Imagine effortlessly crafting breathtaking videos from simple text prompts. Generating high-quality videos with AI models typically requires carefully engineered prompts, a skill often beyond the average user. However, new research introduces "Prompt-A-Video," an innovative system that bridges this gap by automatically refining user prompts to create stunning, dynamic visuals. Traditionally, AI video generation relies on complex descriptions created by large visual language models (LVLMs), making it difficult for simple user input to produce desirable results. Previous attempts to simplify the process faced challenges like focusing too much on static image qualities rather than dynamic video elements, the high cost of developing effective video prompts, and a lack of awareness of individual video model preferences. Prompt-A-Video tackles these issues head-on. This two-stage system uses AI feedback to optimize and align your prompts with the specific video diffusion model you're using. First, a "reward-guided prompt evolution" process uses an LLM like GPT-4 to iteratively refine prompts based on feedback from reward models that assess video quality. This process not only creates better prompts but also generates valuable training data. Next, this data is used to fine-tune the LLM, making it adept at video prompt enhancement. Then, the system employs Direct Preference Optimization (DPO) to further refine the LLM's output, ensuring generated prompts align perfectly with the video model's preferences, producing higher-quality results. Experiments with popular video generation models like Open-Sora and CogVideoX show significant improvements in video quality across various metrics. Plus, the system even generalizes to image generation, demonstrating its versatility. Prompt-A-Video represents a major step towards democratizing video creation, making professional-grade video generation accessible to everyone, regardless of their technical expertise. This research opens exciting possibilities for the future of video content creation, where even simple ideas can be transformed into captivating visual stories with the help of AI.