/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%                            Y   Y  U   U  V   V                              %
%                             Y Y   U   U  V   V                              %
%                              Y    U   U  V   V                              %
%                              Y    U   U   V V                               %
%                              Y     UUU     V                                %
%                                                                             %
%                                                                             %
%            Read/Write Raw CCIR 601 4:1:1 or 4:2:2 Image Format              %
%                                                                             %
%                              Software Design                                %
%                                   Cristy                                    %
%                                 July 1992                                   %
%                                                                             %
%                                                                             %
%  Copyright @ 1999 ImageMagick Studio LLC, a non-profit organization         %
%  dedicated to making software imaging solutions freely available.           %
%                                                                             %
%  You may not use this file except in compliance with the License.  You may  %
%  obtain a copy of the License at                                            %
%                                                                             %
%    https://imagemagick.org/license/                                         %
%                                                                             %
%  Unless required by applicable law or agreed to in writing, software        %
%  distributed under the License is distributed on an "AS IS" BASIS,          %
%  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.   %
%  See the License for the specific language governing permissions and        %
%  limitations under the License.                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%
*/

/*
  Include declarations.
*/
#include "MagickCore/studio.h"
#include "MagickCore/blob.h"
#include "MagickCore/blob-private.h"
#include "MagickCore/cache.h"
#include "MagickCore/colorspace.h"
#include "MagickCore/constitute.h"
#include "MagickCore/exception.h"
#include "MagickCore/exception-private.h"
#include "MagickCore/geometry.h"
#include "MagickCore/image.h"
#include "MagickCore/image-private.h"
#include "MagickCore/list.h"
#include "MagickCore/magick.h"
#include "MagickCore/memory_.h"
#include "MagickCore/monitor.h"
#include "MagickCore/monitor-private.h"
#include "MagickCore/pixel-accessor.h"
#include "MagickCore/resize.h"
#include "MagickCore/quantum-private.h"
#include "MagickCore/static.h"
#include "MagickCore/string_.h"
#include "MagickCore/module.h"
#include "MagickCore/utility.h"

/*
  Forward declarations.
*/
static MagickBooleanType
  WriteYUVImage(const ImageInfo *,Image *,ExceptionInfo *);

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   R e a d Y U V I m a g e                                                   %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  ReadYUVImage() reads an image with digital YUV (CCIR 601 4:1:1, plane
%  or partition interlaced, or 4:2:2 plane, partition interlaced or
%  noninterlaced) bytes and returns it.  It allocates the memory necessary
%  for the new Image structure and returns a pointer to the new image.
%
%  The format of the ReadYUVImage method is:
%
%      Image *ReadYUVImage(const ImageInfo *image_info,ExceptionInfo *exception)
%
%  A description of each parameter follows:
%
%    o image_info: the image info.
%
%    o exception: return any errors or warnings in this structure.
%
*/
static Image *ReadYUVImage(const ImageInfo *image_info,ExceptionInfo *exception)
{
  Image
    *chroma_image,
    *image,
    *resize_image;

  InterlaceType
    interlace;

  MagickBooleanType
    status;

  ssize_t
    x;

  Quantum
    *q;

  unsigned char
    *p;

  ssize_t
    count,
    horizontal_factor,
    vertical_factor,
    y;

  size_t
    extent,
    length,
    quantum;

  unsigned char
    *scanline;

  /*
    Allocate image structure.
  */
  assert(image_info != (const ImageInfo *) NULL);
  assert(image_info->signature == MagickCoreSignature);
  assert(exception != (ExceptionInfo *) NULL);
  assert(exception->signature == MagickCoreSignature);
  if (IsEventLogging() != MagickFalse)
    (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",
      image_info->filename);
  image=AcquireImage(image_info,exception);
  if ((image->columns == 0) || (image->rows == 0))
    ThrowReaderException(OptionError,"MustSpecifyImageSize");
  status=SetImageExtent(image,image->columns,image->rows,exception);
  if (status == MagickFalse)
    return(DestroyImageList(image));
  quantum=(size_t) (image->depth <= 8 ? 1 : 2);
  interlace=image_info->interlace;
  horizontal_factor=2;
  vertical_factor=2;
  if (image_info->sampling_factor != (char *) NULL)
    {
      GeometryInfo
        geometry_info;

