msvideo1.c File Reference

#include <stdarg.h>
#include "windef.h"
#include "winbase.h"
#include "wingdi.h"
#include "winuser.h"
#include "commdlg.h"
#include "vfw.h"
#include "mmsystem.h"
#include "msvidc32_private.h"
#include "wine/debug.h"

Include dependency graph for msvideo1.c:

Go to the source code of this file.

Classes
struct	Msvideo1Context

Macros
#define	CRAM_MAGIC   mmioFOURCC('C', 'R', 'A', 'M')
#define	MSVC_MAGIC   mmioFOURCC('M', 'S', 'V', 'C')
#define	WHAM_MAGIC   mmioFOURCC('W', 'H', 'A', 'M')
#define	compare_fourcc(fcc1, fcc2)   (((fcc1)^(fcc2))&~0x20202020)
#define	PALETTE_COUNT   256
#define	LE_16(x)   ((((const uint8_t *)(x))[1] << 8) | ((const uint8_t *)(x))[0])
#define	CHECK_STREAM_PTR(n)

Typedefs
typedef BYTE	uint8_t
typedef struct Msvideo1Context	Msvideo1Context

Functions
	WINE_DEFAULT_DEBUG_CHANNEL (msvidc32)
static int	get_stride (int width, int depth)
static void	msvideo1_decode_8bit (int width, int height, const unsigned char *buf, int buf_size, unsigned char *pixels, int stride)
static void	msvideo1_decode_16bit (int width, int height, const unsigned char *buf, int buf_size, unsigned short *pixels, int stride)
static LRESULT	CRAM_DecompressQuery (Msvideo1Context *info, LPBITMAPINFO in, LPBITMAPINFO out)
static LRESULT	CRAM_DecompressGetFormat (Msvideo1Context *info, LPBITMAPINFO in, LPBITMAPINFO out)
static LRESULT	CRAM_DecompressBegin (Msvideo1Context *info, LPBITMAPINFO in, LPBITMAPINFO out)
static void	convert_depth (char *input, int depth_in, char *output, BITMAPINFOHEADER *out_hdr)
static LRESULT	CRAM_Decompress (Msvideo1Context *info, ICDECOMPRESS *icd, DWORD size)
static LRESULT	CRAM_DecompressEx (Msvideo1Context *info, ICDECOMPRESSEX *icd, DWORD size)
static LRESULT	CRAM_GetInfo (const Msvideo1Context *info, ICINFO *icinfo, DWORD dwSize)
LRESULT WINAPI	CRAM_DriverProc (DWORD_PTR dwDriverId, HDRVR hdrvr, UINT msg, LPARAM lParam1, LPARAM lParam2)
BOOL WINAPI	DllMain (HINSTANCE hModule, DWORD dwReason, LPVOID lpReserved)

Variables
static HINSTANCE	MSVIDC32_hModule

Detailed Description

Microsoft Video-1 Decoder by Mike Melanson (melan.nosp@m.son@.nosp@m.pcisy.nosp@m.s.ne.nosp@m.t) For more information about the MS Video-1 format, visit: http://www.pcisys.net/~melanson/codecs/

This decoder outputs either PAL8 or RGB555 data, depending on the whether a RGB palette was passed through palctrl; if it's present, then the data is PAL8; RGB555 otherwise.

Definition in file msvideo1.c.

Macro Definition Documentation

CHECK_STREAM_PTR

#define CHECK_STREAM_PTR

(

n

)

Value:

  if ((stream_ptr + n) > buf_size ) { \
    WARN("stream_ptr out of bounds (%d >= %d)\n", \
      stream_ptr + n, buf_size); \
    return; \
  }

Definition at line 59 of file msvideo1.c.

compare_fourcc

#define compare_fourcc	(		fcc1,
			fcc2
	)		(((fcc1)^(fcc2))&~0x20202020)

Definition at line 53 of file msvideo1.c.

CRAM_MAGIC

#define CRAM_MAGIC   mmioFOURCC('C', 'R', 'A', 'M')

Definition at line 50 of file msvideo1.c.

LE_16

#define LE_16

(

x

)

((((const uint8_t *)(x))[1] << 8) | ((const uint8_t *)(x))[0])

Definition at line 56 of file msvideo1.c.

