I have a Java application that uses ffmpeg
library and javacv
to load and process video files.
I am currently using following code, for loading videofile
to my data container.
public boolean add(String videofile) {
FrameGrabber g = new OpenCVFrameGrabber( videofile );
try{
g.start();
}
catch(Exception e){
g = new FFmpegFrameGrabber( videofile );
try {
g.start();
}catch(Exception x){
return false;
}
}
grabbers.add( new Pair(videofile, g) );
frames.add( 0 );
preprocessed=false;
return true;
}
Each time video is loaded, a library outputs a lot of meta information regarding video itself:
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/home/lejlot/data/test.mp4': Metadata: major_brand : isom minor_version : 512 compatible_brands: isomiso2mp41 encoder : Lavf53.21.1 Duration: 00:04:36.27, start: 0.000000, bitrate: 305 kb/s Stream #0:0(und): Video: mpeg4 (Simple Profile) (mp4v / 0x7634706D), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], 303 kb/s, 20,85 fps, 30 tbr, 1k tbn, 1k tbc Metadata: handler_name : VideoHandler
which obviously I do not want to see. I cannot (do not want) to modify the libraries source codes, but rather modify my own so it can intercept this log and discard it.
As far I tried to temporarly block the stdout/stderr streams through
private static final devnull = new PrintStream(new OutputStream() {
@Override
public void write(int b) {
//DO NOTHING
}
@Override
public void write(byte[] b,int x,int y){
}
});
/**
* Blocks messages to stdout
*/
public static void silentStdOut(){
System.setOut(devnull);
}
/**
* Blocks messages to stderr
*/
public static void silentStdErr(){
System.setErr(devnull);
}
but it does not seem to help, log message is still displayed
public boolean add(String videofile) {
Utils.silentStdErr();
Utils.silentStdOut();
FrameGrabber g = new OpenCVFrameGrabber( videofile );
try{
g.start();
}
,,,
"Raw" ffmpeg can be set to be less verbose using
ffmpeg -loglevel panic
but neither OpenCVFrameGrabber
not FFmpegFrameGrabber
give access to the tool's parameters.
To sum up - how can I discard these log messages without modifing the libraries' source codes?
had the same problem a few minutes ago, and also looked on the net, nothing except your question. Then i started digging in the ffmpeg sources and found a solution, add the import:
import com.googlecode.javacv.cpp.avutil;
and then just call:
avutil.av_log_set_level(avutil.AV_LOG_QUIET);
before you create the FFmpegFrameGrabber -> No more messages form ffmpeg.
Regards
Daniel