From Newsgroup: alt.windows7.general

Hello all,

Using libwebp.dll I'm able to extract static images, but would also like to extract frames from animations.

Alas, although I have a description of the file headers and can see where a "vp8 " chunk starts, I cannot seem to find any information (using DDG) to
how to extract-and-decode such a chunk (if at all possible with
libwebp.dll).

Also, although it seems that I need(?) a second dll to handle such animated webp image I can't seem to find which one it should be (where I can download it, and its API description).

Some help would be appriciated.

By the way: win32

Regards,
Rudy Wieser


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From Newsgroup: alt.windows7.general

On 2025/9/29 9:26:32, R.Wieser wrote:

Hello all,

Using libwebp.dll I'm able to extract static images, but would also like to extract frames from animations.

Alas, although I have a description of the file headers and can see where a "vp8 " chunk starts, I cannot seem to find any information (using DDG) to how to extract-and-decode such a chunk (if at all possible with libwebp.dll).

Also, although it seems that I need(?) a second dll to handle such animated webp image I can't seem to find which one it should be (where I can download it, and its API description).

Some help would be appriciated.

By the way: win32

Regards,
Rudy Wieser

Will it play in VLC? That has both frame extract and single-frame
advance capability. Or, will it play in IrfanView? That has
extract-all-frames capability (this can of course take a lot of space).
--
J. P. Gilliver. UMRA: 1960/<1985 MB++G()ALIS-Ch++(p)Ar++T+H+Sh0!:`)DNAf

A man is not contemptible because he thinks science explains everything,
and a man is not contemptible because he doesn't.
- Howard Jacobson, in Radio Times 2010/1/23-29.
--- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: alt.windows7.general

J. P. ,

Will it play in VLC? That has both frame extract and single-frame
advance capability.

Just tried, it doesn't (with the two animated webp's I have).

Or, will it play in IrfanView? That has extract-all-frames capability
(this can of course take a lot of space).

Can't say I ever used that one.

But the target is not those frame images, its about being able to do it
myself (and display them in a program of my own making). :-)

Regards,
Rudy Wieser


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From Newsgroup: alt.windows7.general

On 29/9/2025 4:26 pm, R.Wieser wrote:

Hello all,

Using libwebp.dll I'm able to extract static images, but would also like to extract frames from animations.

Alas, although I have a description of the file headers and can see where a "vp8 " chunk starts, I cannot seem to find any information (using DDG) to
how to extract-and-decode such a chunk (if at all possible with
libwebp.dll).

Find a free video editor using Google... one that supports VP8 format! ;)
--
@~@ Simplicity is Beauty! Remain silent! Drink, Blink, Stretch!
/ v \ May the Force and farces be with you! Live long and prosper!!
/( _ )\ https://sites.google.com/site/changmw/
^ ^ https://github.com/changmw/changmw
--- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: alt.windows7.general

On 29.09.2025 10:26, R.Wieser wrote:

Hello all,

Using libwebp.dll I'm able to extract static images, but would also like to extract frames from animations.

Alas, although I have a description of the file headers and can see where a "vp8 " chunk starts, I cannot seem to find any information (using DDG) to how to extract-and-decode such a chunk (if at all possible with libwebp.dll).

Also, although it seems that I need(?) a second dll to handle such animated webp image I can't seem to find which one it should be (where I can download it, and its API description).

Some help would be appriciated.

By the way: win32

webpmux is part of libwebp https://developers.google.com/speed/webp/docs/webpmux

https://chromium.googlesource.com/webm/libwebp/+/refs/heads/main/examples/webpmux.c

tried this?

ciao..

--- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: alt.windows7.general

On Mon, 9/29/2025 4:26 AM, R.Wieser wrote:

Hello all,

Using libwebp.dll I'm able to extract static images, but would also like to extract frames from animations.

Alas, although I have a description of the file headers and can see where a "vp8 " chunk starts, I cannot seem to find any information (using DDG) to how to extract-and-decode such a chunk (if at all possible with libwebp.dll).