MSVC_MAGIC

#define MSVC_MAGIC   mmioFOURCC('M', 'S', 'V', 'C')

Definition at line 51 of file msvideo1.c.

PALETTE_COUNT

#define PALETTE_COUNT   256

Definition at line 55 of file msvideo1.c.

WHAM_MAGIC

#define WHAM_MAGIC   mmioFOURCC('W', 'H', 'A', 'M')

Definition at line 52 of file msvideo1.c.

Typedef Documentation

Msvideo1Context

typedef struct Msvideo1Context Msvideo1Context

uint8_t

typedef BYTE uint8_t

Definition at line 66 of file msvideo1.c.

Function Documentation

convert_depth()

static void convert_depth ( char *  input, int  depth_in, char *  output, BITMAPINFOHEADER *  out_hdr  )

static

Definition at line 408 of file msvideo1.c.

{
    int x, y;
    int stride_in  = get_stride(out_hdr->biWidth, depth_in);
    int stride_out = get_stride(out_hdr->biWidth, out_hdr->biBitCount);
 
    if (depth_in == 16 && out_hdr->biBitCount == 24)
    {
        static const unsigned char convert_5to8[] =
        {
            0x00, 0x08, 0x10, 0x19, 0x21, 0x29, 0x31, 0x3a,
            0x42, 0x4a, 0x52, 0x5a, 0x63, 0x6b, 0x73, 0x7b,
            0x84, 0x8c, 0x94, 0x9c, 0xa5, 0xad, 0xb5, 0xbd,
            0xc5, 0xce, 0xd6, 0xde, 0xe6, 0xef, 0xf7, 0xff,
        };
 
        for (y = 0; y < out_hdr->biHeight; y++)
        {
            WORD *src_row = (WORD *)(input + y * stride_in);
            char *out_row = output + y * stride_out;
 
            for (x = 0; x < out_hdr->biWidth; x++)
            {
                WORD pixel = *src_row++;
                *out_row++ = convert_5to8[(pixel & 0x7c00u) >> 10];
                *out_row++ = convert_5to8[(pixel & 0x03e0u) >> 5];
                *out_row++ = convert_5to8[(pixel & 0x001fu)];
            }
        }
    }
    else
        FIXME("Conversion from %d to %d bit unimplemented\n", depth_in, out_hdr->biBitCount);
}

Referenced by CRAM_Decompress(), and CRAM_DecompressEx().

CRAM_Decompress()

static LRESULT CRAM_Decompress ( Msvideo1Context *  info, ICDECOMPRESS *  icd, DWORD  size  )

static

Definition at line 442 of file msvideo1.c.

{
    LONG width, height, stride, sz;
    void *output;
 
    TRACE("ICM_DECOMPRESS %p %p %d\n", info, icd, size);
 
    if( (info==NULL) || (info->dwMagic!=CRAM_MAGIC) )
        return ICERR_BADPARAM;
 
    /* FIXME: flags are ignored */
 
    width  = icd->lpbiInput->biWidth;
    height = icd->lpbiInput->biHeight;
    sz = icd->lpbiInput->biSizeImage;
 
    output = icd->lpOutput;
 
    if (icd->lpbiOutput->biBitCount != info->depth)
    {
        output = HeapAlloc(GetProcessHeap(), 0, icd->lpbiOutput->biWidth * icd->lpbiOutput->biHeight * info->depth / 8);
        if (!output) return ICERR_MEMORY;
    }
 
    if (info->depth == 8)
    {
        stride = get_stride(width, 8);
        msvideo1_decode_8bit( width, height, icd->lpInput, sz,
                              output, stride );
    }
    else
    {
        stride = get_stride(width, 16) / 2;
        msvideo1_decode_16bit( width, height, icd->lpInput, sz,
                               output, stride );
    }
 
    if (icd->lpbiOutput->biBitCount != info->depth)
    {
        convert_depth(output, info->depth, icd->lpOutput, icd->lpbiOutput);
        HeapFree(GetProcessHeap(), 0, output);
    }
 
    return ICERR_OK;
}

Referenced by CRAM_DriverProc().

CRAM_DecompressBegin()

static LRESULT CRAM_DecompressBegin ( Msvideo1Context *  info, LPBITMAPINFO  in, LPBITMAPINFO  out  )

static

Definition at line 387 of file msvideo1.c.

