gusucode.com > audiovideo工具箱matlab源码程序 > audiovideo/@VideoWriter/VideoWriter.m
classdef VideoWriter < hgsetget & dynamicprops
%VideoWriter Create a video writer object.
%
% OBJ = VideoWriter(FILENAME) constructs a VideoWriter object to
% write video data to an AVI file that uses Motion JPEG compression.
% FILENAME is a string enclosed in single quotation marks that specifies
% the name of the file to create. If filename does not include the
% extension '.avi', the VideoWriter constructor appends the extension.
%
% OBJ = VideoWriter( FILENAME, PROFILE ) applies a set of properties
% tailored to a specific file format (such as 'Uncompressed AVI') to
% a VideoWriter object. PROFILE is a string enclosed in single
% quotation marks that describes the type of file to create.
% Specifying a profile sets default values for video properties such
% as VideoCompressionMethod. Possible values:
% 'Archival' - Motion JPEG 2000 file with lossless compression
% 'Motion JPEG AVI' - Compressed AVI file using Motion JPEG codec.
% (default)
% 'Motion JPEG 2000' - Compressed Motion JPEG 2000 file
% 'MPEG-4' - Compressed MPEG-4 file with H.264 encoding
% (Windows 7 and Mac OS X 10.7 only)
% 'Uncompressed AVI' - Uncompressed AVI file with RGB24 video.
% 'Indexed AVI' - Uncompressed AVI file with Indexed video.
% 'Grayscale AVI' - Uncompressed AVI file with Grayscale video.
%
% Methods:
% open - Open file for writing video data.
% close - Close file after writing video data.
% writeVideo - Write video data to file.
% getProfiles - List profiles and file format supported by VideoWriter.
%
% Properties:
% ColorChannels - Number of color channels in each output
% video frame.
% Colormap - Numeric matrix having dimensions Px3 that
% contains color information about the video
% file. The colormap can have a maximum of
% 256 entries of type 'uint8' or 'double'.
% The entries of the colormap must integers.
% Each row of Colormap specifies the red,
% green and blue components of a single
% color. The colormap can be set:
% - Explicitly before the call to open OR
% - Using the colormap field of the FRAME
% struct at the time of writing the
% first frame.
% Only applies to objects associated with
% Indexed AVI files. After you call open,
% you cannot change the Colormap value.
% CompressionRatio - Number greater than 1 indicating the
% target ratio between the number of bytes
% in the input image and compressed image.
% Only applies to objects associated with
% Motion JPEG 2000 files. After you call
% open, you cannot change the
% CompressionRatio value.
% Duration - Scalar value specifying the duration of the
% file in seconds.
% FileFormat - String specifying the type of file to write.
% Filename - String specifying the name of the file.
% FrameCount - Number of frames written to the video file.
% FrameRate - Rate of playback for the video in frames per
% second. After you call open, you cannot
% change the FrameRate value.
% Height - Height of each video frame in pixels.
% The writeVideo method sets values for Height
% and Width based on the dimensions of the
% first frame.
% LosslessCompression - Boolean value indicating whether lossy or
% lossless compression is to be used. If
% true, any specified value for the
% CompressionRatio property is ignored. Only
% applies to objects associated with Motion
% JPEG 2000 files. After you call open, you
% cannot change the LosslessCompression value.
% MJ2BitDepth - Number of least significant bits in the
% input image data, from 1 to 16. Only
% applies to objects associated with Motion
% JPEG 2000 files.
% Path - String specifying the fully qualified file
% path.
% Quality - Integer from 0 through 100. Only applies to
% objects associated with the Motion JPEG
% AVI and MPEG-4 profiles. Higher quality
% numbers result in higher video quality and
% larger file sizes. Lower quality numbers
% result in lower video quality and smaller
% file sizes. After you call open, you cannot
% change the Quality value.
% VideoBitsPerPixel - Number of bits per pixel in each output
% video frame.
% VideoCompressionMethod - String indicating the type of video
% compression.
% VideoFormat - String indicating the MATLAB representation
% of the video format.
% Width - Width of each video frame in pixels.
