libmng_jpeg.c

Linux下的基于X11的图形开发环境。

                                       /* whatever we were doing ... */
                                       /* we don't anymore ... */
  pData->bJPEGcompress     = MNG_FALSE;

  pData->bJPEGdecompress   = MNG_FALSE;
  pData->bJPEGhasheader    = MNG_FALSE;
  pData->bJPEGdecostarted  = MNG_FALSE;
  pData->bJPEGscanstarted  = MNG_FALSE;

  pData->bJPEGdecompress2  = MNG_FALSE;
  pData->bJPEGhasheader2   = MNG_FALSE;
  pData->bJPEGdecostarted2 = MNG_FALSE;
  pData->bJPEGscanstarted2 = MNG_FALSE;

#ifdef MNG_SUPPORT_TRACE
  MNG_TRACE (pData, MNG_FN_JPEG_CLEANUP, MNG_LC_END)
#endif

  return MNG_NOERROR;
}

/* ************************************************************************** */
/* *                                                                        * */
/* * JPEG decompression routines (JDAT)                                     * */
/* *                                                                        * */
/* ************************************************************************** */

#ifdef MNG_INCLUDE_JNG_READ
mng_retcode mngjpeg_decompressinit (mng_datap pData)
{
#if defined(MNG_INCLUDE_IJG6B) && defined(MNG_USE_SETJMP)
  mng_retcode iRetcode;
#endif

#ifdef MNG_SUPPORT_TRACE
  MNG_TRACE (pData, MNG_FN_JPEG_DECOMPRESSINIT, MNG_LC_START)
#endif

#ifdef MNG_INCLUDE_IJG6B
  /* allocate and initialize a JPEG decompression object */
  pData->pJPEGdinfo->err = jpeg_std_error (pData->pJPEGderr);

#ifdef MNG_USE_SETJMP                  /* setup local JPEG error-routines */
  pData->pJPEGderr->error_exit     = mng_error_exit;
  pData->pJPEGderr->output_message = mng_output_message;

  iRetcode = setjmp (pData->sErrorbuf);/* setup local JPEG error-recovery */
  if (iRetcode != 0)                   /* got here from longjmp ? */
    MNG_ERRORJ (pData, iRetcode)       /* then IJG-lib issued an error */
#endif /* MNG_USE_SETJMP */

  /* allocate and initialize a JPEG decompression object (continued) */
#ifdef MNG_SUPPORT_TRACE
  MNG_TRACE (pData, MNG_FN_JPEG_DECOMPRESSINIT, MNG_LC_JPEG_CREATE_DECOMPRESS)
#endif
  jpeg_create_decompress (pData->pJPEGdinfo);

  pData->bJPEGdecompress = MNG_TRUE;   /* indicate it's initialized */

  /* specify the source of the compressed data (eg, a file) */
                                       /* no, not a file; we have buffered input */
  pData->pJPEGdinfo->src = pData->pJPEGdsrc;
                                       /* use the default handler */
  pData->pJPEGdinfo->src->resync_to_restart = jpeg_resync_to_restart;
                                       /* setup local source routine & parms */
  pData->pJPEGdinfo->src->init_source       = mng_init_source;
  pData->pJPEGdinfo->src->fill_input_buffer = mng_fill_input_buffer;
  pData->pJPEGdinfo->src->skip_input_data   = mng_skip_input_data;
  pData->pJPEGdinfo->src->term_source       = mng_term_source;
  pData->pJPEGdinfo->src->next_input_byte   = pData->pJPEGcurrent;
  pData->pJPEGdinfo->src->bytes_in_buffer   = pData->iJPEGbufremain;

#endif /* MNG_INCLUDE_IJG6B */

#ifdef MNG_SUPPORT_TRACE
  MNG_TRACE (pData, MNG_FN_JPEG_DECOMPRESSINIT, MNG_LC_END)
#endif

  return MNG_NOERROR;
}
#endif /* MNG_INCLUDE_JNG_READ */

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

#ifdef MNG_INCLUDE_JNG_READ
mng_retcode mngjpeg_decompressdata (mng_datap  pData,
                                    mng_uint32 iRawsize,
                                    mng_uint8p pRawdata)
{
  mng_retcode iRetcode;
  mng_uint32  iRemain;
  mng_uint8p  pWork;

