchannel is stored in a CCD .sub file.
/// The disc drive firmware will discover other mode sectors in the lead-in area, and it will register those in separate data structures.
/// </summary>
public class SynthesizeFromRawTOCEntriesJob
{
public IEnumerable<RawTOCEntry> Entries;
public List<string> Log = new List<string>();
public DiscTOCRaw Result;
public void Run()
{
SynthesizeFromRawTOCEntriesJob job = this;
DiscTOCRaw ret = new DiscTOCRaw();
//just in case this doesnt get set...
ret.FirstRecordedTrackNumber = 0;
ret.LastRecordedTrackNumber = 0;
int maxFoundTrack = 0;
foreach (var te in job.Entries)
{
var q = te.QData;
int point = q.q_index;
//see ECMD-394 page 5-14 for info about point = 0xA0, 0xA1, 0xA2
if (point == 0x00)
job.Log.Add("unexpected POINT=00 in lead-in Q-channel");
else if (point <= 99)
{
maxFoundTrack = Math.Max(maxFoundTrack, point);
ret.TOCItems[point].LBATimestamp = q.AP_Timestamp;
ret.TOCItems[point].Control = q.CONTROL;
ret.TOCItems[point].Exists = true;
}
else if (point == 0xA0)
{
ret.FirstRecordedTrackNumber = q.ap_min.DecimalValue;
if (q.ap_frame.DecimalValue != 0) job.Log.Add("PFRAME should be 0 for POINT=0xA0");
if (q.ap_sec.DecimalValue == 0x00) ret.Session1Format = DiscTOCRaw.SessionFormat.Type00_CDROM_CDDA;
else if (q.ap_sec.DecimalValue == 0x10) ret.Session1Format = DiscTOCRaw.SessionFormat.Type10_CDI;
else if (q.ap_sec.DecimalValue == 0x20) ret.Session1Format = DiscTOCRaw.SessionFormat.Type20_CDXA;
else job.Log.Add("Unrecognized session format: PSEC should be one of {0x00,0x10,0x20} for POINT=0xA0");
}
else if (point == 0xA1)
{
ret.LastRecordedTrackNumber = q.ap_min.DecimalValue;
if (q.ap_sec.DecimalValue != 0) job.Log.Add("PSEC should be 0 for POINT=0xA1");
if (q.ap_frame.DecimalValue != 0) job.Log.Add("PFRAME should be 0 for POINT=0xA1");
}
else if (point == 0xA2)
{
ret.LeadoutTimestamp = q.AP_Timestamp;
}
}
//this is speculative:
//well, nothing to be done here..
if (ret.FirstRecordedTrackNumber == 0) { }
if (ret.LastRecordedTrackNumber == 0) { ret.LastRecordedTrackNumber = maxFoundTrack; }
job.Result = ret;
}
}
public enum SessionFormat
{
Type00_CDROM_CDDA,
Type10_CDI,
Type20_CDXA
}
/// <summary>
/// The TOC specifies the first recorded track number, independently of whatever may actually be recorded (its unclear what happens if theres a mismatch)
/// </summary>
public int FirstRecordedTrackNumber;
/// <summary>
/// The TOC specifies the last recorded track number, independently of whatever may actually be recorded (its unclear what happens if theres a mismatch)
/// </summary>
public int LastRecordedTrackNumber;
/// <summary>
/// The TOC specifies the format of the session, so here it is.
/// </summary>
public SessionFormat Session1Format = SessionFormat.Type00_CDROM_CDDA;
public struct TOCItem
{
public EControlQ Control;
public Timestamp LBATimestamp;
public bool Exists;
}
/// <summary>
/// I think it likely that a firmware would just have a buffer for 100 of these. There can never be more than 100 and it might not match the 0xA0 and 0xA1 -specified values
/// Also #0 is illegal and is always empty.
/// </summary>
public TOCItem[] TOCItems = new TOCItem[100];
/// <summary>
/// POINT=0xA2 specifies this
/// </summary>
public Timestamp LeadoutTimestamp;
}
}