% The writeVideo method sets values for Height
% and Width based on the dimensions of the
% first frame.
%
% Example:
%
% % Prepare the new file.
% vidObj = VideoWriter('peaks.avi');
% open(vidObj);
%
% % Create an animation.
% Z = peaks; surf(Z);
% axis tight
% set(gca,'nextplot','replacechildren');
%
% for k = 1:20
% surf(sin(2*pi*k/20)*Z,Z)
%
% % Write each frame to the file.
% currFrame = getframe;
% writeVideo(vidObj,currFrame);
% end
%
% % Close the file.
% close(vidObj);
%
% See also VideoWriter/open, VideoWriter/close,
% VideoWriter/writeVideo, VideoWriter/getProfiles.
% Authors: NH, DT
% Copyright 2009-2014 The MathWorks, Inc.
properties (Dependent, Transient, SetAccess=private)
Duration = 0; %The total duration of the file, in seconds.
end
properties(SetAccess=private)
Filename %The name of the file to be written.
Path %The path to the file to be written.
end
properties(Dependent, SetAccess=private)
FileFormat %The format of the file to be written.
end
properties(SetAccess=private, Hidden, Transient)
IsOpen = false; %Indicates if the file is open for writing.
IsFilenameValidated = false; % Indicates if the file name was validated. This is done for performance reasons.
end
properties(Access=private)
Profile % The internal profile object.
AllowedDataTypes % Not used. Keep for backwards compatibility.
InternalFramesWritten % Used to determine if we should warn on close since FrameCount is updated via a callback.
end
methods
function obj = VideoWriter(filename, profile)
import audiovideo.internal.writer.profile.ProfileFactory;
if nargin < 1
error(message('MATLAB:audiovideo:VideoWriter:noFile'));
elseif nargin < 2
profile = 'Default';
elseif nargin == 2
if ~ischar(profile)
error(message('MATLAB:audiovideo:VideoWriter:invalidProfile'));
end
try
ProfileFactory.checkIsKnownProfile(profile);
catch err
throw(err);
end
else
narginchk(1,2);
end
try
fullFileName = VideoWriter.generateFullOutputFileName(filename, profile);
catch err
throwAsCaller(err);
end
try
obj.Profile = ProfileFactory.createProfile(profile, fullFileName);
catch err
throw(err);
end
% init file properties
[pathstr, file, ext] = fileparts(fullFileName);
obj.Filename = [file ext];
obj.Path = pathstr;
obj.IsFilenameValidated = true;
obj.initDynamicProperties();
end
function delete(obj)
%DELETE Delete a VideoWriter object.
% DELETE does not need to called directly, as it is called when
% the VideoWriter object is cleared. When DELETE is called, the
% object is closed and the file is no longer writable.
close(obj)
end
function open(obj)
%OPEN Open a VideoWriter object for writing.
% OPEN(OBJ) must be called before calling the writeVideo
% method. After you call OPEN, all properties of the
% VideoWriter object become read only.
%
% See also VideoWriter/writeVideo, VideoWriter/close.
if length(obj) > 1
error(message('MATLAB:audiovideo:VideoWriter:nonScalar'));
end
if obj.IsOpen
% If open is called multiple times, there should be no
% effect.
return;
end
% If the output file location was modified on the system after
% the object was saved, the loaded object will no longer point
% to a valid location. The check is being added in open() as
% well to guard against this.
try
% If the file name validation has already been performed,
% no need to carry it out again.
if ~obj.IsFilenameValidated
fileName = fullfile(obj.Path, obj.Filename);
VideoWriter.generateFullOutputFileName(fileName, obj.Profile.Name);
obj.IsFilenameValidated = true;
end
obj.Profile.open();
catch err
throwAsCaller(err);
end
obj.InternalFramesWritten = 0;
obj.IsOpen = true;
end
function close(obj)
% CLOSE Finish writing and close video file.
%
% CLOSE(OBJ) closes the file associated with video
% writer object OBJ.