Also, although it seems that I need(?) a second dll to handle such animated webp image I can't seem to find which one it should be (where I can download it, and its API description).

Some help would be appriciated.

By the way: win32

Regards,
Rudy Wieser

It seems to involve either just libwebp, or it involves libwebp plus libvpx

https://en.wikipedia.org/wiki/WebP

"library libvpx can extract VP8 key frames from WebM media"

If I was bored, I would concoct an FFMPEG command, asking
FFMPEG to read my source file "sample.webp" and make BMP files
from it (for all the animation frames). See if any FFMPEG
documentation hints at a de-capsulation.

And I agree with J.P, that VLC should also be a candidate for
test, as it uses FFMPEG-like libraries or libavcodec or the like.
The reason for picking FFMPEG, is I probably have source for
some version here, and could pick through it for mention of
the subject.

The Wiki article does not concentrate on any common library making
the rounds. It mentions the release version has made it to 1.0
meaning it was "release" quality. But it does not track
details of the package, or how any binder twine inside it works.

Nominally from here, but good luck with that.

https://developers.google.com/speed/webp/download

https://chromium.googlesource.com/webm/libwebp/

Some mention here.

https://github.com/coil-kt/coil/discussions/1216

"I followed the WEBP container specification docs and modified the b4rtaz/android-webp-encoder"

# But this still gives the impression that you can pick out frames
# as such, but they still need libvpx to do the delta between frames
# to make bitmap images from the results. Which is what a FFMPEG run would
# do for you perhaps.

https://github.com/b4rtaz/android-webp-encoder

I would say this is a delightfully messy research project.
Some hair loss expected.

*******

OK, there is a claim a recent GIMP can extract the animated frames.
And like processing animated GIF in GIMP, you have to figure out
how to save an animated set of layers. I can never remember how
to do that. Apparently for GIF, it's in the Export As dialog that
appears and there is some save option to save as individual frames
from a decoded GIF. That suggests a WEBP animation could have
a similar design. And source for GIMP should be available,
from gimp.org , assuming this decoding actually works.

You can select a 2.10 if you want to avoid 3.0/3.1

https://download.gimp.org/gimp/

https://download.gimp.org/gimp/v2.10/

# Could be x64, not sure.

https://download.gimp.org/gimp/v2.10/windows/gimp-2.10.38-setup.exe

Paul
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From Newsgroup: alt.windows7.general

On 29.09.2025 15:22, Paul wrote:

On Mon, 9/29/2025 4:26 AM, R.Wieser wrote:

Hello all,

Using libwebp.dll I'm able to extract static images, but would also like to >> extract frames from animations.

Alas, although I have a description of the file headers and can see where a >> "vp8 " chunk starts, I cannot seem to find any information (using DDG) to >> how to extract-and-decode such a chunk (if at all possible with
libwebp.dll).

Also, although it seems that I need(?) a second dll to handle such animated >> webp image I can't seem to find which one it should be (where I can download
it, and its API description).

Some help would be appriciated.

By the way: win32

Regards,
Rudy Wieser

It seems to involve either just libwebp, or it involves libwebp plus libvpx

https://en.wikipedia.org/wiki/WebP

"library libvpx can extract VP8 key frames from WebM media"

If I was bored, I would concoct an FFMPEG command, asking
FFMPEG to read my source file "sample.webp" and make BMP files
from it (for all the animation frames). See if any FFMPEG
documentation hints at a de-capsulation.

tried with Win7/64 build:
ffmpeg version 2024-11-28-git-bc991ca048-essentials_build-www.gyan.dev

couldn't decode webp animation

ciao.,.
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From Newsgroup: alt.windows7.general

Schugo,

webpmux is part of libwebp https://developers.google.com/speed/webp/docs/webpmux

Thats a program, not a DLL I can program against.

https://chromium.googlesource.com/webm/libwebp/+/refs/heads/main/examples/webpmux.c

tried this?

Well, I would than first need the involved DLLs, libary and header-files. Which is what I was/am looking for. :-)

And by the way: did you ever try the "txt" download in the lower-right ?
All I get is a base64-encoded blob ...


