Can a VOB File Support Multiple Video Codecs?

A VOB (Video Object) container cannot support multiple video compression codecs simultaneously within the same file. Rooted strictly in the MPEG-2 Program Stream format, the VOB specification was designed specifically for DVD-Video media and restricts video content almost entirely to MPEG-2 or MPEG-1. Unlike modern multimedia containers, VOB lacks the structural framework, multiplexing flexibility, and signaling mechanisms required to host or switch between disparate video compression standards at the same time.

The Technical Constraints of the VOB Container

A VOB file is fundamentally an MPEG-2 Program Stream (ISO/IEC 13818-1) with custom extensions defined by the DVD Forum. The DVD-Video specification explicitly defines the boundaries of what data packets can exist inside this container:

• Strict Codec Limitations: Video inside a standard VOB container must be compressed using MPEG-2 (H.262) or, in limited low-resolution cases, MPEG-1. Modern codecs such as AVC/H.264, HEVC/H.265, AV1, or VP9 cannot be placed inside a VOB container while retaining structural validity.
• Single Active Video Standard: The container architecture relies on a static sequence header that defines the video characteristics. There is no mechanism to decode one part of a continuous file with one codec and another part with a different codec.

What About Multi-Angle and Interleaved Streams?

DVD-Video supports multi-angle features, which may lead to the misconception that a VOB file can carry different types of video streams concurrently.

While a VOB file can contain multiple interleaved video tracks to allow seamless switching between camera angles during playback, all streams must adhere to the exact same encoding profile. Every interleaved stream must use the MPEG-2 codec with identical dimensions, frame rates, and matching Group of Pictures (GOP) structures to allow the decoder hardware to switch instantly without reinitializing. Thus, even when multiple video streams coexist, they cannot use different compression codecs.

Comparison with Modern Extensible Containers

The restriction in VOB files contrasts sharply with modern container formats like Matroska (MKV) or MP4 (ISO Base Media File Format). Modern formats utilize track-based headers that permit diverse compression standards within the same file, allowing multiple video tracks encoded in different codecs to exist side by side.

Because the VOB format was hardcoded to the processing capabilities of late-1990s standalone DVD players, its container syntax cannot describe or manage multiple video codecs within a single file.