nn::jpeg::CTR::JpegMpDecoder::StartJpegDecoder Member Function

#include <nn/jpeg.h>

size_t StartJpegDecoder(
     void * dst,
     size_t dstSize,
     const u8 * src,
     size_t srcSize,
     u32 maxWidth,
     u32 maxHeight,
     PixelFormat dstPixelFormat,
     bool decodeThumbnail
);

	Name	Description
out	dst	Specifies the buffer that stores the decoded result. Must be 4-byte aligned. Must be 128-byte aligned if you are accessing the output buffer directly as a GPU texture. (No check is made when using this function.)
in	dstSize	Specifies the size of dst in bytes. Specify the return value of GetDstBufferSize.
in	src	Specifies the JPEG data to decode.
in	srcSize	Specifies the size of src in bytes.
in	maxWidth	Specifies the maximum width (in pixels) of an image that can be decoded (equal to or less than 65536). After decoding successfully completes, use the GetLastWidth function to get the actual image width and the GetLastOutputBufferWidth function to get the buffer width.
in	maxHeight	Specifies the maximum height (in pixels) of an image that can be decoded (equal to or less than 65536). After decoding successfully completes, use the GetLastHeight function to get the actual image height and the GetLastOutputBufferHeight function to get the buffer height.
in	dstPixelFormat	Specifies the output pixel format.
in	decodeThumbnail	Specify true to decode the thumbnail. Specify false to decode the primary image.

On success, returns the size (in bytes) of the buffer storing the decoded result.
Returns 0 on failure.
Use the GetLastError function to get the reason for failure.

Runs the JPEG decoder.

Processing takes longer if the image size is not a multiple of 8 or 16 pixels.
Depending on the pixel sampling format, images that meet certain conditions can be decoded faster.

• For PIXEL_SAMPLING_YUV444, the width and height of the image must both be multiples of 8.
• For PIXEL_SAMPLING_YUV420, the width and height of the image must both be multiples of 16.
• For PIXEL_SAMPLING_YUV422, the height must be a multiple of 8, and the width must be a multiple of 16.

If JPEG_DECODER_OPTION_MATCH_WIDTH_HEIGHT is specified using SetOption, the values of arguments maxWidth and maxHeight must match, otherwise decoding will fail.

2010/10/21

Added a description of SetOption.

2010/04/14

Initial version.