A codec (compressor-decompressor) is an algorithm that encodes and decodes video data, determining how footage is compressed for storage and decompressed for playback or editing.
A codec is the technology that compresses raw video data into manageable file sizes and decompresses it for viewing or editing. Without codecs, a single minute of uncompressed 4K video would consume approximately 30 gigabytes of storage. Codecs use sophisticated algorithms to reduce file sizes dramatically while preserving as much visual quality as possible, making modern video production and distribution feasible.
Common codecs include H.264 (widely compatible, used for web delivery), H.265/HEVC (more efficient compression at the cost of encoding speed), ProRes (Apple's editing-optimized codec), and DNxHR (Avid's equivalent). Each codec makes different trade-offs between file size, visual quality, encoding speed, and editing performance. Production workflows often use high-quality codecs like ProRes for editing and switch to delivery codecs like H.264 for final distribution.
Understanding codecs helps in making informed decisions about video delivery. A codec optimized for editing (like ProRes) is not ideal for web delivery because files are too large. Conversely, a highly compressed delivery codec (like H.264) is not ideal for editing because the computer must work harder to decode each frame. Choosing the right codec for each stage of the workflow ensures both efficient production and optimal final quality.
Bitrate is the amount of data processed per second in a video file, typically measured in megabits per second (Mbps), directly affecting both file size and visual quality.
Resolution refers to the number of pixels in each dimension of a video frame, typically expressed as width by height (e.g., 1920x1080), which determines the level of detail and clarity in the image.
Transcoding is the process of converting a video file from one codec, format, or specification to another, enabling compatibility across different systems, platforms, and workflows.