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Handle invalid triplets

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"Invalid triplets" are triplets that have failed Hamming 24/18 decoding.

Previously, invalid triplets were converted at load time to either all zero
bits or, in the case of X/26 enhancement triplets, to "dummy" triplets of
reserved mode 11110 with a row address group that hopefully have no effect.
Now the X/26 enhancement triplet list can explicitly store invalid triplets
and will show them as "error decoding triplet".

Invalid triplets in other packets such as X/28/0 will still be zeroed out at
load time.

Since the TTI format has no provision for storing invalid triplets, saving a
page will convert the invalid triplets to reserved mode 11110 as described
above.

The actual bits of invalid triplets are not stored on the assumption that
they are not recoverable. Thus exporting to t42 format will write an invalid
triplet as a Hamming coded result of all zero bits which will still cause a
Hamming decoding failure.
This commit is contained in:
Gavin MacGregor
2025-11-04 17:56:04 +00:00
parent 1b3623d61b
commit 1efa8c196d
8 changed files with 125 additions and 47 deletions
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9
src/qteletextmaker/x26dockwidget.cpp
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@@ -678,6 +678,13 @@ void X26DockWidget::updateAllCookedTripletWidgets(const QModelIndex &index)
{
const int modeExt = index.model()->data(index.model()->index(index.row(), 2), Qt::EditRole).toInt();
if (modeExt == 0xff) {
disableTripletWidgets();
m_cookedModePushButton->setEnabled(true);
m_cookedModePushButton->setText("Replace...");
return;
}
m_cookedModePushButton->setEnabled(true);
m_cookedModePushButton->setText(m_modeTripletNames.modeName(modeExt));
@@ -1034,7 +1041,7 @@ void X26DockWidget::insertTriplet(int modeExt, int row)
if (modeExt >= 0x20 && modeExt != 0x24 && modeExt != 0x25 && modeExt != 0x26 && modeExt != 0x2a) {
const int existingTripletModeExt = index.model()->data(index.model()->index(index.row(), 2), Qt::EditRole).toInt();
if (existingTripletModeExt >= 0x20 && existingTripletModeExt != 0x24 && existingTripletModeExt != 0x25 && existingTripletModeExt != 0x26 && existingTripletModeExt != 0x2a)
if (existingTripletModeExt >= 0x20 && existingTripletModeExt <= 0x3f && existingTripletModeExt != 0x24 && existingTripletModeExt != 0x25 && existingTripletModeExt != 0x26 && existingTripletModeExt != 0x2a)
newTriplet.setAddress(index.model()->data(index.model()->index(index.row(), 0), Qt::UserRole).toInt());
}
// If we're inserting a Set Active Position or Full Row Colour triplet,