How to convert 4K mp4 video into frames?

How do i convert 4K video into frames..

video recorded in gopro camera and stored in mp4 format.

Answer 1

[Nitin Kapgate]

You can refer to the code snippet below which demonstrates extraction of frames and export of the frames to a folder:

% import the in-built video file, replace 'xylophone.mp4' with your file name
vidObj = VideoReader('xylophone.mp4');

% read the total number of frames 
frames = vidObj.NumFrames; 

% file format of the frames to be saved in 
imageFormat ='.png'; 

% create a new folder for frames
mkdir frames

% reading and writing the frames 
for x = 1 : frames 

	% converting integer to string 
	frameIndex = num2str(x); 

	% concatenating 2 strings to get indexed frame name 
	frameName = strcat(frameIndex, imageFormat); 
    
    % read x'th frame from video
	vidFrame = read(vidObj, x);
    
	cd frames 
	% exporting the frames to the folder
	imwrite(vidFrame, frameName); 
	cd .. 
end

You can refer to the documentation for read function here.

[Vimal Raj]

Sir,

Thank you for you answer.. but, I'm getting this error

Error in VideoReader (line 104)

[e-mail](varargin{:});

Error in gopro4k (line 2)

vidObj = VideoReader('GH010440.mp4');

[Nitin Kapgate]

Can you post the complete error log?

[Vimal Raj]

Yes sir,

>> gopro4k

Error using VideoReader/initReader (line 734)

Failed to initialize internal resources.

Error in audiovideo.internal.IVideoReader (line 136)

initReader(obj, fileName, currentTime);

Error in VideoReader (line 104)

[e-mail](varargin{:});

Error in gopro4k (line 2)

vidObj = VideoReader('GH010440.mp4');

[Nitin Kapgate]

I understand that the error "Failed to Initialize internal resources" pops up when trying to use the 'VideoReader' function.

There could be various reasons behind this error which are listed as follows:

1. The required codec is missing for the particular video file. Determine whether the codec is installed on the computer.
2. The video file contains an audio stream (eg. AC-3) not supported by the API (QTKit, in AC-3 case) used by VideoReader. The only workaround is to re-encode the audio stream in the file into a different format such as MPEG-4/AAC and then try to read the file.
3. Sometimes, VideoReader cannot open a video file for reading on Windows platforms. This might occur if you have installed a third-party codec that overrides your system settings. Uninstall the codec and try opening the video file in MATLAB again.

The supported container formats and codecs link explains supported codecs in detail. Go through the troubleshooting section to determine if that could be a possibility in this particular case.

[Vimal Raj]

Thank you sir... Thank you soo Much. it works..

One more clarification sir, after convering the format, the quality seems tobe lowered than the original video.

The reason why i go for 4K is its quality only. but, after conversion process, the video and frames look like a compressed one (diminished colors). Size of the video also reduced to half of the original.

Any way to rectify that sir.. Also, at the end of frame conversion, again getting this error sir

>> gopro4k

Error using pngwritec

PNG library failed: Write Error.

Error in writepng (line 280)

pngwritec(data, map, filename, colortype, bitdepth, ...

Error in imwrite (line 546)

feval(fmt_s.write, data, map, filename, paramPairs{:});

Error in gopro4k (line 27)

imwrite(vidFrame, frameName );

An error was encountered while saving the command history