%
% See also VideoWriter/open, VideoWriter/writeVideo.
for ii = 1:length(obj)
if ~obj(ii).IsOpen
continue;
end
try
obj(ii).Profile.close();
catch err
% Don't want to error on close, but don't just swallow
% the message.
warning(err.identifier, err.message);
end
if obj(ii).InternalFramesWritten == 0
warning(message('MATLAB:audiovideo:VideoWriter:noFramesWritten'));
end
obj(ii).IsOpen = false;
obj(ii).IsFilenameValidated = false;
end
end
function writeVideo(obj,inputFrames)
% writeVideo write video data to a file
%
% writeVideo(OBJ,FRAME) writes a FRAME to the video file
% associated with OBJ. FRAME is a structure typically
% returned by the GETFRAME function that contains two fields:
% cdata and colormap. The height and width must be consistent
% for all frames within a file. The profile determines how
% the writeVideo method uses the FRAME as described below:
% Two-Dimensional cdata (height-by-width)
% Profile Name Action
% Indexed AVI, Grayscale AVI Use frame as provided.
% All other profiles Construct RGB image frames
% using the colormap field
%
% Three-Dimensional cdata (height-by-width-by-3)
% Profile Name Action
% Indexed AVI, Grayscale AVI Error
% All other profiles Colormap field ignored.
% Construct RGB image frames
% using the cdata field
%
% writeVideo(OBJ,MOV) writes a MATLAB movie MOV to a
% video file. MOV is an array of FRAME structures, each of
% which contains fields cdata and colormap.
%
% writeVideo(OBJ,IMAGE) writes data from IMAGE to a
% video file. IMAGE is an array of single, double, or uint8
% values representing grayscale or RGB color images. The
% height and width must be consistent for all frames within
% a file. The profile determines how the writeVideo method
% use the IMAGE as described below:
% Two-Dimensional image (height-by-width)
% Profile Name Action
% Indexed AVI, Grayscale AVI Use image as provided
% Motion JPEG 2000 (1-channel) Use image as provided
% All other profiles Construct RGB image frame
%
% Three-Dimensional image (height-by-width-by-3)
% Profile Name Action
% Indexed AVI, Grayscale AVI Error
% Motion JPEG 2000 (1-channel) Error
% All other profiles Use image as provided
%
% Data of type single or double must be in the range [0,1]
% except when writing Indexed AVI files.
%
% writeVideo(OBJ,IMAGES) writes a sequence of color images to
% a video file. IMAGES is a four-dimensional array of
% grayscale (height-by-width-by-1-by-frames) or RGB
% (height-by-width-by-3-by-frames) images.
%
% You must call OPEN(OBJ) before calling writeVideo.
%
% See also VideoWriter/open, VideoWriter/close.
narginchk(2,2)
if length(obj) > 1
error(message('MATLAB:audiovideo:VideoWriter:nonScalar'));
end
if ~obj.IsOpen
error(message('MATLAB:audiovideo:VideoWriter:notOpen'));
end
if (obj.FrameCount > 0)
[frameHeight, frameWidth] = VideoWriter.getFrameSize(inputFrames);
if (~obj.Profile.validateFrameSize(frameWidth, frameHeight))
error(message('MATLAB:audiovideo:VideoWriter:invalidDimensions', obj.Width, obj.Height));
end
end
try
% Write image frames to the file.
% Convert the input frames into a format that is required
% for writing to the file. This involves both colorspace
% and datatype conversion
outputFrames = VideoWriter.convertToOutput(inputFrames, ...
obj.Profile.getPreferredColorSpace(), ...
obj.Profile.PreferredDataType);
numFrames = VideoWriter.computeNumFrames(outputFrames);
for ii = 1:numFrames
if isstruct(outputFrames)
obj.Profile.writeVideoFrame(outputFrames(ii));
else
obj.Profile.writeVideoFrame(outputFrames(:,:,:,ii))
end
obj.InternalFramesWritten = obj.InternalFramesWritten + 1;
end
catch err
throw(err)
end
end
function value = get.Duration(obj)
value = obj.FrameCount * 1/obj.FrameRate;
end
function set.Duration(~, ~)
error(message('MATLAB:audiovideo:VideoWriter:setDuration'));
end
function value = get.FileFormat(obj)
value = obj.Profile.FileFormat;
end
function set.FileFormat(~, ~)
error(message('MATLAB:audiovideo:VideoWriter:setFileFormat'));
end
end
methods (Hidden)
function setBufferSize(obj, size)
% Sets the buffer size on the plugin. This method can not be
% called while the VideoWriter object is open and should not be
% called by users.
