You can try libqtavi. It is a wrapper around the libgwavi. API looking simple and good integration with Qt classes. But only support MJPG codec and avi format and its bigger output size than mpeg/mp4, hevc/mkv… QAviWriter writer(“demo.avi”, QSize(800, 600), 24, “MJPG”);// set framerate to 24 fps and ‘MJPG’ codec writer.setAudioFileName(“audio.wav”); // set audio track … Read more
It seems to be a bug as previously stated above.
H.264 is a new standard for video compression which has more advanced compression methods than the basic MPEG-4 compression. One of the advantages of H.264 is the high compression rate. It is about 1.5 to 2 times more efficient than MPEG-4 encoding. This high compression rate makes it possible to record more information on the … Read more
If you just want to change the metadata such that mediaplayers that consider the flag play the file rotated, try something like: ffmpeg -i input.mp4 -c copy -metadata:s:v:0 rotate=90 output.mp4 as found elsewhere on stackoverflow.
A couple of things: You need to set the video bitrate. I have never used minrate and maxrate so I don’t know how exactly they work, but by setting the bitrate using the -b switch, I am able to get high quality video. You need to come up with a bitrate that offers a good … Read more
Here is an idea to select frames. Suppose the fps of source video is F and target fps is TF. rate = TF/F Initiate a variable n equal to -rate and add rate each time, when the integer part of n changed, select the frame. e.g. rate = 0.3 n: -0.3 0 0.3 0.6 0.9 … Read more