THM files in Windows file explorer

[david]

How do you make Windows automatically view THM files in file explorer?
https://i.postimg.cc/wxCWFdQf/Clipboard01.jpg

[knuttle]

On 11/24/2023 1:01 PM, david wrote:
> How do you make Windows automatically view THM files in file explorer?
> https://i.postimg.cc/wxCWFdQf/Clipboard01.jpg

Doing a search returns that a THM file is similar to a image thumbnail,
except it is for a video.

https://filmlifestyle.com/what-is-thm-file/

[Big Al]

Rename them to .jpg and you're fine.

--
Linux Mint 21.2 Cinnamon
Al

[Paul]

On 11/24/2023 1:01 PM, david wrote:

> How do you make Windows automatically view THM files in file explorer?
> https://i.postimg.cc/wxCWFdQf/Clipboard01.jpg

Copy the file to your PC, then change the extension to .jpg instead of
.thm thumbnail.

Open with Irfanview, Irfanview will see the JPG extension, and if the
file really isn't JPG, it will ask you whether it can fix the extension
by using another extension type.

*******

You can open the file with a hex editor, examine, and see if there
is a "JFIF" near the top. That might indicate the basic encoding method
is JPG or not.

https://mh-nexus.de/en/hxd/

The Linux "file" command is available in W10/W11 via bash and
WSL/WSLg software. But you have to be a Level 39 Wizard to get
that running. Installing Ubuntu 20.04 from the Microsoft Store,
is only part of the adventure, and there is more fiddling to
do, all so you can have a "file" command. (I was hoping the
automation of this would be better by now, but the last time
I set it up, it was still a lame ass adventure.)

file some.thm

Since I don't have any samples of .THM files here, I am
out of luck with regard to any demonstrations of capability.

It's probably just a JPG, and changing the extension of the file
should get you in business. Then you can set up a binding so
Irfanview will open it. Even if Irfanview whines a bit while
doing so.

Paul

[david]

Using <news:ujr0ph$2f35s$1...@dont-email.me>, Paul wrote:

>> How do you make Windows automatically view THM files in file explorer?
>> https://i.postimg.cc/wxCWFdQf/Clipboard01.jpg
>
> Copy the file to your PC, then change the extension to .jpg instead of
> .thm thumbnail.

Thanks everyone for renaming advice which I saw others had also suggested.

It's messy because the crittercam creates an AVI of the exact same name as
the thumbnail of the AVI (which is the THM file - which is a JPEG file)
and also JPG files (of different names) so it would make it into a mess.

But of course, for thousands of files, I could rename the file name also.
But there must be a better way.
move name.THM name_thumbnail.jpg

But I was hoping for a graceful solution that showed them in the Windows
file explorer as they were intended to be shown as (as AVI thumbnails).

> Open with Irfanview, Irfanview will see the JPG extension, and if the
> file really isn't JPG, it will ask you whether it can fix the extension
> by using another extension type.

Yes. That's what Irfanview just now did. It renamed it to JPG.
But there are already a million JPG files and these are supposed to be
thumbnail files. Not images. But thumbnails. Of what's in the AVI.

Can't Windows be made to treat thumbnail files as thumbnail files?

> It's probably just a JPG, and changing the extension of the file
> should get you in business. Then you can set up a binding so
> Irfanview will open it. Even if Irfanview whines a bit while
> doing so.

Well, I could rename thousands of files but I was hoping that, since AVI
theumbnail files are created by many crittercams, that it would be more
fluid to just ask Windows to display AVI THM files as thumbnail files.

[Big Al]

Look but a bulk rename utility.
https://www.bulkrenameutility.co.uk/Download.php
I use this one.
You could do all that at once, you just have to plan your attack.

[Carlos E. R.]

On 2023-11-24 23:27, david wrote:
> Using <news:ujr0ph$2f35s$1...@dont-email.me>, Paul wrote:
>
>>> How do you make Windows automatically view THM files in file explorer?
>>> https://i.postimg.cc/wxCWFdQf/Clipboard01.jpg
>>
>> Copy the file to your PC, then change the extension to .jpg instead of
>> .thm thumbnail.
>
> Thanks everyone for renaming advice which I saw others had also suggested.
>
> It's messy because the crittercam creates an AVI of the exact same name as
> the thumbnail of the AVI (which is the THM file - which is a JPEG file)
> and also JPG files (of different names) so it would make it into a mess.
>
> But of course, for thousands of files, I could rename the file name also.
> But there must be a better way.
> move name.THM name_thumbnail.jpg
>
> But I was hoping for a graceful solution that showed them in the Windows
> file explorer as they were intended to be shown as (as AVI thumbnails).

