Add experimental YCgCo-R support
Using the latest version of the spec
https://jvet-experts.org/doc_end_user/documents/29_Teleconference/wg11/JVET-AC1008-v2.zip
Add support for MC 15 and 16 as described in the spec linked above.
diff --git a/CMakeLists.txt b/CMakeLists.txt
index f942aee..21a494f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -33,6 +33,8 @@
option(AVIF_ENABLE_WERROR "Treat all compiler warnings as errors" ON)
+option(AVIF_ENABLE_EXPERIMENTAL_YCGCO_R "Enable experimental YCgCo-R matrix code" OFF)
+
option(AVIF_CODEC_AOM "Use the AOM codec for encoding/decoding (see AVIF_CODEC_AOM_DECODE/AVIF_CODEC_AOM_ENCODE)" OFF)
option(AVIF_CODEC_DAV1D "Use the dav1d codec for decoding" OFF)
option(AVIF_CODEC_LIBGAV1 "Use the libgav1 codec for decoding" OFF)
@@ -205,6 +207,10 @@
endif()
endif()
+if(AVIF_ENABLE_EXPERIMENTAL_YCGCO_R)
+ add_compile_definitions(AVIF_ENABLE_EXPERIMENTAL_YCGCO_R)
+endif()
+
set(AVIF_SRCS
src/alpha.c
src/avif.c
diff --git a/apps/avifenc.c b/apps/avifenc.c
index 0b4ba99..9d06223 100644
--- a/apps/avifenc.c
+++ b/apps/avifenc.c
@@ -1479,11 +1479,23 @@
returnCode = 1;
}
// Matrix coefficients.
- if (cicpExplicitlySet && settings.matrixCoefficients != AVIF_MATRIX_COEFFICIENTS_IDENTITY) {
- fprintf(stderr, "Matrix coefficients have to be identity in lossless mode.\n");
- returnCode = 1;
+ if (cicpExplicitlySet) {
+ avifBool incompatibleMC = (settings.matrixCoefficients != AVIF_MATRIX_COEFFICIENTS_IDENTITY);
+#if defined(AVIF_ENABLE_EXPERIMENTAL_YCGCO_R)
+ incompatibleMC &= (settings.matrixCoefficients != AVIF_MATRIX_COEFFICIENTS_YCGCO_RE &&
+ settings.matrixCoefficients != AVIF_MATRIX_COEFFICIENTS_YCGCO_RO);
+#endif
+ if (incompatibleMC) {
+#if defined(AVIF_ENABLE_EXPERIMENTAL_YCGCO_R)
+ fprintf(stderr, "Matrix coefficients have to be identity, YCgCo-Re, or YCgCo-Ro in lossless mode.\n");
+#else
+ fprintf(stderr, "Matrix coefficients have to be identity in lossless mode.\n");
+#endif
+ returnCode = 1;
+ }
+ } else {
+ settings.matrixCoefficients = AVIF_MATRIX_COEFFICIENTS_IDENTITY;
}
- settings.matrixCoefficients = AVIF_MATRIX_COEFFICIENTS_IDENTITY;
if (returnCode == 1)
goto cleanup;
} else {
@@ -1696,7 +1708,6 @@
avifBool hasAlpha = (image->alphaPlane && image->alphaRowBytes);
avifBool usingLosslessColor = (settings.quality == AVIF_QUALITY_LOSSLESS);
avifBool usingLosslessAlpha = (settings.qualityAlpha == AVIF_QUALITY_LOSSLESS);
- avifBool depthMatches = (sourceDepth == image->depth);
avifBool using400 = (image->yuvFormat == AVIF_PIXEL_FORMAT_YUV400);
