Creating a log file for my ffmpeg output

I am trying to find out why my rtsp dos command using FFMPEG is 'freezing'. Ihave been told I would have more luck on SuperUser but I have been told to produce a log file 1st.

I have looked and I have tried several things to produce this log file.

My original command line was this:

ffmpeg.exe -i rtsp://admin:admin@192.168.0.8:554/video_1 -an -f image2pipe -vf fps=fps=6 -qscale 0 -

and changed it to this:

ffmpeg.exe -i rtsp://admin:admin@192.168.0.8:554/video_1 -an -f image2pipe -vf fps=fps=6 -qscale 0 - > log.txt

But the DOS does not get beyond this:

and the log file is empty.

Please can someone advise?

Thanks

2 Answers

ffmpeg logs to stderr, so you have to check that. Since you're already outputting to stdout, you have to redirect stderr to a file, for example:

ffmpeg … 2> log.txt

The -report flag is more what you search for debugging.

Dump full command line and console output to a file named "program-YYYYMMDD-HHMMSS.log" in the current directory. This file can be useful for bug reports. It also implies "-loglevel debug".

Thus have a look at:

• man -P "less -p report" ffmpegas well as
• man -P "less -p loglevel" ffmpeg.

You can change the logfile's location using the FFREPORT variable like so:

FFREPORT=file="/my/log/location/%p-%t.log":level=32 ffmpeg -i [...]