Maximum Video Resolution for PAL VOB Files

A PAL VOB (Video Object) file adheres strictly to standard DVD-Video specifications, which mandate a maximum permissible video resolution of 720 × 576 pixels. This guide details the technical specifications of PAL VOB files, including the maximum resolution limits, supported aspect ratios, frame rate requirements, and alternative valid resolutions within the PAL DVD-Video standard.

The Maximum Resolution Limit

The absolute maximum video resolution allowed for a standard-compliant PAL VOB file is 720 × 576 pixels (commonly known as Full D1). Because the VOB format is fundamentally designed for the DVD-Video standard, it cannot exceed standard-definition (SD) boundaries. Attempting to author or multiplex video with a resolution higher than 720 × 576—such as 720p or 1080p high definition—violates the DVD specification, resulting in files that will fail DVD authoring checks and will not play back on standard standalone DVD hardware.

Key Technical Specifications

A PAL VOB file operating at the maximum 720 × 576 resolution must also conform to specific encoding parameters:

• Frame Rate: 25 frames per second (fps), delivered either as 50 interlaced fields per second (576i) or progressive frames (576p).
• Compression Standard: MPEG-2 (or MPEG-1 for lower resolutions).
• Pixel Aspect Ratio (PAR): PAL video uses non-square (rectangular) pixels.
• Display Aspect Ratio (DAR): While the storage resolution is fixed at 720 × 576, playback displays in either a standard 4:3 or a widescreen 16:9 anamorphic format via display flags embedded in the stream.
• Maximum Bitrate: The video stream bitrate can reach up to 9.8 Mbps, provided the total combined multiplexed stream (video, audio, and subtitles) does not exceed 10.08 Mbps.

Alternative Permissible PAL VOB Resolutions

While 720 × 576 represents the maximum resolution, the PAL DVD-Video standard also permits three lower, officially compliant resolutions:

1. 704 × 576 pixels: Commonly used for broadcast television captures to remove edge-masking (blanking) areas.
2. 352 × 576 pixels (Half D1): Frequently used for long-play recordings to conserve disc space while preserving vertical resolution.
3. 352 × 288 pixels (CIF / SIF): The lowest permissible resolution, encoded via either MPEG-1 or MPEG-2, equivalent to Video CD (VCD) quality.

Any resolution outside these four strict standards is not permissible for compliant PAL VOB authoring.