[FFmpeg-user] Piping uncompressed from ffmpeg to ffplay

[Moritz Barsnick]

On Tue, Nov 17, 2015 at 09:54:33 -0800, John Pilgrim wrote:
> I'm currently using the following command to play DCPs
> ffmpeg -ss 0 -lowres 1 -i video.mxf -i audio.mxf -f matroska - | ffplay -

Let me ask you: You are using a pipe because ffplay cannot play from
two separate files simultaneously? OK then... :)

> I notice that the video is being transcoded to h264:
> Stream mapping:
>   Stream #0:0 -> #0:0 (jpeg2000 (native) -> h264 (libx264))
>   Stream #1:0 -> #0:1 (pcm_s24le (native) -> vorbis (libvorbis))
> 
> My Question: What would be a revision to this invocation to send
> uncompressed (v210) video to ffplay instead of h264?

Why v210? I pretend to understand that all you want to do is play. You
shouldn't need to recode, not even to "raw" formats. Just use "-c copy"
to map the files' streams directly to the output.

I am told "nut" is a very flexible container for this sort of piping
task. I tried, it can carry both jpeg2000 and pcm_s24le. But so can
matroska.

Try this:

$ ffmpeg -ss 0 -lowres 1 -i video.mxf -i audio.mxf -c copy -f nut - | ffplay -

Feel free to stick with matroska if it works for you.

> Also using rawvideo didn't seem to send the audio.

No, pure rawvideo (without a container) is just that: video.

> Thanks for your help!

Hope this helps. Or Paul's answer, though I don't see why you should
encode to FLAC intermediately.
Moritz