{
    TRACE("ICM_DECOMPRESS_BEGIN %p %p %p\n", info, in, out);
 
    if( (info==NULL) || (info->dwMagic!=CRAM_MAGIC) )
        return ICERR_BADPARAM;
 
    TRACE("bitmap is %d bpp\n", in->bmiHeader.biBitCount);
    if( in->bmiHeader.biBitCount == 8 )
        info->depth = 8;
    else if( in->bmiHeader.biBitCount == 16 )
        info->depth = 16;
    else
    {
        info->depth = 0;
        FIXME("Unsupported output format %i\n", in->bmiHeader.biBitCount);
    }
 
    return ICERR_OK;
}

Referenced by CRAM_DriverProc().

CRAM_DecompressEx()

static LRESULT CRAM_DecompressEx ( Msvideo1Context *  info, ICDECOMPRESSEX *  icd, DWORD  size  )

static

Definition at line 488 of file msvideo1.c.

{
    LONG width, height, stride, sz;
    void *output;
 
    TRACE("ICM_DECOMPRESSEX %p %p %d\n", info, icd, size);
 
    if( (info==NULL) || (info->dwMagic!=CRAM_MAGIC) )
        return ICERR_BADPARAM;
 
    /* FIXME: flags are ignored */
 
    width  = icd->lpbiSrc->biWidth;
    height = icd->lpbiSrc->biHeight;
    sz = icd->lpbiSrc->biSizeImage;
 
    output = icd->lpDst;
 
    if (icd->lpbiDst->biBitCount != info->depth)
    {
        output = HeapAlloc(GetProcessHeap(), 0, icd->lpbiDst->biWidth * icd->lpbiDst->biHeight * info->depth / 8);
        if (!output) return ICERR_MEMORY;
    }
 
    if (info->depth == 8)
    {
        stride = get_stride(width, 8);
        msvideo1_decode_8bit( width, height, icd->lpSrc, sz, 
                              output, stride );
    }
    else
    {
        stride = get_stride(width, 16) / 2;
        msvideo1_decode_16bit( width, height, icd->lpSrc, sz,
                               output, stride );
    }
 
    if (icd->lpbiDst->biBitCount != info->depth)
    {
        convert_depth(output, info->depth, icd->lpDst, icd->lpbiDst);
        HeapFree(GetProcessHeap(), 0, output);
    }
 
    return ICERR_OK;
}

Referenced by CRAM_DriverProc().

CRAM_DecompressGetFormat()

static LRESULT CRAM_DecompressGetFormat ( Msvideo1Context *  info, LPBITMAPINFO  in, LPBITMAPINFO  out  )

static

Definition at line 357 of file msvideo1.c.

{
    DWORD size;
 
    TRACE("ICM_DECOMPRESS_GETFORMAT %p %p %p\n", info, in, out);
 
    if( (info==NULL) || (info->dwMagic!=CRAM_MAGIC) )
        return ICERR_BADPARAM;
 
    size = in->bmiHeader.biSize;
    if (in->bmiHeader.biBitCount <= 8)
        size += in->bmiHeader.biClrUsed * sizeof(RGBQUAD);
 
    if (in->bmiHeader.biBitCount != 8 && in->bmiHeader.biBitCount != 16)
        return ICERR_BADFORMAT;
 
    if( out )
    {
        memcpy( out, in, size );
        out->bmiHeader.biWidth = in->bmiHeader.biWidth & ~1;
        out->bmiHeader.biHeight = in->bmiHeader.biHeight & ~1;
        out->bmiHeader.biCompression = BI_RGB;
        out->bmiHeader.biSizeImage = in->bmiHeader.biHeight *
                                     get_stride(out->bmiHeader.biWidth, out->bmiHeader.biBitCount);
        return ICERR_OK;
    }
 
    return size;
}

Referenced by CRAM_DriverProc().

CRAM_DecompressQuery()

static LRESULT CRAM_DecompressQuery ( Msvideo1Context *  info, LPBITMAPINFO  in, LPBITMAPINFO  out  )

static

Definition at line 300 of file msvideo1.c.

