EnigmA Amiga Run 1995 October

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======================================================================= ======================================================================= Easy_MPEG Version 1.03 - MPEG for the masses... ======================================================================= ======================================================================= by ME: ******************************************************************* Scott Tribbey 885 N.W. 45th Street Pompano Beach FL, 33064 or 4600 Glenwood Drive Coconut Creek Fl, 33066 Internet Address: secrd2@gate.net OR TRIBB@DELPHI.COM If you have any problems, suggestions, or would just like to say thanks, feel free to contact me. It would be nice to hear that this is useful to someone aside from myself. CREDIT: *************************************************************** This package is the result of the combined effort of a number of talented programmers (including me). I wrote this Arexx program in order to make MPEG easier to use for myself, and accessible to those who might wish to use it like any other WorkBench program. The arprexxlib.library was of great help in accomplishing this goal. This is my first Arexx program. Although I have programmed in "C" for years now, if I wrote this in "C", it would have taken much longer, and been a much bigger program. Also, the Arexx program is easier to modify for me and anyone else who has special needs. This is a great example of the power that can be had using Arexx. Do yourself a favor... LEARN IT!!! WHATISIT: ************************************************************* Easy_MPEG.rexx is an Arexx program that will automatically generate MPEG format video files from a sequence of IFF frames that have been generated or are being generated by a rendering program or other graphics application. Easy_MPEG sports an Intuition interface for ease of use and easily recovers after being interrupted. If 100 to 1 compression whets your appetite, read on... Also note that programs like this are only beginning to come out on other platforms like the PC. In fact XING Technology Corp. has one for the PC that is selling for around $1000, gimme a break! I haven't even seen one for the MAC yet. Just another reason that Apple was stupid for not including a command line interface in their operating system. Us Amiga people can use the Unix stuff almost without modification while the MAC mavens have to wait for someone to write a nice little interface for it and then pay through the nose to get it. DISCLAIMER: *********************************************************** +----------------------------------------------------------------------+ | | | D I S C L A I M E R N O T I C E | | | | I make no warranty, | | express or implied, or assume any liability or responsibility for | | accuracy, completeness or usefulness of any information, appara- | | tus, product or process disclosed, or represent that its use will | | not infringe privately-owned rights. Mention of any product, its | | manufacturer, or suppliers shall not, nor is it intended to, imply | | approval, disapproval, or fitness for any particular use. I retain | | the right to use and disseminate same for any purpose whatsoever. | | | +----------------------------------------------------------------------+ In other words... If you should happen to run this program on a computer used by the defense department to target nuclear warheads and the system goes berzerk sending 1500 megatons of kaboom down on Sadaam Husein's head... It's not my fault. ( not that he would be a loss ) Or... If anything bad happens when using this program, it's not my fault I will not be held responsible. Use this software at your own risk. However, I can say that no one or thing has been injured due to the use of this software up to this point. COPYRIGHT: ************************************************************ Easy_MPEG.rexx Version 1.00 ============================== Copyright (C) 1994 by Scott A. Tribbey ( all rights reserved ) This program is not Public Domain, it is Freeware. I charge no fees for its use by private individuals. However, it is not to be sold in any form without prior written authorization from Scott A. Tribbey. This software may not be used for any commercial venture without prior written consent from Scott A. Tribbey REQUIREMENTS: ********************************************************* Amiga - 68020 or better with 68881 or better FPU Actually I'm not sure about this, but I've never tried running this on anything less. Even if you can run it on a 68000, it will crawl, and so will your graphics program. AREXX - If you don't have Arexx then don't bother reading on. Just go out and get the AmigaDOS 3.1 upgrade, and then continue reading Memory - Gobs... I would suggest at least 6 MEGS of ram. More is always better. I have 14 MEGS and I'd like more. For even better results use a virtual memory program like VMM or Gigamem if you have a 68030 or '040. Priority - The Easy_MPEG program must be run at a priority equal to or higher than the rendering program that