obj.Profile.setBufferSize(size)
end
function [pluginPath] = getProfilePluginPath(obj)
% Return the base path of the profile's underlying asyncio
% plugin, converter, and filter. Used for clients
% (like system objects or Simulink blocks) who wish to
% create an asyncio channel themselves.
pluginPath = obj.Profile.getPluginPath();
end
function [pluginName, converterName, options] = getProfilePluginInitOptions(obj)
% Get the Profiles underlying asyncio plugin, converter, and
% initialization options. Used for clients
% (like system objects or Simulink blocks) who wish to
% create an asyncio channel themselves.
[pluginName, converterName, ~, options] = obj.Profile.getPluginInitOptions();
end
function [filterName, options] = getProfileFilterInitOptions(obj)
% Get the Profile's underlying asyncio filter and initialization
% options. Used for clients (like system objects or Simulink
% blocks) who wish to create an asyncio channel themselves.
[filterName, options] = obj.Profile.getPluginFilterInitOptions();
end
function [options] = getProfileOpenOptions(obj)
% Get the Profile's underlying asyncio filter and initialization
% options. Used for clients (like system objects or Simulink
% blocks) who wish to create an asyncio channel themselves.
options = obj.Profile.getPluginOpenOptions();
end
function disp(obj)
if (length(obj) > 1 || isempty(obj))
% defer to built in disp() for arrays or emptys
disp@hgsetget(obj);
else
% Handles a Scalar VideoWriter object
% Prints package name hyperlink
fprintf(internal.DisplayFormatter.getDisplayHeader(obj));
% Prints properties in categories
printProperties(obj);
% Prints Methods hyperlink line
fprintf(internal.DisplayFormatter.getDisplayFooter(obj));
end
end
function getdisp(obj)
if (length(obj) > 1)
% Defer to built in
getdisp@hgsetget(obj);
return;
end
% One line break after the command on the command line
fprintf('\n');
% Prints properties in categories
printProperties(obj);
end
function c = horzcat(varargin)
%HORZCAT Horizontal concatenation of VideoWriter objects.
% Horizontal concatenation of VideoWriter objects is not
% allowed.
%
% See also VideoWriter/vertcat, VideoWriter/cat.
if (nargin == 1)
c = varargin{1};
else
error(message('MATLAB:audiovideo:VideoWriter:noconcatenation'));
end
end
function c = vertcat(varargin)
%VERTCAT Vertical concatenation of VideoWriter objects.
%
% Vertical concatenation of VideoWriter objects is not
% allowed.
%
% See also VideoWriter/horzcat, VideoWriter/cat.
if (nargin == 1)
c = varargin{1};
else
error(message('MATLAB:audiovideo:VideoWriter:noconcatenation'));
end
end
function c = cat(varargin)
%CAT Concatenation of VideoWriter objects.
%
% Concatenation of VideoWriter objects is not allowed.
%
% See also VideoWriter/horzcat, VideoWriter/vertcat.
if (nargin > 2)
error(message('MATLAB:audiovideo:VideoWriter:noconcatenation'));
else
c = varargin{2};
end
end
% Hidden methods from the hgsetget super class.