#ifdef MNG_SUPPORT_TRACE
  MNG_TRACE (pData, MNG_FN_JPEG_DECOMPRESSDATA, MNG_LC_START)
#endif

#if defined (MNG_INCLUDE_IJG6B) && defined(MNG_USE_SETJMP)
  iRetcode = setjmp (pData->sErrorbuf);/* initialize local JPEG error-recovery */
  if (iRetcode != 0)                   /* got here from longjmp ? */
    MNG_ERRORJ (pData, iRetcode)       /* then IJG-lib issued an error */
#endif

  pWork   = pRawdata;
  iRemain = iRawsize;

  if (pData->iJPEGtoskip)              /* JPEG-lib told us to skip some more data ? */
  {
    if (iRemain > pData->iJPEGtoskip)  /* enough data in this buffer ? */
    {
      iRemain -= pData->iJPEGtoskip;   /* skip enough to access the next byte */
      pWork   += pData->iJPEGtoskip;

      pData->iJPEGtoskip = 0;          /* no more to skip then */
    }
    else
    {
      pData->iJPEGtoskip -= iRemain;   /* skip all data in the buffer */
      iRemain = 0;                     /* and indicate this accordingly */
    }
                                       /* the skip set current-pointer to NULL ! */
    pData->pJPEGcurrent = pData->pJPEGbuf;
  }

  while (iRemain)                      /* repeat until no more input-bytes */
  {                                    /* need to shift anything ? */
    if ((pData->pJPEGcurrent > pData->pJPEGbuf) &&
        (pData->pJPEGcurrent - pData->pJPEGbuf + pData->iJPEGbufremain + iRemain > pData->iJPEGbufmax))
    {
      if (pData->iJPEGbufremain > 0)   /* then do so */
        MNG_COPY (pData->pJPEGbuf, pData->pJPEGcurrent, pData->iJPEGbufremain)

      pData->pJPEGcurrent = pData->pJPEGbuf;
    }
                                       /* does the remaining input fit into the buffer ? */
    if (pData->iJPEGbufremain + iRemain <= pData->iJPEGbufmax)
    {                                  /* move the lot */
      MNG_COPY ((pData->pJPEGcurrent + pData->iJPEGbufremain), pWork, iRemain)

      pData->iJPEGbufremain += iRemain;/* adjust remaining_bytes counter */
      iRemain = 0;                     /* and indicate there's no input left */
    }
    else
    {                                  /* calculate what does fit */
      mng_uint32 iFits = pData->iJPEGbufmax - pData->iJPEGbufremain;

      if (iFits <= 0)                  /* no space is just bugger 'm all */
        MNG_ERROR (pData, MNG_JPEGBUFTOOSMALL)
                                       /* move that */
      MNG_COPY ((pData->pJPEGcurrent + pData->iJPEGbufremain), pWork, iFits)

      pData->iJPEGbufremain += iFits;  /* adjust remain_bytes counter */
      iRemain -= iFits;                /* and the input-parms */
      pWork   += iFits;
    }

#ifdef MNG_INCLUDE_IJG6B
    pData->pJPEGdinfo->src->next_input_byte = pData->pJPEGcurrent;
    pData->pJPEGdinfo->src->bytes_in_buffer = pData->iJPEGbufremain;

    if (!pData->bJPEGhasheader)        /* haven't got the header yet ? */
    {
      /* call jpeg_read_header() to obtain image info */
#ifdef MNG_SUPPORT_TRACE
      MNG_TRACE (pData, MNG_FN_JPEG_DECOMPRESSDATA, MNG_LC_JPEG_READ_HEADER)
#endif
      if (jpeg_read_header (pData->pJPEGdinfo, TRUE) != JPEG_SUSPENDED)
      {                                /* indicate the header's oke */
        pData->bJPEGhasheader = MNG_TRUE;
                                       /* let's do some sanity checks ! */
        if ((pData->pJPEGdinfo->image_width  != pData->iDatawidth ) ||
            (pData->pJPEGdinfo->image_height != pData->iDataheight)    )
          MNG_ERROR (pData, MNG_JPEGPARMSERR)

        if ( ((pData->iJHDRcolortype == MNG_COLORTYPE_JPEGGRAY ) ||
              (pData->iJHDRcolortype == MNG_COLORTYPE_JPEGGRAYA)    ) &&
             (pData->pJPEGdinfo->jpeg_color_space != JCS_GRAYSCALE  )    )
          MNG_ERROR (pData, MNG_JPEGPARMSERR)

