FFmpeg

foobar2000 uses FFmpeg under the GNU LGPL v2.1.
FFmpeg home page

Downloads

FFmpeg source code with build scripts used by foobar2000 can be obtained from the link below:

FFmpeg 3.4.5

Used in foobar2000 v1.4.3 and newer
Download source code

FFmpeg 3.2.4

Used in foobar2000 v1.3.15 and newer
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FFmpeg 3.2.2

Used in foobar2000 v1.3.14
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FFmpeg 3.1.4

Used in foobar2000 v1.3.13
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FFmpeg 3.1.2

Used in foobar2000 v1.3.11
Download source code