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Add NTSC-J support to ld-chroma-encoder #754

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Jun 9, 2022
Merged

Add NTSC-J support to ld-chroma-encoder #754

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9 changes: 8 additions & 1 deletion tools/ld-chroma-decoder/encoder/main.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -81,6 +81,11 @@ int main(int argc, char *argv[])
QCoreApplication::translate("main", "chroma-mode"));
parser.addOption(chromaOption);

// Option to disable 7.5 IRE setup, as in NTSC-J (--no-setup)
QCommandLineOption setupOption(QStringList() << "no-setup",
QCoreApplication::translate("main", "NTSC only. Do not add 7.5 IRE setup (as in NTSC-J)"));
parser.addOption(setupOption);

// -- Positional arguments --

// Positional argument to specify input video file
Expand Down Expand Up @@ -129,6 +134,8 @@ int main(int argc, char *argv[])
}
}

bool addSetup = !parser.isSet(setupOption);

ChromaMode chromaMode = WIDEBAND_YUV;
QString chromaName;
if (parser.isSet(chromaOption)) {
Expand Down Expand Up @@ -168,7 +175,7 @@ int main(int argc, char *argv[])
// Encode the data
LdDecodeMetaData metaData;
if( system == NTSC ) {
NTSCEncoder encoder(rgbFile, tbcFile, metaData, chromaMode);
NTSCEncoder encoder(rgbFile, tbcFile, metaData, chromaMode, addSetup);
if (!encoder.encode()) {
return -1;
}
Expand Down
12 changes: 5 additions & 7 deletions tools/ld-chroma-decoder/encoder/ntscencoder.cpp
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Expand Up @@ -50,8 +50,8 @@
#include <array>
#include <cmath>

NTSCEncoder::NTSCEncoder(QFile &_rgbFile, QFile &_tbcFile, LdDecodeMetaData &_metaData, ChromaMode &_chromaMode)
: rgbFile(_rgbFile), tbcFile(_tbcFile), metaData(_metaData), chromaMode(_chromaMode)
NTSCEncoder::NTSCEncoder(QFile &_rgbFile, QFile &_tbcFile, LdDecodeMetaData &_metaData, ChromaMode &_chromaMode, bool &_addSetup)
: rgbFile(_rgbFile), tbcFile(_tbcFile), metaData(_metaData), chromaMode(_chromaMode), addSetup(_addSetup)
{
// NTSC subcarrier frequency [Poynton p511]
videoParameters.fSC = 315.0e6 / 88.0;
Expand Down Expand Up @@ -94,9 +94,7 @@ NTSCEncoder::NTSCEncoder(QFile &_rgbFile, QFile &_tbcFile, LdDecodeMetaData &_me
// White level, black level, and blanking level, extended to 16 bits
// [SMPTE p2, Poynton p517]
videoParameters.white16bIre = 0xC800;
const qint32 blankingIre = 0x3C00;
const qint32 ntscSetup = 0x0A80; // 10.5 * 256
videoParameters.black16bIre = blankingIre + ntscSetup; // (60 + 10.5) * 256
videoParameters.black16bIre = blankingIre + (addSetup ? setupIreOffset : 0);
videoParameters.fieldWidth = 910;
videoParameters.fieldHeight = 263;
videoParameters.isMapped = false;
Expand Down Expand Up @@ -284,9 +282,9 @@ static constexpr auto uvFilter = makeFIRFilter(uvFilterCoeffs);

void NTSCEncoder::encodeLine(qint32 fieldNo, qint32 frameLine, const quint16 *rgbData, QVector<quint16> &outputLine)
{
// Resize the output line and fill with black
// Resize the output line and fill with blanking
outputLine.resize(videoParameters.fieldWidth);
outputLine.fill(videoParameters.black16bIre - 0x0A80);
outputLine.fill(blankingIre);

// Skip encoding the last (dummy) frameLine
if (frameLine == 525)
Expand Down
6 changes: 5 additions & 1 deletion tools/ld-chroma-decoder/encoder/ntscencoder.h
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Expand Up @@ -40,7 +40,7 @@ enum ChromaMode {
class NTSCEncoder
{
public:
NTSCEncoder(QFile &rgbFile, QFile &tbcFile, LdDecodeMetaData &metaData, ChromaMode &chromaMode);
NTSCEncoder(QFile &rgbFile, QFile &tbcFile, LdDecodeMetaData &metaData, ChromaMode &chromaMode, bool &addSetup);

// Encode RGB stream to NTSC.
// Returns true on success; on failure, prints an error and returns false.
Expand All @@ -51,10 +51,14 @@ class NTSCEncoder
bool encodeField(qint32 fieldNo);
void encodeLine(qint32 fieldNo, qint32 frameLine, const quint16 *rgbData, QVector<quint16> &outputLine);

const qint32 blankingIre = 0x3C00;
const qint32 setupIreOffset = 0x0A80; // 10.5 * 256

QFile &rgbFile;
QFile &tbcFile;
LdDecodeMetaData &metaData;
ChromaMode chromaMode;
bool addSetup;

LdDecodeMetaData::VideoParameters videoParameters;
qint32 activeWidth;
Expand Down