It does not work, this is why this thread exists. If you have nothing constructive to say please just ignore my post.

thwil

But MSP does not seem to show anywhere which parts of the clips are used in the timeline? That makes the job pretty much impossible.

When you've completed your project, go to Tools and select Clean Project Media.

This will remove all items under your Project Media tab that don't currently exist on your timeline.

You can then use the list of media that remains as your list to archive.

However, you can save yourself a load of trouble by following Cornico's tip regarding the Save As option.

Be prepared to wait though as this can take a long time with a big project.

Which codec do you use if it does?

The trimming is carried out by VMS and requires no intervention from you (ASFAIK).

It does not work, this is why this thread exists.

I know the trimming works in MSP13 but I haven't tried it in VMS14.

@JackS I guess it should work at least in some cases, otherwise why would this option be added. But it does not work on the source media that I have, which is predominantly H.264 files in mp4 and mov containers.

Immediately after Saving As with media, I get a message saying that "Some of the project files were not trimmed to preserve quality". And all media is simply copied in its entirety. Nothing gets trimmed.

Anyway, the only workaround I've found so far is:

* create subclips for all events
* for every subclip in the Properties dialog/Media tab a start time code and duration will be displayed
* this information can be manually used to compile a list which then can be fed to a script that uses ffmpeg to create trimmed copies of all events.

As thwil has noted (3 times) when using the archive feature, only certain codecs are actually trimmed to their used length. Others are copied over as full files, thus negating the point of using the archive function. You might as well copy over the project folder. I myself would not convert to another format for archiving unless you are using a lossless or uncompressed codec. Any other conversion will cause a loss of quality to some degree.

The Save as option for trimmed copies of source media works only for DV-avi, as far I can remember, a relict from those days when HDspace was rare and expensive. I don't mind to archive a complete clip, since I already try not to shoot unnecessary long (UHD) footage. When I need only a few seconds of a scene, I shoot max only twice as long as needed. The time and effort to archive "trimmed" clips doesn't weight against costs of extra HDspace.

Shooting only as much as you need is the smartest thing to do. But I'm mostly filming my kid, and it's always shoot and hope for something to happen. Some takes are just throwaway, some are spot on, but quite often it's a 2 minute take for 5 seconds of action.

Anyway, as an experiment I tried to do as I suggested in my previous post. I created subclips, wrote down a text file with source clip name, in and duration marks, and wrote a .bat file to create trimmed copies. I do not preserve the project structure by doing so, unfortunately, but I get to keep the originals and source archive is 2x smaller. It didn't really take a very long time, although it's really stupid to do such things by hand in 2017. If anyone's interested I can try describing it in more detail.

It's rather strange that I have to go through such hoops, especially because MSP already has the feature that should do all of this automatically, but in reality only works with formats that are irrelevant in this day and age. MAGIX, looking at you.

According Help only following formats are (auto)trimmed:

• Audio/video events are saved in a new AVI file. You can trim DV AVI,uncompressed AVI, and YUV AVI files. Because of the lossy nature of other videoformats, those video files will not be trimmed, but will simply be copied to the project folder.

Normally I keep all recordings (on external backup HDD) or delete them if there's nothing useable. If there is really an important 10 second part in a one hour recording I would just rerender that part in the same format as the original, the quality loss of the one generation render will be not visible .

Very good question thwil. I would myself see a solution to this. But I´m sorry that I don´t have an answer.

I have tried Cyberlinks Powerdirector which claims it can "Smart render".

-"Smart Video Rendering Technology (SVRT) makes video production faster by analyzing your project and rendering only segments of footage that have been modified."

That is even for mp4-files.
I have tried it but found that there are some issues with the resulting video file which is not satisfying. The picture "jumps" at those places where the rendering has taken place.

So maybe it is not so easy to get a program to work with mp4-files in the same way as with DV-AVI. Even if it´s 2017 ;-)

(Sorry for my crappy english.)

Thanks for your input everyone.

To sum up my findings, here's a sample of what I've got in case someone wants to try it.

The hand-compiled list of cuts looks like so. I put it in a file trim.txt in a subfolder where my project media is located. For example the project media is in C:\Users\Myself\Project1, this will be in C:\Users\Myself\Project1\trimmed\trim.txt. The first column is the file name, the second one is the timecode for cue start, the last one is duration.

C4K_20170527_124113.mp4 12.000     10.0
C4K_20170527_124113.mp4 34.000     14.0
C4K_20170527_124113.mp4 56.000     6.0
C4K_20170527_124838.mp4 10.0     6.0
C4K_20170527_124838.mp4 30.0    8.0
C4K_20170527_124838.mp4 44.0     20.0
C4K_20170527_125612.mp4 2.0    6.0
C4K_20170527_125612.mp4 29.0    25.0
C4K_20170527_125722.mp4 3.0    19.0
C4K_20170527_125819.mp4 0.0    11.0

Next to it there is a .bat file, let's call it trim.bat with such contents:

for /F "tokens=1-3" %%a in (trim.txt) do call :trimfile %%a %%~na %%b %%c
goto :eof

:trimfile
rem fullname nameonly start duration
echo %1 %2 %3 %4
set /a counter=0
:loop
set /a counter+=1
set fo="%2-%counter%.mp4"
if EXIST %fo% goto :loop
C:\bin\ffmpeg\bin\ffmpeg.exe -ss %3 -i ..\%1 -t %4 -c copy %fo%
goto :eof

The key here is of course a relatively fresh build of ffmpeg.

After I run this script, I end up with files trimmed according to the trim list, named like so:

C4K_20170527_124113-1.mp4
C4K_20170527_124113-2.mp4
C4K_20170527_124113-3.mp4
C4K_20170527_124838-1.mp4
C4K_20170527_124838-2.mp4
C4K_20170527_124838-3.mp4
C4K_20170527_125612-1.mp4
C4K_20170527_125612-2.mp4
C4K_20170527_125722-1.mp4
C4K_20170527_125819-1.mp4

It is very easy to see that no re-encoding takes place at all, all output media is direct stream copy.

If you want to try it on just one file without bothering with lists, .bat files etc, the syntax is:

ffmpeg -ss {start-timecode}  -i {input-file} -t {duration} -c copy {output-file}

Or you could do the same manually in GUI using Lossless Cut: https://github.com/mifi/lossless-cut -- which is nice to have, but I prefer scripted approach.

If you use Vegas Pro, this thread explains how you can automate the trimming of files with ffmpeg from the timeline, via scripting.