Block diagram
Android apps using directly or indirectly OpenGL cache compiled shaders into com.android.opengl.shaders_cache file.
This page hosts a formal specification of com.android.opengl.shaders_cache file using Kaitai Struct. This specification can be automatically translated into a variety of programming languages to get a parsing library.
meta:
id: android_opengl_shaders_cache
title: com.android.opengl.shaders_cache file
application: Android
tags:
- android
- media
license: Apache-2.0
endian: le
doc: |
Android apps using directly or indirectly OpenGL cache compiled shaders
into com.android.opengl.shaders_cache file.
doc-ref: https://android.googlesource.com/platform/frameworks/native/+/master/opengl/libs/EGL/FileBlobCache.cpp
seq:
- id: magic
contents: "EGL$"
- id: crc32
type: u4
doc: crc32 of `contents`
- id: contents
type: cache
size-eos: true
types:
alignment:
seq:
- id: alignment
size: "(_io.pos + 3) & ~3 - _io.pos"
doc: garbage from memory
prefixed_string:
seq:
- id: len_str
type: u4
-orig-id: mBuildIdLength
- id: str
type: strz
encoding: ascii
size: len_str
-orig-id: mBuildId, buildId
- id: alignment
type: alignment
cache:
doc-ref: https://android.googlesource.com/platform/frameworks/native/+/master/opengl/libs/EGL/BlobCache.cpp
seq:
- id: magic
-orig-id: mMagicNumber, blobCacheMagic
contents: ["$bB_"]
- id: version
type: u4
-orig-id: mBlobCacheVersion, blobCacheVersion
- id: device_version
type: u4
-orig-id: mDeviceVersion, blobCacheDeviceVersion
- id: num_entries
type: u4
-orig-id: mNumEntries
- id: build_id
type: prefixed_string
-orig-id: mBuildIdLength, mBuildId, buildId
if: version >= 3 # hypothesis, needs deeper investigation
- id: entries
type: entry
repeat: expr
repeat-expr: num_entries
types:
entry:
seq:
- id: len_key
type: u4
-orig-id: mKeySize, keySize
- id: len_value
type: u4
-orig-id: mValueSize, valueSize
- id: key
size: len_key
- id: value
size: len_value
- id: alignment
type: alignment