bmp_decoder_api.c

bmp图像文件解码器的arm版本的源代码

/*

*******************************************************************************
*
* FILE NAME:            
*   bmp_decoder_api.c
*
* DESCRIPTION:
*   Contain all function definitions for BMP decoder API.
*
* MODULE: 
*   BMP (BitMaP) decoder.
* 

*  
*******************************************************************************
*/

/*
*******************************************************************************
* Include files
*******************************************************************************
*/

/* -- Include for BMP ressources -- */
#include "bmp_decoder_api.h"
#include "bmpi_decoder.h"


/*
*******************************************************************************
* Macros
*******************************************************************************
*/

/*
*******************************************************************************
* Global variables
*******************************************************************************
*/

/* -- Input buffer pointer -- */
static OP_UINT8             *bmpInputBuffer;

/* -- output buffer pointer -- */
static OP_UINT8             *bmpOutputBuffer;

/* -- input buffer size -- */
static OP_UINT32            bmpInputBufferSize;

/* -- Image information -- */
static BMP_IMAGE_INFO       bmpImageInfo;

/* -- Decoder state -- */
static BMP_DECODER_STATE    bmpDecoderState = BMP_DECODER_STATE_UNINITIALIZED;

/*
*******************************************************************************
* 
* FUNCTION NAME:
*   bmpDecoderInitialize()
*
* FUNCTION DESCRIPTION:
*   This function initializes the BMP decoder and sets the image  
*   decoding configurations to default values.
*
* INPUTS:
*   None
*
* OUTPUTS:
*   None
*   
* RETURN:
*   None
*
* GLOBALS ACCESSED/MODIFIED:
*   bmpInputBuffer, bmpOutputBuffer, bmpInputBufferSize, bmpImageInfo,
*   bmpDecoderState
*
* SPECIAL NOTES:
*
*
*******************************************************************************
*/
void bmpDecoderInitialize
(
    void
)
{
    /* -- Clear input and output buffer pointers -- */
    bmpInputBuffer     = OP_NULL;
    bmpOutputBuffer    = OP_NULL;
    bmpInputBufferSize = 0;

    /* -- Clear image info structure -- */
    bmpImageInfo.u32ImageHeight          = 0;
    bmpImageInfo.u32ImageWidth           = 0;
    bmpImageInfo.u16ImageType            = 0;
    bmpImageInfo.u16NumberOfPlanes       = 0;
    bmpImageInfo.u16BitsPerPixel         = 0;
    bmpImageInfo.u32Compression          = 0;
    bmpImageInfo.u32BitmapDataSize       = 0;
    bmpImageInfo.u32HorizontalResolution = 0;
    bmpImageInfo.u32VerticalResolution   = 0;
    bmpImageInfo.u32NumberOfColors       = 0;
    bmpImageInfo.u32ImportantColors      = 0;

    /* -- Update decoder state -- */
    bmpDecoderState = BMP_DECODER_STATE_INITIALIZED;
}


/*
*******************************************************************************
* 
* FUNCTION NAME:
*   bmpSetInputBuffer()
*
* FUNCTION DESCRIPTION:
*   This function allows the Decoder Controller to pass the decoder
*   the input buffer pointer and the input buffer size. 
*   bmpInputBuffer and bmpInputBufferSize are initialized to the input
*   parameters of this function.
*
* INPUTS:
*   pu8InputBuffer     : input buffer pointer (from decoder controller)
*   u32InputBufferSize : input buffer size (from decoder controller)
*
* OUTPUTS:
*   None
*   
* RETURN:
*   None
*
* GLOBALS ACCESSED/MODIFIED:
*   bmpInputBuffer, bmpInputBufferSize, bmpDecoderState
*
* SPECIAL NOTES:
*
*******************************************************************************
*/
void bmpSetInputBuffer
(
    OP_UINT8    *pu8InputBuffer, 
    OP_UINT32   u32InputBufferSize
)
{

    /* -- Declare local variable -- */
    char        cTemp1;                      /* temporary char */
    char        cTemp2;                      /* temporary char */
    OP_UINT32   u32FileSize;                 /* file size as given in file header */

    if(bmpDecoderState == BMP_DECODER_STATE_INITIALIZED)
    {
        /* -- Store input buffer info -- */
        bmpInputBuffer     = pu8InputBuffer;
        bmpInputBufferSize = u32InputBufferSize;

        /* -- Read file header -- */
        BMPI_ExtractInfoFromFileHeader(bmpInputBuffer, 
                                       &bmpImageInfo,    
                                       &u32FileSize);

        /* -- Check that FileSize is equal to true file size -- */
        if(u32FileSize != u32InputBufferSize)
        {
            return;
        }

