6

I'm trying to get the Firefox Extension "Video Download Helper" (VDH) to convert and record videos. The suggested way of doing this is to install a precompiled version of libav called "Convert Helper" from the VDH Homepage.

I'm not willing to do that for various reasons.¹

So I want to install libav on my Windows 7 (x64) system and point the addon to the right .exe/.dll/whatever it needs. There is an option to enter a "converter path" manually in the settings, although it does not work for me - probably because I'm not entering the correct path. The entered path just disappears after I click on the "Recheck converter" button. (I'm not really sure if the corresponding field is even made for input. You can see a picture of the settings page here in the "Using conversion rules" section.)

The question is: How do I install libav correctly?
libav provides Windows builds in the download section, but I don't know where to put the extracted files or how to make the Firefox addon recognize the installation. Do I just throw the .dlls and .exes in the System32 folder or probably somewhere in the system's $PATH variable? Is there any other way?

Any ideas are much appreciated.

¹One of them is that they want me to pay for a completely free codec to avoid watermarks which is (a part of) why they appear on libav's Hall of Shame (remark 03/29/2016: the Hall of Shame is removed until further notice) (remark 05/06/2025: libav was abandoned in 2020, links replaced with archived ones). On Linux there's no problem whatsoever (see installation instructions for Linux). Another reason is the fact that I want to have some level of control about what's installed on my system and that "ConverterHelper.exe" obviously is not just a compiled version of the libav codec.

Piwi
  • 178

3 Answers3

7

Solution

Use a build from libav.org and extract it to some folder.

Create a .reg file with this content and adjust InstallFolder accordingly, e.g., C:\bin\libav-11.3-win64\win64\usr\bin

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\DownloadHelper\ConvertHelper3]
"InstallFolder"="C:\Program Files\ConvertHelper3"
"Version"="3.1"
"Is32Bits"="no"
"ReliableVP9"="yes"

Background

I powered up a VM and did some analysis of the ConvertHelper3Setup.exe and found:

VDH looks at the registry for this key:

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\DownloadHelper\ConvertHelper3\InstallFolder

Then it looks at this folder (the default would be C:\Program Files\ConvertHelper3) and checks if there is an executable avconv.exe. If it is, the converter works.

The latest ConvertHelper3Setup.exe (as of 29. March 2016) installs avconv 11.2

I downloaded the newest release (11.3) from libav.org, and everything still works. Can be found here:

https://builds.libav.org/windows/release-gpl/libav-11.3-win64.7z

This is the general download folder for builds:

https://builds.libav.org/windows/
Jackdaw
  • 1,834
masgo
  • 2,324
1

I tried the same and discovered two problems with that: First, at least my version (5.3.1) of VDH seems only to look into \Program Files\ConvertHelper3 for the avconv.exe file, no matter what I enter for the path.

Second, the watermarking is not in the downloaded codec, but a native feature of libav used by VDH to mark the result. So even if one exchanges the libav library, VDH still uses it to place the watermark.

To solve this issue you would need to recompile avconv with leaving out the watermark feature (best ignore it at command line) or put a filter program named avconv.exe which calls the real avconv.exe, but with arguments cleaned of the watermark command. Unfortunately, both solutions are quite a bit of work.

Peter B.
  • 451
-1

This reply might be a little "tongue in cheek" but I just kicked myself a little for searching this topic in the first place.... Because... (this should be relevant on a superuser forum) every time I upgrade the hardware Windows is running on, the old PC gets re purposed as my Linux box and I run a KVM switch for them. I've tried VMs and used both OS as hosts, dual boot etc... simply recycling hardware seems to work the best - simplest - least complicated etc. Some stuff has to run on Windows and Linux has better tools. Sooo the video that didn't want to convert on Windows... Hit the scroll lock and load the same url on Linux, problem solved :)

wildew
  • 1