Open a bug with Microsoft :-D

...

--
Cheers,
Carlos E.R.

[Alan Browne]

On 2023-11-24 17:27, david wrote:
> Using <news:ujr0ph$2f35s$1...@dont-email.me>, Paul wrote:
>
>>> How do you make Windows automatically view THM files in file explorer?
>>> https://i.postimg.cc/wxCWFdQf/Clipboard01.jpg
>>
>> Copy the file to your PC, then change the extension to .jpg instead of
>> .thm thumbnail.
>
> Thanks everyone for renaming advice which I saw others had also suggested.
>
> It's messy because the crittercam creates an AVI of the exact same name as
> the thumbnail of the AVI (which is the THM file - which is a JPEG file)
> and also JPG files (of different names) so it would make it into a mess.
>
> But of course, for thousands of files, I could rename the file name also.
> But there must be a better way.
> move name.THM name_thumbnail.jpg
>
> But I was hoping for a graceful solution that showed them in the Windows
> file explorer as they were intended to be shown as (as AVI thumbnails).
>
>> Open with Irfanview, Irfanview will see the JPG extension, and if the
>> file really isn't JPG, it will ask you whether it can fix the extension
>> by using another extension type.
>
> Yes. That's what Irfanview just now did. It renamed it to JPG. But there
> are already a million JPG files and these are supposed to be
> thumbnail files. Not images. But thumbnails. Of what's in the AVI.
>
> Can't Windows be made to treat thumbnail files as thumbnail files?

If a thumbnail is at base a jpg (or other image format/container), then
so what?

>> It's probably just a JPG, and changing the extension of the file
>> should get you in business. Then you can set up a binding so
>> Irfanview will open it. Even if Irfanview whines a bit while
>> doing so.
>
> Well, I could rename thousands of files but I was hoping that, since AVI
> theumbnail files are created by many crittercams, that it would be more
> fluid to just ask Windows to display AVI THM files as thumbnail files.

Jumping in w/o reading much of the thread ...

Can't you simply tell Windows to open .thm with a photoviewer of choice?

(That's what I would do with a Mac).

Another way would be to rename xyz.thm to xyz.thm.jpg

--
“Markets can remain irrational longer than your can remain solvent.”
- John Maynard Keynes.

[Carlos E. R.]

On 2023-11-25 00:48, Alan Browne wrote:
> On 2023-11-24 17:27, david wrote:
>> Using <news:ujr0ph$2f35s$1...@dont-email.me>, Paul wrote:
>>
>>>> How do you make Windows automatically view THM files in file explorer?

...

>> Well, I could rename thousands of files but I was hoping that, since AVI
>> theumbnail files are created by many crittercams, that it would be more
>> fluid to just ask Windows to display AVI THM files as thumbnail files.
>
> Jumping in w/o reading much of the thread ...
>
> Can't you simply tell Windows to open .thm with a photoviewer of choice?

Sure, but he wants the filemanager to show the previews.

--
Cheers,
Carlos E.R.

[Alan Browne]

Is it a bug?

IAC, kudos to Microsoft. A support text chat with them today resolved
an Office license transfer issue of Office 2019 from an older iMac (x86)
to an M3 iMac. (Issue was a bit bizarre relating to the updated version
on the M3 iMac being "too new" for license transfers. Anyway resolved).

[Alan Browne]

Even in Windows a normal sized JPGs will be automatically shown as
thumbnails in the folder viewer (whatever MS calls that this week).

Apps that manage photos (or vids) should do pretty much the same w/o
needing a "sidecar" photo (although such "cached" as a hidden file is
not too obnoxious in order to speed things up).

Sorry I jumped in - I should have known better. I'll run along now.

[Carlos E. R.]

