python OpenCV中mp4视频的编解码器是什么

Question

fourcc = cv2.cv.CV_FOURCC(*'XVID')

The above line is used for avi video. In the same fashion, which codec do we use for mp4 videos in Ubuntu?

Answer 1

You can also use mp4v

fourcc = cv2.cv.CV_FOURCC(*'mp4v')

where the videowriter should look like this:

out = cv2.VideoWriter('output.mp4',fourcc, 15, size)

But there are more codecs available for mp4. You can see the list of them by setting fourcc = -1 , it will show a list like this:

OpenCV: FFMPEG: format mp4 / MP4 (MPEG-4 Part 14)
fourcc tag 0x7634706d/'mp4v' codec_id 000C
fourcc tag 0x31637661/'avc1' codec_id 001B
fourcc tag 0x33637661/'avc3' codec_id 001B
fourcc tag 0x31766568/'hev1' codec_id 00AD
fourcc tag 0x31637668/'hvc1' codec_id 00AD
fourcc tag 0x7634706d/'mp4v' codec_id 0002
fourcc tag 0x7634706d/'mp4v' codec_id 0001
fourcc tag 0x7634706d/'mp4v' codec_id 0007
fourcc tag 0x7634706d/'mp4v' codec_id 003D
....

All of them supports mp4 but h264 is supported by Web browsers if you want to serve the video into the web.

Answer 2

The codec is H.264.

One of these should work for you:

fourcc = cv2.cv.CV_FOURCC(*'H264')
#or 
#fourcc = cv2.cv.CV_FOURCC(*'X264')

However, I should warn you that you'll probably need to have ffmpeg and the x264 libraries installed so since you are in Ubuntu, try doing this command in the terminal :

sudo apt-get install ffmpeg x264 libx264-dev

Also, check out this link from OpenCV tutorials for more details as to the kinds of FourCC codes available for your platform.

In the above link, it says X264 is the FourCC code you should use, but switch between them until you get it to work.

Answer 3

fourcc = cv2.VideoWriter_fourcc('m','p','4','v')

似乎总是有效。

Answer 4

This is an old question. But, if anyone is facing an issue lately using the codec who can't get a saved video. They can use 0X00000021 as the codec value for OpenCV 3 and later.

Answer 5

I had to reinstall ffmpeg and compile opencv from source in order to get this working. I documented the steps in this blog post .