This study compares the technical characteristics of DreamAI and MidJourney in the field of digital video generation. Driven by artificial intelligence, digital video generation has shifted content production from static to dynamic. DreamAI uses a temporal diffusion model with hierarchical noise scheduling and 3D convolutional motion prediction algorithms to achieve continuous dynamic rendering at 5 frames per second for 120-s long videos. The FVD evaluation value is superior to that of MidJourney, enhancing motion coherence; MidJourney's frame interpolation architecture based on potential diffusion models excels in cross-modal generation but exhibits trajectory bias in curve motion prediction. The technological differences between the two lead to distinct cultural expressions. Digital video generation serves as a medium for cultural inheritance and innovation, and their practical applications demonstrate that algorithms must integrate with cultural genes. Future developments in multimodal large models are expected to improve video generation accuracy and spatiotemporal coherence.