[Reuben Martin]

I may be wrong, but I believe the problem with doing it this way is that the data streams are pulled directly from the reference files, which means timestamps (PTS and DTS) jump around whenever the source changes. FFmpeg is an encoder, not an editor, and it expects continuity in the timestamps.

There may be other reasons though. Really you shouldn’t try to use Quicktime Reference outside of software built using the Quicktime API.

[Reuben Martin]

I’m surprised you can’t override the aspect ratio of the input. You can do that for other several other properties.

You can do a stream copy to a new file first and force the 16:9 aspect, and then use the new file on place of the older one. I’ve done this with mp4 files. Not sure if it will work or not the mxf files.

For mp4 I do this:
ffmpeg -i inputfile.mp4 -c:v copy -aspect 16:9 -ca: copy -f mp4 outputfile.mp4

It gives a small warning about doing that, but it’s never cause problems for me. You can try it with mxf and see if it works. I don’t have much mxf content to test with, and there is a small chance that it may not work due to how the format stores its data.

ffmpeg -i inputfile.mxf -c:v copy -aspect 16:9 -ca: copy -f mxf outputfile.mxf

[Reuben Martin]

Add another “-aspect 16:9” in front of the “-i” argument.

[Reuben Martin]

ffmpeg is a general purpose utility that happens to be able to stream, not a dedicated streaming tool.

[Reuben Martin]

I believe the channel mapping is assumed (although I may be wrong).

Are you sure the Hyperdeck needs a single audio stream with 16 channels? Most hardware I’ve run into uses 16 separate audio streams with a single channel each.

[Reuben Martin]

ffmpeg -i INPUT -codec:v copy -filter_complex highpass=f=200 -codec:a AUDIO_CODEC -f FORMAT OUTPUT

[Reuben Martin]

Transcoding alone is not enough. You need to be able to serve it correctly to be of any use.

There is a nginx module I use that might work for you. It supports both rtmp and hls. You can push / pull rtmp as well as convert the source streams to hls. (Hopefully is will soon support MPEG-DASH as well.)

https://github.com/arut/nginx-rtmp-module

[Reuben Martin]

ffmpegX is not the same as ffmpeg. It is a front end that comes with a very old version of ffmpeg.

I would suggest ditching ffmpegX and installing the real thing. This will require learning to use ffmpeg from a terminal. It is a steeper learning curve, but once you get the hang of it, you’ll probably start to prefer the CLI interface. The added bonus is that you can copy/paste the command used so that people on forums like this can help you. When using a front end like ffmpegX, we have no way of knowing what options were set in the GUI interface. Furthermore, there are lots of options available that the GUI does not expose.

MacPorts is a good resource to use for installing ffmpeg on OSX.

[Reuben Martin]

Oh, and set the profile to 3.

[Reuben Martin]

You can’t compare the bitrates of ProRes encoded by ffmpeg to the bitrates encoded by Apple software. The ffmpeg implementations are much more efficient than the apple implementation. Basically the DC transforms used by Apple suck.

Bitrate doesn’t matter. Quality of encoding matters. FFmpeg is not going to use the full 200 MBit bandwith when the content of the video does not require that much bandwidth to encode.

If you want to ensure the absolute highest quality, ditch the bitrate settings, and set the qscale to 1.

-qscale:v 1