Trouble in making video from frames, can anyone help?
11 Ansichten (letzte 30 Tage)
Ältere Kommentare anzeigen
muhammad choudhry
am 31 Aug. 2021
Kommentiert: Walter Roberson
am 31 Aug. 2021
Hi,
I have around 1000 pictures which is like 30th frame from each second of 30 fps. I am trying to make a video with 1 fps hence I am using the code below but the problem is this code is not compiling the video in a sequence manner like frame30.jpg, frame60. jpg instead frames are messed up in video like starting from middle then finish then add the starting frames at the end. what i want is a it reads a frames from first to last hence made a video. I am not sure where I am making a mistake.
Code:
imgFile =dir('*.jpg');
N = length(imgFile);
% create the video writer with 1 FPS
writerObj = VideoWriter('compilingFrames.avi');
writeObj.FrameRate = 1;
%Open the video writer
open(writerObj);
%write the frame to the video
for i=1:N
img = imgFile(i).name;
I = imread(img);
writeVideo(writerObj,I);
end
% close the writer object
close(writerObj);
0 Kommentare
Akzeptierte Antwort
Walter Roberson
am 31 Aug. 2021
Or if the frames are named strictly sequentially and have a predictable prefix, then generate the file names instead of reading them from the directory.
videofile = 'compilingFrames.avi';
writerObj = VideoWriter(videofile);
writeObj.FrameRate = 1;
%Open the video writer
open(writerObj);
N = 1;
while true
filename = sprintf('frame%d.jpg', N);
if ~exist(filename); break; end
try
I = imread(filename);
catch ME
fprintf('Failed to read file "%s", giving up', filename);
break;
end
writeVideo(writerObj, I);
N = N + 1;
end
%to get here we ran out of sequential files, or a file was not readable
% close the writer object
close(writerObj);
if N == 1
fprintf('No frames were written at all, deleting movie!\n');
delete(videofile);
elseif N == 2
fprintf('Only one frame was written to movie, but need at least two for valid movie, deleting movie\n');
delete(videofile);
else
fprintf('Wrote %d frames succesfully\n', N-1);
end
4 Kommentare
Walter Roberson
am 31 Aug. 2021
The line that is already in the code,
writeObj.FrameRate = 1;
should take care of that.
As an experiment, after the above code, try
v = VideoReader(videofile);
if isfield(v, 'FrameRate')
fprintf('Frame rate stored in file is: %g\n', v.FrameRate);
else
fprintf('Somehow file does not have any recorded FrameRate??\n');
end
clear v
Weitere Antworten (1)
Chunru
am 31 Aug. 2021
Bearbeitet: Chunru
am 31 Aug. 2021
If your image file names are well behaved, you can do a simple sorting of the file names:
imgFile =dir('*.jpg');
imgFile = sort({imgFile.name}'); % sort the file name
N = length(imgFile);
% create the video writer with 1 FPS
writerObj = VideoWriter('compilingFrames.avi');
writeObj.FrameRate = 1;
%Open the video writer
open(writerObj);
%write the frame to the video
for i=1:N
img = imgFile{i}; %.name;
I = imreadimg);
writeVideo(writerObj,I);
end
% close the writer object
close(writerObj);
4 Kommentare
Chunru
am 31 Aug. 2021
Yes. You can define the frame sequence with the order you want:
imgFile ={'filename1.jpg', 'filename2.jp', ....}
Siehe auch
Kategorien
Mehr zu Tracking and Motion Estimation finden Sie in Help Center und File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!