function res = eq(obj, varargin)
res = eq@hgsetget(obj, varargin{:});
end
function res = fieldnames(obj, varargin)
res = fieldnames@hgsetget(obj,varargin{:});
end
function res = ge(obj, varargin)
res = ge@hgsetget(obj, varargin{:});
end
function res = gt(obj, varargin)
res = gt@hgsetget(obj, varargin{:});
end
function res = le(obj, varargin)
res = le@hgsetget(obj, varargin{:});
end
function res = lt(obj, varargin)
res = lt@hgsetget(obj, varargin{:});
end
function res = ne(obj, varargin)
res = ne@hgsetget(obj, varargin{:});
end
function res = findobj(obj, varargin)
res = findobj@hgsetget(obj, varargin{:});
end
function res = findprop(obj, varargin)
res = findprop@hgsetget(obj, varargin{:});
end
function res = addlistener(obj, varargin)
res = addlistener@hgsetget(obj, varargin{:});
end
function res = notify(obj, varargin)
res = notify@hgsetget(obj, varargin{:});
end
% Hidden methods from the dynamic proper superclass
function res = addprop(obj, varargin)
res = addprop@dynamicprops(obj, varargin{:});
end
end
methods (Access=private)
function initDynamicProperties( obj )
% Create dynamic properties from our Profile.VideoProperties
% object
vidPropsMeta = metaclass(obj.Profile.VideoProperties);
cellfun(@obj.addDynamicProp, vidPropsMeta.Properties);
end
function addDynamicProp(obj, metaprop)
% Add given a meta-property, expose the property as a dependent
% property in this class with custom get/set methods where
% appropriate.
if ~strcmpi(metaprop.GetAccess,'public')
return;
end
prop = addprop(obj, metaprop.Name);
prop.Dependent = true;
prop.Transient = true;
prop.GetMethod = @(obj) obj.Profile.VideoProperties.(metaprop.Name);
if strcmpi(metaprop.SetAccess,'public')
prop.SetMethod = @(obj, value) obj.setDynamicProp(metaprop.Name, value);
else
prop.SetAccess = 'private';
end
end
function setDynamicProp(obj, propertyName, value)
obj.Profile.VideoProperties.(propertyName) = value;
end
function printProperties(obj)
% Prints VideoWriter properties
fprintf(...
internal.DisplayFormatter.getDisplayCategories(obj,...
getString(message('MATLAB:audiovideo:VideoWriter:GeneralProperties')), ...
{'Filename', 'Path', 'FileFormat', 'Duration'}, ...
getString(message('MATLAB:audiovideo:VideoWriter:VideoProperties')), ...
obj.Profile.VideoProperties.getPropertyNamesForDisp...
));
end
end
methods(Static)
function profiles = getProfiles()
%getProfiles List profiles supported by VideoWriter.
%
% PROFILES = VideoWriter.getProfiles() returns an array of
% audiovideo.writer.ProfileInfo objects that indicate the
% types of files VideoWriter can create.
%
% audiovideo.writer.ProfileInfo objects contain the following
% read-only properties:
% Name - Name of the profile
% Description - Description of the intent of
% the profile.
% FileExtensions - Cell array of strings containing
% file extensions supported by the
% file format.
% VideoCompressionMethod - String indicating the type of
% video compression.
% VideoFormat - String indicating the MATLAB
% representation of the video
% format.
% VideoBitsPerPixel - Number of bits per pixel in each
% output video frame.
% Quality - Number from 0 through 100. Higher
% values correspond to higher
% quality video and larger files.
% Only applies to objects
% associated with the Motion
% JPEG AVI profile.
% FrameRate - Rate of playback for the video in
% frames per second.
% ColorChannels - Number of color channels in each
% output video frame.
%
% See also VideoWriter
import audiovideo.internal.writer.profile.ProfileFactory;
profiles = ProfileFactory.getKnownProfileInfos();
end
end
methods(Static, Hidden)
%------------------------------------------------------------------
% Persistence
%------------------------------------------------------------------
function obj = loadobj(obj)
% Object is already created, initialize any dynamic properties.
% All of VideoWriter's Dynamic properties are transient and
% need to be initialized during construction and load.
obj.IsFilenameValidated = false;
obj.initDynamicProperties();
end
function outFrames = convertFrameDataType(outType, inType, frames)
outFrames = double(frames);
largerRange = double(intmax(outType)) - double(intmin(outType)) + 1;
smallerRange = double(intmax(inType)) - double(intmin(inType)) + 1;
mult = largerRange / smallerRange;
b = double(intmin(outType)) - double(intmin(inType)) * mult;
outFrames = outFrames * mult + b;
outFrames = cast(outFrames, outType);
end
end
methods(Static, Access=private)
function verifyNumBands(frames)
% Verify that an image has either 1 or 3 bands.
if isa(frames, 'struct')
return;
end
% Need to get all four dimensions so that they're not all
% collapsed into the last dimension.