is producing the IFF files. For instance, set the rendering program for a priority of -5 and leave the shell where Easy_MPEG will be run from, at the standard priority of 0. Stack - I'm not really sure what the stack requirements are for mpeg_encode program, but just to be safe, I run it with a stack of 20000 bytes. I suggest you do the same. Run & Wait - Easy_MPEG makes use of these AmigaDOS commands, so make sure they are in your C: directory... They certainly should be! rexxsupport.library - This library is also required. It is a standard part of the Arexx installation so you should already have it in you LIBS: directory rexxarplib.library - This is used to create the GUI for Easy_MPEG thus making it easy. It should be in your LIBS: directory See below for more. arp.library - Required by functions in the rexxarplib.library ixemul.library - The runtime library needed for executables compiled by the GCC C compiler. This library is required by mpeg_encode INCLUDED PROGRAMS: ******************************************************* Included in this archive are several files from other archives that are necessary for this package to be useful. mpeg_encode - The freely redistributable MPEG encoder from Berkley University compiled for the Amiga with the GNU GCC 2.5.8 'C++' compiler There are other MPEG encoder engines out there such as the one from Stanford University, but I chose the Berkley version for its ability to encode the MPEG file in chunks (GOPS), making it perfect for compressing an animation while it's being generated. (I modified this version slightly to get rid of an annoying problem the program was having while searching for a Unix shell file) 24toPPM - Actually, I don't know where this came from, but it is about the fastest 24 bit IFF to PPM converter I've seen This program is used to convert the IFF files to PPM format since this is the image format that the mpeg_encode program expects. ILBMtoPPM - This was taken from the NetPBM package, another excellent piece of software. It will convert IFF files of any format, but it is much slower than 24toPPM It is here because the program uses it if 24toPPM fails due to the input frames being something other than IFF-24 format, like HAM8. rexxarplib.library - An absolutely excellent library of functions for arexx programs. My applause to W.G.J. Langeveld at the Stanford Linear Accelerator Center for really adding to the usefulness of Arexx. SETUP: **************************************************************** 1 - COPY rexxarplib.library TO LIBS: 2 - COPY ixemul.library TO LIBS: 3 - COPY all the other files to a directory of your choice. Gee... that was easy DESCRIPTION: ********************************************************** So, maybe you've seen those MPEG encoders floating around the networks and you're wondering to yourself... "Hmmm, what the heck is MPEG?" What is MPEG and why should you use it? Well, MPEG is quickly becoming a standard in motion video compression. MPEG is a lossy compression scheme based on a technology similar to that used for JPEG still image compression. However, MPEG is also much more sophisticated than JPEG for motion compression and allows for compression ratios of 50,100,150 to 1, or more. The disadvantage to MPEG is that it is extremely computationally intensive and for that reason does not play back at fast frame rates without dedicated decompression hardware. It will play back on the Amiga 4000/040 at up to 20 frames per second with small frames. However, the play back hardware necessary to view the MPEG files is becoming more available. Commodore's own CD32 MPEG module is one, and the Reel Magic card for the P.C. (yech!) costs only around $300 for the Lite version. So, MPEG might be worth looking into if you would like to create some long animations and don't have a 1.5 Gigabyte hard drive. USAGE: **************************************************************** Easy_MPEG is intended to be just that... Easy. I will explain some of the more esoteric features below, but this is not intended to be an exhaustive explanation of the fine points of MPEG compression. The intuition interface of Easy_MPEG allows the user to adjust most of the basic parameters for making an MPEG file and a few of the high level compression options for those a bit more bold. First... how to get started. Easy MPEG is launchable from the shell with command line parameters. If no parameters are given, it will present a nice window full of gadgets for the user to enter data in. Not all of the available parameters can be entered from the command line at this time, because I intended for this to be an easy to use program with an Intuition interface. However, if you wish to change some of the options like PATTERN and Quantization, then you can change them from the Intuition interface, interrupt the program and then call it back up with command line parameters for the basic framename and such. I suppose this would be useful if you want to call Easy_MPEG from some other script. REMEMBER TO SET THE SHELL STACK TO AT LEAST 20000 USING THE STACK COMMAND. Command line parameter launch: ============================== Usage: rx Easy_MPEG Base_Frame_Name Start End Xdim Ydim OutFileName Delay DelOldFrames Example: rx Make_MPEG dh0:IFF/Frame. 