Function av_image_alloc

libavutil/imgutils.c:218–272

}

int av_image_alloc(uint8_t *pointers[4], int linesizes[4],
                   int w, int h, enum AVPixelFormat pix_fmt, int align)
{
    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
    int i, ret;
    ptrdiff_t linesizes1[4];
    size_t total_size, sizes[4];
    uint8_t *buf;

    if (!desc)
        return AVERROR(EINVAL);

    if ((ret = av_image_check_size(w, h, 0, NULL)) < 0)
        return ret;
    if ((ret = av_image_fill_linesizes(linesizes, pix_fmt, align>7 ? FFALIGN(w, 8) : w)) < 0)
        return ret;

    for (i = 0; i < 4; i++) {
        linesizes[i] = FFALIGN(linesizes[i], align);
        linesizes1[i] = linesizes[i];
    }

    if ((ret = av_image_fill_plane_sizes(sizes, pix_fmt, h, linesizes1)) < 0)
        return ret;
    total_size = align;
    for (i = 0; i < 4; i++) {
        if (total_size > SIZE_MAX - sizes[i])
            return AVERROR(EINVAL);
        total_size += sizes[i];
    }
    buf = av_malloc(total_size);
    if (!buf)
        return AVERROR(ENOMEM);
    if ((ret = av_image_fill_pointers(pointers, pix_fmt, h, buf, linesizes)) < 0) {
        av_free(buf);
        return ret;
    }
    if (desc->flags & AV_PIX_FMT_FLAG_PAL) {
        avpriv_set_systematic_pal2((uint32_t*)pointers[1], pix_fmt);
        if (align < 4) {
            av_log(NULL, AV_LOG_ERROR, "Formats with a palette require a minimum alignment of 4\n");
            av_free(buf);
            return AVERROR(EINVAL);
        }
    }

    if (desc->flags & AV_PIX_FMT_FLAG_PAL && pointers[1] &&
        pointers[1] - pointers[0] > linesizes[0] * h) {
        /* zero-initialize the padding before the palette */
        memset(pointers[0] + linesizes[0] * h, 0,
               pointers[1] - pointers[0] - linesizes[0] * h);
    }

    return ret;
}

typedef struct ImgUtils {
    const AVClass *class;