On 2023-11-25 00:53, Alan Browne wrote:
> On 2023-11-24 18:15, Carlos E. R. wrote:
>> On 2023-11-24 23:27, david wrote:
>>> Using <news:ujr0ph$2f35s$1...@dont-email.me>, Paul wrote:
>>>
>>>>> How do you make Windows automatically view THM files in file explorer?
>>>>> https://i.postimg.cc/wxCWFdQf/Clipboard01.jpg
>>>>
>>>> Copy the file to your PC, then change the extension to .jpg instead of
>>>> .thm thumbnail.
>>>
>>> Thanks everyone for renaming advice which I saw others had also
>>> suggested.
>>>
>>> It's messy because the crittercam creates an AVI of the exact same
>>> name as
>>> the thumbnail of the AVI (which is the THM file - which is a JPEG file)
>>> and also JPG files (of different names) so it would make it into a mess.
>>>
>>> But of course, for thousands of files, I could rename the file name
>>> also.
>>> But there must be a better way.
>>> move name.THM name_thumbnail.jpg
>>>
>>> But I was hoping for a graceful solution that showed them in the Windows
>>> file explorer as they were intended to be shown as (as AVI thumbnails).
>>
>> Open a bug with Microsoft :-D
>
> Is it a bug?

Well, that's the procedure in Linux. The same thing happens in Linux, I
declare a bug, and possibly the feature is added in a week.

--
Cheers,
Carlos E.R.

[Carlos E. R.]

On 2023-11-24 23:27, david wrote:

> Using <news:ujr0ph$2f35s$1...@dont-email.me>, Paul wrote:
>
>>> How do you make Windows automatically view THM files in file explorer?
>>> https://i.postimg.cc/wxCWFdQf/Clipboard01.jpg
>>
>> Copy the file to your PC, then change the extension to .jpg instead of
>> .thm thumbnail.
>
> Thanks everyone for renaming advice which I saw others had also suggested.
>
> It's messy because the crittercam creates an AVI of the exact same name as
> the thumbnail of the AVI (which is the THM file - which is a JPEG file)
> and also JPG files (of different names) so it would make it into a mess.

You could delete, or move to a subdir, the previews. The windows
filemanager will probably create previews of its own instead.

--
Cheers,
Carlos E.R.

[RabidPedagog]

They'll add that one feature and break thirty others.

--
RabidPedagog
TG: @RabidPedagog
Friends don't let friends run Linux

[Paul]

Then you would use Feedback Hub, would you not ???

It's too bad it doesn't really work.

If you raise an issue, you need a bunch of "Me too" promotions
of your posting, to get the issue raised so someone even reads it!

They don't even read all the Feedback Hub postings. They read
the "important ones". You'll need a Bot Army to raise your flag for you.

This is not a bug. It's not even a feature request. Microsoft
does not bend over and kiss the ground, when some twit invents
a new file extension. I for example, could invent a file extension
my own self, right this very minute. Why should Microsoft care about
my new .wally extension and that it's a thumbnail ???

What's important, is if Apple makes an .heic or something, uses a
patented technology, and a Windows user has to pay $1.50 or so
at the Microsoft Store, so they can view the image. That's how Microsoft
rolls (flowthru license payment, we don't even know if it's necessary
or not).

*******

I would say, if you want a thumbnail, the question you should be asking
is, "is there a Thumbnail Provider for AVI movies???". That is the
correct question to raise. Not "Can you support this vanity file .ext
for me please???". That's not going to fly. There will be snickering
in the Feedback Hub Cave if you do that :-)

See for example, this DIY solution for people with this need...
Somebody made a Provider, that uses ffmpeg. The same kind of
ffmpeg that yt-dlp uses to mux and demux movies it assembles.
You may be able to use Gyan to get an FFMPEG.exe of your very own.
If the developer of this program does not tell you where to place
the ffmpeg.exe , try placing it next to the icaros.exe or whatever.
That's what I would try as a first attempt. Otherwise, you'll
need to edit %path% to make it easy to find ffmpeg.exe . Or, some
program developers ask you via dialog, to identify where the
ffmpeg.exe is that you want to use.

https://www.videohelp.com/software/Icaros # A Thumbnail Provider for movie formats
# More files will have icons now...

