com.bumptech.glide.load.resource.bitmap

Class VideoBitmapDecoder

java.lang.Object

com.bumptech.glide.load.resource.bitmap.VideoBitmapDecoder

All Implemented Interfaces:

ResourceDecoder<ParcelFileDescriptor,Bitmap>

public class VideoBitmapDecoder
extends Object
implements ResourceDecoder<ParcelFileDescriptor,Bitmap>

An ResourceDecoder that can decode a thumbnail frame Bitmap from a ParcelFileDescriptor containing a video.

See Also:

MediaMetadataRetriever

Field Summary

Fields

Modifier and Type	Field and Description
static long	DEFAULT_FRAME A constant indicating we should use whatever frame we consider best, frequently not the first frame.
static Option<Integer>	FRAME_OPTION An integer indicating the frame option used to retrieve a target frame.
static Option<Long>	TARGET_FRAME A long indicating the time position (in microseconds) of the target frame which will be retrieved.

Constructor Summary

Constructors

Constructor and Description
VideoBitmapDecoder(BitmapPool bitmapPool)
VideoBitmapDecoder(Context context)

Method Summary

Modifier and Type	Method and Description
Resource<Bitmap>	decode(ParcelFileDescriptor resource, int outWidth, int outHeight, Options options) Returns a decoded resource from the given data or null if no resource could be decoded.
boolean	handles(ParcelFileDescriptor data, Options options) Returns true if this decoder is capable of decoding the given source with the given options, and false otherwise.

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_FRAME

public static final long DEFAULT_FRAME

A constant indicating we should use whatever frame we consider best, frequently not the first frame.

See Also:

Constant Field Values

TARGET_FRAME

public static final Option<Long> TARGET_FRAME

A long indicating the time position (in microseconds) of the target frame which will be retrieved. MediaMetadataRetriever.getFrameAtTime(long) is used to extract the video frame.

When retrieving the frame at the given time position, there is no guarantee that the data source has a frame located at the position. When this happens, a frame nearby will be returned. If the long is negative, time position and option will ignored, and any frame that the implementation considers as representative may be returned.

FRAME_OPTION

public static final Option<Integer> FRAME_OPTION

An integer indicating the frame option used to retrieve a target frame.

This option will be ignored if TARGET_FRAME is not set or is set to DEFAULT_FRAME.

See Also:

MediaMetadataRetriever.getFrameAtTime(long, int)

Constructor Detail

VideoBitmapDecoder

public VideoBitmapDecoder(Context context)

VideoBitmapDecoder

public VideoBitmapDecoder(BitmapPool bitmapPool)

Method Detail

handles

public boolean handles(ParcelFileDescriptor data,
                       Options options)

Description copied from interface: ResourceDecoder

Returns true if this decoder is capable of decoding the given source with the given options, and false otherwise.

Decoders should make a best effort attempt to quickly determine if they are likely to be able to decode data, but should not attempt to completely read the given data. A typical implementation would check the file headers verify they match content the decoder expects to handle (i.e. a GIF decoder should verify that the image contains the GIF header block.

Decoders that return true from ResourceDecoder.handles(Object, Options) may still return null from ResourceDecoder.decode(Object, int, int, Options) if the data is partial or formatted incorrectly.

Specified by:

handles in interface ResourceDecoder<ParcelFileDescriptor,Bitmap>

decode

public Resource<Bitmap> decode(ParcelFileDescriptor resource,
                               int outWidth,
                               int outHeight,
                               Options options)
                        throws IOException

Description copied from interface: ResourceDecoder

Returns a decoded resource from the given data or null if no resource could be decoded.

The source is managed by the caller, there's no need to close it. The returned Resource will be released when the engine sees fit.

Note - The width and height arguments are hints only, there is no requirement that the decoded resource exactly match the given dimensions. A typical use case would be to use the target dimensions to determine how much to downsample Bitmaps by to avoid overly large allocations.

Specified by:

decode in interface ResourceDecoder<ParcelFileDescriptor,Bitmap>

Parameters:

resource - The data the resource should be decoded from.

outWidth - The ideal width in pixels of the decoded resource, or Target.SIZE_ORIGINAL to indicate the original resource width.

outHeight - The ideal height in pixels of the decoded resource, or Target.SIZE_ORIGINAL to indicate the original resource height.

options - A map of string keys to objects that may or may not contain options available to this particular implementation. Implementations should not assume that any or all of their option keys are present. However, implementations may assume that if one of their option keys is present, it's value is non-null and is of the expected type.

Throws:

IOException