SubClip No Transcode

Questions and answers on how to get the most out of FFAStrans
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Posts: 8
Joined: Thu Mar 15, 2018 11:16 am

SubClip No Transcode

Post by Manjik » Mon Nov 26, 2018 6:05 pm

I'm going back to this forum to ask a question :
I use FFASTRANS for multiple workflow and it works very good but i would like to customize one workflow to simply implement a subclip without transcoding file (audio / video).
I use an XML file in input to indicate the markin and markout and the file. --> OK very nice

I don't know how to create my Workflow to not transcode my source file but only create a new file with marks.
I try to configure the processor XDCAMHD with processing "none, transwrap" but i'm an error "Source video stream does not comply with the encoder: rawvideo, yuv422p, 25, 1920X1080, 1, -24575276, 1, unknown, -99"
I try to configure a custom FFMPEG processing with options "-c:v copy -c:a copy" without audio codec and video codec checked. I am an error "Encoding failed - No video or audio found in media."

i want to use FFASTRANS to do that to use the same process that the others.
Can you help me to configure a custom Workflow to use markin / markout (a/v media) and that not transcode ?
the goal is to save time, i'm sure that my source file is in good format.

Folder (xml with good information) --> A/V Media --> Processor without transcoding ? --> Folder output
in ffmpeg, simple command with -ss markin -i sourceMxfXDCAMHDfile -c:v copy -c:a copy -t duration outputMxfFile

thanks a lot.

Posts: 8
Joined: Thu Mar 15, 2018 11:16 am

Re: SubClip No Transcode

Post by Manjik » Tue Nov 27, 2018 9:10 am

this morning, some few test :
If i take off the A/V media Processor, the custom FFMPEG Processor work fine without transcoding but of course, the markers are not taken.

finally, how can i combine A/V Media and the custom FFMPEG processing to copy video and audio streams with MarkIn and Markout ?
Whatever i do with this 2 processors, i have always the error "Encoding failed - No video or audio found in media"

thanks for help

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Joined: Sat Feb 08, 2014 10:39 pm

Re: SubClip No Transcode

Post by admin » Sat Dec 01, 2018 10:56 am

Hi Manjik,

By nature the "A/V Media"-decoder....well, it decodes. SO, it will ALWAYS give you uncompressed av-stream in return. Thus any lossy compression encoders will reencode the video. There is no way around it when going through the decoder. Currently, none of the encoders support in/out-points but will be on my to-do-list. So for now you must create a custom ffmpeg node but you MUST skip the "A/V Media"-decoder for this particular workflow.


Posts: 8
Joined: Thu Mar 15, 2018 11:16 am

Re: SubClip No Transcode

Post by Manjik » Mon Dec 03, 2018 4:32 pm

ok thanks
no solution for me at this moment
thanks for your reply

Posts: 213
Joined: Wed Sep 19, 2018 8:11 am

Re: SubClip No Transcode

Post by emcodem » Tue Dec 04, 2018 12:00 pm

Hey Manjik,

not sure if i fully understand what's your problem, why not just use a custom ffmpeg node with settings like this:
-codec copy -ss 10 -t 1

Sure you cannot use the A/V decoder before this custom node, but you could e.g. go paralell from the source, on way into the decoder and the other into the custom ffmpeg node.
Also you can always use just the commandline Node...


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