      MagickStatusType
        flags;

      flags=ParseGeometry(image_info->sampling_factor,&geometry_info);
      if ((flags & RhoValue) != 0)
        horizontal_factor=(ssize_t) geometry_info.rho;
      vertical_factor=horizontal_factor;
      if ((flags & SigmaValue) != 0)
        vertical_factor=(ssize_t) geometry_info.sigma;
      if (((horizontal_factor != 1) && (horizontal_factor != 2)) ||
          ((vertical_factor != 1) && (vertical_factor != 2)))
        ThrowReaderException(CorruptImageError,"UnexpectedSamplingFactor");
    }
  if ((interlace == UndefinedInterlace) ||
      ((interlace == NoInterlace) && (vertical_factor == 2)))
    {
      interlace=NoInterlace;    /* CCIR 4:2:2 */
      if (vertical_factor == 2)
        interlace=PlaneInterlace; /* CCIR 4:1:1 */
    }
  if (interlace != PartitionInterlace)
    {
      /*
        Open image file.
      */
      status=OpenBlob(image_info,image,ReadBinaryBlobMode,exception);
      if (status == MagickFalse)
        {
          image=DestroyImageList(image);
          return((Image *) NULL);
        }
      if (DiscardBlobBytes(image,(MagickSizeType) image->offset) == MagickFalse)
        ThrowFileException(exception,CorruptImageError,"UnexpectedEndOfFile",
          image->filename);
    }
  /*
    Allocate memory for a scanline.
  */
  if (interlace == NoInterlace)
    scanline=(unsigned char *) AcquireQuantumMemory((size_t) (2UL*
      image->columns+2UL),(size_t) quantum*sizeof(*scanline));
  else
    scanline=(unsigned char *) AcquireQuantumMemory(image->columns,
      (size_t) quantum*sizeof(*scanline));
  if (scanline == (unsigned char *) NULL)
    ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");
  status=MagickTrue;
  do
  {
    chroma_image=CloneImage(image,(size_t) ((ssize_t) image->columns+
      (ssize_t) horizontal_factor-1)/(size_t) horizontal_factor,(size_t)
      (image->rows+(size_t) vertical_factor-1)/
      (size_t) vertical_factor,MagickTrue,exception);
    if (chroma_image == (Image *) NULL)
      {
        scanline=(unsigned char *) RelinquishMagickMemory(scanline); 
        ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");
      }
    /*
      Convert raster image to pixel packets.
    */
    if ((image_info->ping != MagickFalse) && (image_info->number_scenes != 0))
      if (image->scene >= (image_info->scene+image_info->number_scenes-1))
        break;
    status=SetImageExtent(image,image->columns,image->rows,exception);
    if (status == MagickFalse)
      break;
    if (interlace == PartitionInterlace)
      {
        AppendImageFormat("Y",image->filename);
        status=OpenBlob(image_info,image,ReadBinaryBlobMode,exception);
        if (status == MagickFalse)
          {
            scanline=(unsigned char *) RelinquishMagickMemory(scanline); 
            image=DestroyImageList(image);
            return((Image *) NULL);
          }
      }
    for (y=0; y < (ssize_t) image->rows; y++)
    {
      Quantum
        *chroma_pixels;

