Meaning of ffmpeg output (tbc, tbn, tbr)

Question

Hey - I am using ffmpeg to tell me video info. Specifically:

'ffmpeg -i video.ext'

I get the output:

'Stream #0.0[0x1e0]: Video: mpeg2video, yuv420p, 704x576 [PAR 12:11 DAR 4:3], 9578 kb/s, 25 tbr, 90k tbn, 50 tbc'

Does anyone know what tbr, tbn and tbc are exactly? I have seen speculation on the net but nothing definitive?

Thanks in advance.

Answer 1

Well it's all about time. FFMpeg uses in fact three different timestamps in different bases in order to work.

• tbn = the time base in AVStream that has come from the container
• tbc = the time base in AVCodecContext for the codec used for a particular stream
• tbr = tbr is guessed from the video stream and is the value users want to see when they look for the video frame rate

2secs in Google, searching "ffmpeg stream tbr". Google is your friend, don't you forget it! http://ffmpeg-users.933282.n4.nabble.com/What-does-the-output-of-ffmpeg-mean-tbr-tbn-tbc-etc-td941538.html