Short: PPM to Videotex (Teletext/Viewdata) Author: chris@unsatisfactorysoftware.co.uk (Chris Young) Uploader: chris unsatisfactorysoftware co uk Type: gfx/pbm Version: 1.3 Architecture: ppc-amigaos >= 4.0.0 ; m68k-amigaos URL: http://www.unsatisfactorysoftware.co.uk/ppmtovtx AppName: ppmtovtx FileName: ppmtovtx.lha SDKVersion: 1.1,1.2 Thumbshot: http://www.unsatisfactorysoftware.co.uk/ppmtovtx/images/knife_t.png Screenshot: http://www.unsatisfactorysoftware.co.uk/ppmtovtx/images/knife.png Publisher: Unsatisfactory Software ppmtovtx converts pictures into Videotex (CEPT-3) format. The Videotex format is shared with Teletext (Level 1) services such as Ceefax, and Viewdata services such as Prestel or Minitel. A Videotex frame is made up of 24 rows of 40 characters. These characters can be either printable ASCII characters, mosaic graphics or formatting commands. The format allows for 8 colours including black, and a graphics resolution of 80x72. Typically the first row on a Videotex service is a header row showing the page number and service name, so the actual useable height is reduced to 23 rows, or 69 mosaic pixels. ppmtovtx expects binary PPM files with a width of 80 pixels. The height can be anything up to 72 pixels, and should be divisible by three. The behaviour of the program in other cases is undocumented. The usual height would be 69 pixels, which gives 23 rows of Videotex data. You can scale pictures to this size using the following command: pnmscale -xsize 80 -ysize 69 picture.ppm >scaledpicture.ppm Where "picture.ppm" is the name of the original file, and "scaledpicture.ppm" is the destination (NB: the ">" is required). pnmscale and tools to convert to and from PPM format files are available in the NetPBM package. (NetPBM is available from http://netpbm.sourceforge.net and an Amiga port is on Aminet) You can then convert this into a Videotex frame using: ppmtovtx scaledpicture.ppm scaledpicture.bin Where "scaledpicture.ppm" is the input file, and "scaledpicture.bin" is the output file in raw data format. There are more options for ppmtocept3: ppmtovtx [options [threshold]] The output filename should end in ".bin" for a raw format file, or anything else for an ESC coded file. The ESC coded files (which I call .vtx format) can be loaded by PstView amongst others, but .bin format is more widely used. Options are one or more of {SHAKRGYBMCW} (case sensitive), as follows: S - Separate mode Separates the mosaic graphics pixels. H - Held graphics mode During colour changes the block with the colour change will be a duplicate of the previous block. Probably not very useful. A - Automatic background colour changes Changes the background colour to improve the colour resolution of the picture. D - Disable black foreground Prevents ppmtovtx using the code for black foreground colour (more compatible) Only works with "A" mode enabled. K - Black background (default) R - Red background G - Green background Y - Yellow background B - Blue background M - Magenta background C - Cyan background W - White background It makes no sense to specify more than one of {AKRGYBMCW}. Later colours override earlier ones, and in conjunction with A at most only the start of the first row will be of the specified colour. ===== History ------- 1.3a (re-release) * Added OS4 port, no other changes. 1.3 * I have absolutely no idea. 1.2 (23.03.2002) * Added an option to prevent ppmtovtx inserting a code for black foreground colour. Black foreground is not officially supported. ppmtovtx will use a workaround instead. * Defaulted output to use .bin format if an extension was not recognised, rather than .vtx 1.1 (16.03.2002) * Fixed a bug where full foreground colour blocks would sometimes be in the background colour * Fixed another bug which caused some of the picture to be in the background colour thus not being visible. 1.0 (07.01.2002) * First release ===== Additional notes for included executables: AmigaOS ------- Copy the file Amiga/ppmtovtx or Amiga/ppmtovtx.os4 (for OS4 users) to somewhere in your path (eg. SYS:C) You should increase the stack before running this program (issue the command "STACK 50000") There seems to be a bug which occasionally causes a Suspend/Reboot requester when the program exits (if you run it more than once) that I haven't managed to track down. OS4 users might be interested in the Videotex Datatype to view the output. See http://www.unsatisfactorysoftware.co.uk/ppmtovtx DOS/Windows ----------- Copy the file DOS/PPMTOVTX.EXE to somewhere in your path (usually C:WINDOWSCOMMAND or C:WINNT) The compiler I used seems to have caused a bug when writing .bin format data - occasionally the output includes a code for red text. I advise recompiling from the source code if at all possible. intent/AmigaDE -------------- Copy the contents of the intent directory to the root of the intent filesystem (usually c:intent) No known bugs in this version. ===== These executable files and source code (in ANSI C) can be freely distributed provided no money changes hands (excluding reasonable costs for media or delivery) and the author is acknowledged and this .readme file is included with the distribution. The executable MUST NOT be distributed without the source code, although it is permitted to distribute the source code without any compiled binaries. Modified binaries and source code MUST NOT be distributed without reasonable contact details for the person who modified them (eg email address). The author does not accept any responsibility for loss of data or other events arising from the use of this software. All use is at your own risk. Any changes made by third parties are their responsibility and not that of the original author. The original author retains copyright for the original source and any binary created using that source code. Although unlikely, permission to distribute or use this source code or a resulting executable can be revoked at any time and without warning. This licence covers both commercial and non-commercial use. If you do not agree with these terms you must immediately delete this software package. -- Chris Young, 13th January 2002 http://www.unsatisfactorysoftware.co.uk -----BEGIN PGP MESSAGE----- Version: 2.6.3in iQB7AwUASRs04rO1+24s2ZO5AQFkKgMsDKrm49NmGGD9AmigTxxd+3l5s4P/QEbm 3lOd9E8dLhPO+JWPm/sn88drCTmt29Ip76uGxsrQVdktZDIdvLNeha6lxBOMfaHd 8pARrrvI3QBipwaxUwPEqjWNBy1QZh8rHJPZldg+ =kwdK -----END PGP MESSAGE-----