[FFmpeg-user] partial file restore from tape

[Swami Kevala]

Hi,

We write large HD video files (MXF) to LTO tape. We want to develop a
solution where we can restore a subclip alone from the tape. (This is
commonly referred to as PFR - partial file restore)

I understand the -ss and -t options can be used to cut out a subclip - but
this is only when the entire file is on disk.

Using our tape software we can restore a certain subsection of the file
(based on a byte offset, and byte length). I want to know if we can use
ffmpeg to convert this into a playable file.

I'm guessing we would need some kind of metadata from the original file. So
the kind of thing I'm looking for is a command that will let me copy this
metadata from the file, before I write it to tape (which I would store on
the local disk). I would then want another command which would let me take
this metadata + any extracted byte-stream as inputs and produce a playable
subclip file as output.

Kind Regards

Swami Kevala

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