      if (interlace == NoInterlace)
        {
          if ((y > 0) || (GetPreviousImageInList(image) == (Image *) NULL))
            {
              length=2*quantum*image->columns;
              count=ReadBlob(image,length,scanline);
              if (count != (ssize_t) length)
                {
                  status=MagickFalse;
                  ThrowFileException(exception,CorruptImageError,
                    "UnexpectedEndOfFile",image->filename);
                  break;
                }
            }
          p=scanline;
          q=QueueAuthenticPixels(image,0,y,image->columns,1,exception);
          if (q == (Quantum *) NULL)
            break;
          chroma_pixels=QueueAuthenticPixels(chroma_image,0,y,
            chroma_image->columns,1,exception);
          if (chroma_pixels == (Quantum *) NULL)
            break;
          for (x=0; x < (ssize_t) (image->columns-1); x+=2)
          {
            SetPixelRed(chroma_image,0,chroma_pixels);
            if (quantum == 1)
              SetPixelGreen(chroma_image,ScaleCharToQuantum(*p++),
                chroma_pixels);
            else
              {
                SetPixelGreen(chroma_image,ScaleShortToQuantum(((*p) << 8) |
                  *(p+1)),chroma_pixels);
                p+=(ptrdiff_t) 2;
              }
            if (quantum == 1)
              SetPixelRed(image,ScaleCharToQuantum(*p++),q);
            else
              {
                SetPixelRed(image,ScaleShortToQuantum(((*p) << 8) | *(p+1)),q);
                p+=(ptrdiff_t) 2;
              }
            SetPixelGreen(image,0,q);
            SetPixelBlue(image,0,q);
            q+=(ptrdiff_t) GetPixelChannels(image);
            SetPixelGreen(image,0,q);
            SetPixelBlue(image,0,q);
            if (quantum == 1)
              SetPixelBlue(chroma_image,ScaleCharToQuantum(*p++),chroma_pixels);
            else
              {
                SetPixelBlue(chroma_image,ScaleShortToQuantum(((*p) << 8) |
                  *(p+1)),chroma_pixels);
                p+=(ptrdiff_t) 2;
              }
            if (quantum == 1)
              SetPixelRed(image,ScaleCharToQuantum(*p++),q);
            else
              {
                SetPixelRed(image,ScaleShortToQuantum(((*p) << 8) | *(p+1)),q);
                p+=(ptrdiff_t) 2;
              }
            chroma_pixels+=(ptrdiff_t) GetPixelChannels(chroma_image);
            q+=(ptrdiff_t) GetPixelChannels(image);
          }
        }
      else
        {
          if ((y > 0) || (GetPreviousImageInList(image) == (Image *) NULL))
            {
              length=quantum*image->columns;
              count=ReadBlob(image,length,scanline);
              if (count != (ssize_t) length)
                {
                  status=MagickFalse;
                  ThrowFileException(exception,CorruptImageError,
                    "UnexpectedEndOfFile",image->filename);
                  break;
                }
            }
          p=scanline;
          q=QueueAuthenticPixels(image,0,y,image->columns,1,exception);
          if (q == (Quantum *) NULL)
            break;
          for (x=0; x < (ssize_t) image->columns; x++)
          {
            if (quantum == 1)
              SetPixelRed(image,ScaleCharToQuantum(*p++),q);
            else
              {
                SetPixelRed(image,ScaleShortToQuantum(((*p) << 8) | *(p+1)),q);
                p+=(ptrdiff_t) 2;
              }
            SetPixelGreen(image,0,q);
            SetPixelBlue(image,0,q);
            q+=(ptrdiff_t) GetPixelChannels(image);
          }
        }
      if (SyncAuthenticPixels(image,exception) == MagickFalse)
        break;
      if (interlace == NoInterlace)
        if (SyncAuthenticPixels(chroma_image,exception) == MagickFalse)
          break;
      if (image->previous == (Image *) NULL)
        {
          status=SetImageProgress(image,LoadImageTag,(MagickOffsetType) y,
            image->rows);
          if (status == MagickFalse)
            break;
        }
    }
    if (interlace == PartitionInterlace)
      {
        if (CloseBlob(image) == MagickFalse)
          break;
        AppendImageFormat("U",image->filename);
        status=OpenBlob(image_info,image,ReadBinaryBlobMode,exception);
        if (status == MagickFalse)
          {
            scanline=(unsigned char *) RelinquishMagickMemory(scanline); 
            image=DestroyImageList(image);
            return((Image *) NULL);
          }
      }
    if (interlace != NoInterlace)
      {
        for (y=0; y < (ssize_t) chroma_image->rows; y++)
        {
          length=quantum*chroma_image->columns;
          count=ReadBlob(image,length,scanline);
          if (count != (ssize_t) length)
            {
              status=MagickFalse;
              ThrowFileException(exception,CorruptImageError,
                "UnexpectedEndOfFile",image->filename);
              break;
            }
          p=scanline;
          q=QueueAuthenticPixels(chroma_image,0,y,chroma_image->columns,1,
            exception);
          if (q == (Quantum *) NULL)
            break;
          for (x=0; x < (ssize_t) chroma_image->columns; x++)
          {
            SetPixelRed(chroma_image,0,q);
            if (quantum == 1)
              SetPixelGreen(chroma_image,ScaleCharToQuantum(*p++),q);
            else
              {
                SetPixelGreen(chroma_image,ScaleShortToQuantum(((*p) << 8) |
                  *(p+1)),q);
                p+=(ptrdiff_t) 2;
              }
            SetPixelBlue(chroma_image,0,q);
            q+=(ptrdiff_t) GetPixelChannels(chroma_image);
          }
          if (SyncAuthenticPixels(chroma_image,exception) == MagickFalse)
            break;
        }
      if (interlace == PartitionInterlace)
        {
          if (CloseBlob(image) == MagickFalse)
            break;
          AppendImageFormat("V",image->filename);
          status=OpenBlob(image_info,image,ReadBinaryBlobMode,exception);
          if (status == MagickFalse)
            {
              scanline=(unsigned char *) RelinquishMagickMemory(scanline); 
              image=DestroyImageList(image);
              return((Image *) NULL);
            }
        }
      for (y=0; y < (ssize_t) chroma_image->rows; y++)
      {
        length=quantum*chroma_image->columns;
        count=ReadBlob(image,length,scanline);
        if (count != (ssize_t) length)
          {
            status=MagickFalse;
            ThrowFileException(exception,CorruptImageError,
              "UnexpectedEndOfFile",image->filename);
            break;
          }
        p=scanline;
        q=GetAuthenticPixels(chroma_image,0,y,chroma_image->columns,1,
          exception);
        if (q == (Quantum *) NULL)
          break;
        for (x=0; x < (ssize_t) chroma_image->columns; x++)
        {
          if (quantum == 1)
            SetPixelBlue(chroma_image,ScaleCharToQuantum(*p++),q);
          else
            {
              SetPixelBlue(chroma_image,ScaleShortToQuantum(((*p) << 8) |
                *(p+1)),q);
              p+=(ptrdiff_t) 2;
            }
          q+=(ptrdiff_t) GetPixelChannels(chroma_image);
        }
        if (SyncAuthenticPixels(chroma_image,exception) == MagickFalse)
          break;
      }
    }
    /*
      Scale image.
    */
    resize_image=ResizeImage(chroma_image,image->columns,image->rows,
      TriangleFilter,exception);
    chroma_image=DestroyImage(chroma_image);
    if (resize_image == (Image *) NULL)
      {
        scanline=(unsigned char *) RelinquishMagickMemory(scanline);
        ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");
      }
    for (y=0; y < (ssize_t) image->rows; y++)
    {
      const Quantum
        *chroma_pixels;