0000 0030 352 240 Movie 30 YES creates Movie.mpg from the files dh0:IFF/Frame.0000 through dh0:IFF/Frame.0030 resolution is 352 by 240, directory scanning every 30 sec. old frames will be deleted NOTE: Typing rx Easy_MPEG ? will print a usage example like that above and exit. Stay tuned for the meaning of these options... Intuition interface launch: =========================== To start the program, just open a shell, CD to the Easy_MPEG directory and type 'rx Easy_MPEG' at the prompt After a short delay, you will see a display of information in the shell window, and and intuition interface window will pop up with numerous gadgets. After clicking a gadget or entering data into a string gadget, the status display in the shell window will update, displaying the current settings the program will use to operate. The Gadgets... Frame Name: This gadget is used to enter the BASE frame name for the IFF files that are to be encoded. Easy_MPEG expects that the output files will be something of the form BlahBlah.000 where BlahBlah can be any combination of letters, numbers, and punctuation and 000 can be any number as long as the program that produces the frames numbers them sequentially. In other words, the program expects to see a series of frames like Pic.00000 Pic.00001 Pic.00002 .... Pic.00356 If your graphics program doesn't do that (most of them do) then you could write an Arexx program to handle it for you. The numbers don't have to start with 0, it could be anything... 0012, 05, 000000567, etc. Also, the period separating the name and the number is not necessary, it's just how some programs number their output frames. Now the important thing to remember here is that this gadget only wants the BASE frame name not the number portion. So an example might be Pic. or DinosaurFrame or Stupid_Pic_No. Notice how the 0000 is not included at the end of the frame name. Input Dir: This gadget is where you enter the directory where the frames exist or are going to be saved when they are generated. This should be self explanatory. An example might be Imagine:Projects/BigGiant.imp/RayTrace.pix/ Remember to include the "/" at the end of the string when typing directly into this gadget. NOTE: BECAUSE OF AN IDIOSYNCRACY IN THE MPEG_ENCODE PROGRAM, THE INPUT FILES MUST RESIDE AT LEAST ONE DIRECTORY LEVEL DOWN FROM THE ROOT DIRECTORY. IN OTHER WORDS, HAVING YOUR IFF FILES IN "WORK:INPUT/" IS OKAY, BUT HAVING THEM IN "WORK:" IS NOT. THIS ALSO GOES FOR ASSIGNMENTS. IF YOUR FILES ARE IN "DH0:FILES/" WHICH IS ASSIGNED TO "ANIMATION-FRAMES:", USE THE ACTUAL PATH NOT THE ASSIGNMENT! THE PROBLEM IS THAT THE MPEG_ENCODE PROGRAM PLACES A "/" AT THE END OF ITS INPUT DIRECTORY PARAMETER WHEN SEARCHING FOR FILES. SINCE DH0:/ MEANS NOTHING TO AMIGADOS, THIS CAUSES THE PROGRAM TO FAIL. File Requester: Aren't you glad I included this. You can use the File requester to find the frame name and input directory your looking for. Just remember to backspace over the numeric portion of the name before pressing OK. Do not just double click on the file name. Start Frame: This is where you enter the string representing the numeric portion of the first frame to be compressed. In this gadget, 0000 is not equivalent to 00. The program uses the number and the length of the string to properly format the file names it is looking for. If your program puts out file names that have four digits at the end, then enter four digits in this gadget. End Frame: This is where you enter the string representing the numeric portion of the last frame to be compressed. The number of digits entered must be equal to the number of digits entered in the Start Frame gadget. Resolution X: This is where the Horizontal resolution of the output frame must be entered. For instance, 128... 160... 352..., etc. Y: Vertical resolution is entered here. 96, 120, 240, etc. Common MPEG resolutions are 128x96, 160x120, and 352x240(SIF) 352x240 is the standard NTSC video resolution for MPEG NOTE: HORIZONTAL AND VERTICAL RESOLUTIONS MUST ALWAYS BE MULTIPLES OF 16 BECAUSE OF THE WAY THAT THE MPEG PROCESS ENCODES INFORMATION. IF THE RESOLUTION IS NOT A MULT. OF 16, IT'S NOT FATAL, THE ENCODER WILL JUST TRUNCATE PORTIONS OF THE FRAME. MAKE SURE THAT THE CORRECT DATA IS ENTERED HERE, OR THE MPEG FILE WILL BE A MESS. These numbers are only used during the last stage of the program when all the smaller portions of the MPEG file are being combined. So if you notice that these numbers are wrong, then interrupt the program while it is waiting for frames, start it again and enter the correct numbers. The next two variables are the only ones that really affect the compression level of the program. Quant. Scale: Quantization Scale is one of those variables controlling a more esoteric feature of the compression process. The numbers entered in the I, P, and B gadgets must be between 1 and 31. Compression is higher for higher numbers, but quality goes down as the numbers get higher. There are three separate numbers for