Disk Output NodeThe Disk Output node enables you to specify how a sequence of images will be written to your hard disk or other storage device. When you are ready to write a sequence to disk, you connect the output of the final process node for the sequence to the input connector of a Disk Output node. The output connector of the Disk Output node is in turn connected to an Exec node for actuation (refer to the Exec Node description in chapter 13, "Tool Nodes "). Exporting Image FilesThe Disk Output node accepts one input and includes parameters that allow you to specify name, directory, file format, and file conversion and compression options. These options can be specified for both final output and for any temps you may want to render. Rendering Temps and FinalsDuring the creation of an effects shot, it is often necessary to create temporary composites (" temp comps"). Composited frames may be needed for evaluation purposes or for reference by another artist before the final shot is ready to be rendered. Temp comps are usually lower resolution than the finals will be, and at times it may be preferable to render them in a different file format. The Disk Output node enables you to specify the name, directory, file format and compression options to use for temps separately from the finals of the same sequence. The file characteristics of finals are specified in the Finals Output tab, while temps, if desired, are specified in the Temps Output tab, which contains the same set of parameters.
Filename and Path ConventionsBy default, the Finals Path entry field contains the following directory path and filename:
Therefore, if you write a 200-frame sequence to disk using a Disk Output node named "output1" and use the File parameter default of "$JOB/$OP/$F4.tiff," Chalice will create 200 files named "0001.tiff" through "0200.tiff" in a directory named "output1" in the directory from which you started Chalice.
Parameter Tabs on the Disk Output Node PanelThe Disk Output parameter tabs include Finals Output and Temps Output tabs for specifying characteristics of the final files you want to output, as well as any temps you may want to render during a project. The rest of the Disk Output tabs are for setting format-specific options, and these options vary slightly according to the system on which Chalice is operating:
The movie-related tabs, which provide options for SGI, QuickTime, and MPEG formats, do not appear on NT because Chalice only exports AVI Video for Windows format on NT. Finals Output Parameter Tab![]() Finals PathThe File parameter enables you to specify the name of the file sequence and the directory location to which the files should be written. You can key the complete pathname into the File data entry field or you can click the File (+) button to open a Choose File dialog box. In the Choose File dialog you can navigate the directory structure of your hard disk or network to select a directory. For more information on using the navigational features of Chalice file dialogs, see Opening an Existing File in chapter 5, "Building Chalice Networks ." FormatThe Format parameter enables you to specify the format in which the image files will be written to disk. The default file format is Tiff. In most cases, you will save the file in the same format as the source file you imported into the Disk Input node. However, you may save the file in any format supported by Chalice. For a complete list see "Image File Formats Supported by Chalice " at the beginning of this chapter. CompressionClick the Compression checkbox to specify that Chalice use compression when writing the files to disk, if you have chosen a format that supports compression. To compress files in Tiff or a movie format, click the Compression checkbox here and go to the Tiff or Movie parameter tab to select additional compression options. Some files, such as Jpegs, are always compressed. To control the quality of Jpeg compression, use the Jpeg/Jfif parameter tab. Vertical FlipCertain file formats invert the orientation of images. Click the Vertical Flip checkbox to invert the imagery when writing the file to disk. This parameter is the complement to the Vertical Flip parameter for the Disk Input node. OverwriteIf the Overwrite box is checked (which is the default), Chalice will overwrite any files with the same name as the name you assign to the output files. Make DirectoriesThe Make Directories box, when checked (which is the default), lets Chalice create new directories, as needed, based on the directory path specified in the File parameter. Strip Off Extra ChannelsSome of the image file formats supported by Chalice only support images with three or fewer channels. The Strip Off Extra Channels box is checked by default whenever you choose to output imagery in one of these formats. If you attempt to output image data that contains more channels than are supported by the selected file format, you will receive an error message. The message will indicate which channels are supported by the format chosen. Temps Output Parameter TabThe Temps Output tab is used only when you need to specify a different pathname, format, or compression option for any temporary composites that may be rendered during a project. Temps are rendered by using the Temps Execute command in the Exec node instead of the Finals Execute command. The Exec node not only controls whether finals or temps are output to disk, but also enables you to set the output file resolution (for temps only) at a fraction of full size. However, you may also want to output temps in a different file format than that specified for the finals, or to output temps using compression and finals uncompressed. It is for this purpose that the Temps Output tab is provided in the Disk Output node. ![]() With the exception of the Temps Path default setting, the parameters