How to edit videos on davinci resolve 16 jobs

Issue Description: I am experiencing a problem with my cPanel email setup. Despite configuring the MX records to point to my server, incoming emails are being delivered to an incorrect server. The delivery reports indicate that emails are being sent to a different IP address and host, not my intended server. Details: MX Records: Configured in cPanel to point to my mail server. Problem: Emails are not reaching my server. Delivery reports show they are being sent to a different IP address and host. What I Need: Guidance: I need someone to walk me through the steps to identify and resolve the issue. Skills Required: cPanel & WHM expertise DNS and MX records configuration Email server setup and troubleshooting

...we are looking for a talented photo editor to join our team. Role Overview: We are seeking an experienced Wedding Photo Editor who can seamlessly use our custom presets to replicate our distinctive editing style. The ideal candidate will have a keen eye for detail, excellent technical skills, and a passion for enhancing wedding photographs. Key Responsibilities: * Photo Editing: Edit wedding photographs using our provided presets to ensure consistency with our established style. * Quality Control: Review and refine images to meet our high standards of quality and aesthetic appeal. * Batch Processing: Efficiently process large volumes of photos while maintaining attention to detail. * Collaboration: Work closely with our photographers and team ...

...(Artificial Intelligence) based chatbot, designed to serve as a one-stop information source for all government services in Qatar. It aims to assist anyone, including citizens, residents, businesses, government employees, and foreign entities, with questions about governmental procedures, laws, regulations, and more. Leveraging the latest advances in Large Language Models (LLMs), the system interprets and generates answers to user inquiries conversationally. Allama aims to provide accurate and up-to-date information, helping users navigate government processes more efficiently. Task Overview: We need a creative freelancer to produce a 60-second social media ad for Allama's launch. The ad will be used on Facebook, Instagram, Twitter,...

...app developer to assist in creating a professional bookmarking app. The app should be compatible with web browsers, iOS devices, and Android devices. Project Description: Plan for Bookmark Manager Overview: Develop a robust and user-friendly bookmark manager that competes with existing solutions like , enhanced with advanced AI features for content aggregation, summarization, interaction, and topic-based organization. The app should also support importing PDF papers, tweets, social media posts, and monitoring for new bookmarks. Phased Development Plan: Phase 1: Core Features and Basic Content Clipping This phase focuses on establishing the essential functionalities of the bookmark manager. Key Features: Content Clipping -Supported Content Types: Articles, videos...

...email configuration. - The problem: I am currently unable to send and receive emails using my Outlook client. - Access: I primarily use email client software like Outlook for handling my emails. We are seeking a skilled IT professional to help resolve email configuration issues within our organization. Our company, has recently faced challenges with our email services, including DNS propagation delays and issues with receiving emails. We need an expert who can quickly diagnose and resolve these problems to ensure smooth and reliable email communication. Responsibilities: Verify and correct DNS records (CNAME, SRV, MX, TXT) for our domain. Ensure proper email configuration and propagation. Diagnose and resolve issues related to email...

...assistant to help streamline my activities and connect with my audience. Here's a nutshell overview of what you'd be doing: 1. Email Management: Skim through my inbox and prioritize emails for my attention. Managing reply and follow-ups are also part of the package. Including sending notes every morning about my upcoming day and potential information I need for a meeting. 2. Calendar Management: Keep my schedule updated, arrange meetings, and remind me about impending appointments. You may also need to resolve any scheduling conflicts that might arise. 3. Social Media Assistance: Engage with my audience on both Facebook and Instagram. Posting updates, managing interactions and messages, and being involved in our online community are essential t...

I have a video i just want a software based on deep learning that can change the name taken in video , as i have list of names that need to changed. with lipsink

This project requires someone with Copilot Pro and Microsoft Business 365 account I'm in need of a skilled and experienced...a skilled and experienced individual who can manage the following tasks: - Copy a Hindi video script (with timestamp) from a YouTube video and paste it to a WordPress platform. The videos duration is 1 hour, 1.5 hours, 2 hours, 2.5 hours, and 3 hours - Translate the script to English using Edge browser. - Format the text using Copilot Pro and the provided prompts. This project requires someone with Copilot Pro and Microsoft Business 365 account, as well as a strong command of both Hindi and English languages. The successful freelancer will need to demonstrate excellent attention to detail and be able to follow inst...