Also, thru your first link I found a download website for all kind of
libwebp versions( https://storage.googleapis.com/downloads.webmproject.org/releases/webp/index.html )
, but when I downloaded libwebp-1.0.3-windows-x86.zip all I got was a set of executables, no DLLs. :-|

I even remember having, months ago, already downloaded the the 1.0.2 version from there - with the same result.

I could have done with some information to what those downloads contain - maybe one of the downloads does actually contain the DLLs I need - but no such documentation seems to be available. :-(

Regards,
Rudy Wieser


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From Newsgroup: alt.windows7.general

Paul,

It seems to involve either just libwebp, or it involves libwebp plus
libvpx

https://en.wikipedia.org/wiki/WebP

"library libvpx can extract VP8 key frames from WebM media"

The page itself doesn't show a download link, and searching for "windows libvpx"t doesn't return anything either (just multiple pages with "you must also like /this/ !" crap. :-( )

If I was bored, I would concoct an FFMPEG command, asking
FFMPEG to read my source file "sample.webp" and make BMP
files from it (for all the animation frames). See if any FFMPEG
documentation hints at a de-capsulation.

I'm "bored" enough to try to write something, but have very little wish to
add a dependancy like that.

https://developers.google.com/speed/webp/download

That shows utilities and source-code only. No DLLs

https://chromium.googlesource.com/webm/libwebp/

Same.

https://github.com/coil-kt/coil/discussions/1216

"I followed the WEBP container specification docs and modified the
b4rtaz/android-webp-encoder"

Not my intention to dive into it /that/ deep. Plus the OS and programming-language difference ofcourse.

# But this still gives the impression that you can pick out frames
# as such, but they still need libvpx to do the delta between frames
# to make bitmap images from the results. Which is what a FFMPEG
# run would do for you perhaps.

I have the idea that WebPBlendAlpha could be helpfull with that. Either
that, or some GDIPlus.

OK, there is a claim a recent GIMP can extract the animated frames. [snip]

Same as for ffmpeg. I'd like to keep my dependancies few, and small.

Thanks for the suggestions.

By the way, if you happen to know how to use one of the functions in libwebp.dll to start decoding at a "VP8 " chunk (WebPDecodeRGBA related)
that would likely already solve my problem ...

Regards,
Rudy Wieser



--- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: alt.windows7.general

On Mon, 9/29/2025 9:22 AM, Paul wrote:

OK, there is a claim a recent GIMP can extract the animated frames.
And like processing animated GIF in GIMP, you have to figure out
how to save an animated set of layers. I can never remember how
to do that. Apparently for GIF, it's in the Export As dialog that
appears and there is some save option to save as individual frames
from a decoded GIF. That suggests a WEBP animation could have
a similar design. And source for GIMP should be available,
from gimp.org , assuming this decoding actually works.

You can select a 2.10 if you want to avoid 3.0/3.1

https://download.gimp.org/gimp/

https://download.gimp.org/gimp/v2.10/

# Could be x64, not sure.

https://download.gimp.org/gimp/v2.10/windows/gimp-2.10.38-setup.exe

Paul

The Linux version was missing the Python plugin for Open Raster format
( file-openraster.py ), but the Windows version of the software had it.

You open the .webp in GIMP, then select Export As and end the
filename with .ora to select Open Raster format. After saving the file,
you use an unzip program on the file, to get the PNG multiple frames.
And then the frames can be individually opened with other packages.

Paul
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From Newsgroup: alt.windows7.general

On Mon, 9/29/2025 10:33 AM, R.Wieser wrote:

Schugo,

webpmux is part of libwebp
https://developers.google.com/speed/webp/docs/webpmux

Thats a program, not a DLL I can program against.

https://chromium.googlesource.com/webm/libwebp/+/refs/heads/main/examples/webpmux.c

tried this?

Well, I would than first need the involved DLLs, libary and header-files. Which is what I was/am looking for. :-)

And by the way: did you ever try the "txt" download in the lower-right ?
All I get is a base64-encoded blob ...

