Making ffmpeg/javacv less verbose in java

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?

2 Answers

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

This is updated solution(w.r.t. javacv from github)

add the import statement given below

import static org.bytedeco.javacpp.avutil.AV_LOG_PANIC;
import static org.bytedeco.javacpp.avutil.av_log_set_level;

call the below statement before you create the FFmpegFrameGrabber -> No more messages form ffmpeg.

av_log_set_level(AV_LOG_PANIC);