Hey Berki!
I checked out the site and noted (reformatted quote);
The following open source libraries implement AC-3:
* libavcodec in ffmpeg (LGPLv2.1+) and libav (LGPLv2.1+)
* Decoder and encoder for AC-3
* To compile only the AC-3 decoder: --disable-everything
--enable-decoder=ac3
--enable-demuxer=ac3
--enable-parser=ac3
(then enable other parsers, demuxers, muxers, decoders, and
encoders that you need)
* To compile the AC-3 decoder and the AC-3 encoder:
--disable-everything
--enable-encoder=ac3
--enable-decoder=ac3
--enable-muxer=ac3
--enable-demuxer=ac3
--enable-parser=ac3
(then enable other parsers, demuxers, muxers, decoders, and
encoders that you need)
* Warning: When preparing to use libavcodec in any product,
you should always start by disabling all encoders, decoders,
parsers, muxers, demuxers, bitstream filters, protocols,
filters, and hwaccels, then selectively enabling the
ones that your product absolutely needs. To do this, use
--disable-everything as your first ./configure option. This
will help protect your product from unnecessary intellectual
property disputes as well as some security vulnerabilities.
If you have not added --disable-everything as your first
option, you should at least manually disable the encoders,
decoders, muxers, demuxers, and parsers for eac3, mlp, and
truehd.
* liba52 (GPLv2) used by VLC and others
* Decoder only for AC-3
* valib from AC3Filter (GPLv2)
* Decoder and encoder for AC-3. Note: Build process does not
allow easy removal of patented E-AC-3 code.
Of the above three listed above I have /usr/lib/liba52.so.0.0.0 and /usr/lib/libavcodec.so.59.37.100.
$ ffmpeg -version
ffmpeg version 5.1.2 Copyright (c) 2000-2022 the FFmpeg developers
built with gcc 12.2.0 (GCC)
configuration: --prefix=/usr --enable-gpl --enable-version3 --enable-nonfree --disable-static --enable-shared --disable-debug --enable-libass --enable-libfdk-aac --enable-libfreetype --enable-libmp3lame --enable-libopus --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libxvid --enable-libx264 --enable-libx265 --enable-openssl --docdir=/usr/share/doc/ffmpeg-5.1.2
libavutil 57. 28.100 / 57. 28.100
libavcodec 59. 37.100 / 59. 37.100
libavformat 59. 27.100 / 59. 27.100
libavdevice 59. 7.100 / 59. 7.100
libavfilter 8. 44.100 / 8. 44.100
libswscale 6. 7.100 / 6. 7.100
libswresample 4. 7.100 / 4. 7.100
libpostproc 56. 6.100 / 56. 6.100
Note that none of the --enables mention anything about ac3 as per the recommendation for both the encoder or decoder. So far it has never been an issue.
I was doubtful but after hearing it, it really made a difference.
I'll take your word for it. I used to like in the good ol' days when they had sound rooms in stores that sold audio equipment so one could listen to before buying.
As I don't want to bother neighbors and prefer headsets anyway, I
opted for one that supports virtual surround.
Understood. If you're getting 2 channel stereo at least that is better than nothing which is what Winmodems (your analogy) true value was. You're probably far ahead of the game already, comparitively speaking.
Life is good,
Maurice
... Fidonet 4K - Sweet Sixteen Penguins of the Apocalypse.
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