# ETC1
Added in[API level 8](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
# ETC1
*** ** * ** ***
Kotlin\|[Java](https://developer.android.com/reference/android/opengl/ETC1 "View this page in Java")
```
open class ETC1
```
|---|--------------------------------------------------------------------------------------------|
| [kotlin.Any](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-any/index.html) ||
| ↳ | [android.opengl.ETC1](https://developer.android.com/reference/kotlin/android/opengl/ETC1#) |
Methods for encoding and decoding ETC1 textures.
The standard for the ETC1 texture format can be found at http://www.khronos.org/registry/gles/extensions/OES/OES_compressed_ETC1_RGB8_texture.txt
The PKM file format is of a 16-byte header that describes the image bounds followed by the encoded ETC1 texture data.
## Summary
| Constants ||
|----------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| static[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html) | [DECODED_BLOCK_SIZE](https://developer.android.com/reference/kotlin/android/opengl/ETC1#DECODED_BLOCK_SIZE:kotlin.Int) Size in bytes of a decoded block. |
| static[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html) | [ENCODED_BLOCK_SIZE](https://developer.android.com/reference/kotlin/android/opengl/ETC1#ENCODED_BLOCK_SIZE:kotlin.Int) Size in bytes of an encoded block. |
| static[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html) | [ETC1_RGB8_OES](https://developer.android.com/reference/kotlin/android/opengl/ETC1#ETC1_RGB8_OES:kotlin.Int) Accepted by the internalformat parameter of glCompressedTexImage2D. |
| static[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html) | [ETC_PKM_HEADER_SIZE](https://developer.android.com/reference/kotlin/android/opengl/ETC1#ETC_PKM_HEADER_SIZE:kotlin.Int) Size of a PKM file header, in bytes. |
| Public constructors ||
|----------------------------------------------------------------------------------------------|---|
| [ETC1](https://developer.android.com/reference/kotlin/android/opengl/ETC1#ETC1())`()`
|
| Public methods ||
|----------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| openstatic[Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [decodeBlock](https://developer.android.com/reference/kotlin/android/opengl/ETC1#decodeBlock(java.nio.Buffer,%20java.nio.Buffer))`(`in:` `[Buffer](https://developer.android.com/reference/kotlin/java/nio/Buffer.html#)!`, `out:` `[Buffer](https://developer.android.com/reference/kotlin/java/nio/Buffer.html#)!`)` Decode a block of pixels. |
| openstatic[Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [decodeImage](https://developer.android.com/reference/kotlin/android/opengl/ETC1#decodeImage(java.nio.Buffer,%20java.nio.Buffer,%20kotlin.Int,%20kotlin.Int,%20kotlin.Int,%20kotlin.Int))`(`in:` `[Buffer](https://developer.android.com/reference/kotlin/java/nio/Buffer.html#)!`, `out:` `[Buffer](https://developer.android.com/reference/kotlin/java/nio/Buffer.html#)!`, `width:` `[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html)`, `height:` `[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html)`, `pixelSize:` `[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html)`, `stride:` `[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html)`)` Decode an entire image. |
| openstatic[Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [encodeBlock](https://developer.android.com/reference/kotlin/android/opengl/ETC1#encodeBlock(java.nio.Buffer,%20kotlin.Int,%20java.nio.Buffer))`(`in:` `[Buffer](https://developer.android.com/reference/kotlin/java/nio/Buffer.html#)!`, `validPixelMask:` `[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html)`, `out:` `[Buffer](https://developer.android.com/reference/kotlin/java/nio/Buffer.html#)!`)` Encode a block of pixels. |
| openstatic[Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [encodeImage](https://developer.android.com/reference/kotlin/android/opengl/ETC1#encodeImage(java.nio.Buffer,%20kotlin.Int,%20kotlin.Int,%20kotlin.Int,%20kotlin.Int,%20java.nio.Buffer))`(`in:` `[Buffer](https://developer.android.com/reference/kotlin/java/nio/Buffer.html#)!`, `width:` `[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html)`, `height:` `[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html)`, `pixelSize:` `[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html)`, `stride:` `[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html)`, `out:` `[Buffer](https://developer.android.com/reference/kotlin/java/nio/Buffer.html#)!`)` Encode an entire image. |
