Video player not showing using videoReader function

Question

Yeiry Chaverra Cordoba 2021-11-9

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1582099-video-player-not-showing-using-videoreader-function

回答： T.Nikhil kumar 2024-4-8

I am trying to display a video using convualion nerual networks. This is my code. It translates from speech to video but when I run the code the video does not show. On top of that it does not give me any error.

%% CNN predicts the translation

cnn_prediction = CNN_Predict(recObj, cnn_trained);

%diretory for pages

full_ref_path_ASLVid = fullfile(ref_dir, output_lang, char(cnn_prediction),append(char(cnn_prediction),'_asl_vid.mp4'));

full_ref_path_FSLVid = fullfile(ref_dir, output_lang, char(cnn_prediction),append(char(cnn_prediction),'_fsl_vid.mp4'));

full_ref_path_BSLVid = fullfile(ref_dir, output_lang, char(cnn_prediction),append(char(cnn_prediction),'_bsl_vid.mp4'));

full_ref_path_SSLVid = fullfile(ref_dir, output_lang, char(cnn_prediction),append(char(cnn_prediction),'_ssl_vid.mp4'));

%select which video to play

if strcmp(output_lang, 'American Sign language')

videoReaderASL = VideoReader(full_ref_path_ASLVid);

videoPlayerASL =vision.VideoPlayer('Name', cnn_prediction);

while hasFrame (videoReaderASL)

frame = readFrame(videoReaderASL);

step(videoPlayerASL, frame);

pause(0.05);

end

elseif strcmp(output_lang, 'British Sign language')

videoReaderBSL = VideoReader(full_ref_path_BSLVid);

videoPlayerBSL =vision.VideoPlayer('Name', cnn_prediction);

while hasFrame (videoReaderASL)

frame = readFrame(videoReaderBSL);

step(videoPlayerBSL, frame);

pause(0.05);

end

release(videoPlayer);

elseif strcmp(output_lang, 'French Sign language')

videoReaderFSL = VideoReader(full_ref_path_FSLVid);

videoPlayerFSL =vision.VideoPlayer('Name', cnn_prediction);

while hasFrame (videoReaderFSL)

frame = readFrame(videoReaderFSL);

step(videoPlayerFSL, frame);

pause(0.05);

end

release(videoPlayer);

elseif strcmp(output_lang, 'Spanish Sign language')

videoReaderSSL = VideoReader(full_ref_path_SSLVid);

videoPlayerSSL =vision.VideoPlayer('Name', cnn_prediction);

while hasFrame (videoReaderSSL)

frame = readFrame(videoReaderSSL);

step(videoPlayerFSL, frame);

pause(0.05);

end

release(videoPlayer);

else

end

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Answer 1

T.Nikhil kumar 2024-4-8

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1582099-video-player-not-showing-using-videoreader-function#answer_1437926

Hello,

As per your question, I get that you’re trying to play a video based on the value of the ‘output_lang’ variable but are facing some issues with it.

Based on my understanding of the above code snippet, I can see some misnaming issues that might be causing the video not to display properly:

In the ‘elseif’ block of ‘British Sign language’, the while loop is checking for frames using ‘hasFrame(videoReaderASL)’ instead of ‘hasFrame(videoReaderBSL)’. This may cause the unexpected behavior since ‘videoReaderASL’ object might not be defined if the ‘output_lang’ is not "American Sign language".
In the ‘elseif’ block of ‘Spanish Sign language’, you are using step(videoPlayerFSL, frame); but it should instead be step(videoPlayerSSL, frame);

I also assume that you have used the ‘release’ function to release system resources for the ‘videoPlayer’ object but note that ‘videoPlayer’ is not defined anywhere. You should instead release the specific video player instance you created for each language, like ‘release(videoPlayerASL);’ for American Sign Language, and so on for each language.

I will also suggest you to check if the file exists before trying to open it with ‘videoReader’. In some cases, if the file specified does not exist, ‘videoReader’ will not be able to open it, but it won't throw an error directly in your script.

Hope this helps you proceed with your work!