[~, ~, bands, ~] = size(frames);
if (bands ~= 1) && (bands ~= 3)
error(message('MATLAB:audiovideo:VideoWriter:badBands'));
end
end
function validateAllowableFrameDataTypes(frames, prefOutputDataType)
if isa(frames, 'struct')
return;
end
dataTypeOfInputData = class(frames);
allowedDataTypes = union(prefOutputDataType, {'single', 'double'});
if any(ismember({'uint16', 'int16'}, prefOutputDataType))
allowedDataTypes = [allowedDataTypes {'uint8', 'int8'}];
end
if ~any(strcmp(dataTypeOfInputData, allowedDataTypes))
allTypes = sprintf('%s, ',allowedDataTypes{:});
allTypes = allTypes(1:end-2);
error(message('MATLAB:audiovideo:VideoWriter:dataType', allTypes));
end
end
function frames = convertToOutput(frames, outputColorSpace, prefOutputDataType)
% Performs colorspace and datatype conversion on the input data
% so that the data is suitable for output.
import audiovideo.internal.writer.profile.OutputColorFormat;
switch (outputColorSpace)
case OutputColorFormat.ANY
if isstruct(frames)
% Frames must always be RGB images or convertible
% to RGB images.
frames = VideoWriter.convertFramesToRGB(frames);
end
case OutputColorFormat.RGB
frames = VideoWriter.convertFramesToRGB(frames);
case OutputColorFormat.MONOCHROME
frames = VideoWriter.convertFramesToMono(frames);
case OutputColorFormat.INDEXED
frames = VideoWriter.convertFramesToIndexed(frames);
frames = VideoWriter.convertToPrefDataTypeForIndexed(frames, prefOutputDataType);
case OutputColorFormat.GRAYSCALE
% No colormap must be specified when writing Grayscale
% AVI files
frames = VideoWriter.convertFramesToIndexed(frames);
if isstruct(frames) && ~all( arrayfun( @(x) isempty(x.colormap), frames) )
error(message('MATLAB:audiovideo:VideoWriter:noColormapForGrayscale'));
end
otherwise
assert(false, 'Unknown ColorFormat for this profile.');
end
% Verify that a valid frame has been provided.
VideoWriter.verifyNumBands(frames);
% Convert the data type to the profile's preferred data type.
% The datatype conversion is to be performed on the image data
% and not on the colormap.
if isstruct(frames)
for cnt = 1:numel(frames)
frames(cnt).cdata = VideoWriter.convertDataType(frames(cnt).cdata, prefOutputDataType);
end
else
frames = VideoWriter.convertDataType(frames, prefOutputDataType);
end
end
function outFrames = convertFramesToRGB(frames)
% Convert frames into an HxWx3xF representation assumed to be
% the RGB color space.
% Are the frames an array?
if ~isstruct(frames)
if (ndims(frames) > 4)
error(message('MATLAB:audiovideo:VideoWriter:badBands'));
end
VideoWriter.verifyNumBands(frames);
% Need to get all four dimensions so that they're not all
% collapsed into the last dimension.
[~, ~, bands, ~] = size(frames);
% If the data is an array, it must be either three banded
% or single banded. Three banded data is assumed to be
% RGB. Single banded data is converted to RGB by
% replicating the data for each band.
if (bands == 3)
outFrames = frames;
return;
elseif (bands == 1)
outFrames = repmat(frames, [1 1 3 1]);
return
end
else
% Data passed in was a struct.
