Club Amiga de Montreal

home *** CD-ROM | disk | FTP | other *** search

/ Club Amiga de Montreal - CAM / CAM_CD_1.iso / files / 079.lha / movie.doc < prev next >

Wrap

Text File | 1986-11-20 | 11.9 KB | 377 lines

MOVIE! a ram animation system by Eric Graham Version 1.01 The MOVIE! ram animation system consists of three programs that must be run from CLI. You will need to be familiar with CLI and with the use of a text editor, such as ED, because you will need to write text files to control the animation. The three programs are: DILBM Calculates the difference between two image files. PILBM Packs several difference files into a single animation file. MOVIE Plays back the animation. To make life easier, I have included a couple of extra programs, DILBMGEN and PILBMGEN (and the C source). These programs generate the script files for a simple loop animation. Before you run these programs, make sure that you have sufficient stack space. Issue the CLI command STACK 16000 unless a similar command is in your startup-sequence. Failure to provide enough stack space will usually result in the system requester and a visit from the Guru. If you have strange problems, here are some hints: 1) You must use Kickstart/workbench 1.2. Be careful using other utility programs, keyboard macros, console filters, etc. If in doubt, return to the original Enhancer disk. 2) You must have enough memory, a 512K machine should play a 200K animation. A 1 meg machine will play back about 700K of animation. 3) You will need at least 16000 bytes stack space. 4) DILBM requires that all images are the same size, the must be full screen or overscan (jumbo), and they must all use the same palette (see below). 5) Check your script files carefully if the movie does not play back correctly. This system differs from other similar programs in several important ways: 1) It is in the public domain. It may be freely copied and distributed for non commercial purposes. Upgrades and enhancements may be provided from time to time. 2) It employs J-type animation compression. This is an adaptive algorithm that employs numerous different strategies to achieve the best compression and fastest playback. Additional strategies will probably be added to improve performance still further. 3) It works with HAM and non-HAM images, either full screen or overscan. It also works with European PAL Amigas. DILBM ----- This program calculates the differences between two images and stores the result as a delta file. The program is called with the names of three files: dilbm image1 image2 delta The two image files must exist. The delta file will be created. The delta file represents the data required to convert image1 into image2. It is not reversible. There is an alternate delta format that is reversible, to generate it, add an 'x' at the end of the command: dilbm image1 image2 delta x Normally, dilbm will display a picture of the differences between the images. To suppress this picture, add a 'q' at the end of the command, this will make dilbm run slightly faster. In order for DILBM to work, both images must use the same palette and have the same size. Images should either be full size or overscan (jumbo size). If the palettes (color maps) differ, or the sizes are not the same, DILBM will produce an informative error message, and then print out so much information that the error message will scroll off the screen, probably before you had a chance to read the message. Paint programs give you direct control over the palette. Be careful that all your images use the same palette. SCULPT 3-D and Animation ------------------------ SCULPT 3-D uses a complicated algorithm to assign values to the color registers, so two images are unlikely to use the same palette. To force SCULPT to use the same palette for several images, later versions have some undocumented and hidden features. (If you have an older version, and you have sent in your registration card, you will be receiving an upgrade). To activate the hidden commands, click on the down window and type control-D. At the prompt, enter the magic number, which is 123. Examine the observer menu and you should see the commands: Mode Color Lock, Mode Color Unlock, Exposure Lock and Exposure Unlock. Once Color Lock is set, new images will use the previous palette. A palette may be established by making an image with mode color unlock, or by loading in an image (with or without color lock). Because the color assignment is performed as the image is rendered, slightly different results will be obtained if you re-render the same image after locking the colors. SCULPT 3-D also has an automatic exposure facility. If this is allowed to operate and change the exposure from frame to frame in an animation, then you will not achieve optimum compression. The Exposure Lock feature disables automatic exposure determination. The manual override will still work, but probably should only be used with the same value for each frame. The actual exposure value is calculated when an image is made, and is saved as a part of the scene, not as part of an image. Here is how to generate images for use in an animation: 1) Render the first image. Save the image and also save the scene after the image has been made (so that the exposure value is saved). 2) Turn on both color lock and exposure lock. Recalculate the first image. Produce the remaining images. 