      q=GetAuthenticPixels(image,0,y,image->columns,1,exception);
      chroma_pixels=GetVirtualPixels(resize_image,0,y,resize_image->columns,1,
        exception);
      if ((q == (Quantum *) NULL) ||
          (chroma_pixels == (const Quantum *) NULL))
        break;
      for (x=0; x < (ssize_t) image->columns; x++)
      {
        SetPixelGreen(image,GetPixelGreen(resize_image,chroma_pixels),q);
        SetPixelBlue(image,GetPixelBlue(resize_image,chroma_pixels),q);
        chroma_pixels+=(ptrdiff_t) GetPixelChannels(resize_image);
        q+=(ptrdiff_t) GetPixelChannels(image);
      }
      if (SyncAuthenticPixels(image,exception) == MagickFalse)
        break;
    }
    resize_image=DestroyImage(resize_image);
    if (SetImageColorspace(image,YCbCrColorspace,exception) == MagickFalse)
      break;
    if (interlace == PartitionInterlace)
      (void) CopyMagickString(image->filename,image_info->filename,
        MagickPathExtent);
    if (EOFBlob(image) != MagickFalse)
      {
        ThrowFileException(exception,CorruptImageError,"UnexpectedEndOfFile",
          image->filename);
        break;
      }
    /*
      Proceed to next image.
    */
    if (image_info->number_scenes != 0)
      if (image->scene >= (image_info->scene+image_info->number_scenes-1))
        break;
    if (interlace == NoInterlace)
      count=ReadBlob(image,(size_t) (2*quantum*image->columns),scanline);
    else
      count=ReadBlob(image,(size_t) quantum*image->columns,scanline);
    if (count != 0)
      {
        /*
          Allocate next image structure.
        */
        AcquireNextImage(image_info,image,exception);
        if (GetNextImageInList(image) == (Image *) NULL)
          {
            status=MagickFalse;
            break;
          }
        image=SyncNextImageInList(image);
        status=SetImageProgress(image,LoadImagesTag,TellBlob(image),
          GetBlobSize(image));
        if (status == MagickFalse)
          break;
      }
  } while (count != 0);
  scanline=(unsigned char *) RelinquishMagickMemory(scanline);
  if (CloseBlob(image) == MagickFalse)
    status=MagickFalse;
  if (status == MagickFalse)
    return(DestroyImageList(image));
  return(GetFirstImageInList(image));
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   R e g i s t e r Y U V I m a g e                                           %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  RegisterYUVImage() adds attributes for the YUV image format to
%  the list of supported formats.  The attributes include the image format
%  tag, a method to read and/or write the format, whether the format
%  supports the saving of more than one frame to the same file or blob,
%  whether the format supports native in-memory I/O, and a brief
%  description of the format.
%
%  The format of the RegisterYUVImage method is:
%
%      size_t RegisterYUVImage(void)
%
*/
ModuleExport size_t RegisterYUVImage(void)
{
  MagickInfo
    *entry;

