libs/ui/PixelFormat.cpp

/*
 * Copyright (C) 2007 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 <ui/PixelFormat.h>
#include <hardware/hardware.h>

// ----------------------------------------------------------------------------
namespace android {
// ----------------------------------------------------------------------------

static const int COMPONENT_YUV = 0xFF;

struct Info {
    size_t      size;
    size_t      bitsPerPixel;
    struct {
        uint8_t     ah;
        uint8_t     al;
        uint8_t     rh;
        uint8_t     rl;
        uint8_t     gh;
        uint8_t     gl;
        uint8_t     bh;
        uint8_t     bl;
    };
    uint8_t     components;
};

static Info const sPixelFormatInfos[] = {
        { 0,  0, { 0, 0,   0, 0,   0, 0,   0, 0 }, 0 },
        { 4, 32, {32,24,   8, 0,  16, 8,  24,16 }, PixelFormatInfo::RGBA },
        { 4, 24, { 0, 0,   8, 0,  16, 8,  24,16 }, PixelFormatInfo::RGB  },
        { 3, 24, { 0, 0,   8, 0,  16, 8,  24,16 }, PixelFormatInfo::RGB  },
        { 2, 16, { 0, 0,  16,11,  11, 5,   5, 0 }, PixelFormatInfo::RGB  },
        { 4, 32, {32,24,  24,16,  16, 8,   8, 0 }, PixelFormatInfo::RGBA },
        { 2, 16, { 1, 0,  16,11,  11, 6,   6, 1 }, PixelFormatInfo::RGBA },
        { 2, 16, { 4, 0,  16,12,  12, 8,   8, 4 }, PixelFormatInfo::RGBA },
        { 1,  8, { 8, 0,   0, 0,   0, 0,   0, 0 }, PixelFormatInfo::ALPHA}
};

static const Info* gGetPixelFormatTable(size_t* numEntries) {
    if (numEntries) {
        *numEntries = sizeof(sPixelFormatInfos)/sizeof(Info);
    }
    return sPixelFormatInfos;
}

// ----------------------------------------------------------------------------

size_t PixelFormatInfo::getScanlineSize(unsigned int width) const
{
    size_t size;
    if (components == COMPONENT_YUV) {
        // YCbCr formats are different.
        size = (width * bitsPerPixel)>>3;
    } else {
        size = width * bytesPerPixel;
    }
    return size;
}

ssize_t bytesPerPixel(PixelFormat format)
{
    PixelFormatInfo info;
    status_t err = getPixelFormatInfo(format, &info);
    return (err < 0) ? err : info.bytesPerPixel;
}

ssize_t bitsPerPixel(PixelFormat format)
{
    PixelFormatInfo info;
    status_t err = getPixelFormatInfo(format, &info);
    return (err < 0) ? err : info.bitsPerPixel;
}

status_t getPixelFormatInfo(PixelFormat format, PixelFormatInfo* info)
{
    if (format < 0)
        return BAD_VALUE;

    if (info->version != sizeof(PixelFormatInfo))
        return INVALID_OPERATION;

    // YUV format from the HAL are handled here
    switch (format) {
    case HAL_PIXEL_FORMAT_YCbCr_422_SP:
    case HAL_PIXEL_FORMAT_YCbCr_422_I:
        info->bitsPerPixel = 16;
        goto done;
    case HAL_PIXEL_FORMAT_YCrCb_420_SP:
    case HAL_PIXEL_FORMAT_YV12:
        info->bitsPerPixel = 12;
     done:
        info->format = format;
        info->components = COMPONENT_YUV;
        info->bytesPerPixel = 1;
        info->h_alpha = 0;
        info->l_alpha = 0;
        info->h_red = info->h_green = info->h_blue = 8;
        info->l_red = info->l_green = info->l_blue = 0;
        return NO_ERROR;
    }

    size_t numEntries;
    const Info *i = gGetPixelFormatTable(&numEntries) + format;
    bool valid = uint32_t(format) < numEntries;
    if (!valid) {
        return BAD_INDEX;
    }

    info->format = format;
    info->bytesPerPixel = i->size;
    info->bitsPerPixel  = i->bitsPerPixel;
    info->h_alpha       = i->ah;
    info->l_alpha       = i->al;
    info->h_red         = i->rh;
    info->l_red         = i->rl;
    info->h_green       = i->gh;
    info->l_green       = i->gl;
    info->h_blue        = i->bh;
    info->l_blue        = i->bl;
    info->components    = i->components;

    return NO_ERROR;
}

// ----------------------------------------------------------------------------
}; // namespace android
// ----------------------------------------------------------------------------