avifBool using444 = (image->yuvFormat == AVIF_PIXEL_FORMAT_YUV444);
avifBool usingFullRange = (image->yuvRange == AVIF_RANGE_FULL);
@@ -1725,9 +1736,9 @@
lossless = AVIF_FALSE;
}
- if (!depthMatches) {
+ if (usingIdentityMatrix && (sourceDepth != image->depth)) {
fprintf(stderr,
- "WARNING: [--lossless] Input depth (%d) does not match output depth (%d). Output might not be lossless.\n",
+ "WARNING: [--lossless] Identity matrix is used but input depth (%d) does not match output depth (%d). Output might not be lossless.\n",
sourceDepth,
image->depth);
lossless = AVIF_FALSE;
@@ -1744,8 +1755,17 @@
lossless = AVIF_FALSE;
}
- if (!usingIdentityMatrix && !using400) {
+ avifBool matrixCoefficientsAreLosslessCompatible = usingIdentityMatrix;
+#if defined(AVIF_ENABLE_EXPERIMENTAL_YCGCO_R)
+ matrixCoefficientsAreLosslessCompatible |= (image->matrixCoefficients == AVIF_MATRIX_COEFFICIENTS_YCGCO_RE ||
+ image->matrixCoefficients == AVIF_MATRIX_COEFFICIENTS_YCGCO_RO);
+#endif
+ if (!matrixCoefficientsAreLosslessCompatible && !using400) {
+#if defined(AVIF_ENABLE_EXPERIMENTAL_YCGCO_R)
+ fprintf(stderr, "WARNING: [--lossless] Input data was RGB and matrixCoefficients isn't set to identity (--cicp x/x/0) or YCgCo-Re/Ro (--cicp x/x/15 or x/x/16); Output might not be lossless.\n");
+#else
fprintf(stderr, "WARNING: [--lossless] Input data was RGB and matrixCoefficients isn't set to identity (--cicp x/x/0); Output might not be lossless.\n");
+#endif
lossless = AVIF_FALSE;
}
}
diff --git a/apps/shared/avifjpeg.c b/apps/shared/avifjpeg.c
index 87ff123..b599b3e 100644
--- a/apps/shared/avifjpeg.c
+++ b/apps/shared/avifjpeg.c
@@ -356,12 +356,32 @@
avif->width = cinfo.output_width;
avif->height = cinfo.output_height;
+#if defined(AVIF_ENABLE_EXPERIMENTAL_YCGCO_R)
+ const avifBool useYCgCoR = (avif->matrixCoefficients == AVIF_MATRIX_COEFFICIENTS_YCGCO_RE ||
+ avif->matrixCoefficients == AVIF_MATRIX_COEFFICIENTS_YCGCO_RO);
+#else
+ const avifBool useYCgCoR = AVIF_FALSE;
+#endif
if (avif->yuvFormat == AVIF_PIXEL_FORMAT_NONE) {
- // Identity is only valid with YUV444.
- avif->yuvFormat = (avif->matrixCoefficients == AVIF_MATRIX_COEFFICIENTS_IDENTITY) ? AVIF_PIXEL_FORMAT_YUV444
- : AVIF_APP_DEFAULT_PIXEL_FORMAT;
+ // Identity and YCgCo-R are only valid with YUV444.
+ avif->yuvFormat = (avif->matrixCoefficients == AVIF_MATRIX_COEFFICIENTS_IDENTITY || useYCgCoR)
+ ? AVIF_PIXEL_FORMAT_YUV444
+ : AVIF_APP_DEFAULT_PIXEL_FORMAT;
}
avif->depth = requestedDepth ? requestedDepth : 8;
