[libcamera-devel] [PATCH 09/11] apps: qcam: Add support for IPU3_Y10

[Dan Scally]

Hi Laurent

On 19/03/2023 23:34, Laurent Pinchart wrote:
> Hi Dan,
>
> Thank you for the patch.
>
> On Sat, Mar 18, 2023 at 11:40:12PM +0000, Daniel Scally via libcamera-devel wrote:
>> Add support for the IPU3_Y10 format to the FormatConverter.
> Before reviewing this patch in details, I'd like to know if there would
> be a way to use the ImgU to convert the IPU3-packed greyscale format to
> a more standard format. Is this something you have considered ?


Sorry for the delay on this. I had concluded some time ago that this wasn't possible, so I hadn't 
particularly considered it lately. Since you ask I have been double checking and the conclusion 
seems to hold - I talked to the ipu3/cio2 maintainers and my understanding from those conversations 
is that the Imgu supports bayer input only, and the CIO2 can only output packed data, so I think we 
are stuck with this or something like this.

>
>> Signed-off-by: Daniel Scally <dan.scally at ideasonboard.com>
>> ---
>>   src/apps/qcam/format_converter.cpp | 50 ++++++++++++++++++++++++++++++
>>   src/apps/qcam/format_converter.h   |  2 ++
>>   2 files changed, 52 insertions(+)
>>
>> diff --git a/src/apps/qcam/format_converter.cpp b/src/apps/qcam/format_converter.cpp
>> index de76b32c..7f5648f3 100644
>> --- a/src/apps/qcam/format_converter.cpp
>> +++ b/src/apps/qcam/format_converter.cpp
>> @@ -169,6 +169,10 @@ int FormatConverter::configure(const libcamera::PixelFormat &format,
>>   		formatFamily_ = MJPEG;
>>   		break;
>>   
>> +	case libcamera::formats::Y10_IPU3:
>> +		formatFamily_ = IPU3Packed;
>> +		break;
>> +
>>   	default:
>>   		return -EINVAL;
>>   	};
>> @@ -199,6 +203,9 @@ void FormatConverter::convert(const Image *src, size_t size, QImage *dst)
>>   	case YUVPlanar:
>>   		convertYUVPlanar(src, dst->bits());
>>   		break;
>> +	case IPU3Packed:
>> +		convertIPU3Packed(src, dst->bits(), size);
>> +		break;
>>   	};
>>   }
>>   
>> @@ -357,3 +364,46 @@ void FormatConverter::convertYUVSemiPlanar(const Image *srcImage, unsigned char
>>   		}
>>   	}
>>   }
>> +
>> +void FormatConverter::convertIPU3Packed(const Image *srcImage, unsigned char *dst, size_t size)
>> +{
>> +	const unsigned char *src = srcImage->data(0).data();
>> +	unsigned int bytesprocessed = 0;
>> +	unsigned int lsb_shift;
>> +	unsigned int msb_shift;
>> +	unsigned int index;
>> +	unsigned int x = 0;
>> +	uint16_t pixel;
>> +
>> +	while (bytesprocessed < size) {
>> +		for (unsigned int i = 0; i < 25; ++i) {
>> +			index = (i * 10) / 8;
>> +			lsb_shift = (i * 10) % 8;
>> +			msb_shift = 8 - lsb_shift;
>> +
>> +			/*
>> +			 * The IPU3-packed format can result in padding at the
>> +			 * end of a 32-byte block if the last pixel in a row is
>> +			 * within that block. Check whether we're on the line's
>> +			 * last pixel and skip the rest of the block if so.
>> +			 */
>> +			if (x == width_) {
>> +				x = 0;
>> +				dst += width_ * 4;
>> +				break;
>> +			}
>> +
>> +			pixel = (((src + bytesprocessed)[index+1] << msb_shift) & 0x3ff)
>> +			      | (((src + bytesprocessed)[index+0] >> lsb_shift) & 0x3ff);
>> +
>> +			dst[4 * x + 0] = (pixel >> 2) & 0xff;
>> +			dst[4 * x + 1] = (pixel >> 2) & 0xff;
>> +			dst[4 * x + 2] = (pixel >> 2) & 0xff;
>> +			dst[4 * x + 3] = 0xff;
>> +
>> +			x++;
>> +		}
>> +
>> +		bytesprocessed += 32;
>> +	}
>> +}
>> diff --git a/src/apps/qcam/format_converter.h b/src/apps/qcam/format_converter.h
>> index 37dbfae2..940f8b6b 100644
>> --- a/src/apps/qcam/format_converter.h
>> +++ b/src/apps/qcam/format_converter.h
>> @@ -31,12 +31,14 @@ private:
>>   		YUVPacked,
>>   		YUVPlanar,
>>   		YUVSemiPlanar,
>> +		IPU3Packed,
>>   	};
>>   
>>   	void convertRGB(const Image *src, unsigned char *dst);
>>   	void convertYUVPacked(const Image *src, unsigned char *dst);
>>   	void convertYUVPlanar(const Image *src, unsigned char *dst);
>>   	void convertYUVSemiPlanar(const Image *src, unsigned char *dst);
>> +	void convertIPU3Packed(const Image *src, unsigned char *dst, size_t size);
>>   
>>   	libcamera::PixelFormat format_;
>>   	unsigned int width_;