Webm support

[phillipberndt]

Webm support

[CamilleScholtz]

That's probably because webm is a video format

[hetraeus]

FYI soundless WEBM is replacing GIFs here and there in the web. It is becoming pretty common.

[phillipberndt]

I thought about generic video support a while ago, but then did not implement it because I could not find any real use case. Yours sounds good enough for me to give it a try.

See the libav branch for an early and experimental version of the new backend.

[phillipberndt]

I've tested the backend with both the libav fork and the latest ffmpeg release now. While everything works somehow, it appears that frames should be read continuously from a separate thread and queued instead of the read-as-needed basis I'm currently using – I'm experiencing load-dependent glitches/frame drops/fragment errors, but only with larger videos. Small animations seem to run fine mostly. Please test this feature, I'm eager for feedback 😉

I'm tempted to leave it in its current state and ship it flagged such that it is not compiled in unless explicitly selected in configure (I share @onodera-punpun's opinion that video support is an uncommon feature for image viewers..).

[hetraeus]

I just tested it. It runs seamlessly between image, gifs, and webm! Excellent!

I did a PKGBUILD, so Arch Linux testers may help theirselves
https://aur.archlinux.org/packages/pqiv-git/
https://aur.archlinux.org/cgit/aur.git/tree/PKGBUILD?h=pqiv-git

Works for me. Should I close this ticket?

[phillipberndt]

Great! I'll close it once I merge this, with which I'm going to wait until I've had a chance to test this further & on different platforms.

[phillipberndt]

I've tested this in Ubuntu with both the libav fork and the latest ffmpeg, on FreeBSD and on Windows using mxe now. Seems to work smoothly everywhere. I merged the code to master now.

The only thing that might turn out to be a problem could be the reading-fames-as-needed thing. We'll see about that.

[CamilleScholtz]

I tried compiling this with the lates ffmpeg (2.8, I also tried 2.7.4) but I keep getting the following:

/usr/bin/ld: backends/libav.o: undefined reference to symbol 'av_frame_alloc@@LIBAVUTIL_54'
/usr/lib/libavutil.so.54: error adding symbols: DSO missing from command line
collect2: error: ld returned 1 exit status
GNUmakefile:115: recipe for target 'pqiv' failed

EDIT: Fixed this: #41

[RaitaroH]

@phillipberndt I am a bit confused regarding webm support. I have version 2.11 and according to the changelog this should support webm, right? Testing it with this file from wikipedia pqiv gives:

$ pqiv Schlossbergbahn.webm
Didn't recognize file `Schlossbergbahn.webm': Both its extension and MIME-type `video/webm' are unknown. Fall-back to default file handler.
Failed to load image Schlossbergbahn.webm: Unrecognized image file format
No images left to display.

I have installed the package from AUR, so 2.11-3 and libwebp is a dependency for it, I am not missing it. Also, the git version for the AUR package in the readme is dead.

EDIT
Actually nevermind. I was dumb and I didn't notice that the pkgbuild is building pqiv without video support 😅