I am looking for an experienced Android developer to refactor my existing app. The main areas of improvement are a redesign of the user interface, and general refactoring to enhance the overall performance and user experience. Key tasks include: - Redesigning the user interface: Adding fields to existing screens and changing one navigation. - Refactor: Some changes on the DB. Ideal skills and experience for this job include: - Jetpack Compose & Navigation - Hilt - Ability to identify and resolve functionality issues in Android apps - Excellent problem-solving skills and attention to detail If you have the expertise and ability to deliver high-quality work in a timely manner, I'd be interested in hearing from you.

I'm looking f...music video for my track "Convergence". The aim is to reflect the energetic mood of the song. Key aspects of the project: - Mood & Style: The video should be energetic and should incorporate a mix of live-action and animation to bring out the desired energy. - Visual Elements: The video should include futuristic elements, which can help set the tone and create an engaging visual narrative. Ideal Skills: - Previous experience in creating music videos, especially in the mixed media format. - A strong portfolio that demonstrates a good understanding of futuristic aesthetics. - Ability to interpret and match the energy of a music track through visuals. I'm excited about this project and can't wait to see wha...

I'm looking for a skilled video editor who specializes in social media content, particularly YouTube. Key Requirements: - Edit and enhance social media videos - Apply Text overlays, Transitions, and Color grading - Ensure videos are YouTube-optimized Ideal candidates should have: - Proven experience with video editing - Knowledge of YouTube content creation trends - Ability to apply engaging and subtle effects - Proficiency in video editing software I'm excited to see how you can elevate my social media content!

...video content creator who can produce engaging promotional videos for multiple uses on our social media platforms. The scope of the project involves creating compelling video content that will primarily serve the purpose of increasing brand awareness and generating leads. Key project requirements: - Expertise in developing high-quality, engaging, and effective promotional videos for social media. - Understanding of video content strategies for brand awareness and lead generation. - Ability to tailor video content to suit different social media platforms and their audiences. - Creative vision and storytelling skills to translate our brand message into visually appealing content. - Familiarity with video editing software and tools to enha...

Objective: To convert PNG images into CDR (CorelDRAW) format suitable for single-color, high-quality prints. The project will ensure that the converted images are print-ready and meet specific editing requirements. Scope of Work: 1. Image Conversion: - Convert PNG images to CDR format. - Ensure the converted images retain high resolution and quality. - Maintain the integrity of the original design during the conversion process. 2. Image Editing: - Edit images as per the provided specifications. - Adapt the images to a single-color format while preserving the design details. - Adjust elements such as size, alignment, and positioning to meet print requirements. 3. Quality Assurance: - Perform quality checks to ensure the conv...

20 second Test Edit Required before Hiring. $40AUD per video. Only apply if you accept. I am in need of a skilled video editor who is proficient in Adobe Premiere Pro. The style of the video I am aiming for is high-energy. The primary purpose of the video is for property sales. Key Requirements: - Proficient in Adobe Premiere Pro - Experience with creating high-energy videos - Previous work on Real Estate footage - Ability to implement speed ramps effectively - Understanding of Real Estate marketing is a plus The ideal candidate should be able to bring creativity to the project, making the video engaging and compelling to potential buyers.

...editor with a solid background in VFX and 3D editing. The primary objective of this project is to create educational content using Adobe After Effects. Key Responsibilities: - Implementing educational content: The editor should be skilled in creating engaging and informative videos for educational purposes. - VFX & 3D Expertise: Proficient in using Adobe After Effects for VFX and manipulation. - Timely Delivery: This project has a specific deadline to meet. Ideal Skills and Experience: - Proficient with Adobe After Effects: The editor should be well-versed in the tool, with a portfolio that showcases their VFX and 3D editing skills. - Strong Understanding of Educational Content: The ability to translate complex topics into easily digestible visual conte...

...the city are, etc. The video material will be provided from our side. Formerly, I used Adobe Premiere Pro & CapCut to make one (the example: ). The videos will be in English! Key Project Details: - The style should be more on the casual/vlog side. - Each reel maximum of 90 seconds. - Subtitles needed – can help with adding names of artists, places, etc - The separate sound from the microphone has to be added, synchronised, and enhanced if needed Ideal Experience: - A portfolio of video editing work. - Familiarity with casual, vlog-style editing and a good sense of pacing. - Ability to work efficiently and effectively. We would like to firstly try out one video, if it works out good – we have more coming!...