Also, thru your first link I found a download website for all kind of libwebp versions( https://storage.googleapis.com/downloads.webmproject.org/releases/webp/index.html )
, but when I downloaded libwebp-1.0.3-windows-x86.zip all I got was a set of executables, no DLLs. :-|

I even remember having, months ago, already downloaded the the 1.0.2 version from there - with the same result.

I could have done with some information to what those downloads contain - maybe one of the downloads does actually contain the DLLs I need - but no such documentation seems to be available. :-(

Regards,
Rudy Wieser

https://storage.googleapis.com/downloads.webmproject.org/releases/webp/libwebp-1.6.0.tar.gz

(Unpack)

./configure

checking build system type... i686-pc-mingw32
checking host system type... i686-pc-mingw32
checking for a BSD-compatible install... /bin/install -c
checking whether sleep supports fractional seconds... yes
checking filesystem timestamp resolution... 2
checking whether build environment is sane... yes
checking for a race-free mkdir -p... /bin/mkdir -p

<lots of lines here snipped, depends on your build environment>

WebP Configuration Summary
--------------------------

Shared libraries: yes
Static libraries: yes
Threading support: yes
libwebp: yes
libwebpdecoder: no
libwebpdemux: yes
libwebpmux: yes
libwebpextras: no

Tools:
cwebp : yes
Input format support
====================
JPEG : no \
PNG : no \___ It's telling me I'm screwed
TIFF : no /
WIC : no /
dwebp : yes
Output format support
=====================
PNG : no
WIC : no
GIF support : no
anim_diff : no
gif2webp : no
img2webp : yes
webpmux : yes
vwebp : no
webpinfo : yes
SDL support : no
vwebp_sdl : no

You are likely to need a libjpeg-dev (.h,.dll), libpng-dev, libtiff-dev, libwic-dev?
and so on. The reason I suggest that, is "libwebpdecoder: no" and
some amount of dependencies must be satisfied to get that to work.
If you were to find a libwebp-dev, it might have dependencies on
the other image libraries or something.

I can't go any further on this OS, as all I have here is mingw32
for small time programming, and I don't have JPEG/PNG/TIFF/GIF
and so on for this sort of activity.

There is "vcpkg" for Visual Studio but that looks to be a bit
on the embrace and extend side, in that if you're using an older
tool flow, that might get no closer to your "orbit" than any other
approach.

CYGWIN could have some of this stuff I suppose, but it's another
"orbit" problem in the making.

The only way to build a tree it seems, is to build a fucking tree.
Which of course, takes forever (at work when I tried to build
my own web browser with absolutely nothing for a tree, it took
40 hours work, a whole week, to do it). It was like climbing
Mt.Everest, but it's an essential component of doing this
work constantly, is assembling such a tree if you're going to
work with images and so on.

Some version of MINGW-64 might have a tree that can be
downloaded... but then the output is x64 and you are
strictly an x86 person so that won't fly either. That's
getting closer.

Paul


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Paul,

https://storage.googleapis.com/downloads.webmproject.org/releases/webp/libwebp-1.6.0.tar.gz

(Unpack)

./configure

checking build system type... i686-pc-mingw32

:-) There was a reason I asked for DLLs. I do not have access to the needed build environment for those source-files. I'm strictly an
Assembler-language person. (I've dabbed into other languages, but always returned to it).

And something I just remembered : I did not get my libwebp DLL from any "official" website either. I had to download it from some "DLL repair" website. :-\

It looks like I'm out of luck here. :-(

Update: I can't find DLLs to extract frames, but I can, in the file (thats loaded into memory) move a frame to a position where the decoding function that I have thinks it looks at an ordinary static image.

Not the best solution, but for the moment it has to do.

Regards,
Rudy Wieser


--- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: alt.windows7.general

On 2025/10/1 7:9:34, R.Wieser wrote:

[]

:-) There was a reason I asked for DLLs. I do not have access to the needed build environment for those source-files. I'm strictly an
Assembler-language person. (I've dabbed into other languages, but always returned to it).

