如何在MATLAB中创建GUI来播放，暂停，快进和快退视频? [英] How to create a GUI to play, pause, fast forward and rewind video in MATLAB?

问题描述

我是MATLAB的新手.我正在尝试创建一个GUI，以逐帧播放，暂停，快进和倒带avi视频.目前，我可以通过切换按钮播放和暂停视频，但是当我再次按下播放"时，视频将从零帧开始播放.我知道我需要存储下次按下播放时要使用的帧号，但是我不知道该怎么做. 任何帮助将非常感激.我意识到MATLAB中有一个implay选项，但是我还有其他一些要实现的代码已经实现，这就是为什么我要创建自己的GUI的原因.下面是暂停/播放视频的代码.

I am a newbie to MATLAB. I am trying to create a GUI to play, pause, fast forward and rewind an avi video frame by frame. At the moment I can play and pause the video, via a toggle button, but when I press play again the video plays from frame zero. I realise I need to store the frame number to be used the next time I press play but I don't know how to do this. Any help would be much appreciated. I realise there is an implay option in MATLAB but I have some other code to implement which I have already got right and that is why I want to create my own GUI. Below is the code to pause/play the video.

我最近的代码如下，

   function varargout = N_Play_Pause_2(varargin)
% N_PLAY_PAUSE_2 MATLAB code for N_Play_Pause_2.fig
%      N_PLAY_PAUSE_2, by itself, creates a new N_PLAY_PAUSE_2 or raises the existing
%      singleton*.
%
%      H = N_PLAY_PAUSE_2 returns the handle to a new N_PLAY_PAUSE_2 or the handle to
%      the existing singleton*.
%
%      N_PLAY_PAUSE_2('CALLBACK',hObject,eventData,handles,...) calls the local
%      function named CALLBACK in N_PLAY_PAUSE_2.M with the given input arguments.
%
%      N_PLAY_PAUSE_2('Property','Value',...) creates a new N_PLAY_PAUSE_2 or raises the
%      existing singleton*.  Starting from the left, property value pairs are
%      applied to the GUI before N_Play_Pause_2_OpeningFcn gets called.  An
%      unrecognized property name or invalid value makes property application
%      stop.  All inputs are passed to N_Play_Pause_2_OpeningFcn via varargin.
%
%      *See GUI Options on GUIDE's Tools menu.  Choose "GUI allows only one
%      instance to run (singleton)".
%
% See also: GUIDE, GUIDATA, GUIHANDLES

% Edit the above text to modify the response to help N_Play_Pause_2

% Last Modified by GUIDE v2.5 29-Aug-2013 08:39:38

% Begin initialization code - DO NOT EDIT
gui_Singleton = 1;
gui_State = struct('gui_Name',       mfilename, ...
                   'gui_Singleton',  gui_Singleton, ...
                   'gui_OpeningFcn', @N_Play_Pause_2_OpeningFcn, ...
                   'gui_OutputFcn',  @N_Play_Pause_2_OutputFcn, ...
                   'gui_LayoutFcn',  [] , ...
                   'gui_Callback',   []);
if nargin && ischar(varargin{1})
    gui_State.gui_Callback = str2func(varargin{1});
end

if nargout
    [varargout{1:nargout}] = gui_mainfcn(gui_State, varargin{:});
else
    gui_mainfcn(gui_State, varargin{:});
end
% End initialization code - DO NOT EDIT


% --- Executes just before N_Play_Pause_2 is made visible.
function N_Play_Pause_2_OpeningFcn(hObject, eventdata, handles, varargin)
% This function has no output args, see OutputFcn.
% hObject    handle to figure
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
% varargin   command line arguments to N_Play_Pause_2 (see VARARGIN)

% Choose default command line output for N_Play_Pause_2
handles.output = hObject;
handles.VidObj = VideoReader('x05.avi');
handles.nFrames = handles.VidObj.NumberOfFrames;
handles.videoPos = 1; %Current video position. Starts at 1.