...editor with a solid background in VFX and 3D editing. The primary objective of this project is to create educational content using Adobe After Effects. Key Responsibilities: - Implementing educational content: The editor should be skilled in creating engaging and informative videos for educational purposes. - VFX & 3D Expertise: Proficient in using Adobe After Effects for VFX and manipulation. - Timely Delivery: This project has a specific deadline to meet. Ideal Skills and Experience: - Proficient with Adobe After Effects: The editor should be well-versed in the tool, with a portfolio that showcases their VFX and 3D editing skills. - Strong Understanding of Educational Content: The ability to translate complex topics into easily digestible visual conte...

I need 3 YouTube content videos. Each video will be 30 minutes and should be visually rich. must be supported by graphics. The videos will be about the development of artificial intelligence and will contain interesting information. I am waiting for offers from users who think they can do it.

As an expert in video editing, I'm looking for a skilled professional who can assist me with editing my Instagram reels and YouTube s...with editing my Instagram reels and YouTube shorts. Key Responsibilities: - Perform intermediate editing such as adding transitions, effects, and music to create engaging videos - Ensure the videos are of high quality and meet the standards of the respective platforms Ideal Candidate: - Proficient in video editing software and techniques - Experienced in editing short-form content for social media platforms - Creative with understanding of social media trends - Strong attention to detail If you are passionate about video editing and understand the nuances of creating content for Instagram and YouTube, I would love t...

...presence to post cooking recipes across various social media platforms and a blog. - Social Media Platforms: You will be required to post on Instagram, YouTube, Facebook, and Twitter. - Frequency: Recipes should be posted daily for maximum audience engagement. - Cuisine Focus: While there's flexibility in the type of cuisine or cooking style you can provide, please ensure it's appealing to a broad audience. Your ideal skills and experiences will include: - Proven experience as a chef, with a portfolio of recipes and cooking videos. - A strong social media presence with a significant following. - Excellent communication and engagement skills. - Ability to create and post visually appealing content. - Regular and consistent posting hab...

...content specifically for YouTube. This involves working with social media footage to generate clear and captivating narratives and design eye-catching YouTube thumbnails for my audience. Ideal skills and experience: - Proven experience in video editing - Excellent understanding of YouTube's content requirements and standards - Ability to create videos exceeding 3 minutes in length - Experience improving and refining raw footage - Ability to meet strict deadlines Content creation will involve - Using provided footage to create a coherent and engaging story - Adding text, sound, graphics, or special effects where required - Ensuring each video meets quality and length requirements. Here is a sample link to my channel;

I'm looking for an engaging 1-2 minute 2D animation video to promote a new product. Key Requirements: - Duration: 1-2 minutes - Goal: Primarily to introduce and explain a new product - Style: 2D animation The video should be creative, professional, and able to grasp the viewer's attention from start to finish. It should clearly and effectively present the features and benefits of the product, essentially persuading viewers to take an interest in it. Ideal Skills: - Proficiency in 2D animation - Previous experience creating product introduction videos - Creative storyboard development - Strong understanding of marketing and how to engage audiences If you're confident in your ability to create a compelling pro...

...video editor to create short form like produced by natt jongsala. The videos will be less than a minute long and should be tailored for Instagram. Key Requirements: - Video Duration: The final videos should be less than a minute in length. The ideal candidate would have experience in creating engaging, fast-paced content within this timeframe. - Editing Style: The preferred style is fast-paced and dynamic. The editor should be proficient in adding high-energy cuts, transitions, and effects,adding sfx , motion graphics , to create a visually exciting piece. - Platform: The videos are intended for Instagram. Experience working with this platform and a good understanding of Instagram's video editing requirements is essential. Applicants with a port...

...experiences. Are you passionate about providing excellent customer service? Are you ready to assist customers in the green mobility industry? Join our dynamic team as an Inbound Customer Service Representative at United Call Centers, where you'll play a vital role in ensuring customer satisfaction for our clients in this innovative sector. Key Responsibilities: - Assist customers of our green mobility industry client. - Handle inbound calls and emails professionally and efficiently. - Provide information, resolve issues, and address customer concerns. - Maintain accurate records of customer interactions in our CRM system. - Collaborate effectively with team members to ensure top-notch service. - Adapt to rotating shifts in our 24/7 operation. Qualifi...

