Video sample description extensions

'gama'

A 32-bit fixed-point number indicating the gamma level at which the image was captured. The decompressor can use this value to gamma-correct at display time.

'fiel'

Two 8-bit integers that define field handling. This information is used by applications to modify decompressed image data or by decompressor components to determine field display order. This extension is mandatory for all uncompressed Y´CbCr data formats. The first byte specifies the field count, and may be set to 1 or 2. A value of 1 is used for progressive-scan images; a value of 2 indicates interlaced images. When the field count is 2, the second byte specifies the field ordering: which field contains the topmost scan-line, which field should be displayed earliest, and which is stored first in each sample. Each sample consists of two distinct compressed images, each coding one field: the field with the topmost scan-line, T, and the other field, B. The following defines the permitted variants: 0 – There is only one field. 1 – T is displayed earliest, T is stored first in the file. 6 – B is displayed earliest, B is stored first in the file. 9 – B is displayed earliest, T is stored first in the file. 14 – T is displayed earliest, B is stored first in the file.

'mjqt'

The default quantization table for a Motion-JPEG data stream.

'mjht'

The default Huffman table for a Motion-JPEG data stream.

'esds'

An MPEG-4 elementary stream descriptor atom. This extension is required for MPEG-4 video. For details, see Mpeg 4_elementary_stream_descriptor_atom.

'avcC'

An H.264 AVCConfigurationBox. This extension is required for H.264 video as defined in ISO/IEC 14496-15. For details, see Avc_decoder_configuration_atom.

'pasp'

Pixel aspect ratio. This extension is mandatory for video formats that use non-square pixels. For details, see Pixel_aspect_ratio.

'colr'

Color parameters—an image description extension required for all uncompressed Y´CbCr video types. For details, see Color_parameter_atom.

'clap'

Clean aperture—spatial relationship of Y´CbCr components relative to a canonical image center. This allows accurate alignment for compositing of video images captured using different systems. This is a mandatory extension for all uncompressed Y´CbCr data formats. For details, see Clean_aperture.