Архив рубрики: Форматы файлов

Графический файл GIF


Ответственность составителей документа
Предоставление лицензии
Структура документа
Общее описание
Номера версий
Таблицы цветов
Основные и дополнительные блоки, а также границы их действия
Размер блока
Использование формата GIF в составе более общего протокола
Субблоки данных
Дескриптор логического экрана
Глобальная таблица цветов
Дескриптор изображения
Локальная таблица цветов
Кодирование изображений методом таблиц
Дополнительный блок управления изображением
Дополнительный блок комментария
Дополнительный блок с простым текстом
Дополнительный блок приложений
Завершающий блок

Читать далее

Еще одно описание WMF файла

A metafile for the Windows operating system consists of a collection of graphics  device interface (GDI) functions  that describe an image. Because metafiles take up less space and are more device- independent than bitmaps, they  provide convenient storage for images that appear repeatedly in an application or  need to be moved from one  application to another. To generate a metafile, a Windows application creates a special device context that sends GDI commands to a file or memory for storage. The application can later play back the metafile and display the image. During playback, Windows breaks the metafile down into records and identifies  each object with an index to a handle table. Читать далее

Графический файл WMF

Also Known As: WMF, Enhanced Metafile, EMF, APM

Type Metafile
Colors 24-bit
Compression None
Maximum Image Size NA
Multiple Images Per File Yes
Numerical Format Little-endian
Originator Microsoft Corporation
Platform Microsoft Windows
Supporting Applications Numerous Microsoft Windows-based graphics applications
Usage Storage of vector drawings and bitmaps. Читать далее

ZIP файлы (Архивы)

Although PKWARE will attempt to supply current and accurate information relating to its file formats, algorithms, and the subject programs, the possibility of error can not be eliminated. PKWARE therefore expressly disclaims any warranty that the information contained in the associated materials relating to the subject programs and/or the format of the files created or accessed by the subject programs and/or the algorithms used by the subject programs, or any other matter, is current, correct or accurate as delivered.  Any risk of damage due to any possible inaccurate information is assumed by the user of the information. Furthermore, the information relating to the subject programs and/or the file formats created or accessed by the subject programs and/or the algorithms used by the subject programs is subject to change without notice.

General Format of a ZIP file  Files stored in arbitrary order.  Large zipfiles can span multiple diskette media. Читать далее

CSV файлы (Comma Seperated Value)

*.CSV (Comma Seperated Value) format is mostly self-explanatory ASCII text format. If you export a file from a database in CSV format and look at it you will find that it is simply a list of entries seperated by commas:

<CSV_file> ::= { <CSV_line> }
<CSV_line> ::= <value> { "," <value> } <spaces_and_tabs>
<value> ::= <spaces_and_tabs>
          { <any_text_except_quotas_and_commas_and_smth_else>
        | <single_or_double_quote>

That’s all I think… and there is some problem with this format: different database systems have different definitions of the term <any_text_except_quotas_and_commas_and_smth_else> Also Paradox version approx.4 has the bug. When converting to .CSV, it always writes values surrounded by «s — but if in the source database file we have a field containing «s, them will not be doubled in CSV.
E.g.: abc»dfg will be translated to «abc»dfg» instead of «abc»»dfg».

Формат COM файлов

Intel byte order
DISCLAIMER:  THIS MATERIAL IS PROVIDED «AS IS».  I verify the information contained in this list to the best of my ability, but I cannot be held responsible for any problems caused by use or misuse of the information, especially for those file formats foreign to the PC, like AMIGA or SUN file formats. If an information it is marked «guesswork» or undocumented, you should check it carefully to make sure your program will not break with an unexpected value (and please let me know whether or not it works the same way). Information marked with «???» is known to be incomplete or guesswork.
Some file formats were not released by their creators, others are regarded as proprietary, which means that if your programs deal with them, you might be looking for trouble. I don’t care about this.
The COM files are raw binary executables and are a leftover from the old CP/M machines with 64K RAM.  A COM program can only have a size of less than one segment (64K), including code and static data since no fixups for segment relocation or anything else is included. One method to check for a COM file is to check if the first byte in the file could be a valid jump or call opcode, but this is a very weak test since a COM file is not required to start with a jump or a call. In principle, a COM file is just loaded at offset 100h in the segment and then executed. Читать далее

TopSpeed TPS файл

                       О С Н О В Н О Й   T P S - Ф А Й Л

                             ФИЗИЧЕСКАЯ ОРГАНИЗАЦИЯ


      (+0)       (+4)          (+6)           (+0Ah)          (+0Eh)
  00 00 00 00    00 00      00 05 00 00     00 05 00 00     74 4F 70 53
   Смещение      Размер     Длина файла     Длина файла     Метка файла
  заголовка    заголовка                                      TOPSPEED

  (+12h)      (+14h)          (+18h)                (+1Ch)
  00 00     00 00 00 06     07 00 00 00           00 00 00 00
   Нули      Последний   Счетчик изменений     Верхняя управляющая
   (?)         номер           файла        страница (адрес минус 200h,
                                                деленный на 100h)

  Далее следуют 2 массива длиной (длина_заголовка-20h)/2 четырехбайтовых
чисел (ниже порядок байт перевернут):

Читать далее

Структура индексных файлов Clarion

This bulletin explains the layout of Clarion index and key files. Clarion Index and Key Files While Technical Bulletin #117, «Clarion Data File,» covered the layout of Clarion Professional Developer’s data files, it only touched on the subject of the index and key files that Professional Developer uses to access your data in a specific order.  The purpose of this technical bulletin is to explain how Clarion’s key and index files are laid out.
This technical bulletin assumes a knowledge of basic data structures and the C programming language.  While you don’t have to be a C guru to understand the material presented here, a passing knowledge helps, as C makes it easy to create many types of data structures.
As far as this discussion is concerned, there are NO internal differences between index and key files.  Index files are simply key files that are not updated automatically by adding, deleting, of changing records in your data base. Also, this bulletin will not explain how you create key files, only how to read them.  Our method of managing B+ Trees is proprietary and quite complicated.  In all fairness, we can only support products that create key files using our own code.  When you see a non-Clarion product that creates and/or maintains Clarion key files, it means they have licensed our code for use in their product. Читать далее

Clarion DAT файл

This bulletin explains the format of Clarion data files.

Clarion Data Files
This technical bulletin explains the format of data files created by the
Clarion Professional Developer and the Clarion Personal Developer (Version 2 and
above).  It will only cover data files; key and index files are covered in
Clarion Technical Bulletin #118.  Use this information carefully because an
erroneous change to a data file will make your file unreadable.  Due to the
risks of data integrity, encryption is not covered in this bulletin.
A file defined with Clarion contains a lot of information on data such as
fields, keys, indexes, pictures, arrays, etc.  When the file is first
created, you will have a .DAT file and optionally one or more .K??, .I??, and .MEM
files (where ?? is a two digit number).  The .DAT file also contains
information on keys, fields and their layouts, and many fields that allow
Professional Developer to efficiently use the space on your disk.
First, let us discuss the .DAT file.  This file consists of several
sections (some sections are optional): Читать далее