/* SPDX-License-Identifier: LGPL-2.1-or-later */ /* * Copyright (C) 2020, Google Inc. * * encoder_libjpeg.cpp - JPEG encoding using libjpeg native API */ #include "encoder_libjpeg.h" #include <fcntl.h> #include <iomanip> #include <iostream> #include <sstream> #include <string.h> #include <sys/mman.h> #include <unistd.h> #include <vector> #include <libcamera/base/log.h> #include <libcamera/camera.h> #include <libcamera/formats.h> #include <libcamera/pixel_format.h> #include "libcamera/internal/formats.h" using namespace libcamera; LOG_DECLARE_CATEGORY(JPEG) namespace { struct JPEGPixelFormatInfo { J_COLOR_SPACE colorSpace; const PixelFormatInfo &pixelFormatInfo; bool nvSwap; }; const std::map<PixelFormat, JPEGPixelFormatInfo> pixelInfo{ { formats::R8, { JCS_GRAYSCALE, PixelFormatInfo::info(formats::R8), false } }, { formats::RGB888, { JCS_EXT_BGR, PixelFormatInfo::info(formats::RGB888), false } }, { formats::BGR888, { JCS_EXT_RGB, PixelFormatInfo::info(formats::BGR888), false } }, { formats::NV12, { JCS_YCbCr, PixelFormatInfo::info(formats::NV12), false } }, { formats::NV21, { JCS_YCbCr, PixelFormatInfo::info(formats::NV21), true } }, { formats::NV16, { JCS_YCbCr, PixelFormatInfo::info(formats::NV16), false } }, { formats::NV61, { JCS_YCbCr, PixelFormatInfo::info(formats::NV61), true } }, { formats::NV24, { JCS_YCbCr, PixelFormatInfo::info(formats::NV24), false } }, { formats::NV42, { JCS_YCbCr, PixelFormatInfo::info(formats::NV42), true } }, }; const struct JPEGPixelFormatInfo &findPixelInfo(const PixelFormat &format) { static const struct JPEGPixelFormatInfo invalidPixelFormat { JCS_UNKNOWN, PixelFormatInfo(), false }; const auto iter = pixelInfo.find(format); if (iter == pixelInfo.end()) { LOG(JPEG, Error) << "Unsupported pixel format for JPEG encoder: " << format.toString(); return invalidPixelFormat; } return iter->second; } } /* namespace */ EncoderLibJpeg::EncoderLibJpeg() { /* \todo Expand error handling coverage with a custom handler. */ compress_.err = jpeg_std_error(&jerr_); jpeg_create_compress(&compress_); } EncoderLibJpeg::~EncoderLibJpeg() { jpeg_destroy_compress(&compress_); } int EncoderLibJpeg::configure(const StreamConfiguration &cfg) { const struct JPEGPixelFormatInfo info = findPixelInfo(cfg.pixelFormat); if (info.colorSpace == JCS_UNKNOWN) return -ENOTSUP; compress_.image_width = cfg.size.width; compress_.image_height = cfg.size.height; compress_.in_color_space = info.colorSpace; compress_.input_components = info.colorSpace == JCS_GRAYSCALE ? 1 : 3; jpeg_set_defaults(&compress_); pixelFormatInfo_ = &info.pixelFormatInfo; nv_ = pixelFormatInfo_->numPlanes() == 2; nvSwap_ = info.nvSwap; return 0; } void EncoderLibJpeg::compressRGB(Span<const uint8_t> frame) { unsigned char *src = const_cast<unsigned char *>(frame.data()); /* \todo Stride information should come from buffer configuration. */ unsigned int stride = pixelFormatInfo_->stride(compress_.image_width, 0); JSAMPROW row_pointer[1]; while (compress_.next_scanline < compress_.image_height) { row_pointer[0] = &src[compress_.next_scanline * stride]; jpeg_write_scanlines(&compress_, row_pointer, 1); } } /* * Compress the incoming buffer from a supported NV format. * This naively unpacks the semi-planar NV12 to a YUV888 format for libjpeg. */ void EncoderLibJpeg::compressNV(Span<const uint8_t> frame) { uint8_t tmprowbuf[compress_.image_width * 3]; /* * \todo Use the raw api, and only unpack the cb/cr samples to new line * buffers. If possible, see if we can set appropriate pixel strides * too to save even that copy. * * Possible hints at: * https://sourceforge.net/p/libjpeg/mailman/message/30815123/ */ unsigned int y_stride = pixelFormatInfo_->stride(compress_.image_width, 0); unsigned int c_stride = pixelFormatInfo_->stride(compress_.image_width, 1); unsigned int horzSubSample = 2 * compress_.image_width / c_stride; unsigned int vertSubSample = pixelFormatInfo_->planes[1].verticalSubSampling; unsigned int c_inc = horzSubSample == 1 ? 2 : 0; unsigned int cb_pos = nvSwap_ ? 1 : 0; unsigned int cr_pos = nvSwap_ ? 0 : 1; const unsigned char *src = frame.data(); const unsigned char *src_c = src + y_stride * compress_.image_height; JSAMPROW row_pointer[1]; row_pointer[0] = &tmprowbuf[0]; for (unsigned int y = 0; y < compress_.image_height; y++) { unsigned char *dst = &tmprowbuf[0]; const unsigned char *src_y = src + y * compress_.image_width; const unsigned char *src_cb = src_c + (y / vertSubSample) * c_stride + cb_pos; const unsigned char *src_cr = src_c + (y / vertSubSample) * c_stride + cr_pos; for (unsigned int x = 0; x < compress_.image_width; x += 2) { dst[0] = *src_y; dst[1] = *src_cb; dst[2] = *src_cr; src_y++; src_cb += c_inc; src_cr += c_inc; dst += 3; dst[0] = *src_y; dst[1] = *src_cb; dst[2] = *src_cr; src_y++; src_cb += 2; src_cr += 2; dst += 3; } jpeg_write_scanlines(&compress_, row_pointer, 1); } } int EncoderLibJpeg::encode(const FrameBuffer &source, Span<uint8_t> dest, Span<const uint8_t> exifData, unsigned int quality) { MappedFrameBuffer frame(&source, PROT_READ); if (!frame.isValid()) { LOG(JPEG, Error) << "Failed to map FrameBuffer : " << strerror(frame.error()); return frame.error(); } return encode(frame.maps()[0], dest, exifData, quality); } int EncoderLibJpeg::encode(Span<const uint8_t> src, Span<uint8_t> dest, Span<const uint8_t> exifData, unsigned int quality) { unsigned char *destination = dest.data(); unsigned long size = dest.size(); jpeg_set_quality(&compress_, quality, TRUE); /* * The jpeg_mem_dest will reallocate if the required size is not * sufficient. That means the output won't be written to the correct * buffers. * * \todo Implement our own custom memory destination to prevent * reallocation and prefer failure with correct reporting. */ jpeg_mem_dest(&compress_, &destination, &size); jpeg_start_compress(&compress_, TRUE); if (exifData.size()) /* Store Exif data in the JPEG_APP1 data block. */ jpeg_write_marker(&compress_, JPEG_APP0 + 1, static_cast<const JOCTET *>(exifData.data()), exifData.size()); LOG(JPEG, Debug) << "JPEG Encode Starting:" << compress_.image_width << "x" << compress_.image_height; if (nv_) compressNV(src); else compressRGB(src); jpeg_finish_compress(&compress_); return size; }