Renesas / GraphicsFramework

Graphics framework for GR-PEACH. When you use this program, we judge you have agreed to the following contents. https://developer.mbed.org/teams/Renesas/wiki/About-LICENSE

Dependents:   ImageZoomInout_Sample ImageRotaion_Sample ImageScroll_Sample GR-PEACH_LCD_4_3inch_Save_to_USB ... more

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Table of Contents

  1. JPEG Converter
  2. Hello World!
  3. API
  4. Correspondence file
  5. Notice
  6. Color format
  7. Decode/encode settings are optional
  8. Synchronous/asynchronous switching
  9. Quality

JPEG Converter

The JPEG Converter driver implements encode and decode functionality which uses the JCU in the RZ/A Series.

Hello World!

Import programJCU_HelloWorld

Hello World for JCU(JPEG Codec Unit). JCU is JPEG codec unit of RZ/A1. When you use this program, we judge you have agreed to the following contents. https://developer.mbed.org/teams/Renesas/wiki/About-LICENSE

Last commit 28 Dec 2018 by Renesas

API

Import library
GraphicsFramework - JPEG_Converter Class Reference

Data Structures

struct bitmap_buff_info_t
Bitmap data setting struct. More...
struct encode_options_t
Encode option setting. More...

Public Types

enum jpeg_conv_error_t {
JPEG_CONV_OK = 0, JPEG_CONV_JCU_ERR = -1, JPEG_CONV_FORMA_ERR = -2, JPEG_CONV_PARAM_ERR = -3,
JPEG_CONV_PARAM_RANGE_ERR = -7
}

Error codes.

More...
enum wr_rd_swa_t {
WR_RD_WRSWA_NON = 0, WR_RD_WRSWA_8BIT = 1, WR_RD_WRSWA_16BIT = 2, WR_RD_WRSWA_16_8BIT = 3,
WR_RD_WRSWA_32BIT = 4, WR_RD_WRSWA_32_8BIT = 5, WR_RD_WRSWA_32_16BIT = 6, WR_RD_WRSWA_32_16_8BIT = 7
}

Write/Read image pixcel frame buffer swap setting.

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enum wr_rd_format_t { WR_RD_YCbCr422 = 0x00, WR_RD_ARGB8888 = 0x01, WR_RD_RGB565 = 0x02 }

Write/Read image pixcel format selects.

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enum sub_sampling_t { SUB_SAMPLING_1_1 = 0x00, SUB_SAMPLING_1_2 = 0x01, SUB_SAMPLING_1_4 = 0x02, SUB_SAMPLING_1_8 = 0x03 }

Thinning output image selects.

More...
enum cbcr_offset_t { CBCR_OFFSET_0 = 0x00, CBCR_OFFSET_128 = 0x01 }

Cb/Cr range selects for decode.

More...

Public Member Functions

JPEG_Converter ()
Constructor method of JPEG converter(encode/decode)
virtual ~JPEG_Converter ()
Destructor method of JPEG converter(encode/decode)
JPEG_Converter::jpeg_conv_error_t decode (void *pJpegBuff, bitmap_buff_info_t *psOutputBuff)
Decode JPEG to rinear data.
JPEG_Converter::jpeg_conv_error_t decode (void *pJpegBuff, bitmap_buff_info_t *psOutputBuff, decode_options_t *pOptions)
JPEG data decode to bitmap.
JPEG_Converter::jpeg_conv_error_t encode ( bitmap_buff_info_t *psInputBuff, void *pJpegBuff, size_t *pEncodeSize)
Encode rinear data to JPEG.
JPEG_Converter::jpeg_conv_error_t encode ( bitmap_buff_info_t *psInputBuff, void *pJpegBuff, size_t *pEncodeSize, encode_options_t *pOptions)
Bitmap data encode to JPEG.

Correspondence file

A correspondence file of JPEG Converter is as the following table.

JPEGCorrespondence
Width>0(greater than 0)
Height>0(greater than 0)
Color formatYCbCr444, YCbCr422, YCbCr420, YCbCr411
BitmapCorrespondence
Width>0(greater than 0)
Height>0(greater than 0)
Color formatYCbCr422

Notice

You run JPEG converter once destruction each time.

You set whether these JPEG files aren't input, or it check error setting decode(set in "flag" = true). The JPEG file which becomes correspondence outside will be the following condition.

  • File besides the above-mentioned correspondence file.
  • As information in the JPEG file, WIDTH or HEIGHT is larger than output buffer setting.

Buffer area is used encode/decode, set 8 bytes align and non-cash memory area. The output buffer when decoding, is made beyond the size decided in the size of the JPEG file, the format, setting of thinning out. You make output buffer for decode/encode to enough big size in order to stock this result. JPEG Converter, if you do not particularly perform specified, does not check size against the output data at the time of encoding and decoding. You set the output buffer so that there is no effect of corruption by the output data.

Color format

Color format in case to be converted from Bitmap to JPEG is either ARGB8888 or RGB555, YCbCr422. Color format of the If you want to convert from JPEG file to Bitmap file is YCbCr422. You correct "alpha(member of decode_options_t)" of setting and "output_cb_cr_offset(member of decode_options_t)" according to color format when decoding.

  • example
    decode to ARGB8888(WR_RD_ARGB8888 set in format member of bitmap_buff_info_t)
    alpha = 0x01-0xFF
    output_cb_cr_offset = CBCR_OFFSET_0

    decode to YCbCr422(WR_RD_YCbCr422 set in format member of bitmap_buff_info_t)
    alpha = 0
    output_cb_cr_offset = CBCR_OFFSET_0 or CBCR_OFFSET_128

    decode to RGB565(WR_RD_RGB565 set in format member of bitmap_buff_info_t)
    alpha = 0
    output_cb_cr_offset = CBCR_OFFSET_0

Decode/encode settings are optional

If omitted encode/decode settings, it will work with the following settings.
[Decode option setting (member of decode_options_t)]

  • Vertical sub sampling is thinning output image to 1/1.
  • Horizontal sub sampling is thinning output image to 1/1.
  • Output data of Cb/Cr range is -128 to 127.
  • Output data of swap in 8-bit units: 2-1-4-3-6-5-8-7.
  • Alpha value of 0.
  • JPEG format correspondence outside error check.
  • It decode in a synchronous function.

[Encode option setting (member of encode_options_t)]

  • DRI value is 0.
  • Encoding JPEG file start width offset is 0.
  • Encoding JPEG file start height offset is 0.
  • Input data of Cb/Cr range of input data is -128 to 127.
  • Input data swap in 8-bit units: 2-1-4-3-6-5-8-7.
  • It don't check encode size.
  • Quantization Y use default table(Quality75).
  • Quantization C use default table(Quality75).
  • Huffman Y DC use default table.
  • Huffman C DC use default table.
  • Huffman Y AC use default table.
  • Huffman C AC use default table.
  • It encode in a synchronous function.

Synchronous/asynchronous switching

Decoding and encoding setting to operate asynchronously by setting a callback function(decode_options_t and encode_options_t).

Quality

Quality changes are possible. If you want to change the Quality, please specify the table made of Quality you want to change the address of the setting. If you do not want to change the Quality, it will operate at Quality75.

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