# If the FFMPEG isn't inside the previous item, as a mini-version,
# you can get a full one. These are static compiles with no pile of
# DLL files to lug around.

https://www.gyan.dev/ffmpeg/builds/

latest release version: 6.1 2023-11-11

ffmpeg-release-full.7z

previous release version: 6.0 (complete archive @ mirror)

ffmpeg-6.0-full_build.7z

(A year ago, this is what I got. SHA256: 037BDB2183189DC0EFA642B1FDE7D6B33C6114036FA06FAF35F777E8DF07D863 , 47,431,656 bytes )
(It's no longer on the gyan server, but the archive.org copy should be OK.)

https://web.archive.org/web/20230111100754/https://www.gyan.dev/ffmpeg/builds/packages/ffmpeg-5.1.2-full_build.7z

When the version of FFMPEG changes, the command syntax can change slightly,
which adds to the "fun" sometimes, of getting stuff to work. That icaros
program likely does not need much in the way of fancy commands to
do a conversion to a raster file. I'm really surprised FFMPEG has
enough still image formats, to make using it as a converter a
worthwhile endeavor. One advantage of the developer doing it this
way, is the developer harnesses the bug busting skills of the
ffmpeg folks, to keep the exploit bugs out of the converter :-)

For every file type you want to see a Thumbnail representation,
you use a Thumbnail Provider to do that. Adobe Acrobat Reader,
is an example of a Thumbnail Provider for PDF files (64-bit version).

Paul

[Char Jackson]

On Fri, 24 Nov 2023 15:27:14 -0700, david <th...@is.invalid> wrote:

>Using <news:ujr0ph$2f35s$1...@dont-email.me>, Paul wrote:
>
>>> How do you make Windows automatically view THM files in file explorer?
>>> https://i.postimg.cc/wxCWFdQf/Clipboard01.jpg
>>
>> Copy the file to your PC, then change the extension to .jpg instead of
>> .thm thumbnail.
>
>Thanks everyone for renaming advice which I saw others had also suggested.
>
>It's messy because the crittercam creates an AVI of the exact same name as
>the thumbnail of the AVI (which is the THM file - which is a JPEG file)
>and also JPG files (of different names) so it would make it into a mess.

<snip>

AVI? In 2023? That's disappointing. I thought we had left that dinosaur behind
20+ years ago.

[Paul]

On 11/24/2023 6:59 PM, Alan Browne wrote:
> On 2023-11-24 18:52, Carlos E. R. wrote:
>> On 2023-11-25 00:48, Alan Browne wrote:

>>> Can't you simply tell Windows to open .thm with a photoviewer of choice?

What you want, is to install a Thumbnail Provider, for the
desired foreign file formats.

You don't, in fact, want anything to do with the .thm file at all!

Instead, the "key" file is the AVI. Copy the AVI ? And the job is done for you.

1) Copy AVI to a Windows folder, let's say.

2) When Windows sees the .avi file, it asks the question
"Do I have a Thumbnail Provider for this format?".
The answer would appear to be No.

3) Install a Thumbnail Provider. Videohelp says there is one.

4) Now, go back and open the folder. What happens ?
The .avi file now has its own thumbnail, instead of
the "blank sheet of paper" icon it might normally use.

Windows has minimal support for thumbnails. It might have
JPG, GIF, TIF perhaps. It doesn't have PDF, but if you
install Adobe Acrobat Reader (x64), then suddenly the
PDF files acquire thumbnails. I do not know whether
there is a "master" list of what gets a thumbnail.

Videohelp says this program may be a solution, so the AVI
file itself is all you need, and those blasted .thm files
can stay on the other device. The .thm files are low res (160x120).
The thumbnailer Windows has, supports multiple resolutions
and you can make some pretty big thumbnails.

https://www.videohelp.com/software/Icaros

I would scan the program on Virustotal, or at least
make sure that Windows Defender has scanned it.

Paul

[Paul]

I made my own, and at 160x120 the .thm was awful.

Paul

[Carlos E. R.]