{
    TRACE("ICM_DECOMPRESS_QUERY %p %p %p\n", info, in, out);
 
    if( (info==NULL) || (info->dwMagic!=CRAM_MAGIC) )
        return ICERR_BADPARAM;
 
    TRACE("in->planes  = %d\n", in->bmiHeader.biPlanes );
    TRACE("in->bpp     = %d\n", in->bmiHeader.biBitCount );
    TRACE("in->height  = %d\n", in->bmiHeader.biHeight );
    TRACE("in->width   = %d\n", in->bmiHeader.biWidth );
    TRACE("in->compr   = 0x%x\n", in->bmiHeader.biCompression );
 
    if( ( in->bmiHeader.biCompression != CRAM_MAGIC ) &&
        ( in->bmiHeader.biCompression != MSVC_MAGIC ) &&
        ( in->bmiHeader.biCompression != WHAM_MAGIC ) )
    {
        TRACE("can't do 0x%x compression\n", in->bmiHeader.biCompression);
        return ICERR_BADFORMAT;
    }
 
    if( ( in->bmiHeader.biBitCount != 16 ) &&
        ( in->bmiHeader.biBitCount != 8 ) )
    {
        TRACE("can't do %d bpp\n", in->bmiHeader.biBitCount );
        return ICERR_BADFORMAT;
    }
 
    /* output must be same dimensions as input */
    if( out )
    {
        TRACE("out->planes = %d\n", out->bmiHeader.biPlanes );
        TRACE("out->bpp    = %d\n", out->bmiHeader.biBitCount );
        TRACE("out->height = %d\n", out->bmiHeader.biHeight );
        TRACE("out->width  = %d\n", out->bmiHeader.biWidth );
 
        if ((in->bmiHeader.biBitCount != out->bmiHeader.biBitCount) &&
            (in->bmiHeader.biBitCount != 16 || out->bmiHeader.biBitCount != 24))
        {
            TRACE("incompatible depth requested\n");
            return ICERR_BADFORMAT;
        }
 
        if(( in->bmiHeader.biPlanes != out->bmiHeader.biPlanes ) ||
          ( in->bmiHeader.biHeight != out->bmiHeader.biHeight ) ||
          ( in->bmiHeader.biWidth != out->bmiHeader.biWidth ))
        {
            TRACE("incompatible output requested\n");
            return ICERR_BADFORMAT;
        }
    }
 
    TRACE("OK!\n");
    return ICERR_OK;
}

Referenced by CRAM_DriverProc().

CRAM_DriverProc()

LRESULT WINAPI CRAM_DriverProc	(	DWORD_PTR	dwDriverId,
		HDRVR	hdrvr,
		UINT	msg,
		LPARAM	lParam1,
		LPARAM	lParam2
	)

Definition at line 560 of file msvideo1.c.

{
    Msvideo1Context *info = (Msvideo1Context *) dwDriverId;
    LRESULT r = ICERR_UNSUPPORTED;
 
    TRACE("%ld %p %04x %08lx %08lx\n", dwDriverId, hdrvr, msg, lParam1, lParam2);
 
    switch( msg )
    {
    case DRV_LOAD:
        TRACE("Loaded\n");
        r = 1;
        break;
 
    case DRV_ENABLE:
        break;
 
    case DRV_OPEN:
    {
        ICINFO *icinfo = (ICINFO *)lParam2;
 
        TRACE("Opened\n");
 
        if (icinfo && compare_fourcc(icinfo->fccType, ICTYPE_VIDEO)) return 0;
 
        info = HeapAlloc( GetProcessHeap(), 0, sizeof (Msvideo1Context) );
        if( info )
        {
            memset( info, 0, sizeof *info );
            info->dwMagic = CRAM_MAGIC;
        }
        r = (LRESULT) info;
        break;
    }
 
    case DRV_CLOSE:
        HeapFree( GetProcessHeap(), 0, info );
        break;
 
    case DRV_DISABLE:
        break;
 
    case DRV_FREE:
        break;
 
    case ICM_GETINFO:
        r = CRAM_GetInfo( info, (ICINFO *)lParam1, (DWORD)lParam2 );
        break;
 
    case ICM_DECOMPRESS_QUERY:
        r = CRAM_DecompressQuery( info, (LPBITMAPINFO) lParam1,
                                       (LPBITMAPINFO) lParam2 );
        break;
 