I, P, and B type frames. Each number affects the compression level of the appropriate frame type I, P or B. This will be further explained below in the Frame Pattern section. If you have no idea what I'm talking about, use standard numbers like 2,4,6 and you'll be just fine. Frm Pattern: Frame Pattern is the repeating pattern that will be used to encode the IFF files. This controls the number of frames that Easy_MPEG will wait for before encoding a portion of an MPEG file called a GOP (Group of Pictures). Be aware that larger patterns will cause the mpeg_encode program to use more memory. So, if you don't have a lot of memory, I would suggest a pattern of no more that four characters. Although you can use only 1 if you wish. Enter the pattern in capital letters. There are three different types of frames in an MPEG file. I frames are the reference frames that MPEG uses to predict the motion of objects from frame to frame. This is similar to the concept of a key frame in animation. The compression of I frames is similar to JPEG compression for still images. **** THE PATTERN MUST ALWAYS START WITH LEAST ONE I. P frames are frames that MPEG predicts from previous I frames. These frames get significantly higher compression than I frames because most of the information for the frame is predicted from the previous frame. This can be a disadvantage when a frame is filled with fast moving objects. If the P frame can not properly locate where a portion of the image should be, then small blocks of the object may seem out of place in a particular frame. Also, if a very short duration event like the flash out of the end of a gun takes place during what is being encoded as a series of P or B frames, it will not show up at all, since it was not in the previous or succeeding I frames. B frames are predicted from the previous and following frames. B frames achieve even higher compression than I or P. However, the same disadvantage exists as for P frames. **** DO NOT END YOUR PATTERN WITH A B SINCE THE FOLLOWING FRAME WILL NOT BE AVAILABLE WHEN THE GOP IS ENCODED. This option really takes time and understanding to use properly, so I've included some example patterns that you can use. IIII - Encodes the MPEG file with only I frames, this will provide the highest quality, but lower compression. Compression of 20 to 1 is easily attained with this pattern. II - Same as above, but uses less memory during compression. IP - Achieves greater compression but be careful with fast motion. IPBP - (Default) Still better compression, but once again be careful with fast moving objects. I use this pattern quite often with excellent results. Using Quantization scale numbers of 2,4,6, and this pattern, I recently compressed an animation from 11.2 megs to 114k with virtually no loss of quality. That's 100 to 1 compression for those of you without calculators. IPBBPBBP - This is a standard pattern that I have seen used in several different MPEG applications. It will require a fair amount of memory though. Enough about this, if you don't understand, than use IPBP as your pattern and you should be just fine. HINT HINT .... Easy_MPEG is excellent for use with Virtual memory systems like VMM. Using a VM system with an mpeg encoder allows you to use a significant amount of memory for the encoder without having to limit the memory requirments of a running rendering program like Imagine or Lightwave. Out File: Well, this one's easy. All you need to enter here is the name of the MPEG file to be created. The MPEG file will be placed in the directory of the original IFF frames with the extension .mpg which is the standard extension for Amiga, PC, and Unix MPEG files. So if you enter BigGiantMovie in this gadget, the MPEG file BigGiantMovie.mpg will be placed in the Input Dir. Of course, if you want this file to be used on other platforms, it would be best to keep the filename to 8 characters or less. Dir. Scan: This option specifies the amount of time the program will sit around waiting before checking to see if enough new frames have been generated to produce a GOP. Remember, if your pattern is IPBP then four new frames must be complete for the mpeg_encode program to produce a GOP. So, if you type 60 into this gadget, then the program will check the Input Dir. every 60 seconds for the existence of the necessary IFF files. If your animation program spits out a frame every 30 minutes, then don't set your delay for 5 seconds, your just wasting processing time. A more reasonable value would be maybe 60 or 120 seconds. Also, don't set this parameter for 350000 seconds, as you don't want Easy_MPEG sitting around doing nothing for 350000 seconds if the last frame just completed rendering. In the case where the full animation has already been produced, the just set this value to 1 and the compression will proceed uninterrupted. I would not advise setting this to 0 at any time, as it may become difficult to break out of the loop. Actually what Easy_MPEG does is to check for the existence of the frame just following the last one in the GOP to be encoded. In other words, if Easy_MPEG is waiting for Pic.0000 