使用ffmpeg在Android上为捕获的视频加水印

Question

I'm now researching on a project which utilizes ffmpeg to watermark captured video on Android. At the moment I can capture a video from the camera firstly and then use ffmpeg to watermark it. I don't know if it is possible to operate the video while it is being captured?

Answer 1

Here is an example, how to capture a webcam video on my Windows system and draw a counting timestamp.

To list all devices that can be used as input :

ffmpeg -list_devices true -f dshow -i dummy

To use my webcam as input and draw the timestamp (with -t 00:01:00 1 minute is recorded):

ffmpeg -f dshow -i video="1.3M HD WebCam" -t 00:01:00 -vf "drawtext=fontfile=Arial.ttf: timecode='00\:00\:00\:00': r=25: x=(w-tw)/2: y=h-(2*lh): fontcolor=white: box=1: boxcolor=0x00000000@1" -an -y output.mp4

The font-file Arial.ttf was located in the folder I was with the terminal in.

(Source : http://trac.ffmpeg.org/wiki/How%20to%20capture%20a%20webcam%20input and http://trac.ffmpeg.org/wiki/FilteringGuide )

I hope it may help.

Have a nice day ;)