| openstatic[Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [formatHeader](https://developer.android.com/reference/kotlin/android/opengl/ETC1#formatHeader(java.nio.Buffer,%20kotlin.Int,%20kotlin.Int))`(`header:` `[Buffer](https://developer.android.com/reference/kotlin/java/nio/Buffer.html#)!`, `width:` `[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html)`, `height:` `[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html)`)` Format a PKM header |
| openstatic[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html) | [getEncodedDataSize](https://developer.android.com/reference/kotlin/android/opengl/ETC1#getEncodedDataSize(kotlin.Int,%20kotlin.Int))`(`width:` `[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html)`, `height:` `[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html)`)` Return the size of the encoded image data (does not include size of PKM header). |
| openstatic[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html) | [getHeight](https://developer.android.com/reference/kotlin/android/opengl/ETC1#getHeight(java.nio.Buffer))`(`header:` `[Buffer](https://developer.android.com/reference/kotlin/java/nio/Buffer.html#)!`)` Read the image height from a PKM header |
| openstatic[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html) | [getWidth](https://developer.android.com/reference/kotlin/android/opengl/ETC1#getWidth(java.nio.Buffer))`(`header:` `[Buffer](https://developer.android.com/reference/kotlin/java/nio/Buffer.html#)!`)` Read the image width from a PKM header |
| openstatic[Boolean](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-boolean/index.html) | [isValid](https://developer.android.com/reference/kotlin/android/opengl/ETC1#isValid(java.nio.Buffer))`(`header:` `[Buffer](https://developer.android.com/reference/kotlin/java/nio/Buffer.html#)!`)` Check if a PKM header is correctly formatted. |
## Constants
### DECODED_BLOCK_SIZE
Added in[API level 8](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
static val DECODED_BLOCK_SIZE: Int
```
Size in bytes of a decoded block.
Value: 48
### ENCODED_BLOCK_SIZE
Added in[API level 8](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
static val ENCODED_BLOCK_SIZE: Int
```
Size in bytes of an encoded block.
Value: 8
### ETC1_RGB8_OES
Added in[API level 8](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
static val ETC1_RGB8_OES: Int
```
Accepted by the internalformat parameter of glCompressedTexImage2D.
Value: 36196
### ETC_PKM_HEADER_SIZE
Added in[API level 8](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
static val ETC_PKM_HEADER_SIZE: Int
```
Size of a PKM file header, in bytes.
Value: 16
## Public constructors
### ETC1
```
ETC1()
```
## Public methods
### decodeBlock
Added in[API level 8](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
open static fun decodeBlock(
in: Buffer!,
out: Buffer!
): Unit
```
Decode a block of pixels.
| Parameters ||
|-------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| `in` | [Buffer](https://developer.android.com/reference/kotlin/java/nio/Buffer.html#)!:a native order direct buffer of size ENCODED_BLOCK_SIZE that contains the ETC1 compressed version of the data. |
| `out` | [Buffer](https://developer.android.com/reference/kotlin/java/nio/Buffer.html#)!:a native order direct buffer of size DECODED_BLOCK_SIZE that will receive the decoded data. The data represents a 4 x 4 square of 3-byte pixels in form R, G, B. Byte (3 \* (x + 4 \* y) is the R value of pixel (x, y). |
### decodeImage
Added in[API level 8](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
open static fun decodeImage(
in: Buffer!,
out: Buffer!,
width: Int,
height: Int,
pixelSize: Int,
stride: Int
): Unit
```
Decode an entire image.
| Parameters ||
|-------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| `in` | [Buffer](https://developer.android.com/reference/kotlin/java/nio/Buffer.html#)!:native order direct buffer of the encoded data. |
| `out` | [Buffer](https://developer.android.com/reference/kotlin/java/nio/Buffer.html#)!:native order direct buffer of the image data. Will be written such that pixel (x,y) is at pIn + pixelSize \* x + stride \* y. Must be large enough to store entire image. |
| `pixelSize` | [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html):must be 2 or 3. 2 is an GL_UNSIGNED_SHORT_5_6_5 image, 3 is a GL_BYTE RGB image. |
### encodeBlock
Added in[API level 8](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
open static fun encodeBlock(
in: Buffer!,
validPixelMask: Int,
out: Buffer!