+#if defined(AVIF_ENABLE_EXPERIMENTAL_YCGCO_R)
+ if (useYCgCoR) {
+ if (avif->matrixCoefficients == AVIF_MATRIX_COEFFICIENTS_YCGCO_RO) {
+ fprintf(stderr, "AVIF_MATRIX_COEFFICIENTS_YCGCO_RO cannot be used with JPEG because it has an even bit depth.\n");
+ goto cleanup;
+ }
+ if (requestedDepth && requestedDepth != 10) {
+ fprintf(stderr, "Cannot request %u bits for YCgCo-Re as it uses 2 extra bits.\n", requestedDepth);
+ goto cleanup;
+ }
+ avif->depth = 10;
+ }
+#endif
avifRGBImageSetDefaults(&rgb, avif);
rgb.format = AVIF_RGB_FORMAT_RGB;
rgb.chromaDownsampling = chromaDownsampling;
diff --git a/apps/shared/avifpng.c b/apps/shared/avifpng.c
index bcd908a..bb18ebc 100644
--- a/apps/shared/avifpng.c
+++ b/apps/shared/avifpng.c
@@ -313,9 +313,18 @@
avif->width = rawWidth;
avif->height = rawHeight;
avif->yuvFormat = requestedFormat;
+#if defined(AVIF_ENABLE_EXPERIMENTAL_YCGCO_R)
+ if (avif->matrixCoefficients == AVIF_MATRIX_COEFFICIENTS_YCGCO_RO) {
+ fprintf(stderr, "AVIF_MATRIX_COEFFICIENTS_YCGCO_RO cannot be used with PNG because it has an even bit depth.\n");
+ goto cleanup;
+ }
+ const avifBool useYCgCoR = (avif->matrixCoefficients == AVIF_MATRIX_COEFFICIENTS_YCGCO_RE);
+#else
+ const avifBool useYCgCoR = AVIF_FALSE;
+#endif
if (avif->yuvFormat == AVIF_PIXEL_FORMAT_NONE) {
- if (avif->matrixCoefficients == AVIF_MATRIX_COEFFICIENTS_IDENTITY) {
- // Identity is only valid with YUV444.
+ if (avif->matrixCoefficients == AVIF_MATRIX_COEFFICIENTS_IDENTITY || useYCgCoR) {
+ // Identity and YCgCo-R are only valid with YUV444.
avif->yuvFormat = AVIF_PIXEL_FORMAT_YUV444;
} else if ((rawColorType == PNG_COLOR_TYPE_GRAY) || (rawColorType == PNG_COLOR_TYPE_GRAY_ALPHA)) {
avif->yuvFormat = AVIF_PIXEL_FORMAT_YUV400;
@@ -331,6 +340,19 @@
avif->depth = 12;
}
}
+#if defined(AVIF_ENABLE_EXPERIMENTAL_YCGCO_R)
+ if (useYCgCoR) {
+ if (imgBitDepth != 8) {
+ fprintf(stderr, "AVIF_MATRIX_COEFFICIENTS_YCGCO_RE cannot be used on 16 bit input because it adds two bits.\n");
+ goto cleanup;
+ }
+ if (requestedDepth && requestedDepth != 10) {
+ fprintf(stderr, "Cannot request %u bits for YCgCo-Re as it uses 2 extra bits.\n", requestedDepth);
+ goto cleanup;
+ }
+ avif->depth = 10;
+ }
+#endif
avifRGBImageSetDefaults(&rgb, avif);
rgb.chromaDownsampling = chromaDownsampling;
@@ -396,12 +418,22 @@
volatile int rgbDepth = requestedDepth;
if (rgbDepth == 0) {
- if (avif->depth > 8) {
- rgbDepth = 16;
- } else {
- rgbDepth = 8;
- }
+ rgbDepth = (avif->depth > 8) ? 16 : 8;
}
+#if defined(AVIF_ENABLE_EXPERIMENTAL_YCGCO_R)