...stylesheet does not work on Google Chrome On Firefox and on Safari no issues The booking widget from is not loading which might be rather a stylesheet issue than .htacess on Google Chrome and the stylesheet for the header links does not work On Firefox and Safari the widget is loading, just load the site on different browsers and you will see For the .htaccess file, I need: All links on the left column are resolving to .hmtl but it should resolve to .php One example: Now the links (pages ) are not loaded but if you change the links in the browser line to .php the pages are loaded. NOT WORKING WORKIND To me it is a .htacces issue

I'm looking for a skilled developer with experience in EPiServer and Moodle to help migrate our existing EPiServer CMS 7.5 website onto the Moodle Learning Management System (LMS). Key Requirements: - Migrate EPiServer website to Moodle LMS: This is the main focus of the project. The professional should be able to handle the migration process from start to finish. - Freelancer's time zone should be within a 4-hour difference from Sydney (GMT+10) - When you make an offer, provide a plan, primary tasks, and cost for each. - Also mention your years of experience with EPiServer, and your years of experience with Moodle. - Please don't email nor call. Just apply and send communication through freelancer.com. Required Skills and Experience: - Proficie...

I'm in search of a talented video editor who excels in advanced editing techniques, namely color correction and audio mixing. The content's ultimate goal is to advertise a product or service. The video should communicate the message in an informal and humorous tone. Ideal Skills/Experience: - Advanced video editing capabilities - Experience in creating engaging advertisement videos - Proven ability in color correction and audio mixing - A sense of humor and ability to translate that into visual content Need someone who can create engaging yet simple form content for Instagram reels

...utilize video stock footage to create engaging 5-12 minute videos on health and diet topics. The videos will focus on weight loss and healthy eating tips, catering to an adult and senior audience. Key responsibilities and requirements: - Create 5-12 minute videos using video stock footage on health and diet topics - Incorporate a mix of informative and inspirational content - Prior experience in creating similar content or demonstrating knowledge in health and diet field - Strong video editing skills to ensure the final product is engaging and informative - Able to cater the video content specifically to an adult and senior audience Ideal Skills: - Video editing - Content creation in health and diet fields -...

...producer to help us create a short, inspirational corporate video celebrating our 11th year milestone. The primary goal of this video is to convey a message of gratitude and achievement to our audience - Past and Present Employees, customers, investors and different stakeholders. Key Requirements: - The video should be centered around the celebration of our 11 years in business, reflecting the journey, growth and success. - Drone footage and some pictures will be provided for you to incorporate into the video. - The tone of the video should be inspirational and uplifting, aiming to evoke positive emotions in the viewers. Ideal Skills and Experience: - Previous experience in creating corporate videos, particularly for milestone celebrations or ...

I'm in need of an intermediate level video editor with a knack for creating cinematic styled pieces. My project involves personal videos that require polishing and a professional touch. Skills and Experience Needed: - Proficiency in video editing software - Experience in cinematic editing - Ability to deliver strong storytelling and pacing - Previous experience with personal or home videos is a plus My aim is to bring a heightened quality and filmic touch to my personal videos. I'm excited to see your interpretation of my vision.

My PHP + Twig + Javascript website is currently experiencing functionality issues. I am looking for a skilled developer to diagnose and address these issues promptly. Key Points: - The website is built on PHP, Twig and Javascript, so expertise in these languages is essential. - I need the professional to investigate and resolve the functionality problems I've detected. - The specific issues are not clearly defined, but it's related to how the website operates. - The developer should have experience with identifying and rectifying common PHP, Twig, and Javascript functionality errors. This project requires a proactive and experienced developer who can quickly understand the website's code and rectify the identified issues.

...informative and engaging how-to videos for new car owners. - The videos should be tailored to be 1-2 minutes long, ensuring they meet the attention span of our audience. Platforms: The videos will primarily be used on Instagram and YouTube. Experience with creating content for these platforms is highly desired. Skills and Experience: - Proven experience in videography, especially in product showcases. - Proficiency in creating content for Instagram and YouTube. - Strong editing skills to produce slick, professional-looking videos. - Ability to take direction and capture the desired atmosphere. - Familiarity with the automotive industry or a passion for cars is a plus. If you're a creative videographer who can...