  entry=AcquireMagickInfo("YUV","YUV","CCIR 601 4:1:1 or 4:2:2");
  entry->decoder=(DecodeImageHandler *) ReadYUVImage;
  entry->encoder=(EncodeImageHandler *) WriteYUVImage;
  entry->flags^=CoderAdjoinFlag;
  entry->flags|=CoderRawSupportFlag;
  (void) RegisterMagickInfo(entry);
  return(MagickImageCoderSignature);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   U n r e g i s t e r Y U V I m a g e                                       %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  UnregisterYUVImage() removes format registrations made by the
%  YUV module from the list of supported formats.
%
%  The format of the UnregisterYUVImage method is:
%
%      UnregisterYUVImage(void)
%
*/
ModuleExport void UnregisterYUVImage(void)
{
  (void) UnregisterMagickInfo("YUV");
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   W r i t e Y U V I m a g e                                                 %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  WriteYUVImage() writes an image to a file in the digital YUV
%  (CCIR 601 4:1:1, plane or partition interlaced, or 4:2:2 plane, partition
%  interlaced or noninterlaced) bytes and returns it.
%
%  The format of the WriteYUVImage method is:
%
%      MagickBooleanType WriteYUVImage(const ImageInfo *image_info,
%        Image *image,ExceptionInfo *exception)
%
%  A description of each parameter follows.
%
%    o image_info: the image info.
%
%    o image:  The image.
%
%    o exception: return any errors or warnings in this structure.
%
*/
static MagickBooleanType WriteYUVImage(const ImageInfo *image_info,Image *image,
  ExceptionInfo *exception)
{
  Image
    *chroma_image,
    *yuv_image;

  InterlaceType
    interlace;

  MagickBooleanType
    status;

  MagickOffsetType
    scene;

  const Quantum
    *p,
    *s;

  ssize_t
    x;

  size_t
    height,
    number_scenes,
    quantum,
    width;

  ssize_t
    horizontal_factor,
    vertical_factor,
    y;

  assert(image_info != (const ImageInfo *) NULL);
  assert(image_info->signature == MagickCoreSignature);
  assert(image != (Image *) NULL);
  assert(image->signature == MagickCoreSignature);
  if (IsEventLogging() != MagickFalse)
    (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
  quantum=(size_t) (image->depth <= 8 ? 1 : 2);
  interlace=image->interlace;
  horizontal_factor=2;
  vertical_factor=2;
  if (image_info->sampling_factor != (char *) NULL)
    {
      GeometryInfo
        geometry_info;

