libs/ultrahdr/jpegencoderhelper.cpp

/*
 * Copyright 2022 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <cstring>
#include <memory>
#include <vector>

#include <ultrahdr/jpegencoderhelper.h>
#include <utils/Log.h>

namespace android::ultrahdr {

#define ALIGNM(x, m) ((((x) + ((m)-1)) / (m)) * (m))

// The destination manager that can access |mResultBuffer| in JpegEncoderHelper.
struct destination_mgr {
    struct jpeg_destination_mgr mgr;
    JpegEncoderHelper* encoder;
};

JpegEncoderHelper::JpegEncoderHelper() {}

JpegEncoderHelper::~JpegEncoderHelper() {}

bool JpegEncoderHelper::compressImage(const void* image, int width, int height, int quality,
                                      const void* iccBuffer, unsigned int iccSize,
                                      bool isSingleChannel) {
    mResultBuffer.clear();
    if (!encode(image, width, height, quality, iccBuffer, iccSize, isSingleChannel)) {
        return false;
    }
    ALOGI("Compressed JPEG: %d[%dx%d] -> %zu bytes", (width * height * 12) / 8, width, height,
          mResultBuffer.size());
    return true;
}

void* JpegEncoderHelper::getCompressedImagePtr() {
    return mResultBuffer.data();
}

size_t JpegEncoderHelper::getCompressedImageSize() {
    return mResultBuffer.size();
}

void JpegEncoderHelper::initDestination(j_compress_ptr cinfo) {
    destination_mgr* dest = reinterpret_cast<destination_mgr*>(cinfo->dest);
    std::vector<JOCTET>& buffer = dest->encoder->mResultBuffer;
    buffer.resize(kBlockSize);
    dest->mgr.next_output_byte = &buffer[0];
    dest->mgr.free_in_buffer = buffer.size();
}

boolean JpegEncoderHelper::emptyOutputBuffer(j_compress_ptr cinfo) {
    destination_mgr* dest = reinterpret_cast<destination_mgr*>(cinfo->dest);
    std::vector<JOCTET>& buffer = dest->encoder->mResultBuffer;
    size_t oldsize = buffer.size();
    buffer.resize(oldsize + kBlockSize);
    dest->mgr.next_output_byte = &buffer[oldsize];
    dest->mgr.free_in_buffer = kBlockSize;
    return true;
}

void JpegEncoderHelper::terminateDestination(j_compress_ptr cinfo) {
    destination_mgr* dest = reinterpret_cast<destination_mgr*>(cinfo->dest);
    std::vector<JOCTET>& buffer = dest->encoder->mResultBuffer;
    buffer.resize(buffer.size() - dest->mgr.free_in_buffer);
}

void JpegEncoderHelper::outputErrorMessage(j_common_ptr cinfo) {
    char buffer[JMSG_LENGTH_MAX];

    /* Create the message */
    (*cinfo->err->format_message)(cinfo, buffer);
    ALOGE("%s\n", buffer);
}

bool JpegEncoderHelper::encode(const void* image, int width, int height, int jpegQuality,
                               const void* iccBuffer, unsigned int iccSize, bool isSingleChannel) {
    jpeg_compress_struct cinfo;
    jpeg_error_mgr jerr;

    cinfo.err = jpeg_std_error(&jerr);
    // Override output_message() to print error log with ALOGE().
    cinfo.err->output_message = &outputErrorMessage;
    jpeg_create_compress(&cinfo);
    setJpegDestination(&cinfo);

    setJpegCompressStruct(width, height, jpegQuality, &cinfo, isSingleChannel);
    jpeg_start_compress(&cinfo, TRUE);

    if (iccBuffer != nullptr && iccSize > 0) {
        jpeg_write_marker(&cinfo, JPEG_APP0 + 2, static_cast<const JOCTET*>(iccBuffer), iccSize);
    }

    bool status = compress(&cinfo, static_cast<const uint8_t*>(image), isSingleChannel);
    jpeg_finish_compress(&cinfo);
    jpeg_destroy_compress(&cinfo);