        if ( ((pData->iJHDRcolortype == MNG_COLORTYPE_JPEGCOLOR ) ||
              (pData->iJHDRcolortype == MNG_COLORTYPE_JPEGCOLORA)    ) &&
             (pData->pJPEGdinfo->jpeg_color_space != JCS_YCbCr       )    )
          MNG_ERROR (pData, MNG_JPEGPARMSERR)
                                       /* indicate whether or not it's progressive */
        pData->bJPEGprogressive = (mng_bool)jpeg_has_multiple_scans (pData->pJPEGdinfo);
                                       /* progressive+alpha can't display "on-the-fly"!! */
        if ((pData->bJPEGprogressive) &&
            ((pData->iJHDRcolortype == MNG_COLORTYPE_JPEGGRAYA ) ||
             (pData->iJHDRcolortype == MNG_COLORTYPE_JPEGCOLORA)    ))
          pData->fDisplayrow = MNG_NULL;
                                       /* allocate a row of JPEG-samples */
        if (pData->pJPEGdinfo->jpeg_color_space == JCS_YCbCr)
          pData->iJPEGrowlen = pData->pJPEGdinfo->image_width * 3;
        else
          pData->iJPEGrowlen = pData->pJPEGdinfo->image_width;

        MNG_ALLOC (pData, pData->pJPEGrow, pData->iJPEGrowlen)

        pData->iJPEGrgbrow = 0;        /* quite empty up to now */
      }

      pData->pJPEGcurrent   = (mng_uint8p)pData->pJPEGdinfo->src->next_input_byte;
      pData->iJPEGbufremain = (mng_uint32)pData->pJPEGdinfo->src->bytes_in_buffer;
    }
                                       /* decompress not started ? */
    if ((pData->bJPEGhasheader) && (!pData->bJPEGdecostarted))
    {
      /* set parameters for decompression */

      if (pData->bJPEGprogressive)     /* progressive display ? */
        pData->pJPEGdinfo->buffered_image = TRUE;

      /* jpeg_start_decompress(...); */
#ifdef MNG_SUPPORT_TRACE
      MNG_TRACE (pData, MNG_FN_JPEG_DECOMPRESSDATA, MNG_LC_JPEG_START_DECOMPRESS)
#endif
      if (jpeg_start_decompress (pData->pJPEGdinfo) == TRUE)
                                       /* indicate it started */
        pData->bJPEGdecostarted = MNG_TRUE;

      pData->pJPEGcurrent   = (mng_uint8p)pData->pJPEGdinfo->src->next_input_byte;
      pData->iJPEGbufremain = (mng_uint32)pData->pJPEGdinfo->src->bytes_in_buffer;
    }
                                       /* process some scanlines ? */
    if ((pData->bJPEGhasheader) && (pData->bJPEGdecostarted) &&
	    ((!jpeg_input_complete (pData->pJPEGdinfo)) ||
         (pData->pJPEGdinfo->output_scanline < pData->pJPEGdinfo->output_height)))
    {
      mng_int32 iLines;

      /* for (each output pass) */
      do
      {                                /* address the row output buffer */
        JSAMPROW pRow = (JSAMPROW)pData->pJPEGrow;

                                       /* init new pass ? */
        if ((pData->bJPEGprogressive) &&
            ((!pData->bJPEGscanstarted) ||
             (pData->pJPEGdinfo->output_scanline >= pData->pJPEGdinfo->output_height)))
        {
          pData->bJPEGscanstarted = MNG_TRUE;

          /* adjust output decompression parameters if required */
          /* nop */

          /* start a new output pass */
#ifdef MNG_SUPPORT_TRACE
          MNG_TRACE (pData, MNG_FN_JPEG_DECOMPRESSDATA, MNG_LC_JPEG_START_OUTPUT)
#endif
          jpeg_start_output (pData->pJPEGdinfo, pData->pJPEGdinfo->input_scan_number);

          pData->iJPEGrow = 0;         /* start at row 0 in the image again */
        }

        /* while (scan lines remain to be read) */
        do
        {
          /*   jpeg_read_scanlines(...); */
#ifdef MNG_SUPPORT_TRACE
          MNG_TRACE (pData, MNG_FN_JPEG_DECOMPRESSDATA, MNG_LC_JPEG_READ_SCANLINES)
#endif
          iLines = jpeg_read_scanlines (pData->pJPEGdinfo, (JSAMPARRAY)&pRow, 1);

          pData->pJPEGcurrent   = (mng_uint8p)pData->pJPEGdinfo->src->next_input_byte;
          pData->iJPEGbufremain = (mng_uint32)pData->pJPEGdinfo->src->bytes_in_buffer;

          if (iLines > 0)              /* got something ? */
          {
            if (pData->fStorerow2)     /* store in object ? */
            {
              iRetcode = ((mng_storerow)pData->fStorerow2) (pData);

              if (iRetcode)            /* on error bail out */
                return iRetcode;