I am looking for a skilled video edit...skilled video editor who can help me create engaging YouTube videos for my cashcow/ automated channel. Key Requirements: - Editing: The videos will need to be edited in a way that captivates viewers - keeping them engaged and coming back for more. - Length: The final video should be between 5 and 20 minutes long. Ideal Skills & Experience: - Proficiency in video editing software (e.g., Adobe Premiere Pro, Final Cut Pro, etc.) - Experience in editing YouTube videos in a way that increases audience retention. - Creativity to come up with engaging visual content. - Understanding of the YouTube algorithm and video SEO would be a plus. If you're a talented video editor and understand the nuances of success...

...editor with a solid background in VFX and 3D editing. The primary objective of this project is to create educational content using Adobe After Effects. Key Responsibilities: - Implementing educational content: The editor should be skilled in creating engaging and informative videos for educational purposes. - VFX & 3D Expertise: Proficient in using Adobe After Effects for VFX and manipulation. - Timely Delivery: This project has a specific deadline to meet. Ideal Skills and Experience: - Proficient with Adobe After Effects: The editor should be well-versed in the tool, with a portfolio that showcases their VFX and 3D editing skills. - Strong Understanding of Educational Content: The ability to translate complex topics into easily digestible visual conte...

...Assistant (VA) to help build a content library by creating videos using an AI platform. This role involves entering pre-constructed AI prompts, reviewing AI-created videos, ensuring quality, and making necessary edits through the AI platform. Additionally, the VA will create video thumbnails using Canva and upload both the videos and thumbnails to a YouTube channel. Key Responsibilities: - Input pre-constructed AI prompts into the AI video creation platform. - Review AI-generated videos to ensure: - Images match the scenes. - Music and voice are appropriate. - Edit videos through the AI platform as needed. - Create eye-catching video thumbnails using Canva. - Upload videos and thumbnails to a YouTube chann...

I am looking for a data entry specialist to collect Phone, Email and Link Ideal Skills: - Search company name via google and collect Email, Phone and Link - Only Yellow Mark need to collect Rate for Per Valid Leads=0.25 INR Rate for Per Valid Phone=0.25 INR Rate for Per Valid Leads + Phone =0.50 INR Before Place the bid check rate and everything Then place your bid

Hi Need a flyer made very quickly based on existing PSD template Full details are here = Need it done today

I'm urgently seeking a Yii2 expert who can help me resolve an issue with emails not being sent from my application. It is hosted on Godaddy and was working fine but suddenly stopped working. Key Points: - The issue is urgent, but can wait a bit for resolution - I haven't been able to identify the root cause Your responsibilities will include: - Analyzing the existing code base for potential email-sending bugs - Identifying and fixing any issues that might be causing the problem Ideal Skills: - Proficiency in Yii2 framework - Experience with email sending systems - Strong debugging skills Please bid only if you have the necessary experience in Yii2 and can get started on this immediately.

I'm in need of a proficient video editor with solid experience on Adobe Premiere Pro. The ideal candidate should be able to apply an energetic and fast-paced editing style to my YouTube videos. Also, incorporating animated text elements into the videos is required. Please provide examples of your previous work where similar requirements have been met. Strong attention to detail and creativity are a must for this project.

...looking for a skilled videographer to create impactful corporate and branding videos to increase our brand awareness and promote our products or services. These videos should cater primarily to our customers, with an aim to inform and engage them about our offerings. Ideal Skills and Experience: - Proven experience in video production, particularly for branding and corporate videos. - Ability to create informative and straightforward style videos. - Strong understanding of branding and marketing principles. - Prior experience targeting content to customers in the business sector. Your role will be: • Assisting with scripting and pre-planning • Conceptualizing and capturing engaging content in l...

...office 365 B2B leads. Primarily, I'm targeting large corporations in the technology sector, with a specific focus on CEO/President titles. Key requirements: - The leads should be sourced from Zoominfo and strictly validated. - Quality control is paramount; the leads must be debounced and filtered to ensure correctness and relevance. Ideal Skills: - Extensive experience with Zoominfo and B2B lead generation. - Familiarity with the technology sector and its key players. - A proven track record of acquiring high-validity leads, particularly for CEO/President roles in large corporations. Please only bid if you can demonstrate a strong understanding of these requirements and the skills to deliver high-quality results. Looking for leads for the following: 1. ...