    return status;
}

void JpegEncoderHelper::setJpegDestination(jpeg_compress_struct* cinfo) {
    destination_mgr* dest = static_cast<struct destination_mgr*>(
            (*cinfo->mem->alloc_small)((j_common_ptr)cinfo, JPOOL_PERMANENT,
                                       sizeof(destination_mgr)));
    dest->encoder = this;
    dest->mgr.init_destination = &initDestination;
    dest->mgr.empty_output_buffer = &emptyOutputBuffer;
    dest->mgr.term_destination = &terminateDestination;
    cinfo->dest = reinterpret_cast<struct jpeg_destination_mgr*>(dest);
}

void JpegEncoderHelper::setJpegCompressStruct(int width, int height, int quality,
                                              jpeg_compress_struct* cinfo, bool isSingleChannel) {
    cinfo->image_width = width;
    cinfo->image_height = height;
    cinfo->input_components = isSingleChannel ? 1 : 3;
    cinfo->in_color_space = isSingleChannel ? JCS_GRAYSCALE : JCS_YCbCr;
    jpeg_set_defaults(cinfo);
    jpeg_set_quality(cinfo, quality, TRUE);
    cinfo->raw_data_in = TRUE;
    cinfo->dct_method = JDCT_ISLOW;
    cinfo->comp_info[0].h_samp_factor = cinfo->in_color_space == JCS_GRAYSCALE ? 1 : 2;
    cinfo->comp_info[0].v_samp_factor = cinfo->in_color_space == JCS_GRAYSCALE ? 1 : 2;
    for (int i = 1; i < cinfo->num_components; i++) {
        cinfo->comp_info[i].h_samp_factor = 1;
        cinfo->comp_info[i].v_samp_factor = 1;
    }
}

bool JpegEncoderHelper::compress(jpeg_compress_struct* cinfo, const uint8_t* image,
                                 bool isSingleChannel) {
    return isSingleChannel ? compressSingleChannel(cinfo, image) : compressYuv(cinfo, image);
}

bool JpegEncoderHelper::compressYuv(jpeg_compress_struct* cinfo, const uint8_t* yuv) {
    JSAMPROW y[kCompressBatchSize];
    JSAMPROW cb[kCompressBatchSize / 2];
    JSAMPROW cr[kCompressBatchSize / 2];
    JSAMPARRAY planes[3]{y, cb, cr};

    size_t y_plane_size = cinfo->image_width * cinfo->image_height;
    size_t uv_plane_size = y_plane_size / 4;
    uint8_t* y_plane = const_cast<uint8_t*>(yuv);
    uint8_t* u_plane = const_cast<uint8_t*>(yuv + y_plane_size);
    uint8_t* v_plane = const_cast<uint8_t*>(yuv + y_plane_size + uv_plane_size);
    std::unique_ptr<uint8_t[]> empty = std::make_unique<uint8_t[]>(cinfo->image_width);
    memset(empty.get(), 0, cinfo->image_width);

    const int aligned_width = ALIGNM(cinfo->image_width, kCompressBatchSize);
    const bool is_width_aligned = (aligned_width == cinfo->image_width);
    std::unique_ptr<uint8_t[]> buffer_intrm = nullptr;
    uint8_t* y_plane_intrm = nullptr;
    uint8_t* u_plane_intrm = nullptr;
    uint8_t* v_plane_intrm = nullptr;
    JSAMPROW y_intrm[kCompressBatchSize];
    JSAMPROW cb_intrm[kCompressBatchSize / 2];
    JSAMPROW cr_intrm[kCompressBatchSize / 2];
    JSAMPARRAY planes_intrm[3]{y_intrm, cb_intrm, cr_intrm};
    if (!is_width_aligned) {
        size_t mcu_row_size = aligned_width * kCompressBatchSize * 3 / 2;
        buffer_intrm = std::make_unique<uint8_t[]>(mcu_row_size);
        y_plane_intrm = buffer_intrm.get();
        u_plane_intrm = y_plane_intrm + (aligned_width * kCompressBatchSize);
        v_plane_intrm = u_plane_intrm + (aligned_width * kCompressBatchSize) / 4;
        for (int i = 0; i < kCompressBatchSize; ++i) {
            y_intrm[i] = y_plane_intrm + i * aligned_width;
            memset(y_intrm[i] + cinfo->image_width, 0, aligned_width - cinfo->image_width);
        }
        for (int i = 0; i < kCompressBatchSize / 2; ++i) {
            int offset_intrm = i * (aligned_width / 2);
            cb_intrm[i] = u_plane_intrm + offset_intrm;
            cr_intrm[i] = v_plane_intrm + offset_intrm;
            memset(cb_intrm[i] + cinfo->image_width / 2, 0,
                   (aligned_width - cinfo->image_width) / 2);
            memset(cr_intrm[i] + cinfo->image_width / 2, 0,
                   (aligned_width - cinfo->image_width) / 2);
        }
    }