through Pic.0003 then it actually checks to see if Pic.0004 exists (although it doesn't have to been complete yet). Easy_MPEG then assumes that the previous frames are done and compresses them into a GOP. If the last GOP is being produced, then Easy_MPEG will check to see if the last frame is actually completed before proceeding with the encoding. The GOP files will have the extension .gop and are only stored until the final MPEG file is produced at which time they are deleted. Del.Old Frames - This gadget will toggle the state of the DelOldFrms line in the shell window when pressed. If this option has a YES next to it then the original IFF frames will be deleted after producing a GOP. This option is great when you want to produce a large animation but don't have a huge hard drive. However, make sure that you have the MPEG parameters just the way you want them, because you'll have to regenerate all the frames if you don't get what you want the first time. If you're really not sure and have all the hard drive space you need, then just set this option to NO and the original IFF frames will be left in the Input Directory. That way you can try different encoding parameters until you get just what you want. Quit Program - What do you think! Hmmm... I'll just bet the program quits if you click this button. The window CLOSE gadget will also have the same effect. Start Scanning - This is it! You've set all the parameters correctly and you're ready to go. Press this button and it's all automatic. Come back in a few minutes, hours or days and Presto!, your MPEG file is complete! You'll notice that the Intuition window disappears when you press this button. From here until the MPEG file is complete, the shell window tells you everything. The status display is mainly a summary of the parameters you fed to the program, but is also tells you how many GOPS have been produced out of the total number and the percentage complete. While Easy_MPEG is waiting for frames, it will occasionally print messages telling you what frame it is waiting for. During this time it is safe to press the CONTROL-C key combination to halt the program. Easy_MPEG will recover from this when you run it again. In fact, I envisioned that this feature might be used fairly often, so the program writes a file called MPEG.settings every time it is run, and reads it every time it is started up. This allows you to start the program from where you left off without having to enter any data. The program will start up with the same parameters you entered last time. All you need to do is press the Start Scanning button and the program will tell you how many GOPS are complete and continue waiting for the rest. When Easy_MPEG has found the frames it is waiting for, it will start the encoding process. During this period of time, you will see the actual encoding process taking place. First of all, the frames all have to be converted to a graphics file format called PPM. Then the PPM files are fed to the mpeg_encode program. During the encoding process, do not interrupt the program. You may have trouble starting over where you left off if you interrupt the program during any time other then when it is waiting for IFF frames. Completion - Upon completion, Easy_MPEG will display a little "Processing Complete" box with an OK button for you to click. NOTE: You will notice that during each session, Easy_MPEG writes a file called BlahBlah.param to its home directory. This file is a special file that contains all necessary parameters for the mpeg_encode program to work. The mpeg_encode program uses this file to figure out what to do with the incoming PPM files. The name of the .param file is actually the name of the Output MPEG file with .param on the end. For instance if you specified BigMovie as your Output file name, then the parameter file would be called BigMovie.param. These .param files only take up about 500 bytes or so, but as you work with the program more and more, you may want to occasionally delete the .param files from the Easy_MPEG directory. The program does not automatically delete them, because they serve as a record of the parameters used to create a certain MPEG file. This can be useful when experimenting with numerous different compression parameters. Conclusion: *************************************************************** Well, that's about it, I didn't cover everything in detail, but I think it should be enough to get most of you going. If you have problems, contact me at one of the addresses above. If you would like further technical details on the MPEG compression scheme, or the particulars of the mpeg_encode program from Berkley, the archives containing these have been floating around the BBS world for a while. files worth looking for are; Amipeg04.lha - MPEG player for AGA/ECS mp103.lha - MPEG player for AGA/ECS MPEGPLAY_201.lha - MPEG player for AGA/ECS MPEG12.lha - Stanford University MPEG encoder mpeg_enc.lha - Berkley University MPEG encoder BMPEG.lha - Stanford Encoder modified for use with Image F/X These are all on the Aminet ( Internet ) Happy MPEGing!... Scott A. Tribbey 1994