What is an ABC file?
A file with .abc extension is an ActionScript Byte Code File created by Flash compiler as a result of compiling the ActionScript script files. The byte code contained in the ABC file is executed by the ActionScript Virtual Machine (AVM and AVM2). The byte code comprises of constant data, instructions from the AVM2 instruction set, and various kinds of metadata. When an ABC file is loaded into the AVM or AVM2, it undergoes verification. If it does not conform to the AVM2 Overview, it is rejected. ABC files can be opened in Adobe Flash Player that has been discontinued long time ago.
ABC File Format - More Information
ABC files are saved to disc in binary file format that are readable by AVM or AVM2 virtual machines. Its internal file structure represents executable code block with all its constant data, type descriptors, code, and metadata.
ABC File Structure
ABC file structure is as shown below.
abcFile
{
u16 minor_version
u16 major_version
cpool_info constant_pool
u30 method_count
method_info method[method_count]
u30 metadata_count
metadata_info metadata[metadata_count]
u30 class_count
instance_info instance[class_count]
class_info class[class_count]
u30 script_count
script_info script[script_count]
u30 method_body_count
method_body_info method_body[method_body_count]
}
ABC File Fields
| Field Name | Description |
|---|---|
| minor_version, major_version | The values of major_version and minor_version are the major and minor version numbers of the abcFile format. |
| constant_pool | The constant_pool is a variable length structure composed of integers, doubles, strings, namespaces, namespace sets, and multinames. |
| method_count, method | The value ofmethod_count is the number of entries in the method array. Each entry in the method array is a variable length method_info structure. |
| metadata_count, metadata | The value of metadata_count is the number of entries in the metadata array. Each metadata entry is a metadata_infostructure that maps a name to a set of string values. |
| class_count, instance, class | The value of class_count is the number of entries in the instance and class arrays. |
| script_count, script | The value of script_count is the number of entries in the script array. Each script entry is a script_info structure that defines the characteristics of a single script in this file. |
| method_body_count, method_body | The value of method_body_count is the number of entries in the method_body array. Each method_bodyentry consists of a variable length method_body_info structure which contains the instructions for an individual method or function. |