+ if (avif->matrixCoefficients == AVIF_MATRIX_COEFFICIENTS_YCGCO_RO) {
+ fprintf(stderr, "AVIF_MATRIX_COEFFICIENTS_YCGCO_RO cannot be used with PNG because it has an even bit depth.\n");
+ goto cleanup;
+ }
+ if (avif->matrixCoefficients == AVIF_MATRIX_COEFFICIENTS_YCGCO_RE) {
+ if (avif->depth != 10 || (requestedDepth && requestedDepth != 8)) {
+ fprintf(stderr, "Cannot request %u bits for YCgCo-Re as it only works for 8 bits.\n", requestedDepth);
+ goto cleanup;
+ }
+
+ rgbDepth = 8;
+ }
+#endif
volatile avifBool monochrome8bit = (avif->yuvFormat == AVIF_PIXEL_FORMAT_YUV400) && !avif->alphaPlane && (avif->depth == 8) &&
(rgbDepth == 8);
diff --git a/include/avif/avif.h b/include/avif/avif.h
index 5a59e22..12fbec4 100644
--- a/include/avif/avif.h
+++ b/include/avif/avif.h
@@ -331,7 +331,12 @@
AVIF_MATRIX_COEFFICIENTS_SMPTE2085 = 11,
AVIF_MATRIX_COEFFICIENTS_CHROMA_DERIVED_NCL = 12,
AVIF_MATRIX_COEFFICIENTS_CHROMA_DERIVED_CL = 13,
- AVIF_MATRIX_COEFFICIENTS_ICTCP = 14
+ AVIF_MATRIX_COEFFICIENTS_ICTCP = 14,
+#if defined(AVIF_ENABLE_EXPERIMENTAL_YCGCO_R)
+ AVIF_MATRIX_COEFFICIENTS_YCGCO_RE = 15,
+ AVIF_MATRIX_COEFFICIENTS_YCGCO_RO = 16,
+#endif
+ AVIF_MATRIX_COEFFICIENTS_LAST
};
typedef uint16_t avifMatrixCoefficients; // AVIF_MATRIX_COEFFICIENTS_*
diff --git a/include/avif/internal.h b/include/avif/internal.h
index ae0763f..050c64f 100644
--- a/include/avif/internal.h
+++ b/include/avif/internal.h
@@ -120,7 +120,11 @@
{
AVIF_REFORMAT_MODE_YUV_COEFFICIENTS = 0, // Normal YUV conversion using coefficients
AVIF_REFORMAT_MODE_IDENTITY, // Pack GBR directly into YUV planes (AVIF_MATRIX_COEFFICIENTS_IDENTITY)
- AVIF_REFORMAT_MODE_YCGCO // YUV conversion using AVIF_MATRIX_COEFFICIENTS_YCGCO
+ AVIF_REFORMAT_MODE_YCGCO, // YUV conversion using AVIF_MATRIX_COEFFICIENTS_YCGCO
+#if defined(AVIF_ENABLE_EXPERIMENTAL_YCGCO_R)
+ AVIF_REFORMAT_MODE_YCGCO_RE, // YUV conversion using AVIF_MATRIX_COEFFICIENTS_YCGCO_RE
+ AVIF_REFORMAT_MODE_YCGCO_RO, // YUV conversion using AVIF_MATRIX_COEFFICIENTS_YCGCO_RO
+#endif
} avifReformatMode;
typedef enum avifAlphaMultiplyMode
diff --git a/src/reformat.c b/src/reformat.c
index c66f240..a8e8441 100644
--- a/src/reformat.c
+++ b/src/reformat.c
@@ -47,12 +47,20 @@
//
// YCgCo performs limited-full range adjustment on R,G,B but the current implementation performs range adjustment
// on Y,U,V. So YCgCo with limited range is unsupported.
+#if defined(AVIF_ENABLE_EXPERIMENTAL_YCGCO_R)
+ const avifBool useYCgCoRe = (image->matrixCoefficients == AVIF_MATRIX_COEFFICIENTS_YCGCO_RE);