On 2023-11-25 03:00, Paul wrote:
> On 11/24/2023 7:38 PM, Carlos E. R. wrote:
>> On 2023-11-25 00:53, Alan Browne wrote:
>>> On 2023-11-24 18:15, Carlos E. R. wrote:
>>>> On 2023-11-24 23:27, david wrote:
>>>>> Using <news:ujr0ph$2f35s$1...@dont-email.me>, Paul wrote:
>>>>>
>>>>>>> How do you make Windows automatically view THM files in file explorer?
>>>>>>> https://i.postimg.cc/wxCWFdQf/Clipboard01.jpg
>>>>>>
>>>>>> Copy the file to your PC, then change the extension to .jpg instead of
>>>>>> .thm thumbnail.
>>>>>
>>>>> Thanks everyone for renaming advice which I saw others had also suggested.
>>>>>
>>>>> It's messy because the crittercam creates an AVI of the exact same name as
>>>>> the thumbnail of the AVI (which is the THM file - which is a JPEG file)
>>>>> and also JPG files (of different names) so it would make it into a mess.
>>>>>
>>>>> But of course, for thousands of files, I could rename the file name also.
>>>>> But there must be a better way.
>>>>> move name.THM name_thumbnail.jpg
>>>>>
>>>>> But I was hoping for a graceful solution that showed them in the Windows
>>>>> file explorer as they were intended to be shown as (as AVI thumbnails).
>>>>
>>>> Open a bug with Microsoft :-D
>>>
>>> Is it a bug?
>>
>> Well, that's the procedure in Linux. The same thing happens in Linux, I declare a bug, and possibly the feature is added in a week.
>>
>
> Then you would use Feedback Hub, would you not ???

No, bugzilla, with the distro I use. Works many times, with many
variances :-)

In this case, if you can prove that there is a new industry standard to
create those files, you can get traction ;-)

On the other hand, there may be an easy way to implement a preview with
some plugin mechanism, so you only have to develop the plugin and add it.

[Carlos E. R.]

Probably they are designed to be viewed on the camera.

--
Cheers,
Carlos E.R.

[Paul]

The format is a function of the hardware support.

AVI is what you might do, if all you've got is a CPU core
to work with. A movie compressor logic block, would make it
possible to make other (more efficient) outputs.

https://cloudinary.com/guides/video-formats/avi-format-should-you-still-use-avi

"Some popular codecs used with AVI files include DivX, XviD, and MJPEG."

I think when I made an AVI a long time ago, I used HUFFUV which is a
lossless compressor, and it cuts the file size down to about 70% of a
completely uncompressed movie. That's not very good compression, but
it is lossless so it is archival quality.

If you use

ffprobe some.avi # Or use MediaInfo

it might give some idea what method was used. One of the reasons MJPEG
is popular, is you can use a bunch of CPU cores in parallel, each
one compressing a frame in MJPEG format. It has nice scaling properties
(if you can use the word "nice" and "avi" in the same sentence).

Paul

[Joel]

Paul <nos...@needed.invalid> wrote:
>On 11/24/2023 9:08 PM, Char Jackson wrote:
>>
>> AVI? In 2023? That's disappointing. I thought we had left that dinosaur behind
>> 20+ years ago.
>
>The format is a function of the hardware support.
>
>AVI is what you might do, if all you've got is a CPU core
>to work with. A movie compressor logic block, would make it
>possible to make other (more efficient) outputs.
>
>https://cloudinary.com/guides/video-formats/avi-format-should-you-still-use-avi
>
> "Some popular codecs used with AVI files include DivX, XviD, and MJPEG."

Interesting point - obsolete codecs still have use on "obsolete"
hardware, or for archived files. I've tended to refresh my approaches
to accessing media, save for my music collection, but the support of
legacy gear and media can be something to judge a modern system by.

--
Joel W. Crump

[geoff]

Nothing to do with Microsoft.

Simply associate .THM files with an application that can display them.

Start/Settings/Apps/Default Apps/ "Set a default for the file type of
link type."

ACDSee (for one) views THM file natively.

geoff

[geoff]

Yes.

geoff

[geoff]

So why not view then in something more appropriate for the purpose than
File Explorer ?

Several viewing(+) apps I know of not only do this but generate a
database of images in the desire folders.

geoff

[Carlos E. R.]

On 2023-11-25 08:06, geoff wrote:
> On 25/11/2023 12:15 pm, Carlos E. R. wrote:
>> On 2023-11-24 23:27, david wrote:
>>> Using <news:ujr0ph$2f35s$1...@dont-email.me>, Paul wrote:
>>>
>>>>> How do you make Windows automatically view THM files in file explorer?
>>>>> https://i.postimg.cc/wxCWFdQf/Clipboard01.jpg
>>>>
>>>> Copy the file to your PC, then change the extension to .jpg instead of
>>>> .thm thumbnail.
>>>
>>> Thanks everyone for renaming advice which I saw others had also
>>> suggested.
>>>
>>> It's messy because the crittercam creates an AVI of the exact same
>>> name as
>>> the thumbnail of the AVI (which is the THM file - which is a JPEG file)
>>> and also JPG files (of different names) so it would make it into a mess.
>>>
>>> But of course, for thousands of files, I could rename the file name
>>> also.
>>> But there must be a better way.
>>> move name.THM name_thumbnail.jpg
>>>
>>> But I was hoping for a graceful solution that showed them in the Windows
>>> file explorer as they were intended to be shown as (as AVI thumbnails).
>>
>> Open a bug with Microsoft :-D
>>
>> ...
>>
>
> Nothing to do with Microsoft.
>
> Simply associate .THM files with an application that can display them.

