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Open forum for proposed fulldome standards proposals, publication and comment operated by IMERSA Standards Committee and affiliates.
About the Standards Foundation Process
- Establish volunteer Standards Committee from IMERSA Supporting Members and Affiliates.
- Disseminate Draft Standards for comment on work group web site (fulldome.org).
- Broad-based public, member and allied organization review and comment on Draft Standards.
- Standards Committee consideration of and response to submitted comments.
- Incorporation of approved changes (via formal Standards Committee vote) into a Draft Standard.
- Phase 2 of dissemination, comment, review and revisions.
- Incorporation of approved changes into a Working Standard.
- Standards Committee consensus on Working Standard and ratification recommendation.
- Ratification of Working Standard by IMERSA Board and other user organizations.
- Continued review of comments, concerns and revisions as required by Standards Committee.
- Develop a standard data format and procedure for transferring fulldome programs between users.
- Facilitate the automated display of fulldome programs with minimal human interaction.
- Define metadata and Intellectual Property identification procedures.
- Allow for the expansion of the Working Standard to include 3D datasets, spatialized audio and future technologies.
Fulldome Master Show File Working Standard
Basic Elements of a Fulldome Master Show File
I. Metadata Specifications
Sufficient information for future automated reading and processing of program files, including important owner information about the program.
- A description document file should describe all drive/DVD contents and program specifications
- must include plain text version of the document file
- may include XML version of the document file
- Show name, version, producer, copyright statement, and other intellectual property data
- Total number of Dome Master frames, including number of files and/or length of encoded video file
- Resolution of Dome Master frames (diameter in pixels)
- Dome Master file format — e.g., “TGA” or “JPEG”
- First frame designation — e.g., “00001” or “0001”
- Number of audio tracks —e.g., “2” or “6”
- Audio file format — e.g., “WAV” or “AC3”
- Audio file format parameters including sample rate and bit depth — e.g., “48Khz 16bit”
- Audio track parameters including track designation — e.g., 5.1 or stereo, or virtual tracks
- Time code start and end value — e.g., “00:00:00 - 23:50:00”
- Frame rate — e.g., “30 fps”, “29.97 fps”
- Media structure — location of files, number and names of folders, etc.
- Other program data needed for identification or proper playback
II. Dome Master Working Specification
The “Dome Master” refers to the individual images projected by the fulldome system. For purposes of this working specification, only circular dome masters (i.e., a square source frame) are considered.
- Geometry – equidistant azimuthal “fisheye” render representing up to full sphere with bottom of the frame representing the front bottom of the dome screen, and the right and left hand sides of the dome master corresponding with the respective right and left sides of the dome to a viewer sitting at dome center within the theater. Top and sides of polar image are tangent to edges of image frame.
- Recommended file formats: sequentially numbered lossless files — e.g., PNG, TIFF or TARGA with RLE compression
- other sequentially numbered files — e.g., JPEG at highest-quality setting
- Recommended file name format — e.g., “Name_00001.jpg”, “Name_000001.jpg”
- Recommended folder name format “filename_000001_010,000”
- Color Bit Depth — e.g., 8, 10, or 12 bits/color
- Frame Size, frame must be square, with standard diameter resolutions of 720x720, 1024x1024, 1536x1536, 2048x2048, 3200x3200, 3600x3600, 4096x4096, 8192x8192
- Recommended frame rates — 30 fps or 60 fps,
- other frame rates — 24 fps, 25 fps, 29.97 fps, 30 fps, 48 fps, 59.94 fps, 60 fps
- Alignment Frames — set of standard frames included in dome master that establish synch and test proper geometric alignment, gamma, color balance, etc.
- Other design recommendations:
- Unidirectional “Safe Action” area approx. ±50° longitude (measured from dome front/center), and ranging from 10–60° latitude (altitude)
- Nominal camera tilt of 15° great circle (cf. reference frame)
10. Exterior to active pixel area:
- region colored black (except for time and frame data)
- user-defined show name, timecode, and frame number text
- recommended arrangement: timecode (top line), frame number (second line), and frame rate (third line) in upper left-hand corner, with show name in upper right-hand corner.
III. Audio Files
Audio Format. To accommodate for variations in sound systems in different venues, the original digital “stem” tracks can be available for re-mixing or encoding for individual venues. A “generic” 5.1 mix is derived from these files as well as a number of odd formats such as 16.1. It is preferable to re-mix the sound in each venue when possible utilizing a portable editing system.
- Surround Format – e.g., stereo, 5.1, 7.1, stem tracks, or other
- File Format – e.g., WAV, AIFF, other
- Leader with test tones at -18dBV
- Handles and pips for sync at installation
- Sampling Frequency and bit depth — e.g., 48-kHz 16-bit
- Frame rate for video sync — e.g., 25, 29.97 or 30 fps
- Start frame of either “01:00:00:00” or “00:00:00:01”
- Basic audio file naming convention for discrete channels[RJW2] :
- Front Left: filename_L.wav
- Front Right: filename_R.wav
- Rear Left Surround: filename_Ls.wav
- Rear Right Surround: filename_Rs.wav
- Center Front: filename_C.wav
- Center High (Top): filename_T.wav
- Low-frequency channel (Sub-bass): filename_LFE.wav
- Other: filename_XXX.wav
IV. Standard Tech Trailer
Common test program including:
- Test patterns
- Audio files
- Media synchronization file
- Color balance
- Pink noise
- Annunciated channel check
V. Program Distribution Medium (same metadata should appear on all program media)
- Content should be delivered on either DVDs or hard drives:
- Media < 4GB delivered on DVDs
- Media > 4GB delivered on PC-formatted (NTFS file system) 6-pin, Firewire + USB 2.0 drives
- When multiple drives are used, the same metadata should appear on each drive
- Video should be organized into folders according to frame numbers, typically with a maximum of 10,000 frames per folder
- Audio should be organized into folders according to frame rate (e.g., 25fps, 29.97fps, and 30fps folders), with sub-folders for stereo and x.x surround mixes
- Top level directories: “Frames”, “Audio”, “Extra”, etc.
VI. Digital Rights Management: Encryption, etc.