    case ICM_DECOMPRESS_GET_FORMAT:
        r = CRAM_DecompressGetFormat( info, (LPBITMAPINFO) lParam1,
                                       (LPBITMAPINFO) lParam2 );
        break;
 
    case ICM_DECOMPRESS_GET_PALETTE:
        FIXME("ICM_DECOMPRESS_GET_PALETTE\n");
        break;
 
    case ICM_DECOMPRESSEX_QUERY:
        FIXME("ICM_DECOMPRESSEX_QUERY\n");
        break;
 
    case ICM_DECOMPRESS:
        r = CRAM_Decompress( info, (ICDECOMPRESS*) lParam1,
                                  (DWORD) lParam2 );
        break;
 
    case ICM_DECOMPRESS_BEGIN:
        r = CRAM_DecompressBegin( info, (LPBITMAPINFO) lParam1,
                                       (LPBITMAPINFO) lParam2 );
        break;
 
    case ICM_DECOMPRESSEX:
        r = CRAM_DecompressEx( info, (ICDECOMPRESSEX*) lParam1,
                                  (DWORD) lParam2 );
        break;
 
    case ICM_DECOMPRESS_END:
        r = ICERR_OK;
        break;
 
    case ICM_COMPRESS_QUERY:
        r = ICERR_BADFORMAT;
        /* fall through */
    case ICM_COMPRESS_GET_FORMAT:
    case ICM_COMPRESS_END:
    case ICM_COMPRESS:
        FIXME("compression not implemented\n");
        break;
 
    case ICM_CONFIGURE:
        break;
 
    default:
        FIXME("Unknown message: %04x %ld %ld\n", msg, lParam1, lParam2);
    }
 
    return r;
}

CRAM_GetInfo()

static LRESULT CRAM_GetInfo ( const Msvideo1Context *  info, ICINFO *  icinfo, DWORD  dwSize  )

static

Definition at line 534 of file msvideo1.c.

{
    if (!icinfo) return sizeof(ICINFO);
    if (dwSize < sizeof(ICINFO)) return 0;
 
    icinfo->dwSize = sizeof(ICINFO);
    icinfo->fccType = ICTYPE_VIDEO;
#ifdef __REACTOS__
    icinfo->fccHandler = MSVC_MAGIC;
#else
    icinfo->fccHandler = info ? info->dwMagic : CRAM_MAGIC;
#endif
    icinfo->dwFlags = 0;
    icinfo->dwVersion = ICVERSION;
    icinfo->dwVersionICM = ICVERSION;
 
    LoadStringW(MSVIDC32_hModule, IDS_NAME, icinfo->szName, ARRAY_SIZE(icinfo->szName));
    LoadStringW(MSVIDC32_hModule, IDS_DESCRIPTION, icinfo->szDescription, ARRAY_SIZE(icinfo->szDescription));
    /* msvfw32 will fill icinfo->szDriver for us */
 
    return sizeof(ICINFO);
}

Referenced by CRAM_DriverProc().

DllMain()

BOOL WINAPI DllMain	(	HINSTANCE	hModule,
		DWORD	dwReason,
		LPVOID	lpReserved
	)

Definition at line 669 of file msvideo1.c.

{
    TRACE("(%p,%d,%p)\n", hModule, dwReason, lpReserved);
 
    switch (dwReason)
    {
    case DLL_PROCESS_ATTACH:
        DisableThreadLibraryCalls(hModule);
        MSVIDC32_hModule = hModule;
        break;
    }
    return TRUE;
}

get_stride()

static int get_stride ( int  width, int  depth  )

inlinestatic

Definition at line 73 of file msvideo1.c.

{
    return ((depth * width + 31) >> 3) & ~3;
}

Referenced by convert_depth(), CRAM_Decompress(), CRAM_DecompressEx(), and CRAM_DecompressGetFormat().

msvideo1_decode_16bit()

static void msvideo1_decode_16bit ( int  width, int  height, const unsigned char *  buf, int  buf_size, unsigned short *  pixels, int  stride  )

static

Definition at line 183 of file msvideo1.c.