are identical to those in the Finals Output tab. Refer to the Finals Output parameter descriptions (above) if you need more information. Temps PathThe Temps Path parameter works exactly like the Finals Path parameter in the Finals Output tab. The Temps Path parameter, however, defaults to a different filename (temp$F4), although temps are written into the same directory as the finals unless you change the path. For more information, refer to the section on Filename and Path Conventions at the beginning of this node description. DPX and Fido Parameter TabsThe DPX Parameter Tab and the Fido Parameter Tab both feature the same set of parameters to facilitate the conversion of linear data (16-bit or floating point) to these Cineon 10-bit log formats for output. Therefore, both tabs are described here, illustrated by the Fido Tab. ![]() ConvertThe Convert parameter popup menu offers five conversion options: None, Extract from 16-bit, Extract from Float, Remap from 16-bit, and Remap from Float. The following chart illustrates the type of conversion to choose for your data: Select None if the image data is already in 10-bit log format. Otherwise, select the "remap from" or "extract from" option that corresponds to the method used to linearize the Cineon files originally (in the Disk Input node, e.g.). The Extract From options perform the inverse of the "insert into" method used in the Disk Input node to convert log files to linear. Use Extract from 16-bit or Extract from Float if the data was originally converted to linear by the Insert into 16-bit or Insert into Float options. The Remap From options perform the inverse of the "remap to" method used in the Disk Input node to convert log files to linear. Use Remap from 16-bit or Remap from Float if the data was originally converted to linear by the Remap to 16-bit or Remap to Float options. Converting non-Cineon imagery: If the imagery to be output as Cineon was never converted from Cineon (if it was created in SoftImage or Photoshop, for example), select the appropriate "remap from" option for the data type (16-bit or float). Conversion ParametersThe following chart illustrates which conversion parameter applies to each conversion method. The values shown represent the defaults, which are based on specifications for Cineon conversion published by Cinesite and Kodak. Log 90% WhiteThe Log 90% White parameter enables you to modify the default RGB log values of 685 for the 90% white card. Film GammaThe Film Gamma parameter enables you to modify the default RGB conversion values for film gamma. Lin. 90% WhiteThe Linear 90% White parameter enables you to modify the default RGB linear values of 4095 for peak white in the conversion from 16-bit linear color space. Reference BlackThe Reference Black parameter enables you to modify the default RGB log values of 95 for reference black. Display GammaThe Display Gamma value is used in the Softclip conversion algorithm. The default value of 1.0 should not need modification in most cases. FRP Parameter Tab"FRP" stands for " Fast Realtime Playback." As its name implies, FRP enables you to save a sequence to disk and play it back in realtime, assuming you have the necessary hardware support. FRP files can be played in a flipbook by accessing the Play command in the Chalice File menu. ![]() When you save a sequence in FRP format, the frames are saved (at their native resolution) as 8-bit data in a single file. FRP is platform specific; that is, an FRP file created on IRIX cannot be shared with an NT system running Chalice.
For best performance, it is essential that the optimal segment size for your filesystem is used when writing the data to your disk, or disk array. To calculate this value, Chalice uses the information in the FRP tab parameters. Ensuring that accurate data is entered for these parameters will improve playback speed dramatically.
Drive CountThis parameter value should reflect the number of drives in your filesystem. The default value is 1, unless you have changed the "Number of drives in filesystem" parameter in the Monitor Preferences panel (which is accessed from the Preferences menu). Block SizeThis parameter value should represent the blocksize of your filesystem, in bytes (e.g., 4096). Like the Drive Count parameter, the default Block Size value is based on the corresponding parameter in the Monitor Preferences panel. Byte OrderThis popup menu enables you to select the most appropriate setting for your workstation. Choosing the correct byte order will improve playback performance of the FRP; however, it is frame buffer dependent, so we can only offer the general guidelines that NT users will most likely want to select RGB, while SGI users of O2 and Reality Engine hardware will want RGBA, and users of Indigos and Octanes, ABGR. Jpeg / Jfif Parameter Tab![]() QualityThe Quality parameter lets you determine the relative image quality for a file you wish to subject to Jpeg compression. You set the Quality parameter by keying in a numerical value in the range of 1 to 100 or by using the mouse to set the tuner to the desired value. The lower the numerical value assigned, the lower the image quality will be, but the higher the level of compression will be. The default is 90; the actual useful range is approximately 35-90 (with an image compressed to 35 being a very low quality image). Movie Parameter Tab (IRIX Only)If you have elected to export an image sequence as a movie file by selecting Movie from the Format parameter menu in the Output tab, you can use the Movie parameter tab to specify the type of movie format, compression, and other options. The optimal values of some parameter settings may vary based on the type of movie file you wish to create. For more information about these movie file formats, consult chapter 3, Media Convert, of the Digital Media Tools Guide in your IRIS InSight online library. ![]() FormatThe Format parameter popup menu enables you to specify which movie format Chalice should use: SGI Movie Type 1, Type 2, or Type 3; Apple QuickTime; or MPEG-1 Systems. The default format is SGI Movie Type 3. CompressionThe Compression parameter popup menu enables you to specify the type of compression Chalice should use:
