This dictionary contains high level classes and attributes used in audio and visual products. It also contains classes with attributes used during active mission operations. Many of these classes are designed to be extended into local mission dictionaries. ## CHANGE LOG ## 1.0.0.0 - initial version 1.0.1.0 - R. Deen - Changed video_frame_rate and acquisition_frame rate from units of frequency to units of frame_rate. This is a backward-incompatible change, but the LDD has been published for less than an hour so I think this won't break anything and addresses a bug (it was inconsistent across acquisition, intermediate, and video frame rates, and frame_rate is technically not quite the same as frequency). Contains metadata related to the Audio/Video container, and a set of Tracks for each component of the A/V container. Note that the Local_Internal_Reference points to the local_identifier in this label of the container to which this metadata applies (useful if there is more than one) Class describing an Audio track The Audio_Video class contains metadata for Encoded_Audio or Encoded_Video data. Most attributes are taken directly from the EXIF/XMP keywords often found in A/V files. If there is any ambiguity in the definitions, refer to the EXIF/XMP standards for clarification. This metadata herein is not intended to be comprehensive; it is a subset of the available metadata, wihch is part of the stream itself. This subset is intended to facilitate searching using PDS tools and thus contains those items most likely to be useful for searches. Class containing information relating to a Track within the stream (typically the audio or video portions separated). This class contains metadata common to all Tracks. Children Audio_Track and Video_Track hold metadata specific to those kinds of tracks. Other types of tracks (e.g. Metadata) may not have a child. Class describing a Video track This section contains the simpleTypes that provide more constraints than those at the base data type level. The simpleTypes defined here build on the base data types. This is another component of the common dictionary and therefore falls within the common namespace. Specifies the rate at which unique frames in a movie were acquired by the original camera. This may not match the video_frame_rate for a variety of reasons, for example removing frames or adding duplicate frames to make the movie play at a standard frame rate. If not present, the assumption is this matches the video_frame_rate. Number of bits used to represent each audio sample Number of independent audio signals, or channels, in the sound track. Usually 1 indicates mono, 2 indicates stereo, 6 indicates 5.1 surround, etc. Specifies the audio codec (Coder/Decoder) used for this data, in PDS terms. Identifies the specific codec or encoding method used to compress and store the audio data. This comes directly form the metadata and has not been converted to standard form like audio_codec, but may provide additional information. Frequencey at which the audio is sampled, measured in Hz Overall average bitrate combining both video and audio streams Specifies left/right audio panning. 0 indicates evenly balanced. Bits per channel of color information 4-letter code for the compressor used. It may indicate the software rathar than the codec. More descriptive name of the compressor used. This comes directly from the metadata and has not been converted to standard form like video_codec, but may provide additional information. Specifies the type (format) of the container in PDS terms. Specifies which track ID this trak is describing (typically for metadata tracks) Original recording time of the entire stream Describes the camera or recording device used Indicates the time duration of the stream in hh:mm:ss format Indicates the time duration of the stream in seconds Defines the high-level functional role of a track, whether it is actual media data or metadata. Human-readable description of the handler Defines the type of the track: audio, video, metadata, etc. The value descriptions are human-readable versions; they contain the actual 4-letter code used in the file in parentheses for reference. Height of the video image in pixels in its current form Width of the video image in pixels in its current form Specifies the frame rate for an intermediate product that led to the current track. Rates might be different for example to accommodate standard playback rates when converting the video to a different format. If not present, the assumption is this matches the video_frame_rate. Identifies the primary brand/specification of an ISO base meda file. 3-letter ISO 639-2/T code identifying the language of a specific media track (e.g. "eng" for English, "fra" for French). Specifies the size of the detector in megapixels. This is not intended to be a precise measurement but rather indicates the general size or class of the detector. Specifies the data structure of metadata tracks Indicates when the stream was last edited or saved Indicates the intended playback speed of the video. A value of 1 typically represents normal, real-time speed, while other values can indicate slow motion or fast-forward preferences. Indicates the default playback volume for the stream, with 1.0 indicating normal volume. Height of the video image in pixels when it was originally captured Width of the video image in pixels when it was originally captured Indicates the timing resolution of the movie, defined as the number of time units that pass per second. It dictates the precision of the video's duration and frame rate. Indicates the time duration of this track in hh:mm:ss format Indicates the time duration of this track in seconds ID number for this track Defines the visual stacking order for different tracks in a video. Tracks with lower numbers (including negative) appear in front of tracks with higher numbers. It can also be used to help distinguish between primary and supplementary tracks. Indicates the loudness or gain adjustment applied to this track, often used to normalize volume levels. A value of 1.0 indicates normal volume. Specifies the video codec (Coder/Decoder) used for this data, in PDS terms. Number of video frames per second in the track as stored in this product.