aaf.essence

EssenceData

class aaf.essence.EssenceData

Bases: aaf.base.AAFObject

position
read()
size
source_mob
write()

EssenceFormat

class aaf.essence.EssenceFormat

Bases: aaf.base.AAFBase

all_keys()
count()
get_format_specifier_auid()
get_format_specifier_name()
get_format_specifier_type()
get_format_specifier_value()
has_key()
keys()
set_format_specifier()
to_dict()

EssenceMultiAccess

class aaf.essence.EssenceMultiAccess

Bases: aaf.base.AAFBase

EssenceAccess

class aaf.essence.EssenceAccess

Bases: aaf.essence.EssenceMultiAccess

codecID
codec_flavour
codec_name
complete_write()

Handle any format related writing at the end and adjust mob lengths. Must be called before releasing a write essence access.

get_emptyfileformat()
get_fileformat()
get_fileformat_parameters()
index_sample_size()

The size in bytes of the given sample

max_sample_size

The size in bytes of the largest sample in the essence.

read()

Read a given number of samples from an opened essence stream. This call will only return a single channel of essence from an interleaved stream. A video sample is a frame.

samples

The number of samples in the essence

seek()

Seek to Given frame index in essence, Useful only on reading, you can’t seek aound while writing essence.

set_fileformat()
write()

Writes data to the given essence stream. A single video frame is ONE sample. Data Length must be large enough to hold the total sample size.

Locator

class aaf.essence.Locator

Bases: aaf.base.AAFObject

path

Absolute Uniform Resource Locator (URL) complying with RFC 1738 or relative Uniform Resource Identifier (URI) complying with RFC 2396 for file containing the essence. If it is a relative URI, the base URI is determined from the URI of the AAF file itself.

NetworkLocator

class aaf.essence.NetworkLocator

Bases: aaf.essence.Locator

EssenceDescriptor

class aaf.essence.EssenceDescriptor

Bases: aaf.base.AAFObject

append_locator()
locators()

FileDescriptor

class aaf.essence.FileDescriptor

Bases: aaf.essence.EssenceDescriptor

container_format
sample_rate

WAVEDescriptor

class aaf.essence.WAVEDescriptor

Bases: aaf.essence.FileDescriptor

The WAVEDescriptor class specifies that a File SourceMob is associated with audio essence formatted according to the RIFF Waveform Audio File Format (WAVE). The WAVEDescriptor class is a sub-class of the FileDescriptor class. A WAVEDescriptor object shall be owned by a file SourceMob.

AIFCDescriptor

class aaf.essence.AIFCDescriptor

Bases: aaf.essence.FileDescriptor

The AIFCDescriptor class specifies that a File SourceMob is associated with audio essence formatted according to the Audio Interchange File Format with Compression (AIFC)

summary

TIFFDescriptor

class aaf.essence.TIFFDescriptor

Bases: aaf.essence.FileDescriptor

The TIFFDescriptor class specifies that a File SourceMob is associated with video essence formatted according to the TIFF specification.

DigitalImageDescriptor

class aaf.essence.DigitalImageDescriptor

Bases: aaf.essence.FileDescriptor

The DigitalImageDescriptor class specifies that a File SourceMob is associated with video essence that is formatted either using RGBA or luminance/chrominance formatting. The DigitalImageDescriptor class is a sub-class of the FileDescriptor class. The DigitalImageDescriptor class is an abstract class.

aspect_ratio

Image Aspect Ratio. This ratio describes the ratio between the horizontal size and the vertical size in the intended final image.

compression
display_view

the dimension of display view. Typically this includes the active picture area, but excludes leading blank video lines and any VITC lines. Set takes a tuple (width, height x_offset, y_offset)

image_alignment

Specifies the alignment when storing the digital essence. For example, a value of 16 means that the image is stored on 16-byte boundaries. The starting point for a field will always be a multiple of 16 bytes. If the field does not end on a 16-byte boundary, it is padded out to the next 16-byte boundary.

layout

The frame layout. The frame layout describes whether all data for a complete sample is in one frame or is split into more than/ one field. Set Takes a str.

Values are:
“fullframe” - Each frame contains a full sample in progressive
scan lines.
“separatefields” - Each sample consists of two fields,
which when interlaced produce a full sample.
“onefield” - Each sample consists of two interlaced
fields, but only one field is stored in the data stream.

“mixxedfields” - Similar to FullFrame, except the two fields

Note: value is always converted to lowercase

line_map

The VideoLineMap property. The video line map specifies the scan line in the analog source that corresponds to the beginning of each digitized field. For single-field video, there is 1 value in the array. For interleaved video, there are 2 values in the array. Set Takes a Tuple, example: (0) or (0,1).

sampled_view

The dimensions of sampled view. Typically this includes any VITC lines as well as the active picture area, but excludes leading blank video lines. Set takes a tuple (width, height x_offset, y_offset)

stored_view

The dimension of the stored view. Typically this includes leading blank video lines, any VITC lines, as well as the active picture area. Set takes a tuple (width, height)

CDCIDescriptor

class aaf.essence.CDCIDescriptor

Bases: aaf.essence.DigitalImageDescriptor

The CDCIDescriptor class specifies that a file SourceMob is associated with video essence formatted with one luminance component and two color-difference components as specified in this document. Informative note: This format is commonly known as YCbCr. The CDCIDescriptor class is a sub-class of the DigitalImageDescriptor class. A CDCIDescriptor object shall be owned by a file SourceMob.

color_range

The ColorRange property. Specifies the range of allowable digital chrominance component values. Chrominance values are unsigned and the range is centered on 128 for 8-bit video and 512 for 10-bit video. This value is used for both chrominance components.

component_width

The ComponentWidth property. Specifies the number of bits used to store each component. Typical values can be 8, 10, 12, 14, or 16, but others are permitted by the reference implementation. Each component in a sample is packed contiguously; the sample is filled with the number of bits specified by the optional PaddingBits property. If the PaddingBits property is omitted, samples are packed contiguously.

horizontal_subsampling

The HorizontalSubsampling property. Specifies the ratio of luminance sampling to chrominance sampling in the horizontal direction. For 4:2:2 video, the value is 2, which means that there are twice as many luminance values as there are color-difference values. Another typical value is 1; however other values are permitted by the reference implementation.

vertical_subsampling

The VerticalSubsampling property. Specifies the ratio of luminance sampling to chrominance sampling in the vertical direction. For 4:2:2 video, the value is 2, which means that there are twice as many luminance values as there are color-difference values. Another typical value is 1; however other values are permitted by the reference implementation.

RGBADescriptor

class aaf.essence.RGBADescriptor

Bases: aaf.essence.DigitalImageDescriptor

SoundDescriptor

class aaf.essence.SoundDescriptor

Bases: aaf.essence.FileDescriptor

PCMDescriptor

class aaf.essence.PCMDescriptor

Bases: aaf.essence.SoundDescriptor

TapeDescriptor

class aaf.essence.TapeDescriptor

Bases: aaf.essence.EssenceDescriptor

FilmDescriptor

class aaf.essence.FilmDescriptor

Bases: aaf.essence.EssenceDescriptor

PhysicalDescriptor

class aaf.essence.PhysicalDescriptor

Bases: aaf.essence.EssenceDescriptor

ImportDescriptor

class aaf.essence.ImportDescriptor

Bases: aaf.essence.PhysicalDescriptor

RecordingDescriptor

class aaf.essence.RecordingDescriptor

Bases: aaf.essence.PhysicalDescriptor

AuxiliaryDescriptor

class aaf.essence.AuxiliaryDescriptor

Bases: aaf.essence.PhysicalDescriptor