[FFmpeg-user] Incorrect Parameters for -vcodec copy / -acodec copy

Matt Goble mattgoble at gmail.com
Fri Jul 20 16:51:03 CEST 2012

> (Why do you want to stream copy the contents of a file
> into the same container? There should be no desync on playback,
> or am I wrong?)

Our current workflow is to run an ffindex on the files, then via AVISynth,
resize and apply logos, BITC, filenames etc, before transcoding to FLV via
Procoder.  We are noticing that these files are out of sync.

My concern is that we have too many tools in the chain, and / or the offset
is not being interpreted by the tools decoding the video.  As such, I
wanted to try and simplify things by correcting the sync in the source
file.  The file has been created by an Omneon generating XDCAM in a MOV
wrapper.  We don't have this issue with IMX50 movs we create - Our thinking
seems to be inline with Tim's that this is down to the LongGOP nature of
the source material, that this is somehow introducing the offset to begin
with, and possibly preventing us from fixing it.

The solution may be to transcode from XDCAM to something else, but my first
thought was just a simple re-wrap to do the job quicker.

Many Thanks


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