VideoWriter.validateFrameStruct(frames);
sizes = arrayfun(@(x) size(x.cdata), frames, 'UniformOutput', false);
hasColormap = arrayfun(@(x) ~isempty(x.colormap), frames);
if any(hasColormap) && ~all(hasColormap)
error(message('MATLAB:audiovideo:VideoWriter:allColormap'));
end
if all(hasColormap)
% Data here should be HxW or HxWx1 only
if ((length(sizes{1}) ~= 2) && sizes{1}(3) ~= 1)
error(message('MATLAB:audiovideo:VideoWriter:badCData'));
end
outFrames = zeros([sizes{1}, 3, length(frames)]);
for ii = 1:length(frames)
try
outFrames(:,:,:,ii) = ind2rgb(frames(ii).cdata, frames(ii).colormap);
catch err
error(message('MATLAB:audiovideo:VideoWriter:invalidind2rgb'));
end
end
else
% Make sure that all of the cdata elements have the
% same data type.
dataTypes = arrayfun(@(x) class(x.cdata), frames, 'UniformOutput', false);
if ~all(strcmp(dataTypes{1}, dataTypes))
error(message('MATLAB:audiovideo:VideoWriter:inconsistentDataTypes'));
end
% Make sure that all of the cdata fields are three
% banded.
if (numel(sizes{1}) ~= 3)
error(message('MATLAB:audiovideo:VideoWriter:RGBImageInFrame'))
end
outFrames = zeros([sizes{1} length(frames)], class(frames(1).cdata));
for ii = 1:length(frames)
outFrames(:,:,:,ii) = frames(ii).cdata;
end
end
end
end
function frames = convertFramesToMono(frames)
% Convert frames to monochrome. Currently no colorspace
% conversion is done, so this function just validates, and if
% necessary converts, the frames to a HxWx1xF array.
if ~isstruct(frames)
if(ndims(frames) > 4)
error(message('MATLAB:audiovideo:VideoWriter:badBands'));
end
[m, n, bands, numFrames] = size(frames);
if ( (numFrames ~= 1) && (bands ~= 1) )
error(message('MATLAB:audiovideo:VideoWriter:badBands'));
end
frames = reshape(frames, [m n 1 max(bands, numFrames)]);
return;
else
error(message('MATLAB:audiovideo:VideoWriter:framesUnsupported'));
end
end
function frames = convertFramesToIndexed(frames)
% Convert frames to indexed.
if ~isstruct(frames)
[~, ~, bands, ~] = size(frames);
if bands == 3
error(message('MATLAB:audiovideo:VideoWriter:invalidDataDimsGrayscaleIndexed'));
end
frames = VideoWriter.convertFramesToMono(frames);
else
VideoWriter.validateFrameStruct(frames);
sizes = arrayfun(@(x) size(x.cdata), frames, 'UniformOutput', false);
% Data here should be HxW or HxWx1 only
if ((length(sizes{1}) ~= 2) && sizes{1}(3) ~= 1)
error(message('MATLAB:audiovideo:VideoWriter:badCData'));
end
% Make sure that all of the cdata elements have the
% same data type.
dataTypes = arrayfun(@(x) class(x.cdata), frames, 'UniformOutput', false);
if ~all(strcmp(dataTypes{1}, dataTypes))
error(message('MATLAB:audiovideo:VideoWriter:inconsistentDataTypes'));
end
end
end
function outputFrames = convertDataType(inputFrames, prefDataType)
% Convert the frames to the correct data type. Frames that are
% doubles or singles must be in the range [0, 1]. Frames that
% are of an integer type smaller than that requested by the
% profile are upconverted.
% Figure out the allowed data types for the profile and
% determine if the supplied image is of an allowable type.
VideoWriter.validateAllowableFrameDataTypes(inputFrames, prefDataType);
curDataType = class(inputFrames);
% No conversion case.
if ismember(curDataType, prefDataType)
outputFrames = inputFrames;
return;
end
% Validate range for floating point data.
if any(strcmp(curDataType, {'single', 'double'}))
if (min(inputFrames(:)) < 0) || (max(inputFrames(:)) > 1)
error(message('MATLAB:audiovideo:VideoWriter:invalidRange', curDataType));
end
end
if length(prefDataType) ~= 1
error(message('MATLAB:audiovideo:VideoWriter:invalidConversion', curDataType));
end
if any(strcmp(curDataType, {'single', 'double'}))
% Convert single and double frames into the appropriate data
% type.