3) If the sequence is interrupted, for example by a reboot, load the first image (to get the palette). Then load the first scene (to get the exposure value). Now lock the colors and exposure. Start rendering. NOTE that if the exposure is locked, loading a scene will not affect the exposure lock, the exposure value, the color lock or the color values. Reading in an image will always change the palette. The new features have script equivalents: MODE COLor LOCk MODE COLor UNLock EXPosure LOCk EXPosure UNLock Here is a sample script file: load scene "abc0.scene" start mode color lock exposure lock start save image "abc0.image" save scene "abc0.scene" exposure lock erase all load scene "abc1.scene" start save image "abc1.image" erase all load scene "abc2.scene" start save image "abc2.image" erase all load scene "abc3.scene" start save image "abc3.image" erase all To continue the sequence, use load scene "abc0.scene" load image "abc0.image" mode color lock exposure lock erase all load scene "abc4.scene" start save image "abc4.image" erase all load scene "abc5.scene" start save image "abc5.image" erase all etc. SSG and Animation ----------------- Just as with SCULPT, you must force SSG to use the same color palette for each frame. This can be done with the command line argument 'r=filename', where 'filename is the name of an image that serves to define the palette. It need not be a full size image. For example SSG i=robot1.dat o=palette s=1 SSG i=robot1.dat o=robot1 r=palette SSG i=robot2.dat o=robot2 r=palette The file 'palette' is a half size image (s=1) that is used to define the colors for the images 'robot1' and 'robot2'. Remember to use TOILBM to convert SSG images into IFF format for use by DILBM. PILBM ----- This program packs delta files together to create an animation. It takes a single argument that is the name of a text file that contains a description of the animation. The following format must be followed: line 1 a The name of the animation that is to be produced. 2 i The name of the initial image. 3 d0 The name of the initial delta file. 4 d1 The name of the first delta file. 5 d2 The name of the second delta file. ... n+3 dn The name of the last delta file. n+4 * An asterisk to denote the start of sequence control n+5 m t m is a delta number and t is a time delay n+6 m t ... m t The animation works by double buffering, so you must specify two images. The file 'i' specifies the first image. The delta file 'd0' defines the second image in terms of the first. The delta file 'd0' is discarded after the second image file is constructed. The remaining delta files, d1 to dn are stored in memory. When the animation is replayed, the following actions take place: The first image is displayed on the screen. Then the second image is displayed. While the second image is displayed, the first image is changed with a delta file. Then it is displayed while the second image is modified with another delta file. This process is repeated. The sequence control determines the order in which the delta files are used. The value 'm' determines which delta file is to be used. The value t specifies how much time (in jiffies) is to be used for the change. If t is negative, then m is used to indicate a transfer to the m'th m-t pair. Thus the following sequence * 3 2 5 2 9 2 12 2 2 -1 would stand for the following sequence of delta files: d3 d5 d9 d12 d5 d9 d12 d5 d9 d12 d5 d9 d12 etc. Not all delta files need to be used (although that would be wasteful) and some may be used many times, if the sequence control specifies a loop. Deciding which images to use to construct delta files, and the correct sequence of delta files is complicated because of the nature of double buffering. Here is an example, suppose that we wish to display images in the following sequence: 15 14 13 12 11 10 9 8 7 8 9 10 11 12 13 14 15 14 13 12 11 etc then we can use the 'x' type of reversible deltas and compute the following files (it is a good idea to place the dilbm commands in a text file and use an 'execute' command). dilbm pic15.image pic14.image dx15-14 x q dilbm pic15.image pic13.image dx15-13 x q dilbm pic14.image pic12.image dx14-12 x q dilbm pic13.image pic11.image dx13-11 x q dilbm pic12.image pic10.image dx12-10 x q dilbm pic11.image pic9.image dx11-9 x q dilbm pic10.image pic8.image dx10-8 x q dilbm pic9.image pic7.image dx9-7 x q dilbm pic8.image pic8.image dx8-8 x q pilbm buildx.script The file buildx.script contains the following: picx.anim phongm15.image dx15-14 dx15-13 dx14-12 dx13-11 dx12-10 dx11-9 dx10-8 dx9-7 dx8-8 * 1 2 2 2 3 2 4 2 5 2 6 2 7 2 8 2 7 2 6 2 5 2 4 2 3 2 2 2 1 2 8 2 1 -1 Note that the delta file dx8-8 causes no action to take place, so it is also used in place of dx14-14. MOVIE ----- The movie playback program is particularly simple. Give it the name of an animation file. Press the 'escape' key to stop an animation that is looping. The program may also be run from workbench, set the default tool of the project (the animation file) to be 'movie'. Alternatively, hold down the shift key and click on the project and then while still holding down the shift key, double click on the movie icon. DILBMGEN and PILBMGEN --------------------- The first one generates a file for executing DILBM. Call it from CLI as follows DILBMGEN >fff 16 This will create a file called 'fff' that contains commands for executing DILBM as needed for a 16 frame animation loop. The image files are assumed to be pic0.image, pic1.image, ... pic15.image. Execute the file 'fff' as follows: EXECUTE fff Use PILBMGEN in a similar way. Call it as follows PILBMGEN >ggg 16 This will create a file called 'ggg' that contains commands for executing PILBM to assemble a 16 frame animation loop. Execute the file from PILBM as follows: PILBM ggg A file called 'anim' will be created. Play it as follows MOVIE anim Good luck!