You haven't read the thread, have you? :-DD

>
> Start/Settings/Apps/Default Apps/ "Set a default for the file type of
> link type."
>
> ACDSee (for one) views THM file natively.
>
> geoff

--
Cheers,
Carlos E.R.

[Carlos E. R.]

And something that must not be done, is convert the old avi files to
something modern, because any conversion loses some quality. Unless what
is done is replace the container, and leave the data streams intact, but
to what purpose?

So yes, we need to keep supporting avi and more importantly, the codecs
used with it.

--
Cheers,
Carlos E.R.

[Carlos E. R.]

On 2023-11-25 00:59, Alan Browne wrote:
> On 2023-11-24 18:52, Carlos E. R. wrote:
>> On 2023-11-25 00:48, Alan Browne wrote:
>>> On 2023-11-24 17:27, david wrote:
>>>> Using <news:ujr0ph$2f35s$1...@dont-email.me>, Paul wrote:
>>>>
>>>>>> How do you make Windows automatically view THM files in file
>>>>>> explorer?
>>
>> ...
>>
>>>> Well, I could rename thousands of files but I was hoping that, since
>>>> AVI
>>>> theumbnail files are created by many crittercams, that it would be more
>>>> fluid to just ask Windows to display AVI THM files as thumbnail files.
>>>
>>> Jumping in w/o reading much of the thread ...
>>>
>>> Can't you simply tell Windows to open .thm with a photoviewer of choice?
>>
>> Sure, but he wants the filemanager to show the previews.
>
> Even in Windows a normal sized JPGs will be automatically shown as
> thumbnails in the folder viewer (whatever MS calls that this week).

Sure, but not .thm files, that's the issue.

>
> Apps that manage photos (or vids) should do pretty much the same w/o
> needing a "sidecar" photo (although such "cached" as a hidden file is
> not too obnoxious in order to speed things up).

Creating a preview of a video takes time, likely a few seconds per file.
The camera tries to help by saving the previews alongside the videos.

>
> Sorry I jumped in - I should have known better.  I'll run along now.
>

--

Cheers,
Carlos E.R.

[Alan Browne]

On this computer video previews (a frame) go at about 100 per second
judging by how fast the list fills out on screen. And that's reading
from an external, encrypted disk.

[Paul]

All you need, is a lossless conversion.

And as the person doing this, you have to do the research,
to see that this is true. For example, if your source material
is 4:4:4 and a "lossless" container happens to be 4:2:0,
then you need to understand whether that is "really lossless"
or not.

It's not a trivial matter.

That's why when I was converting 200GB source files into
more economical containers, I had to be very careful about
what I was doing. Sure, I can make a 7GB MP4 faster than
you can snap your fingers, out of one of those, but
technically the process is lossy, and you can't keep
doing that from one generation to another, without
some effect.

My video card can convert such a video file (single pass), at 11x real time.
A 60 minute video could be converted in 6 minutes. But the
problem is, the Q factor is wrong on the defaults NVidia
uses, and the actual output is not what it is supposed to be.
You'd be surprised how many "traps for the unwary" there
are, for this topic.

Paul

[Paul]

Windows keeps a thumbnail cache.

"slow" formats benefit the most from this. PDF thumbnailing
is painfully slow. Caching of PDF thumbnails then, actually makes sense.
This is the use case, that justifies caching.

For JPEG and GIF, Windows uses some "turbojpeg" or such,
that it turns out, doing realtime conversion every time the
folder opens, is actually FASTER than the cache path.
Which I think is hilarious. You would think a cache path
would always be faster, than doing the work over again,
but someone tested, and it isn't.