): Unit
```
Encode a block of pixels.
| Parameters ||
|------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| `in` | [Buffer](https://developer.android.com/reference/kotlin/java/nio/Buffer.html#)!:a native order direct buffer of size DECODED_BLOCK_SIZE that represent a 4 x 4 square of 3-byte pixels in form R, G, B. Byte (3 \* (x + 4 \* y) is the R value of pixel (x, y). |
| `validPixelMask` | [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html):is a 16-bit mask where bit (1 \<\< (x + y \* 4)) indicates whether the corresponding (x,y) pixel is valid. Invalid pixel color values are ignored when compressing. |
| `out` | [Buffer](https://developer.android.com/reference/kotlin/java/nio/Buffer.html#)!:a native order direct buffer of size ENCODED_BLOCK_SIZE that receives the ETC1 compressed version of the data. |
### encodeImage
Added in[API level 8](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
open static fun encodeImage(
in: Buffer!,
width: Int,
height: Int,
pixelSize: Int,
stride: Int,
out: Buffer!
): Unit
```
Encode an entire image.
| Parameters ||
|-------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| `in` | [Buffer](https://developer.android.com/reference/kotlin/java/nio/Buffer.html#)!:a native order direct buffer of the image data. Formatted such that pixel (x,y) is at pIn + pixelSize \* x + stride \* y; |
| `out` | [Buffer](https://developer.android.com/reference/kotlin/java/nio/Buffer.html#)!:a native order direct buffer of the encoded data. Must be large enough to store entire encoded image. |
| `pixelSize` | [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html):must be 2 or 3. 2 is an GL_UNSIGNED_SHORT_5_6_5 image, 3 is a GL_BYTE RGB image. |
### formatHeader
Added in[API level 8](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
open static fun formatHeader(
header: Buffer!,
width: Int,
height: Int
): Unit
```
Format a PKM header
| Parameters ||
|----------|---------------------------------------------------------------------------------------------------------------------------|
| `header` | [Buffer](https://developer.android.com/reference/kotlin/java/nio/Buffer.html#)!:native order direct buffer of the header. |
| `width` | [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html):the width of the image in pixels. |
| `height` | [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html):the height of the image in pixels. |
### getEncodedDataSize
Added in[API level 8](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
open static fun getEncodedDataSize(
width: Int,
height: Int
): Int
```
Return the size of the encoded image data (does not include size of PKM header).
### getHeight
Added in[API level 8](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
open static fun getHeight(header: Buffer!): Int
```
Read the image height from a PKM header
| Parameters ||
|----------|---------------------------------------------------------------------------------------------------------------------------|
| `header` | [Buffer](https://developer.android.com/reference/kotlin/java/nio/Buffer.html#)!:native order direct buffer of the header. |
### getWidth
Added in[API level 8](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
open static fun getWidth(header: Buffer!): Int
```
Read the image width from a PKM header
| Parameters ||
|----------|---------------------------------------------------------------------------------------------------------------------------|
| `header` | [Buffer](https://developer.android.com/reference/kotlin/java/nio/Buffer.html#)!:native order direct buffer of the header. |
### isValid
Added in[API level 8](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
open static fun isValid(header: Buffer!): Boolean
```
Check if a PKM header is correctly formatted.
| Parameters ||
|----------|---------------------------------------------------------------------------------------------------------------------------|
| `header` | [Buffer](https://developer.android.com/reference/kotlin/java/nio/Buffer.html#)!:native order direct buffer of the header. |