{
    int block_ptr, pixel_ptr;
    int total_blocks;
    int pixel_x, pixel_y;  /* pixel width and height iterators */
    int block_x, block_y;  /* block width and height iterators */
    int blocks_wide, blocks_high;  /* width and height in 4x4 blocks */
    int block_inc;
    int row_dec;
 
    /* decoding parameters */
    int stream_ptr;
    unsigned char byte_a, byte_b;
    unsigned short flags;
    int skip_blocks;
    unsigned short colors[8];
 
    stream_ptr = 0;
    skip_blocks = 0;
    blocks_wide = width / 4;
    blocks_high = height / 4;
    total_blocks = blocks_wide * blocks_high;
    block_inc = 4;
#ifdef ORIGINAL
    row_dec = stride + 4;
#else
    row_dec = - (stride - 4); /* such that -row_dec > 0 */
#endif
 
    for (block_y = blocks_high; block_y > 0; block_y--) {
#ifdef ORIGINAL
        block_ptr = ((block_y * 4) - 1) * stride;
#else
        block_ptr = ((blocks_high - block_y) * 4) * stride;
#endif
        for (block_x = blocks_wide; block_x > 0; block_x--) {
            /* check if this block should be skipped */
            if (skip_blocks) {
                block_ptr += block_inc;
                skip_blocks--;
                total_blocks--;
                continue;
            }
 
            pixel_ptr = block_ptr;
 
            /* get the next two bytes in the encoded data stream */
            CHECK_STREAM_PTR(2);
            byte_a = buf[stream_ptr++];
            byte_b = buf[stream_ptr++];
 
            /* check if the decode is finished */
            if ((byte_a == 0) && (byte_b == 0) && (total_blocks == 0)) {
                return;
            } else if ((byte_b & 0xFC) == 0x84) {
                /* skip code, but don't count the current block */
                skip_blocks = ((byte_b - 0x84) << 8) + byte_a - 1;
            } else if (byte_b < 0x80) {
                /* 2- or 8-color encoding modes */
                flags = (byte_b << 8) | byte_a;
 
                CHECK_STREAM_PTR(4);
                colors[0] = LE_16(&buf[stream_ptr]);
                stream_ptr += 2;
                colors[1] = LE_16(&buf[stream_ptr]);
                stream_ptr += 2;
 
                if (colors[0] & 0x8000) {
                    /* 8-color encoding */
                    CHECK_STREAM_PTR(12);
                    colors[2] = LE_16(&buf[stream_ptr]);
                    stream_ptr += 2;
                    colors[3] = LE_16(&buf[stream_ptr]);
                    stream_ptr += 2;
                    colors[4] = LE_16(&buf[stream_ptr]);
                    stream_ptr += 2;
                    colors[5] = LE_16(&buf[stream_ptr]);
                    stream_ptr += 2;
                    colors[6] = LE_16(&buf[stream_ptr]);
                    stream_ptr += 2;
                    colors[7] = LE_16(&buf[stream_ptr]);
                    stream_ptr += 2;
 
                    for (pixel_y = 0; pixel_y < 4; pixel_y++) {
                        for (pixel_x = 0; pixel_x < 4; pixel_x++, flags >>= 1)
                            pixels[pixel_ptr++] =
                                colors[((pixel_y & 0x2) << 1) +
                                    (pixel_x & 0x2) + ((flags & 0x1) ^ 1)];
                        pixel_ptr -= row_dec;
                    }
                } else {
                    /* 2-color encoding */
                    for (pixel_y = 0; pixel_y < 4; pixel_y++) {
                        for (pixel_x = 0; pixel_x < 4; pixel_x++, flags >>= 1)
                            pixels[pixel_ptr++] = colors[(flags & 0x1) ^ 1];
                        pixel_ptr -= row_dec;
                    }
                }
            } else {
                /* otherwise, it's a 1-color block */
                colors[0] = (byte_b << 8) | byte_a;
 
                for (pixel_y = 0; pixel_y < 4; pixel_y++) {
                    for (pixel_x = 0; pixel_x < 4; pixel_x++)
                        pixels[pixel_ptr++] = colors[0];
                    pixel_ptr -= row_dec;
                }
            }
 
            block_ptr += block_inc;
            total_blocks--;
        }
    }
}

Referenced by CRAM_Decompress(), and CRAM_DecompressEx().

msvideo1_decode_8bit()

static void msvideo1_decode_8bit ( int  width, int  height, const unsigned char *  buf, int  buf_size, unsigned char *  pixels, int  stride  )

static

Definition at line 79 of file msvideo1.c.