For the OPs AVI, it should be faster if the AVI preview comes
from the system Thumbnail cache. When you thumbnail a video,
you don't take the first frame, and there is some sampling
heuristic to select an "interesting frame" for the purpose.
That would be part of what makes it potentially slow.

This is what I like about FFMPEG as an engine. If there's
something you want to do, someone has already done it. It
really is the Swiss Army Knife of video tools. That Videohelp
addon, could be using a command like this for the purpose.

https://superuser.com/questions/538112/meaningful-thumbnails-for-a-video-using-ffmpeg

"The filter "thumbnail" tries to find the most representative frames in the video:

ffmpeg -i input.mp4 -vf "thumbnail,scale=640:360" -frames:v 1 thumb.png
"

Paul

[Paul]

On 11/25/2023 2:06 AM, geoff wrote:

>
> Nothing to do with Microsoft.
>
> Simply associate .THM files with an application that can display them.
>
> Start/Settings/Apps/Default Apps/ "Set a default for the file type of link type."
>
> ACDSee (for one) views THM file natively.
>
> geoff

Nobody wants to see a 160:120 thumbnail stored in a 3KB or 5KB file.
That would be awful. They want the system thumbnailer, to make
a representation from the actual content. That would look nice,
relatively speaking. Then, you don't even need to copy *any* .THM
files to the system, since the system is going to "paint" the AVI
file icon with an "actual thumbnail".

In the following picture, shows a directory of identical JPEG files,
with Extra-Large, Large, and Medium thumbnails. The thumbnails were
made by File Explorer, using a built-in Thumbnail Provider. if you
have a favorite file type, for which you want generated-on-the-spot
thumbnails made, for easy selection, then you add a Thumbnail Provider
to the Windows system.

[Picture]

https://i.postimg.cc/C1gV5J4w/Windows-File-Thumbnail-Sizes.gif

The Small thumbnail representation, uses the bound application icon instead,
which is boring (all the files look the same then, because the irfanview
icon is used instead). If you have not configured this ("what opens a JPG"),
there is a "danger" the Windows Photo.App could open :-) Once you see
that scanning your system at high speed, you won't make the mistake of
opening that a second time :-/

Paul

[Carlos E. R.]

On 2023-11-25 18:46, Paul wrote:
> On 11/25/2023 9:31 AM, Alan Browne wrote:
>> On 2023-11-25 08:11, Carlos E. R. wrote:
>>> On 2023-11-25 00:59, Alan Browne wrote:
>>>> On 2023-11-24 18:52, Carlos E. R. wrote:
>>>>> On 2023-11-25 00:48, Alan Browne wrote:
>>>>>> On 2023-11-24 17:27, david wrote:
>>>>>>> Using <news:ujr0ph$2f35s$1...@dont-email.me>, Paul wrote:



>>>> Apps that manage photos (or vids) should do pretty much the same w/o needing a "sidecar" photo (although such "cached" as a hidden file is not too obnoxious in order to speed things up).
>>>
>>> Creating a preview of a video takes time, likely a few seconds per file. The camera tries to help by saving the previews alongside the videos.
>>
>> On this computer video previews (a frame) go at about 100 per second judging by how fast the list fills out on screen.  And that's reading from an external, encrypted disk.
>
> Windows keeps a thumbnail cache.
>
> "slow" formats benefit the most from this. PDF thumbnailing
> is painfully slow. Caching of PDF thumbnails then, actually makes sense.
> This is the use case, that justifies caching.
>
> For JPEG and GIF, Windows uses some "turbojpeg" or such,
> that it turns out, doing realtime conversion every time the
> folder opens, is actually FASTER than the cache path.
> Which I think is hilarious. You would think a cache path
> would always be faster, than doing the work over again,
> but someone tested, and it isn't.

Often, photos contain a preview inside, so the browser only has to open
the file, read the metadata, get the preview block, then display it. As
compared to open both photo and cache files, maybe load the metadata on
both, decide if the preview block in the cache pertains to the photo
file, and display it.

>
> For the OPs AVI, it should be faster if the AVI preview comes
> from the system Thumbnail cache. When you thumbnail a video,
> you don't take the first frame, and there is some sampling
> heuristic to select an "interesting frame" for the purpose.
> That would be part of what makes it potentially slow.

Absolutely.

[Carlos E. R.]

Thus, I prefer not to do it :-)



--
Cheers,
Carlos E.R.