Frame RateYou specify the frame rate for the movie by keying a value in the range of 8 to 60 frames per second into the data entry field, or by using the mouse to set the tuner to the desired value. The default value is 30 frames per second. OptimizeCheck this parameter if you wish to optimize the movie file for faster playback. The process involves creating a temporary copy of the file, however, which means that optimization not only takes longer but requires twice as much temporary disk space. OrientationThe Orientation parameter popup menu allows you to specify the order in which the pixel data for each frame is written: Bottom-to-top or Top-to-bottom. The default is Bottom-to-top, which is optimal for software playback on your SGI system. However, if the movie is destined for playback on a VCR or other analog device, specify Top-to-bottom. InterlacingThe Interlacing parameter enables you to specify whether the file should be interlaced. The default is None . However, you can specify Odd to interlace the frames starting with the Odd field lines, or Even to interlace the frames starting with the Even field lines. BasisIf you have selected a lossy compression method such as Jpeg, the Basis parameter popup menu enables you to select the Quality or Bit Rate options for modifying compression settings. The default basis is Quality. The lower the numerical value assigned in the Quality or Bit Rate parameter, the lower the image quality will be, but the higher the level of compression will be. QualityThe Quality parameter enables you to specify the relative image quality for a file by keying a numerical value in the range of 1 to 100 (the default setting is 90) into the data entry field or by using the mouse to set the tuner to the desired value. Bit RateThe Bit Rate parameter enables you to specify the level of compression in terms of bits per second of transmission, rather than image quality. You set the Bit Rate parameter by keying a numerical value the range of 1 million to 10 million into the data entry field or by using the tuner dial to set a value. The default is 1,158,000 bits per second. Movie / MPEG Parameter Tab (IRIX Only)If you have elected to export an image sequence as an MPEG-1 Systems movie using MPEG compression, you can use the Movie/MPEG parameter tab to modify the default MPEG compression options.
![]() MPEG PrefilterThis parameter enables you to specify whether Chalice should perform low-pass filtering on the image data before compression to reduce noise and thus facilitate the compression process. The default is None (no prefiltering); however, you can use the Prefilter popup menu to specify one of two levels of prefiltering: Medium or Maximum. MPEG Distance ParametersMPEG compresses frames in groups, rather than singly. These parameters allow you to modify the frame pattern by changing the default values for the distance between reference frames and the distance between "I" (Intra, or key) frames. MPEG I DistYou can modify the default value of 12 for the distance between I frames by keying an integer value in the range of 1 to 60 into the data entry field or by using the mouse to set the tuner to the desired value. MPEG Ref DistYou can modify the default value of 4 frames for the reference distance by keying an integer value in the range of 1 to 12 into the data entry field or by using the mouse to set the tuner to the desired value. P and B Vector Range ParametersThese parameters allow you to modify the pixel values representing the search vectors used in the compression. The P Vector Range represents the predicted motion vector; the B Vector Range, the bidirectional vector. You can modify the default settings by keying new values into the data entry fields. The field on the left represents the X (horizontal) axis; the field on the right, the Y (vertical) axis. Higher values will result in a higher quality image but will be correspondingly slower. Tiff Parameter TabIf you have elected to export image files in Tiff format, you can use the Tiff parameter tab to specify the type and level of compression to be used. ![]() CompressionThe Compression parameter menu enables you to select the type of compression you wish to apply to a Tiff file: JPEG, LZW (the default), Packbits, or Zip (the highest compression).
Prediction EncodingThis parameter allows you to specify whether Chalice should use prediction encoding to optimize the compression process (the default is checked, or on). This method calculates the difference between adjacent pixels and encodes the difference rather than the original data. Certain types of imagery, such as computer generated models, encode very well using this method. However, for noisy images it may be preferable to turn prediction encoding off to obtain the best result. Jpeg QualityThe Jpeg quality parameter enables you to determine the relative image quality of files for which you have specified Jpeg compression in the Compression parameter menu. The lower the numerical value assigned, the lower the image quality will be, but the higher the level of compression will be. Zip LevelThe Zip Level parameter enables you to set the level of compression of files for which you have specified Zip compression in the Compression parameter menu. Because, unlike Jpeg, Zip is a lossless compression method, the only penalty for assigning higher numerical values, which represent higher levels of compression, is that the compression process will take correspondingly longer. |