            }
          }
        }
        while ((pData->pJPEGdinfo->output_scanline < pData->pJPEGdinfo->output_height) &&
               (iLines > 0));          /* until end-of-image or not enough input-data */

        /* terminate output pass */
        if ((pData->bJPEGprogressive) &&
            (pData->pJPEGdinfo->output_scanline >= pData->pJPEGdinfo->output_height))
        {
#ifdef MNG_SUPPORT_TRACE
          MNG_TRACE (pData, MNG_FN_JPEG_DECOMPRESSDATA, MNG_LC_JPEG_FINISH_OUTPUT)
#endif
          jpeg_finish_output (pData->pJPEGdinfo);
                                       /* this scan has ended */
          pData->bJPEGscanstarted = MNG_FALSE;
        }
      }
      while ((!jpeg_input_complete (pData->pJPEGdinfo)) && (iLines > 0));
    }
                                       /* end of image ? */
    if ((pData->bJPEGhasheader) && (pData->bJPEGdecostarted) &&
        (jpeg_input_complete (pData->pJPEGdinfo)) &&
        (pData->pJPEGdinfo->input_scan_number == pData->pJPEGdinfo->output_scan_number))
    {
      /* jpeg_finish_decompress(...); */
#ifdef MNG_SUPPORT_TRACE
      MNG_TRACE (pData, MNG_FN_JPEG_DECOMPRESSDATA, MNG_LC_JPEG_FINISH_DECOMPRESS)
#endif
      if (jpeg_finish_decompress (pData->pJPEGdinfo) == TRUE)
      {                                /* indicate it's done */
        pData->bJPEGhasheader   = MNG_FALSE;
        pData->bJPEGdecostarted = MNG_FALSE;
        pData->pJPEGcurrent     = (mng_uint8p)pData->pJPEGdinfo->src->next_input_byte;
        pData->iJPEGbufremain   = (mng_uint32)pData->pJPEGdinfo->src->bytes_in_buffer;
                                       /* remaining fluff is an error ! */
        if ((pData->iJPEGbufremain > 0) || (iRemain > 0))
          MNG_ERROR (pData, MNG_TOOMUCHJDAT)
      }
    }
#endif /* MNG_INCLUDE_IJG6B */
  }

#ifdef MNG_SUPPORT_TRACE
  MNG_TRACE (pData, MNG_FN_JPEG_DECOMPRESSDATA, MNG_LC_END)
#endif

  return MNG_NOERROR;
}
#endif /* MNG_INCLUDE_JNG_READ */

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

#ifdef MNG_INCLUDE_JNG_READ
mng_retcode mngjpeg_decompressfree (mng_datap pData)
{
#if defined(MNG_INCLUDE_IJG6B) && defined(MNG_USE_SETJMP)
  mng_retcode iRetcode;
#endif

#ifdef MNG_SUPPORT_TRACE
  MNG_TRACE (pData, MNG_FN_JPEG_DECOMPRESSFREE, MNG_LC_START)
#endif

#ifdef MNG_INCLUDE_IJG6B
#ifdef MNG_USE_SETJMP
  iRetcode = setjmp (pData->sErrorbuf);/* setup local JPEG error-recovery */
  if (iRetcode != 0)                   /* got here from longjmp ? */
    MNG_ERRORJ (pData, iRetcode)       /* then IJG-lib issued an error */
#endif
                                       /* free the row of JPEG-samples*/
  MNG_FREE (pData, pData->pJPEGrow, pData->iJPEGrowlen)

  /* release the JPEG decompression object */
#ifdef MNG_SUPPORT_TRACE
  MNG_TRACE (pData, MNG_FN_JPEG_DECOMPRESSFREE, MNG_LC_JPEG_DESTROY_DECOMPRESS)
#endif
  jpeg_destroy_decompress (pData->pJPEGdinfo);

  pData->bJPEGdecompress = MNG_FALSE;  /* indicate it's done */