{
    int block_ptr, pixel_ptr;
    int total_blocks;
    int pixel_x, pixel_y;  /* pixel width and height iterators */
    int block_x, block_y;  /* block width and height iterators */
    int blocks_wide, blocks_high;  /* width and height in 4x4 blocks */
    int block_inc;
    int row_dec;
 
    /* decoding parameters */
    int stream_ptr;
    unsigned char byte_a, byte_b;
    unsigned short flags;
    int skip_blocks;
    unsigned char colors[8];
 
    stream_ptr = 0;
    skip_blocks = 0;
    blocks_wide = width / 4;
    blocks_high = height / 4;
    total_blocks = blocks_wide * blocks_high;
    block_inc = 4;
#ifdef ORIGINAL
    row_dec = stride + 4;
#else
    row_dec = - (stride - 4); /* such that -row_dec > 0 */
#endif
 
    for (block_y = blocks_high; block_y > 0; block_y--) {
#ifdef ORIGINAL
        block_ptr = ((block_y * 4) - 1) * stride;
#else
        block_ptr = ((blocks_high - block_y) * 4) * stride;
#endif
        for (block_x = blocks_wide; block_x > 0; block_x--) {
            /* check if this block should be skipped */
            if (skip_blocks) {
                block_ptr += block_inc;
                skip_blocks--;
                total_blocks--;
                continue;
            }
 
            pixel_ptr = block_ptr;
 
            /* get the next two bytes in the encoded data stream */
            CHECK_STREAM_PTR(2);
            byte_a = buf[stream_ptr++];
            byte_b = buf[stream_ptr++];
 
            /* check if the decode is finished */
            if ((byte_a == 0) && (byte_b == 0) && (total_blocks == 0))
                return;
            else if ((byte_b & 0xFC) == 0x84) {
                /* skip code, but don't count the current block */
                skip_blocks = ((byte_b - 0x84) << 8) + byte_a - 1;
            } else if (byte_b < 0x80) {
                /* 2-color encoding */
                flags = (byte_b << 8) | byte_a;
 
                CHECK_STREAM_PTR(2);
                colors[0] = buf[stream_ptr++];
                colors[1] = buf[stream_ptr++];
 
                for (pixel_y = 0; pixel_y < 4; pixel_y++) {
                    for (pixel_x = 0; pixel_x < 4; pixel_x++, flags >>= 1)
                        pixels[pixel_ptr++] = colors[(flags & 0x1) ^ 1];
                    pixel_ptr -= row_dec;
                }
            } else if (byte_b >= 0x90) {
                /* 8-color encoding */
                flags = (byte_b << 8) | byte_a;
 
                CHECK_STREAM_PTR(8);
                memcpy(colors, &buf[stream_ptr], 8);
                stream_ptr += 8;
 
                for (pixel_y = 0; pixel_y < 4; pixel_y++) {
                    for (pixel_x = 0; pixel_x < 4; pixel_x++, flags >>= 1)
                        pixels[pixel_ptr++] =
                            colors[((pixel_y & 0x2) << 1) +
                                (pixel_x & 0x2) + ((flags & 0x1) ^ 1)];
                    pixel_ptr -= row_dec;
                }
            } else {
                /* 1-color encoding */
                colors[0] = byte_a;
 
                for (pixel_y = 0; pixel_y < 4; pixel_y++) {
                    for (pixel_x = 0; pixel_x < 4; pixel_x++)
                        pixels[pixel_ptr++] = colors[0];
                    pixel_ptr -= row_dec;
                }
            }
 
            block_ptr += block_inc;
            total_blocks--;
        }
    }
}

Referenced by CRAM_Decompress(), and CRAM_DecompressEx().

WINE_DEFAULT_DEBUG_CHANNEL()

WINE_DEFAULT_DEBUG_CHANNEL

(

msvidc32

)

Variable Documentation

MSVIDC32_hModule

HINSTANCE MSVIDC32_hModule

static

Definition at line 48 of file msvideo1.c.

Referenced by CRAM_GetInfo(), and DllMain().