        /* -- Check that image type is 'BM' (Windows identifier) -- */
        cTemp1 = (char)((bmpImageInfo.u16ImageType>>8) & 0x00ff);
        cTemp2 = (char)(bmpImageInfo.u16ImageType & 0x00ff);
        if( (cTemp1 != 'B') || (cTemp2 != 'M') )
        {
            return;
        }
        
        /* -- Read information header without the palette -- */
        BMPI_ExtractInfoFromInfoHeader(bmpInputBuffer, 
                                       &bmpImageInfo);
        /* -- Check that input image size is limited to 16-bit range --*/
        if( (bmpImageInfo.u32ImageHeight > 0x0000ffff) || (bmpImageInfo.u32ImageWidth > 0x0000ffff) )
        {
            return;
        }

        /* -- Check that number of planes is limited to one -- */
        if (bmpImageInfo.u16NumberOfPlanes > 1)
        {
            return;
        }

        /* -- Update decoder state -- */
        bmpDecoderState = BMP_DECODER_STATE_READY;
    }

}



/*
*******************************************************************************
* 
* FUNCTION NAME:
*   bmpGetImageInfo() 
*
* FUNCTION DESCRIPTION:
*   This function returns image information to Image Decoder 
*   Controller.   
*
* INPUTS:
*   None.
*
* OUTPUTS:
*   psInfo : pointer to BMP image info structure
*   
* RETURN:
*   BMP_DECODER_ERR_NONE if successful, an error code otherwise.
*
* GLOBALS ACCESSED/MODIFIED:
*   bmpImageInfo, bmpDecoderState
*
* SPECIAL NOTES:
*
*******************************************************************************
*/
BMP_DECODER_ERR bmpGetImageInfo(BMP_IMAGE_INFO *psInfo)
{

    if(bmpDecoderState == BMP_DECODER_STATE_READY)
    {
        /* -- copy image info -- */
        psInfo->u16ImageType            = bmpImageInfo.u16ImageType;
        psInfo->u32ImageWidth           = bmpImageInfo.u32ImageWidth;
        psInfo->u32ImageHeight          = bmpImageInfo.u32ImageHeight;
        psInfo->u16NumberOfPlanes       = bmpImageInfo.u16NumberOfPlanes;
        psInfo->u16BitsPerPixel         = bmpImageInfo.u16BitsPerPixel;
        psInfo->u32Compression          = bmpImageInfo.u32Compression;
        psInfo->u32BitmapDataSize       = bmpImageInfo.u32BitmapDataSize;
        psInfo->u32HorizontalResolution = bmpImageInfo.u32HorizontalResolution;
        psInfo->u32VerticalResolution   = bmpImageInfo.u32VerticalResolution;
        psInfo->u32NumberOfColors       = bmpImageInfo.u32NumberOfColors;
        psInfo->u32ImportantColors      = bmpImageInfo.u32ImportantColors;
        return(BMP_DECODER_ERR_NONE);
    }
    else
    {
        return(BMP_DECODER_ERR_INVALID_STATE);
    }

    bmpDecoderState = BMP_DECODER_STATE_INITIALIZED;

}



/*
*******************************************************************************
* 
* FUNCTION NAME:
*   bmpDecodeImage() 
*
* FUNCTION DESCRIPTION:
*   This function decodes the BMP image.   
*
* INPUTS:
*   pu8OutputBuffer : pointer to output buffer 
*   func            : pointer to callback function
*
* OUTPUTS:
*   pu8OutputBuffer : pointer to output buffer   
*   
* RETURN:
*   BMP_DECODER_ERR_NONE if successful, an error code otherwise.
*
* GLOBALS ACCESSED/MODIFIED:
*   bmpInputBuffer, bmpInputBufferSize, bmpDecoderState, bmpImageInfo
*
* SPECIAL NOTES:
*
*******************************************************************************
*/
BMP_DECODER_ERR bmpDecodeImage
(
    OP_UINT8        *pu8OutputBuffer,
    OP_BOOLEAN      func(OP_UINT16 x, OP_UINT16 y)
)
{

    /* -- Check if we are in the right state -- */
    if(bmpDecoderState == BMP_DECODER_STATE_READY)
    {
        /* -- Save output buffer pointer -- */
        bmpOutputBuffer = pu8OutputBuffer;

        /* -- Update decoder state -- */
        bmpDecoderState = BMP_DECODER_STATE_ACTIVE;

        /* -- Decode BMP image -- */
        BMPI_DecodeBitmap(bmpInputBuffer, 
                          bmpImageInfo,
                          func,
                          (IMAGE_DECODER_OUTPUT_TYPE *)pu8OutputBuffer);  
        
        return(BMP_DECODER_ERR_NONE);
    }

    /* -- Decoder is not in a right state -- */
    else
    {
        return(BMP_DECODER_ERR_INVALID_STATE);
    }

}