      MagickStatusType
        flags;

      flags=ParseGeometry(image_info->sampling_factor,&geometry_info);
      if ((flags & RhoValue) != 0)
        horizontal_factor=(ssize_t) geometry_info.rho;
      vertical_factor=horizontal_factor;
      if ((flags & SigmaValue) != 0)
        vertical_factor=(ssize_t) geometry_info.sigma;
      if (((horizontal_factor != 1) && (horizontal_factor != 2)) ||
          ((vertical_factor != 1) && (vertical_factor != 2)))
        ThrowWriterException(CorruptImageError,"UnexpectedSamplingFactor");
    }
  if ((interlace == UndefinedInterlace) ||
      ((interlace == NoInterlace) && (vertical_factor == 2)))
    {
      interlace=NoInterlace;    /* CCIR 4:2:2 */
      if (vertical_factor == 2)
        interlace=PlaneInterlace; /* CCIR 4:1:1 */
    }
  if (interlace != PartitionInterlace)
    {
      /*
        Open output image file.
      */
      status=OpenBlob(image_info,image,WriteBinaryBlobMode,exception);
      if (status == MagickFalse)
        return(status);
    }
  else
    {
      AppendImageFormat("Y",image->filename);
      status=OpenBlob(image_info,image,WriteBinaryBlobMode,exception);
      if (status == MagickFalse)
        return(status);
    }
  scene=0;
  number_scenes=GetImageListLength(image);
  do
  {
    /*
      Sample image to an even width and height, if necessary.
    */
    image->depth=(size_t) (quantum == 1 ? 8 : 16);
    width=image->columns+(image->columns & (unsigned int) (horizontal_factor
      -1));
    height=image->rows+(image->rows & (unsigned int) (vertical_factor-1));
    yuv_image=ResizeImage(image,width,height,TriangleFilter,exception);
    if (yuv_image == (Image *) NULL)
      {
        (void) CloseBlob(image);
        return(MagickFalse);
      }
    (void) TransformImageColorspace(yuv_image,YCbCrColorspace,exception);
    /*
      Downsample image.
    */
    chroma_image=ResizeImage(image,(size_t) ((ssize_t) width/horizontal_factor),
      (size_t) ((ssize_t) height/vertical_factor),TriangleFilter,exception);
    if (chroma_image == (Image *) NULL)
      {
        (void) CloseBlob(image);
        return(MagickFalse);
      }
    (void) TransformImageColorspace(chroma_image,YCbCrColorspace,exception);
    if (interlace == NoInterlace)
      {
        /*
          Write noninterlaced YUV.
        */
        for (y=0; y < (ssize_t) yuv_image->rows; y++)
        {
          p=GetVirtualPixels(yuv_image,0,y,yuv_image->columns,1,exception);
          if (p == (const Quantum *) NULL)
            break;
          s=GetVirtualPixels(chroma_image,0,y,chroma_image->columns,1,
            exception);
          if (s == (const Quantum *) NULL)
            break;
          for (x=0; x < (ssize_t) (yuv_image->columns-1); x+=2)
          {
            if (quantum == 1)
              {
                (void) WriteBlobByte(image,ScaleQuantumToChar(
                  GetPixelGreen(yuv_image,s)));
                (void) WriteBlobByte(image,ScaleQuantumToChar(
                  GetPixelRed(yuv_image,p)));
                p+=(ptrdiff_t) GetPixelChannels(yuv_image);
                (void) WriteBlobByte(image,ScaleQuantumToChar(
                  GetPixelBlue(yuv_image,s)));
                (void) WriteBlobByte(image,ScaleQuantumToChar(
                  GetPixelRed(yuv_image,p)));
              }
            else
              {
                (void) WriteBlobByte(image,ScaleQuantumToChar(
                  GetPixelGreen(yuv_image,s)));
                (void) WriteBlobShort(image,ScaleQuantumToShort(
                  GetPixelRed(yuv_image,p)));
                p+=(ptrdiff_t) GetPixelChannels(yuv_image);
                (void) WriteBlobByte(image,ScaleQuantumToChar(
                  GetPixelBlue(yuv_image,s)));
                (void) WriteBlobShort(image,ScaleQuantumToShort(
                  GetPixelRed(yuv_image,p)));
              }
            p+=(ptrdiff_t) GetPixelChannels(yuv_image);
            s+=(ptrdiff_t) GetPixelChannels(chroma_image);
          }
          if (image->previous == (Image *) NULL)
            {
              status=SetImageProgress(image,SaveImageTag,(MagickOffsetType) y,
                image->rows);
              if (status == MagickFalse)
                break;
