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View Full Version : MXF with DNxHD using FFMpeg


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1st January 2008, 00:15
ffmpeg -y -i retry3.avs -vcodec dnxhd -b 185Mb -flags +ildct -acodec pcm_s16le outfile.mov

Above is what I have tried and created outfile.mov. When importing to Avid Media Composer 2.7.5 it will go through the process of rendering (I think at least) the video (I'm new to Avid MC too). It loads the video track, but not the audio (There is no "A1" track). When I click around the frames in the source monitor randomly, it seeks to the frame, but when I press play, Avid MC crashes.

I just started out in this. Am I mistaking to think that I need to import a .mxf file into Avid to not re-render. If so, how do I create a .mxf that MC will reconigze with both video and sound...and not crash. Whatever it is doing now (re-rendering?), it takes longer than "Fast Importing" the .m2t file itself, much, much longer. It says "Creating video from QT" when I try to import the outfile.mov.

Can FFMpeg even create a .mxf file? I see it in formats, just not sure if that is input only.

The source is from a Canon HV20. I'm using Avisynth to down resize it to a compatible DNxHD format. I'm not sure if I should be doing any other conversions like changing the color space, bit depth, etc. I do want to eventually be able to do some very minor DFX like compositing, which I've read I need to promote the video to atleast 4:2:2. Not sure how to do that in Avisynth though (what does matrix="PC.709" do in Avisynth?).

The DNxHD format seems to be very clean, it's lossy but looks just as clean as CineForm. Now to get it into a proper MXF container. I hope someone understands.

BTW this is 1080i HDV I'm currently trying this with from the Canon and I get 8fps with FFMpeg in 185Mb DNxHD encoding.