[libcamera-devel] [PATCH 2/2] qcam: dng_writer: Add support for IPU3 Bayer formats

[Niklas Söderlund]

Add support for the Bayer formats produced on the IPU3. The format uses
a memory layout that is hard to repack and keep the 10-bit sample size,
therefore scale the samples to 16-bit when creating the scanlines.

Signed-off-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>
---
 src/qcam/dng_writer.cpp | 77 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 77 insertions(+)

diff --git a/src/qcam/dng_writer.cpp b/src/qcam/dng_writer.cpp
index 9435eeec5438f158..8c128041c37f26fe 100644
--- a/src/qcam/dng_writer.cpp
+++ b/src/qcam/dng_writer.cpp
@@ -83,6 +83,55 @@ void thumbScanlineSBGGRxxP(const FormatInfo &info, void *output,
 	}
 }
 
+void packScanlineIPU3(void *output, const void *input, unsigned int width)
+{
+	const uint8_t *in = static_cast<const uint8_t *>(input);
+	uint16_t *out = static_cast<uint16_t *>(output);
+
+	/*
+	 * Upsacle the 10-bit format to 16-bit as it's none trivial to pack it
+	 * it as 10-bits without gaps.
+	 *
+	 * \todo Improve packig to keep the 10-bit sample size.
+	 */
+	for (unsigned int x = 0; x < width; x += 25) {
+		for (unsigned int i = 0; i < 6; i++) {
+			*out++ = ((in[1] & 0x02) << 8 | in[0]) << 6;
+			*out++ = ((in[2] & 0x0f) << 6 | in[1] >> 2) << 6;
+			*out++ = ((in[3] & 0x3f) << 4 | in[2] >> 4) << 6;
+			*out++ = ((in[4] & 0xff) << 2 | in[3] >> 6) << 6;
+			in += 5;
+		}
+
+		*out++ = ((in[1] & 0x02) << 8 | in[0]) << 6;
+		in += 2;
+	}
+}
+
+void thumbScanlineIPU3(const FormatInfo &info, void *output,
+		       const void *input, unsigned int width,
+		       unsigned int stride)
+{
+	const uint8_t *in = static_cast<const uint8_t *>(input);
+	uint8_t *out = static_cast<uint8_t *>(output);
+
+	/* Number of bytes corresponding to 25 pixels. */
+	unsigned int skip = 32;
+
+	for (unsigned int x = 0; x < width; x++) {
+		uint8_t val1 = ((in[1] & 0x02) << 8 | in[0]) << 6;
+		uint8_t val2 = ((in[2] & 0x0f) << 6 | in[1] >> 2) << 6;
+		uint8_t val3 = ((in[stride + 1] & 0x02) << 8 | in[stride + 0]) << 6;
+		uint8_t val4 = ((in[stride + 2] & 0x0f) << 6 | in[stride + 1] >> 2) << 6;
+		uint8_t value = (val1 + val2 + val3 + val4) >> 2;
+
+		*out++ = value;
+		*out++ = value;
+		*out++ = value;
+		in += skip;
+	}
+}
+
 static const std::map<PixelFormat, FormatInfo> formatInfo = {
 	{ PixelFormat(DRM_FORMAT_SBGGR10, MIPI_FORMAT_MOD_CSI2_PACKED), {
 		.bitsPerSample = 10,
@@ -140,6 +189,34 @@ static const std::map<PixelFormat, FormatInfo> formatInfo = {
 		.thumbDownscaleFactor = 16,
 		.thumbScanline = thumbScanlineSBGGRxxP,
 	} },
+	{ PixelFormat(DRM_FORMAT_SBGGR10, IPU3_FORMAT_MOD_PACKED), {
+		.bitsPerSample = 16,
+		.pattern = { CFAPatternBlue, CFAPatternGreen, CFAPatternGreen, CFAPatternRed },
+		.packScanline = packScanlineIPU3,
+		.thumbDownscaleFactor = 25,
+		.thumbScanline = thumbScanlineIPU3,
+	} },
+	{ PixelFormat(DRM_FORMAT_SGBRG10, IPU3_FORMAT_MOD_PACKED), {
+		.bitsPerSample = 16,
+		.pattern = { CFAPatternGreen, CFAPatternBlue, CFAPatternRed, CFAPatternGreen },
+		.packScanline = packScanlineIPU3,
+		.thumbDownscaleFactor = 25,
+		.thumbScanline = thumbScanlineIPU3,
+	} },
+	{ PixelFormat(DRM_FORMAT_SGRBG10, IPU3_FORMAT_MOD_PACKED), {
+		.bitsPerSample = 16,
+		.pattern = { CFAPatternGreen, CFAPatternRed, CFAPatternBlue, CFAPatternGreen },
+		.packScanline = packScanlineIPU3,
+		.thumbDownscaleFactor = 25,
+		.thumbScanline = thumbScanlineIPU3,
+	} },
+	{ PixelFormat(DRM_FORMAT_SRGGB10, IPU3_FORMAT_MOD_PACKED), {
+		.bitsPerSample = 16,
+		.pattern = { CFAPatternRed, CFAPatternGreen, CFAPatternGreen, CFAPatternBlue },
+		.packScanline = packScanlineIPU3,
+		.thumbDownscaleFactor = 25,
+		.thumbScanline = thumbScanlineIPU3,
+	} },
 };
 
 int DNGWriter::write(const char *filename, const Camera *camera,
-- 
2.26.2