            }
        }
        yuv_image=DestroyImage(yuv_image);
      }
    else
      {
        /*
          Initialize Y channel.
        */
        for (y=0; y < (ssize_t) yuv_image->rows; y++)
        {
          p=GetVirtualPixels(yuv_image,0,y,yuv_image->columns,1,exception);
          if (p == (const Quantum *) NULL)
            break;
          for (x=0; x < (ssize_t) yuv_image->columns; x++)
          {
            if (quantum == 1)
              (void) WriteBlobByte(image,ScaleQuantumToChar(
                GetPixelRed(yuv_image,p)));
            else
              (void) WriteBlobShort(image,ScaleQuantumToShort(
                GetPixelRed(yuv_image,p)));
            p+=(ptrdiff_t) GetPixelChannels(yuv_image);
          }
          if (image->previous == (Image *) NULL)
            {
              status=SetImageProgress(image,SaveImageTag,(MagickOffsetType) y,
                image->rows);
              if (status == MagickFalse)
                break;
            }
        }
        yuv_image=DestroyImage(yuv_image);
        if (image->previous == (Image *) NULL)
          {
            status=SetImageProgress(image,SaveImageTag,1,3);
            if (status == MagickFalse)
              break;
          }
        /*
          Initialize U channel.
        */
        if (interlace == PartitionInterlace)
          {
            if (CloseBlob(image) == MagickFalse)
              break;
            AppendImageFormat("U",image->filename);
            status=OpenBlob(image_info,image,WriteBinaryBlobMode,exception);
            if (status == MagickFalse)
              return(status);
          }
        for (y=0; y < (ssize_t) chroma_image->rows; y++)
        {
          p=GetVirtualPixels(chroma_image,0,y,chroma_image->columns,1,
            exception);
          if (p == (const Quantum *) NULL)
            break;
          for (x=0; x < (ssize_t) chroma_image->columns; x++)
          {
            if (quantum == 1)
              (void) WriteBlobByte(image,ScaleQuantumToChar(
                GetPixelGreen(chroma_image,p)));
            else
              (void) WriteBlobShort(image,ScaleQuantumToShort(
                GetPixelGreen(chroma_image,p)));
            p+=(ptrdiff_t) GetPixelChannels(chroma_image);
          }
        }
        if (image->previous == (Image *) NULL)
          {
            status=SetImageProgress(image,SaveImageTag,2,3);
            if (status == MagickFalse)
              break;
          }
        /*
          Initialize V channel.
        */
        if (interlace == PartitionInterlace)
          {
            if (CloseBlob(image) == MagickFalse)
              break;
            AppendImageFormat("V",image->filename);
            status=OpenBlob(image_info,image,WriteBinaryBlobMode,exception);
            if (status == MagickFalse)
              return(status);
          }
        for (y=0; y < (ssize_t) chroma_image->rows; y++)
        {
          p=GetVirtualPixels(chroma_image,0,y,chroma_image->columns,1,
            exception);
          if (p == (const Quantum *) NULL)
            break;
          for (x=0; x < (ssize_t) chroma_image->columns; x++)
          {
            if (quantum == 1)
              (void) WriteBlobByte(image,ScaleQuantumToChar(
                GetPixelBlue(chroma_image,p)));
            else
              (void) WriteBlobShort(image,ScaleQuantumToShort(
                GetPixelBlue(chroma_image,p)));
            p+=(ptrdiff_t) GetPixelChannels(chroma_image);
          }
        }
        if (image->previous == (Image *) NULL)
          {
            status=SetImageProgress(image,SaveImageTag,2,3);
            if (status == MagickFalse)
              break;
          }
      }
    chroma_image=DestroyImage(chroma_image);
    if (interlace == PartitionInterlace)
      (void) CopyMagickString(image->filename,image_info->filename,
        MagickPathExtent);
    if (GetNextImageInList(image) == (Image *) NULL)
      break;
    image=SyncNextImageInList(image);
    status=SetImageProgress(image,SaveImagesTag,scene++,number_scenes);
    if (status == MagickFalse)
      break;
  } while (image_info->adjoin != MagickFalse);
  if (CloseBlob(image) == MagickFalse)
    status=MagickFalse;
  return(status);
}