[]

When I originally saw your post, I - as did some others - thought you
just wanted to be able to extract the frames (so suggested what I'd try,
VL and IrfanView - you said VLC wouldn't play the file and hadn't tried IrfanView). But it of course became clear that you're wanting to create software that involves the extraction.

Just out of curiosity, what are you trying to do? Of course, don't say
if it's confidential.
--
J. P. Gilliver. UMRA: 1960/<1985 MB++G()ALIS-Ch++(p)Ar++T+H+Sh0!:`)DNAf
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From Newsgroup: alt.windows7.general

J. P. ,

When I originally saw your post, I - as did some others - thought
you just wanted to be able to extract the frames

You thought absolutily correct - just not in the way I imagined it.

But it of course became clear that you're wanting to create
software that involves the extraction.

Thats why I, I thought rather explicitily, asked for a DLL.

(so suggested what I'd try, VL and IrfanView - you said VLC
wouldn't play the file and hadn't tried IrfanView)

I tried, as having an alternate (backup) method is never a bad thing to
have.

Just out of curiosity, what are you trying to do? Of course, don't say
if it's confidential.

:-) I'm a hobbyist, and wanted to be able to at least see what's in the .webp files that are, on the web, offered as "animated GIF"s *. I already have an image-viewer written for static images which uses Gdiplus,
FreeImage, and libwebp to display a wide(r) range of image-formats. Adding
a "preview" of the animated webp (the first frame) should be (easily?) do-able.

* like sometimes here https://www.picdumps.com/

Perhaps I will even try to add the animation of all frames to it. I first have to see what different animated webp files return, using my "trick", for each of the frame-images.

Regards,
Rudy Wieser


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From Newsgroup: alt.windows7.general

On 2025/10/1 10:19:6, R.Wieser wrote:

J. P. ,

When I originally saw your post, I - as did some others - thought
you just wanted to be able to extract the frames

You thought absolutily correct - just not in the way I imagined it.

But it of course became clear that you're wanting to create
software that involves the extraction.

Thats why I, I thought rather explicitily, asked for a DLL.

Sorry, didn't spot that.

(so suggested what I'd try, VL and IrfanView - you said VLC
wouldn't play the file and hadn't tried IrfanView)

I tried, as having an alternate (backup) method is never a bad thing to have.

Did Irfan work?

Just out of curiosity, what are you trying to do? Of course, don't say>> if it's confidential.

:-) I'm a hobbyist, and wanted to be able to at least see what's in the .webp files that are, on the web, offered as "animated GIF"s *. I already have an image-viewer written for static images which uses Gdiplus, FreeImage, and libwebp to display a wide(r) range of image-formats. Adding a "preview" of the animated webp (the first frame) should be (easily?) > do-able.

Ideally, a selected frame rather than just the first one, which is often
blank or a title only.>

* like sometimes here https://www.picdumps.com/

(Presented me a page in German where I had to pick one of two buttons.)>

Perhaps I will even try to add the animation of all frames to it. I first have to see what different animated webp files return, using my "trick", for each of the frame-images.

Regards,
Rudy Wieser

--
J. P. Gilliver. UMRA: 1960/<1985 MB++G()ALIS-Ch++(p)Ar++T+H+Sh0!:`)DNAf
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From Newsgroup: alt.windows7.general

J. P. ,

I tried, as having an alternate (backup) method is never a bad thing
to have.

Did Irfan work?

I did not try Irfan, as I don't have it (and am quite reluctant to install stuff, especially for a one-off test).

Adding a "preview" of the animated webp (the first frame) should be
(easily?) do-able.

Ideally, a selected frame rather than just the first one, which is
often blank or a title only.

Even that of webp "animated GIFs" (iow, *not* webm movies) ? I've looked
at just a handfull of such files, but got a nice, full-sized picture every time.

* like sometimes here https://www.picdumps.com/

(Presented me a page in German where I had to pick one of two buttons.)