% Update handles structure
guidata(hObject, handles);

% UIWAIT makes N_Play_Pause_2 wait for user response (see UIRESUME)
% uiwait(handles.figure1);


% --- Outputs from this function are returned to the command line.
function varargout = N_Play_Pause_2_OutputFcn(hObject, eventdata, handles) 
% varargout  cell array for returning output args (see VARARGOUT);
% hObject    handle to figure
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Get default command line output from handles structure
varargout{1} = handles.output;


% --- Executes on button press in togglebutton1.
function togglebutton1_Callback(hObject, eventdata, handles)
% hObject    handle to togglebutton1 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Hint: get(hObject,'Value') returns toggle state of togglebutton1
while get(hObject,'Value')
    snapshot = read(handles.VidObj,handles.videoPos); % Here we use the stored video position 
     if handles.videoPos >= handles.nFrames % Protect your code not to go be number of frames available
      break;
    end
    handles.videoPos=handles.videoPos+1;     % Increment the stored position
    imshow(snapshot),title(handles.videoPos);
end
guidata(hObject,handles) % Save the modifications done at the handles structure at the figure handle
set(hObject,'Value',false);


% --- Executes on button press in pushbutton1.
function pushbutton1_Callback(hObject, eventdata, handles)
% hObject    handle to pushbutton1 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
if get(hObject,'Value')
    snapshot = read(handles.VidObj,handles.videoPos); % Here we use the stored video position 
    handles.videoPos=handles.videoPos+1;     % Increment the stored position
    imshow(snapshot),title(handles.videoPos);
end
guidata(hObject,handles) % Save the modifications done at the handles structure at the figure handle
set(hObject,'Value',false);


% --- Executes on button press in pushbutton2.
function pushbutton2_Callback(hObject, eventdata, handles)
% hObject    handle to pushbutton2 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
if get(hObject,'Value')
    snapshot = read(handles.VidObj,handles.videoPos); % Here we use the stored video position 
    handles.videoPos=handles.videoPos-1;     % Increment the stored position
    imshow(snapshot),title(handles.videoPos);
end
guidata(hObject,handles) % Save the modifications done at the handles structure at the figure handle
set(hObject,'Value',false);


% --- Executes on button press in pushbutton3.
function pushbutton3_Callback(hObject, eventdata, handles)
% hObject    handle to pushbutton3 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
if get(hObject,'Value')
    snapshot = read(handles.VidObj,handles.videoPos); % Here we use the stored video position 
    handles.videoPos=handles.videoPos+10;     % Increment the stored position
    imshow(snapshot),title(handles.videoPos);
end
guidata(hObject,handles) % Save the modifications done at the handles structure at the figure handle
set(hObject,'Value',false);


% --- Executes on button press in pushbutton4.
function pushbutton4_Callback(hObject, eventdata, handles)
% hObject    handle to pushbutton4 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
if get(hObject,'Value')
    snapshot = read(handles.VidObj,handles.videoPos); % Here we use the stored video position 
    handles.videoPos=handles.videoPos-10;     % Increment the stored position
    imshow(snapshot),title(handles.videoPos);
end
guidata(hObject,handles) % Save the modifications done at the handles structure at the figure handle
set(hObject,'Value',false);

推荐答案

最终解决方案

因此，我还没有看到您更新过代码.查看代码非常容易，显示图像后似乎正在增加，因此，如果按下播放按钮，它将在图像之前显示

Final solution

So, I haven't seen that you updated your code. Seeing your code is quite easier, it seems that you are incrementing after you show your image, so if you push the play button it will show the image before

function varargout = N_Play_Pause2(varargin)
% N_PLAY_PAUSE2 MATLAB code for N_Play_Pause2.fig
%      N_PLAY_PAUSE2, by itself, creates a new N_PLAY_PAUSE2 or raises the existing
%      singleton*.
%
%      H = N_PLAY_PAUSE2 returns the handle to a new N_PLAY_PAUSE2 or the handle to
%      the existing singleton*.
%
%      N_PLAY_PAUSE2('CALLBACK',hObject,eventData,handles,...) calls the local
%      function named CALLBACK in N_PLAY_PAUSE2.M with the given input arguments.
%
%      N_PLAY_PAUSE2('Property','Value',...) creates a new N_PLAY_PAUSE2 or raises the
%      existing singleton*.  Starting from the left, property value pairs are
%      applied to the GUI before N_Play_Pause2_OpeningFcn gets called.  An
%      unrecognized property name or invalid value makes property application
%      stop.  All inputs are passed to N_Play_Pause2_OpeningFcn via varargin.
%
%      *See GUI Options on GUIDE's Tools menu.  Choose "GUI allows only one
%      instance to run (singleton)".
%
% See also: GUIDE, GUIDATA, GUIHANDLES