+ const avifBool useYCgCoRo = (image->matrixCoefficients == AVIF_MATRIX_COEFFICIENTS_YCGCO_RO);
+#else
+ const avifBool useYCgCoRe = AVIF_FALSE;
+ const avifBool useYCgCoRo = AVIF_FALSE;
+#endif
if ((image->matrixCoefficients == 3 /* CICP reserved */) ||
- ((image->matrixCoefficients == AVIF_MATRIX_COEFFICIENTS_YCGCO) && (image->yuvRange == AVIF_RANGE_LIMITED)) ||
+ ((image->matrixCoefficients == AVIF_MATRIX_COEFFICIENTS_YCGCO || useYCgCoRe || useYCgCoRo) &&
+ (image->yuvRange == AVIF_RANGE_LIMITED)) ||
(image->matrixCoefficients == AVIF_MATRIX_COEFFICIENTS_BT2020_CL) ||
(image->matrixCoefficients == AVIF_MATRIX_COEFFICIENTS_SMPTE2085) ||
(image->matrixCoefficients == AVIF_MATRIX_COEFFICIENTS_CHROMA_DERIVED_CL) ||
- (image->matrixCoefficients >= AVIF_MATRIX_COEFFICIENTS_ICTCP)) { // Note the >= catching "future" CICP values here too
+ (image->matrixCoefficients == AVIF_MATRIX_COEFFICIENTS_ICTCP) || (image->matrixCoefficients >= AVIF_MATRIX_COEFFICIENTS_LAST)) {
return AVIF_FALSE;
}
@@ -68,6 +76,12 @@
state->mode = AVIF_REFORMAT_MODE_IDENTITY;
} else if (image->matrixCoefficients == AVIF_MATRIX_COEFFICIENTS_YCGCO) {
state->mode = AVIF_REFORMAT_MODE_YCGCO;
+#if defined(AVIF_ENABLE_EXPERIMENTAL_YCGCO_R)
+ } else if (useYCgCoRe) {
+ state->mode = AVIF_REFORMAT_MODE_YCGCO_RE;
+ } else if (useYCgCoRo) {
+ state->mode = AVIF_REFORMAT_MODE_YCGCO_RO;
+#endif
}
if (state->mode != AVIF_REFORMAT_MODE_YUV_COEFFICIENTS) {
@@ -158,7 +172,13 @@
// YCgCo performs limited-full range adjustment on R,G,B but the current implementation performs range adjustment
// on Y,U,V. So YCgCo with limited range is unsupported.
+#if defined(AVIF_ENABLE_EXPERIMENTAL_YCGCO_R)
+ assert((state->mode != AVIF_REFORMAT_MODE_YCGCO && state->mode != AVIF_REFORMAT_MODE_YCGCO_RE &&
+ state->mode != AVIF_REFORMAT_MODE_YCGCO_RO) ||
+ (state->yuvRange == AVIF_RANGE_FULL));
+#else
assert((state->mode != AVIF_REFORMAT_MODE_YCGCO) || (state->yuvRange == AVIF_RANGE_FULL));
+#endif
if (state->mode == AVIF_REFORMAT_MODE_IDENTITY) {
unorm = (int)avifRoundf(v * state->rangeY + state->biasY);
@@ -313,6 +333,19 @@
yuvBlock[bI][bJ].y = 0.5f * rgbPixel[1] + 0.25f * (rgbPixel[0] + rgbPixel[2]);
yuvBlock[bI][bJ].u = 0.5f * rgbPixel[1] - 0.25f * (rgbPixel[0] + rgbPixel[2]);
yuvBlock[bI][bJ].v = 0.5f * (rgbPixel[0] - rgbPixel[2]);
+#if defined(AVIF_ENABLE_EXPERIMENTAL_YCGCO_R)
+ } else if (state.mode == AVIF_REFORMAT_MODE_YCGCO_RE || state.mode == AVIF_REFORMAT_MODE_YCGCO_RO) {
+ // Formulas from JVET-U0093.