    while (cinfo->next_scanline < cinfo->image_height) {
        for (int i = 0; i < kCompressBatchSize; ++i) {
            size_t scanline = cinfo->next_scanline + i;
            if (scanline < cinfo->image_height) {
                y[i] = y_plane + scanline * cinfo->image_width;
            } else {
                y[i] = empty.get();
            }
            if (!is_width_aligned) {
                memcpy(y_intrm[i], y[i], cinfo->image_width);
            }
        }
        // cb, cr only have half scanlines
        for (int i = 0; i < kCompressBatchSize / 2; ++i) {
            size_t scanline = cinfo->next_scanline / 2 + i;
            if (scanline < cinfo->image_height / 2) {
                int offset = scanline * (cinfo->image_width / 2);
                cb[i] = u_plane + offset;
                cr[i] = v_plane + offset;
            } else {
                cb[i] = cr[i] = empty.get();
            }
            if (!is_width_aligned) {
                memcpy(cb_intrm[i], cb[i], cinfo->image_width / 2);
                memcpy(cr_intrm[i], cr[i], cinfo->image_width / 2);
            }
        }
        int processed = jpeg_write_raw_data(cinfo, is_width_aligned ? planes : planes_intrm,
                                            kCompressBatchSize);
        if (processed != kCompressBatchSize) {
            ALOGE("Number of processed lines does not equal input lines.");
            return false;
        }
    }
    return true;
}

bool JpegEncoderHelper::compressSingleChannel(jpeg_compress_struct* cinfo, const uint8_t* image) {
    JSAMPROW y[kCompressBatchSize];
    JSAMPARRAY planes[1]{y};

    uint8_t* y_plane = const_cast<uint8_t*>(image);
    std::unique_ptr<uint8_t[]> empty = std::make_unique<uint8_t[]>(cinfo->image_width);
    memset(empty.get(), 0, cinfo->image_width);

    const int aligned_width = ALIGNM(cinfo->image_width, kCompressBatchSize);
    bool is_width_aligned = (aligned_width == cinfo->image_width);
    std::unique_ptr<uint8_t[]> buffer_intrm = nullptr;
    uint8_t* y_plane_intrm = nullptr;
    uint8_t* u_plane_intrm = nullptr;
    JSAMPROW y_intrm[kCompressBatchSize];
    JSAMPARRAY planes_intrm[]{y_intrm};
    if (!is_width_aligned) {
        size_t mcu_row_size = aligned_width * kCompressBatchSize;
        buffer_intrm = std::make_unique<uint8_t[]>(mcu_row_size);
        y_plane_intrm = buffer_intrm.get();
        for (int i = 0; i < kCompressBatchSize; ++i) {
            y_intrm[i] = y_plane_intrm + i * aligned_width;
            memset(y_intrm[i] + cinfo->image_width, 0, aligned_width - cinfo->image_width);
        }
    }

    while (cinfo->next_scanline < cinfo->image_height) {
        for (int i = 0; i < kCompressBatchSize; ++i) {
            size_t scanline = cinfo->next_scanline + i;
            if (scanline < cinfo->image_height) {
                y[i] = y_plane + scanline * cinfo->image_width;
            } else {
                y[i] = empty.get();
            }
            if (!is_width_aligned) {
                memcpy(y_intrm[i], y[i], cinfo->image_width);
            }
        }
        int processed = jpeg_write_raw_data(cinfo, is_width_aligned ? planes : planes_intrm,
                                            kCompressBatchSize);
        if (processed != kCompressBatchSize / 2) {
            ALOGE("Number of processed lines does not equal input lines.");
            return false;
        }
    }
    return true;
}

} // namespace android::ultrahdr