minval = double(intmin(prefDataType{1}));
maxval = double(intmax(prefDataType{1}));
outputFrames = cast(inputFrames .* (maxval - minval) - minval, prefDataType{1});
return
end
% Otherwise we need to convert from a smaller data type to a
% larger data type.
try
outputFrames = VideoWriter.convertFrameDataType(prefDataType{1}, curDataType, inputFrames);
catch err
error(message('MATLAB:audiovideo:VideoWriter:invalidUpConversion', curDataType, prefDataType{1}));
end
end
function frames = convertToPrefDataTypeForIndexed(frames, prefDataType)
dataTypeConvFcn = str2func(prefDataType{1});
% If the 'cdata' is of type 'double' or 'single', then the
% value 1 points to the first row of the colormap. For uint8,
% the value 0 points to the first row of the colormap.
if isstruct(frames)
arrayfun(@(x) validateattributes(x.cdata, {'uint8', 'single', 'double'}, ...
{'integer', ...
'>=', 0, ...
'<=', 255}), ...
frames);
if ~isa(frames(1).cdata, prefDataType{1})
dataTypeConvFcn = str2func(prefDataType{1});
for cnt = 1:numel(frames)
frames(cnt).cdata = dataTypeConvFcn(frames(cnt).cdata-1);
end
end
else
validateattributes(frames, {'uint8', 'single', 'double'}, ...
{'integer', '>=', 0, '<=', 255});
if ~isa(frames, prefDataType{1})
frames = dataTypeConvFcn(frames-1);
end
end
end
function numFrames = computeNumFrames(frames)
if isstruct(frames)
numFrames = length(frames);
else
numFrames = size(frames, 4);
end
end
function validateFrameStruct(frames)
if ~isa(frames, 'struct')
return;
end
fields = fieldnames(frames);
% Structs must have only cdata and colormap fields.
if ~isequal({'cdata'; 'colormap'}, sort(fields(:)))
error(message('MATLAB:audiovideo:VideoWriter:badStruct'));
end
% Verify that the cdata is actually provided.
dataPresent = arrayfun(@(x) ~isempty(x.cdata), frames);
if ~all(dataPresent)
error(message('MATLAB:audiovideo:VideoWriter:noCData'));
end
% Verify that the sizes of the images are all the same.
sizes = arrayfun(@(x) size(x.cdata), frames, 'UniformOutput', false);
if (length(sizes) > 1) && ~isequal(sizes{:})
error(message('MATLAB:audiovideo:VideoWriter:cdataSize'));
end
end
function [height, width] = getFrameSize(frame)
% Determine the height and width of a frame independent of the
% input format.
if isstruct(frame)
[height, width, ~] = size(frame(1).cdata);
else
[height, width, ~] = size(frame);
end
end
function fullFileName = generateFullOutputFileName(fileName, profile)
% Helper function that validates the output file specified and
% also generates the fully qualified file path
import audiovideo.internal.writer.profile.ProfileFactory;
% The output file name can only be a row of characters.
validateattributes(fileName, {'char'}, {'row', 'nonempty'}, 'VideoWriter');
% Validate that the filename has the correct extension.
try
validExtensions = ProfileFactory.getFileExtensions(profile);
catch err
throw(err);
end
% Verify if the extension specified for the file is valid for
% the profile chosen. If the extension does not match or if no
% extension is provded, append the default extension for the
% profile to the file name.
[~, ~, fileExt] = fileparts(fileName);
newFileName = fileName;
if ~ismember(lower(fileExt), validExtensions)
newFileName = [fileName validExtensions{1}];
end
fileObj = audiovideo.internal.FilePath(newFileName);
% Check if the path specified is valid
if isempty(fileObj.Absolute)
pathStr = fileparts(fileObj.Path);
error(message('MATLAB:audiovideo:VideoWriter:folderNotFound', pathStr));
end
if ~fileObj.Writeable
error(message('MATLAB:audiovideo:VideoWriter:fileNotWritable', fileName));
end
fullFileName = fileObj.Absolute;
end
end
end