+ const int R = (int)avifRoundf(AVIF_CLAMP(rgbPixel[0] * rgbMaxChannelF, 0.f, rgbMaxChannelF));
+ const int G = (int)avifRoundf(AVIF_CLAMP(rgbPixel[1] * rgbMaxChannelF, 0.f, rgbMaxChannelF));
+ const int B = (int)avifRoundf(AVIF_CLAMP(rgbPixel[2] * rgbMaxChannelF, 0.f, rgbMaxChannelF));
+ const int Co = R - B;
+ const int t = B + (Co >> 1);
+ const int Cg = G - t;
+ yuvBlock[bI][bJ].y = (t + (Cg >> 1)) / state.rangeY;
+ yuvBlock[bI][bJ].u = Cg / state.rangeUV;
+ yuvBlock[bI][bJ].v = Co / state.rangeUV;
+#endif
} else {
float Y = (kr * rgbPixel[0]) + (kg * rgbPixel[1]) + (kb * rgbPixel[2]);
yuvBlock[bI][bJ].y = Y;
@@ -701,6 +734,22 @@
G = Y + Cb;
B = t - Cr;
R = t + Cr;
+#if defined(AVIF_ENABLE_EXPERIMENTAL_YCGCO_R)
+ } else if (state->mode == AVIF_REFORMAT_MODE_YCGCO_RE || state->mode == AVIF_REFORMAT_MODE_YCGCO_RO) {
+ const int bitOffset = (state->mode == AVIF_REFORMAT_MODE_YCGCO_RE) ? 2 : 1;
+ const int maxValue = (1 << (state->yuvDepth - bitOffset)) - 1;
+ assert((float)maxValue == rgbMaxChannelF);
+ const int YY = unormY;
+ const int Cg = (int)avifRoundf(Cb * yuvMaxChannel);
+ const int Co = (int)avifRoundf(Cr * yuvMaxChannel);
+ const int t = YY - (Cg >> 1);
+ G = AVIF_CLAMP(t + Cg, 0, maxValue);
+ B = AVIF_CLAMP(t - (Co >> 1), 0, maxValue);
+ R = AVIF_CLAMP(B + Co, 0, maxValue);
+ G /= rgbMaxChannelF;
+ B /= rgbMaxChannelF;
+ R /= rgbMaxChannelF;
+#endif
} else {
// Normal YUV
R = Y + (2 * (1 - kr)) * Cr;
diff --git a/tests/gtest/aviflosslesstest.cc b/tests/gtest/aviflosslesstest.cc
index 82c446c..a4e31c5 100644
--- a/tests/gtest/aviflosslesstest.cc
+++ b/tests/gtest/aviflosslesstest.cc
@@ -21,8 +21,12 @@
const testutil::AvifImagePtr ground_truth_image =
testutil::ReadImage(data_path, file_name);
- for (auto matrix_coefficient :
- {AVIF_MATRIX_COEFFICIENTS_IDENTITY, AVIF_MATRIX_COEFFICIENTS_YCGCO}) {
+ for (auto matrix_coefficient : {
+#if defined(AVIF_ENABLE_EXPERIMENTAL_YCGCO_R)
+ AVIF_MATRIX_COEFFICIENTS_YCGCO_RE, AVIF_MATRIX_COEFFICIENTS_YCGCO_RO,
+#endif
+ AVIF_MATRIX_COEFFICIENTS_IDENTITY, AVIF_MATRIX_COEFFICIENTS_YCGCO
+ }) {
// Read a ground truth image but ask for certain matrix coefficients.
testutil::AvifImagePtr image(avifImageCreateEmpty(), avifImageDestroy);
ASSERT_NE(image, nullptr);
@@ -36,6 +40,14 @@
/*ignoreXMP=*/false, image.get(),
/*outDepth=*/nullptr, /*sourceTiming=*/nullptr,
/*frameIter=*/nullptr);
+#if defined(AVIF_ENABLE_EXPERIMENTAL_YCGCO_R)
+ if (matrix_coefficient == AVIF_MATRIX_COEFFICIENTS_YCGCO_RO) {
+ // AVIF_MATRIX_COEFFICIENTS_YCGCO_RO does not work because the input
+ // depth is not odd.
+ ASSERT_EQ(file_format, AVIF_APP_FILE_FORMAT_UNKNOWN);
+ continue;
+ }
+#endif
ASSERT_NE(file_format, AVIF_APP_FILE_FORMAT_UNKNOWN);
// Encode.
@@ -70,7 +82,12 @@
// Verify that the ground truth and decoded images are the same.
const bool are_images_equal =
testutil::AreImagesEqual(*ground_truth_image, *decoded_default);
- if (matrix_coefficient == AVIF_MATRIX_COEFFICIENTS_IDENTITY) {
+
+ if (matrix_coefficient == AVIF_MATRIX_COEFFICIENTS_IDENTITY
+#if defined(AVIF_ENABLE_EXPERIMENTAL_YCGCO_R)
+ || matrix_coefficient == AVIF_MATRIX_COEFFICIENTS_YCGCO_RE
+#endif
+ ) {
ASSERT_TRUE(are_images_equal);
} else {
// AVIF_MATRIX_COEFFICIENTS_YCGCO is not lossless because it does not