I need a proficient Android developer to assist me in designing the User Interface (UI) of my application. This is a small task but it is important to me that the UI is modern and minimalist. Key Skills and Experience: - Proficiency in Android UI design - Experience in creating modern and minimalist designs - Ability to incorporate user-friendly features Please note that the question about responsiveness was skipped, so you may need to clarify with me whether the design needs to be responsive across different devices.

...intuitive university search tool. - Admission Requirements Database: A comprehensive database of admission requirements for various universities is crucial. - Scholarship Information: A database of scholarships to help students fund their education is also needed. - Student Profile & Document Upload: A platform for students to create profiles and upload necessary documents. - Student Timeline Planner: A tool to help students plan their application timelines. - Counsellor Profile & Meeting Booking: A profile for counsellors with the ability to see student application profiles, and a booking form to schedule meetings. - AI Chatbot: An AI chatbot for answering common queries. - Admin Panels: Role-based admin panels for different access levels. - i...

Word Doc to Canva Template Use this file to get the text Canva links and description:

...Please gather product information on vehicles that are equipped with the technology described in the section "2. Technology Description". *Note: Do not limit your information gathering to only the details mentioned in "1. Background" and "3. Reference Technology" (sections 【1】 and 【3】 are for reference only). 【1:Background】 This is about the electric vehicle charging reservation system. With this technology, for example, when using charging stations installed at locations such as car dealerships or beauty salons, customers can receive services while efficiently communicating with the shop's staff. In this way, it allows customers to seamlessly receive shop services timed with their vehicle charging. <<NOTICE>> The ta...

...gather product information on vehicles that are equipped with the technology described in the section "2. Technology Description". *Note: Do not limit your information gathering to only the details mentioned in "1. Background" and "3. Reference Technology" (sections 【1】 and 【3】 are for reference only). 【1:Background】 This technology is related to vehicle information display systems. In conventional technology, it was possible to control autonomous driving through a switch unit installed near the driver's seat, and choices could be made using a display device in front of the driver's seat. However, there was an issue where the position of the switch unit did not align with the display location of the choices. 【2:Techno...

I currently run a WordPres...bar, history, and notifications seem to be experiencing issues. I need a professional who can repair the broken link in this area. Key requirements: - The project involves fixing the broken link in the order status bar, history, and notifications on the website - The website is built with WordPress, and I suspect the issue may be related to the custom themes we use - It's crucial that the repair work does not disrupt the rest of the website functionality Ideal skills and experienced PHP developer: - Proficient in WordPress - Experience in order status bar, history, and notifications repair - Ability to work with and understand custom themes Please bid if you're confident in your ability to resolve...

I need a proficient video editor skilled in advanced editing techniques like special effects and transitions. The project involves enhancing an instructional/tutorial video using animated graphics and text. CRUCIAL REQUIREMENTS: - Proven experience in advanced video editing - Excellent in an...proficient video editor skilled in advanced editing techniques like special effects and transitions. The project involves enhancing an instructional/tutorial video using animated graphics and text. CRUCIAL REQUIREMENTS: - Proven experience in advanced video editing - Excellent in animated graphics and text production - Background in creating engaging instructional videos Your expertise and creativity will help bring these tutorial videos to life, enhancing their effective...

...attached image for contest details** __________________________________________________________________________ <Overview> Please collect product information on vehicles information that have or will have the technologies described in the “Technology Description” section below. <<NOTICE>> The target car brands in this search are limited to US, European, Chinese, and South Korean brands. <Requirements for Payment> ・Submit documentary evidence that clearly states the details of the subject product, the name of the company selling the product, and the company that plans to sell the product. Documentary evidence includes websites, YouTube videos, repair manuals, photos of the actual product, vehicle owner's manuals etc....

I'm in need of an experienced Shopify expert to assist with managing products, inventory, and media within my store. Key Responsibilities: - Efficiently managing product listings, ensuring accuracy, and timely updates - Organizing and optimizing inventory tracking for better stock management - Uploading and managing photos and videos of products in a visually appealing manner I have limited budget for this but I need someone who really knows Shopify in order to connect it to web services via soap API And I need all the products info to appear on the product page videos and photos