Package org.ngengine.stbimage

Class JpegDecoder

java.lang.Object

org.ngengine.stbimage.JpegDecoder

All Implemented Interfaces:

StbDecoder

public class JpegDecoder
extends Object
implements StbDecoder

JPEG decoder - baseline (sequential) and progressive DCT decoder, implemented to match stb_image.h behavior closely. Supported: - Baseline (SOF0) and Extended Sequential (SOF1) - Progressive (SOF2) - CMYK (via APP14 marker) Not supported: - Arithmetic coding Notes: - Output matches stb_image's resampling + YCbCr conversion (including the hv_2 filter).

Constructor Summary

Constructors

Constructor	Description
JpegDecoder(ByteBuffer src, IntFunction<ByteBuffer> allocator, boolean flipVertically)	Creates a JPEG decoder instance.

Method Summary

Modifier and Type	Method	Description
IntFunction<ByteBuffer>	getAllocator()	Returns the allocator used by this decoder for output buffers.
StbImageInfo	info()	Reads image metadata without fully decoding pixel data.
static boolean	isJpeg(ByteBuffer buffer)	Tests whether the input starts with JPEG SOI marker bytes.
StbImageResult	load(int desiredChannels)	Decodes image pixels.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.ngengine.stbimage.StbDecoder

load16, loadAllFrames, loadf, loadNextFrame

Constructor Details

JpegDecoder

public JpegDecoder(ByteBuffer src,
 IntFunction<ByteBuffer> allocator,
 boolean flipVertically)

Creates a JPEG decoder instance.

Parameters:

src - source data

allocator - output allocator

flipVertically - true to vertically flip decoded output

Method Details

isJpeg

public static boolean isJpeg(ByteBuffer buffer)

Tests whether the input starts with JPEG SOI marker bytes.

Parameters:

buffer - source bytes

Returns:

true for JPEG signature

getAllocator

public IntFunction<ByteBuffer> getAllocator()

Returns the allocator used by this decoder for output buffers.

Specified by:

getAllocator in interface StbDecoder

Returns:

allocator function

info

public StbImageInfo info()

Reads image metadata without fully decoding pixel data.

Specified by:

info in interface StbDecoder

Returns:

image information

load

public StbImageResult load(int desiredChannels)

Decodes image pixels.

Specified by:

load in interface StbDecoder

Parameters:

desiredChannels - requested output channels (0 keeps source/default behavior)

Returns:

decoded image result