Hmmm... I definitily do not see any such thing (caveat: I've got JS disabled). It is a German website though, linking to other German picdump websites.

Regards,
Rudy Wieser


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On Wed, 1 Oct 2025 17:42:31 +0200, "R.Wieser" <address@is.invalid>
wrote:

about extracting animated .webp images

Did Irfan work?

yes, Irfanview v4.72 ( latest ) can extract all .webp frames

--- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: alt.windows7.general

Using libwebp.dll I'm able to extract static images, but would also like
to extract frames from animations.

It turns out that libwebp.dll is capable of doing that by itself. The info was quite hidden (in a header file I found) for pople, like me, who don't
know what to look for.

Next step: combine the current frame (which might have holes) with the ones before it to get a full frame.

Regards,
Rudy Wieser


--- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: alt.windows7.general

On Sat, 10/4/2025 1:47 PM, R.Wieser wrote:

Using libwebp.dll I'm able to extract static images, but would also like
to extract frames from animations.

It turns out that libwebp.dll is capable of doing that by itself. The info was quite hidden (in a header file I found) for pople, like me, who don't know what to look for.

Next step: combine the current frame (which might have holes) with the ones before it to get a full frame.

Regards,
Rudy Wieser

https://developers.google.com/speed/webp/docs/riff_container?csw=1

"An animated image with Exif metadata may look as follows:

RIFF/WEBP
+- VP8X (descriptions of features used)
+- ANIM (global animation parameters)
+- ANMF (frame1 parameters + data)
+- ANMF (frame2 parameters + data)
+- ANMF (frame3 parameters + data)
+- ANMF (frame4 parameters + data)
+- EXIF (metadata)

"

https://colinbendell.github.io/webperf/animated-gif-decode/3.webp

https://en.wikipedia.org/wiki/Resource_Interchange_File_Format # Uses 4CC codes, as in the presentation
# of the expected chunks above

In a regular video (mostly lossy codecs), there is motion blur
and I-B-P frames. It does not appear this format works this way,
as "animation" is not quite the same thing as a movie.

None of my tools are gaining traction on the topic, so good luck.

The RIFF container buys you "packetization". At least you know the
simple scheme that delineates the thing. The packet length, allows
you to "step over" things you don't understand (or that your parser
design does not parse). This is how EXIF is "stepped over" by
a viewer application, as the EXIF has nothing to do with the
presentation, and it only exists to help humans sort the files.
(EXIF fields, a small subset, are searchable from File Explorer search box.)

You might need a fair number of samples of animated webp, before
finding ones which are more "movie-like" inside. You can see the
"3.webp" file in the link, it's not exactly conventional multimedia.
But I don't know if they all look that wooden.

Paul
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Paul,

"An animated image with Exif metadata may look as follows:

[snip]

Yep, thats the part I've just finished. Now I have frame-images with
"holes" in them.

https://colinbendell.github.io/webperf/animated-gif-decode/3.webp

:-) Yep, found that one too. A bad example though, as pretty-much everything/color changes and only a small area around the right sholder of
the standing woman seems to stay somewhat static (shows as holes in the frame-images).

In a regular video

At the moment I'm not doing video. Just some "animated GIF" webp stuff.

None of my tools are gaining traction on the topic, so good luck.

My apologies for that, but my whole fun with the matter is to make my own tools for it - just to see if I can. iow, having a result is nice, but walking the path to it is at least twice as interresting.

You might need a fair number of samples of animated webp,
before finding ones which are more "movie-like" inside.

I already have problems with finding ones that have been created for the purpose of being an example, showing the best the "animated GIF" format can
do (like small sub-images moving over a large canvas).

Regards,
Rudy Wieser


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Yep, thats the part I've just finished. Now I have frame-images
with "holes" in them.

To clarify that : for debugging purposes saved to disk as PNG images (after first having made the mistake to save them as JPGs, which, using GDIPlus,
have its alpha stripped - "where are the images 'holes', they are supposed
to be there !" :-\ ).

Regards,
Rudy Wieser


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