FPS when transcoding does not appear to work correctly

[transcoder]

Transcoding from NTSC VOB to MP4 specifying an fps of 29.97 or 25 results in reported framerates of 30.3 recurring and 25.6 recurring respectively.

Without specifying the framerate, I get 30.3 recurring.

Is there anyway to force VLC to use the input framerate? Why does the above inaccuracy appear? The 30.3 videos can not be played on an iPod.

[transcoder]

Videora does not exhibit this flaw but uses ffmpeg. The same files come out of Videora at 25 and 29.97029 fps.

Is there any way to find out what switches are supplied to the library and why the output rate is wrong?

[transcoder]

Handbrake for Windows also encodes correctly.

[transcoder]

no-one has any ideas or can confirm if it's a bug?

[loqu]

Transcoder,

I've discovered that the frame-rate reported in VLC is not correct. If the file is examined in Quicktime Player, you can see that the set FPS is the actual FPS of the file. (FPS set with the "--sout-transcode-fps 25" option)


Quicktime on left, VLC on right.

I've put some frame-rate(FPS) samples online to test yourself:
http://www.kludgeroo.com/linked/videola ... FPS_25.mp4
http://www.kludgeroo.com/linked/videola ... FPS_30.mp4

These files were created with the following command:

Code: Select all

vlc.exe -vvv "%infile%" :sout="#transcode{vcodec=mp4v, vb=1024, acodec=mp4a, ab=96, channels=2, samplerate=22050} :standard{access=file, mux=mp4, url=%outfile%}" vlc:quit --sout-transcode-width 320 --sout-transcode-canvas-height 240 --sout-transcode-fps 25 --stop-time 15

If you're still having a problem with ipod conversion, I'm willing to guess that it is NOT the FPS issue.

[transcoder]

really? ok, that's good news, ty

it's hard to fault find when all the free tools appear to be broken in subtly different ways!

i'll dig out my batch files and give it another whirl. if the frame rates are ok, my next suspect is possibly the audio.

many thanks for the reply.