% Edit the above text to modify the response to help N_Play_Pause2

% Last Modified by GUIDE v2.5 23-Aug-2013 13:50:30

% Begin initialization code - DO NOT EDIT
gui_Singleton = 1;
gui_State = struct('gui_Name',       mfilename, ...
                   'gui_Singleton',  gui_Singleton, ...
                   'gui_OpeningFcn', @N_Play_Pause2_OpeningFcn, ...
                   'gui_OutputFcn',  @N_Play_Pause2_OutputFcn, ...
                   'gui_LayoutFcn',  [] , ...
                   'gui_Callback',   []);
if nargin && ischar(varargin{1})
    gui_State.gui_Callback = str2func(varargin{1});
end

if nargout
    [varargout{1:nargout}] = gui_mainfcn(gui_State, varargin{:});
else
    gui_mainfcn(gui_State, varargin{:});
end
% End initialization code - DO NOT EDIT


% --- Executes just before N_Play_Pause2 is made visible.
function N_Play_Pause2_OpeningFcn(hObject, eventdata, handles, varargin)
% This function has no output args, see OutputFcn.
% hObject    handle to figure
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
% varargin   command line arguments to N_Play_Pause2 (see VARARGIN)

handles.output = hObject;
handles.VidObj = VideoReader('x05.avi');
handles.nFrames = handles.VidObj.NumberOfFrames;
handles.videoPos = 1; % Current video position, starts at first frame.

snapshot = read(handles.VidObj,handles.videoPos); % Here we use the stored video position 
imshow(snapshot),title(handles.videoPos);

% Choose default command line output for N_Play_Pause2
handles.output = hObject;

% Update handles structure
guidata(hObject, handles);

% UIWAIT makes N_Play_Pause2 wait for user response (see UIRESUME)
% uiwait(handles.figure1);


% --- Outputs from this function are returned to the command line.
function varargout = N_Play_Pause2_OutputFcn(hObject, eventdata, handles) 
% varargout  cell array for returning output args (see VARARGOUT);
% hObject    handle to figure
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Get default command line output from handles structure
varargout{1} = handles.output;


% --- Executes on button press in togglebutton1.
function togglebutton1_Callback(hObject, eventdata, handles)
% hObject    handle to togglebutton1 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Hint: get(hObject,'Value') returns toggle state of togglebutton1

while get(hObject,'Value')  && handles.videoPos < handles.nFrames 
    handles.videoPos=handles.videoPos+1;     % Increment the stored position
    snapshot = read(handles.VidObj,handles.videoPos); % Here we use the stored video position 
    imshow(snapshot),title(handles.videoPos);
    end
end
guidata(hObject,handles) % Save the modifications done at the handles structure at the figure handle

% --- Executes on button press in pushbutton1.
function pushbutton1_Callback(hObject, eventdata, handles)
% hObject    handle to pushbutton1 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
if get(hObject,'Value')
    handles.videoPos=handles.videoPos+1;     % Increment the stored position
    snapshot = read(handles.VidObj,handles.videoPos); % Here we use the stored video position 
    imshow(snapshot),title(handles.videoPos);
end
guidata(hObject,handles) % Save the modifications done at the handles structure at the figure handle


% --- Executes on button press in pushbutton2.
function pushbutton2_Callback(hObject, eventdata, handles)
% hObject    handle to pushbutton2 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
if get(hObject,'Value') && handles.videoPos>1
    handles.videoPos=handles.videoPos-1;     % Increment the stored position
    snapshot = read(handles.VidObj,handles.videoPos); % Here we use the stored video position 
    imshow(snapshot),title(handles.videoPos);
end
guidata(hObject,handles) % Save the modifications done at the handles structure at the figure handle


% --- Executes on button press in pushbutton3.
function pushbutton3_Callback(hObject, eventdata, handles)
% hObject    handle to pushbutton3 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
if get(hObject,'Value') && handles.videoPos<handles.nFrames-9
    handles.videoPos=handles.videoPos+10;     % Increment the stored position
    snapshot = read(handles.VidObj,handles.videoPos); % Here we use the stored video position 
    imshow(snapshot),title(handles.videoPos);
end
guidata(hObject,handles) % Save the modifications done at the handles structure at the figure handle


