To copy locally or not to copy locally

Scrat

May contain acorns
I have backups of unwatched video from a T2 and Foxsat on one of my servers. These are straight TS files, but my Sony BD player will not play them back: I get a coloured splodge on-screen and no sound. No great problem, as I have other players that will handle them, but I know that if I get VideoRedo to convert them to .mpg, they are fine on the Sony. This got me thinking...

There is about 300Gb of stuff on the server on my LAN. VideoRedo has a batch mode and each hour of video takes around 10 seconds on my laptop to convert (there's SSD for you!), so my natural thought was:

a) Copy files to laptop
b) Convert on laptop
c) Copy back to sever

However, this requires copies, and each takes time. If I convert the files directly on the server, each hour takes far more than 10 seconds, but the reading and writing are presumably happening concurrently. So, which takes less time? Is it better to feed VideoRedo the files directly from the server?
 

Black Hole

May contain traces of nut
Logically, the operations break down in more detail like this:

File on NAS > network transfer > file on local storage;
File on local storage > process > file on local storage;
File on local storage > network transfer > file on NAS.

Therefore it seems obvious to me that:

File on NAS > network transfer > process > network transfer > File on NAS

will be quicker.
 
OP
Scrat

Scrat

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Is it obvious though? If it takes 5 minutes to download the file and 5 more to upload it, plus a small time to process it, and assuming the processing is a fast frame copy, that takes just over 10 minutes.

However, pointing VideoRedo directly at the server means that it can read and write simultaneously, giving just over 5 minutes for the process.

File on NAS → process → file on NAS
 

Black Hole

May contain traces of nut
However, pointing VideoRedo directly at the server means that it can read and write simultaneously, giving just over 5 minutes for the process.
Is that true? Is Ethernet traffic full-duplex, or does simultaneous upload and download share the same bandwidth (both on the network and on the processor activity at each end)?

File on NAS → process → file on NAS
I think that's the same as what I said (your arrows represent my network transfer).
 

af123

Administrator
Staff member
Is that true? Is Ethernet traffic full-duplex, or does simultaneous upload and download share the same bandwidth
Switched Ethernet is full-duplex, unswitched isn't. For a data stream in one direction there is typically a small amount of data in the other for acknowledgements although that depends on the protocol (TCP does use some reverse bandwidth, UDP doesn't for example).
 
OP
Scrat

Scrat

May contain acorns
It's definitely faster to read from and write to the NAS directly rather than copy, process, copy.

One thing I found, though, is that VideoRedo isn't doing a fast frame copy on any of the HD files, it does a full recode, which takes forever. Is that what people would expect? I am not sure now whether the TS files originated on Freeview or Freesat.
 

Black Hole

May contain traces of nut
Are you saying that StDef files are remuxed, but HiDef files are re-encoded? I don't know VideoRedo, but it sounds like you are asking it to output something which is not compatible with H.264.
 
OP
Scrat

Scrat

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I have no knowledge of the nitty gritty of these formats, just that most of my files have been converted in seconds but the HD ones, probably from the Foxsat HDR, take about 4 hours to convert from TS to MPG.
 

Black Hole

May contain traces of nut
But that's the point. There's no transcoding when "converting" SdDef TS to MPG - just repackaging. Sometimes you can even get away with just renaming the file.
 
OP
Scrat

Scrat

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The point was that other converters did a full transcode anyway. The USP of this one was that it didn't. So you could cut adverts out and not have to wait hours for the result. Other utilities had an idea of how to compress and by how much, and went into full transcoding mode. This one had the option of keeping the file at the same compression and just copying the content with the cuts you had made.

Ah well, as it turned out, I only have around 30 files like this. I will leave them as ts files and I have converted everything else to mpg.

Sent using Android ForumReader app
 

Black Hole

May contain traces of nut
Oh, right, so you don't just use it for conversion, you are editing too. I still don't see how this is a black mark against VideoRedo if it is not possible to get H.264 into an MPG stream. Is there no option to output something which does not require transcoding of the H.264? If there isn't, and if nothing else offers that either, then VideoRedo is still ahead of the pack shirley?
 
OP
Scrat

Scrat

May contain acorns
There are loads of output formats. Trouble is if the compression isn't the same it goes into major recode mode.

You gave me an idea though. Perhaps just changing the extension from ts to mp4 or whatever may work. I may try later.

Edit: Nah!
 
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