审片文件和交付文件分开：审片优先稳定播放和较小体积，母版保留更高码率和原始帧率。导出前固定分辨率、帧率、色彩空间与音频采样率，避免平台二次转码放大问题。 Separate review files from delivery masters. Reviews favor reliable playback and smaller files; masters retain higher bitrate and the original frame rate. Lock resolution, frame rate, color space, and audio sample rate before export.