% --- Executes on button press in pushbutton4.
function pushbutton4_Callback(hObject, eventdata, handles)
% hObject    handle to pushbutton4 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
if get(hObject,'Value') && handles.videoPos>10
    handles.videoPos=handles.videoPos-10;     % Increment the stored position
    snapshot = read(handles.VidObj,handles.videoPos); % Here we use the stored video position 
    imshow(snapshot),title(handles.videoPos);
end
guidata(hObject,handles) % Save the modifications done at the handles structure at the figure handle

---

似乎您对编码有些困惑，我已经对其进行了编辑并注释了您的错误. 它们以% COMMENT:

---

Seems you got confused a little bit with the coding, I've edited it and commented your errors. They are preceded by % COMMENT:

function varargout = N_Play_Pause(varargin)
% N_PLAY_PAUSE MATLAB code for N_Play_Pause.fig
%      N_PLAY_PAUSE, by itself, creates a new N_PLAY_PAUSE or raises the existing
%      singleton*.
%
%      H = N_PLAY_PAUSE returns the handle to a new N_PLAY_PAUSE or the handle to
%      the existing singleton*.
%
%      N_PLAY_PAUSE('CALLBACK',hObject,eventData,handles,...) calls the local
%      function named CALLBACK in N_PLAY_PAUSE.M with the given input arguments.
%
%      N_PLAY_PAUSE('Property','Value',...) creates a new N_PLAY_PAUSE or raises the
%      existing singleton*.  Starting from the left, property value pairs are
%      applied to the GUI before N_Play_Pause_OpeningFcn gets called.  An
%      unrecognized property name or invalid value makes property application
%      stop.  All inputs are passed to N_Play_Pause_OpeningFcn via varargin.
%
%      *See GUI Options on GUIDE's Tools menu.  Choose "GUI allows only one
%      instance to run (singleton)".
%
% See also: GUIDE, GUIDATA, GUIHANDLES

% Edit the above text to modify the response to help N_Play_Pause

% Last Modified by GUIDE v2.5 13-Aug-2013 16:26:32

% Begin initialization code - DO NOT EDIT

gui_Singleton = 1;
gui_State = struct('gui_Name',       mfilename, ...
                   'gui_Singleton',  gui_Singleton, ...
                   'gui_OpeningFcn', @N_Play_Pause_OpeningFcn, ...
                   'gui_OutputFcn',  @N_Play_Pause_OutputFcn, ...
                   'gui_LayoutFcn',  [] , ...
                   'gui_Callback',   []);
if nargin && ischar(varargin{1})
    gui_State.gui_Callback = str2func(varargin{1});
end

if nargout
    [varargout{1:nargout}] = gui_mainfcn(gui_State, varargin{:});
else
    gui_mainfcn(gui_State, varargin{:});
end
% End initialization code - DO NOT EDIT


% --- Executes just before N_Play_Pause is made visible.
function N_Play_Pause_OpeningFcn(hObject, eventdata, handles, varargin)
% This function has no output args, see OutputFcn.
% hObject    handle to figure
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
% varargin   command line arguments to N_Play_Pause (see VARARGIN)

% Choose default command line output for N_Play_Pause
handles.output = hObject;
handles.VidObj = VideoReader('x05.avi'); % COMMENT: PAY ATTENTION, 's' was missing!
handles.nFrames = handle.VidObj.NumberOfFrames;
handles.videoPos = 1; % Current video position, starts at first frame.

% Update handles structure
guidata(hObject, handles); % Here you are saving the handles method at the hObject, this is the handle from your GUI figure.

% COMMENT: In the original code here, you would save guidata twice, you didn't need that, just save guidata after you make ALL ALTERATIONS IN IT!


% --- Outputs from this function are returned to the command line.
function varargout = N_Play_Pause_OutputFcn(hObject, eventdata, handles) 
% varargout  cell array for returning output args (see VARARGOUT);
% hObject    handle to figure
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Get default command line output from handles structure
varargout{1} = handles.output;


% --- Executes on button press in togglebutton1.
function togglebutton1_Callback(hObject, eventdata, handles)
% hObject    handle to togglebutton1 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Hint: get(hObject,'Value') returns toggle state of togglebutton1


while get(hObject,'Value')
    snapshot = read(handles.VidObj,handles.videoPos); % Here we use the stored video position 
    imshow(snapshot),title(double2str(handles.videoPos));            
    if handles.videoPos >= handles.nFrames % Protect your code not to go be number of frames available
      break;
    end
    handles.videoPos=handles.videoPos+1;     % Increment the stored position
end
guidata(hObject,handles) % Save the modifications done at the handles structure at the figure handle

---

在阅读您的问题标题时，我想，您还需要什么?您还想要沙漠吗?但是开玩笑的是，我错了，至少您有工作的余地.

---

Reading your question title I was like, what else you need? Do you also want a desert? But jokes a part, I was wrong, at least you have something working.

我不是matlab的图像专家，而是在回调函数中执行a = 0(因此将视频重置为开始位置)，则需要将视频位置保存在GUI中.可以使用多种方法，一种方法是使用guidata，setappdata或通过参数将其传递给回调函数.您可以将其称为变量videoPos并将其添加到使用guidata存储的handles结构中.还要在此结构中保存nFrames变量.

I am not an image specialist at matlab, but instead doing a = 0 in your callback function (and therefore reseting your video to start position), you will need to save your video position at your GUI. There are several ways of doing it, one way would be by using guidata, setappdata, or to pass it via arguments to your callbacks. You could call it a variable videoPos and add it to the handles struct that you store with guidata. Also save your nFrames variable in this struct.

快进将与您显示的相同，但是执行videoPos = videoPos + 1时将执行videoPos = videoPos + n，其中n是您希望快进的速度倍增器.要倒带，只需减小videoPos或将其重置为1，即可.

The fast forward would be the same as you showed, but instead doing videoPos = videoPos + 1 you would do videoPos = videoPos + n, where n is the speed multiplier you want on the fast forward. To rewind, just decrement your videoPos, or reset it to 1, depending what you want.

注意:不要忘记添加检查器，您不会希望您的videoPos小于0或大于nFrames.

Note: Don't forget to add checkers, you won't want your videoPos lesser than 0 or greater than nFrames.

在功能上:N_Play_Pause_OpeningFcn添加以下数据:

On the function: N_Play_Pause_OpeningFcn Add the following data:

handle.VidObj = VideoReader('x05.avi');
handle.nFrames = VidObj.NumberOfFrames;
handle.videoPos = 1; % Current video position, starts at first frame.

% Update handles structure
guidata(hObject, handles); % Here you are saving the handles method at the hObject, this is the handle from your GUI figure.

然后，按照您的功能togglebutton1_Callback执行:

Then, at your function togglebutton1_Callback do:

% --- Executes on button press in togglebutton1.
function togglebutton1_Callback(hObject, eventdata, handles)
% hObject    handle to togglebutton1 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Hint: get(hObject,'Value') returns toggle state of togglebutton1


% You won't need this line anymore a=0;
% If you would like to retrieve the stored guidata you would do it here, by doing **handles=guidata(hObject);** but this is not needed, the handles data stored at the figure handle is already given to you as the third argument internally by the matlab!    

while get(hObject,'Value')
    snapshot = read(VidObj,handles.videoPos); % Here we use the stored video position 
    imshow(snapshot),title(double2str(handles.videoPos));            
    if handles.videoPos >= handles.nFrames % Protect your code not to go be number of frames available
      break;
    end
    handles.videoPos=handles.videoPos+1;     % Increment the stored position
end
guidata(hObject,handles) % Save the modifications done at the handles structure at the figure handle

请注意，每次退出方法时都需要更新guidata，以便使其保持更新状态并保存在图形手柄上.还有一个细节是，您为guidata传递的对象不必是图形手柄，而是它所持有的任何对象，就像您创建的播放按钮一样.如guidata帮助中所述:

Note that you need to update the guidata everytime you quit your methods, so that you keep it updated and saved on the figure handle. One more detail is that the object you pass for the guidata don't need to be the figure handle, but any object holden by it, as the play button you have created. As in the guidata help:

GUIDATA(H，DATA)将指定的数据存储在图形的 应用程序数据.

GUIDATA(H, DATA) stores the specified data in the figure's application data.

H is a handle that identifies the figure - it can be the figure
itself, or any object contained in the figure.

现在只需添加更多按钮并使用togglebutton1方法，快进将是相同的，但是使用+n代替+1.

Now just add more buttons and work with the togglebutton1 method, the fastforward would be the same, but using instead of +1, +n.

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