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af: remove deprecated audio filters

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These couldn't be relicensed, and won't survive the LGPL transition. The
other existing filters are mostly LGPL (except libaf glue code).

This remove the deprecated pan option. I guess it could be restored by
inserting a libavfilter filter (if there's one), but for now let it be
gone.

This temporarily breaks volume control (and things related to it, like
replaygain).
This commit is contained in:
wm4
2017-11-29 20:13:28 +01:00
parent 23d9dc5457
commit 3d27a0792b
13 changed files with 1 additions and 1153 deletions
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176
DOCS/man/af.rst
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@@ -91,81 +91,6 @@ Available filters are:
Select the libavcodec encoder used. Currently, this should be an AC-3
encoder, and using another codec will fail horribly.
``equalizer=g1:g2:g3:...:g10``
10 octave band graphic equalizer, implemented using 10 IIR band-pass
filters. This means that it works regardless of what type of audio is
being played back. The center frequencies for the 10 bands are:
=== ==========
No. frequency
=== ==========
0 31.25 Hz
1 62.50 Hz
2 125.00 Hz
3 250.00 Hz
4 500.00 Hz
5 1.00 kHz
6 2.00 kHz
7 4.00 kHz
8 8.00 kHz
9 16.00 kHz
=== ==========
If the sample rate of the sound being played is lower than the center
frequency for a frequency band, then that band will be disabled. A known
bug with this filter is that the characteristics for the uppermost band
are not completely symmetric if the sample rate is close to the center
frequency of that band. This problem can be worked around by upsampling
the sound using a resampling filter before it reaches this filter.
``<g1>:<g2>:<g3>:...:<g10>``
floating point numbers representing the gain in dB for each frequency
band (-12-12)
.. admonition:: Example
``mpv --af=equalizer=11:11:10:5:0:-12:0:5:12:12 media.avi``
Would amplify the sound in the upper and lower frequency region
while canceling it almost completely around 1 kHz.
``channels=nch[:routes]``
Can be used for adding, removing, routing and copying audio channels. If
only ``<nch>`` is given, the default routing is used. It works as follows:
If the number of output channels is greater than the number of input
channels, empty channels are inserted (except when mixing from mono to
stereo; then the mono channel is duplicated). If the number of output
channels is less than the number of input channels, the exceeding
channels are truncated.
``<nch>``
number of output channels (1-8)
``<routes>``
List of ``,`` separated routes, in the form ``from1-to1,from2-to2,...``.
Each pair defines where to route each channel. There can be at most
8 routes. Without this argument, the default routing is used. Since
``,`` is also used to separate filters, you must quote this argument
with ``[...]`` or similar.
.. admonition:: Examples
``mpv --af=channels=4:[0-1,1-0,2-2,3-3] media.avi``
Would change the number of channels to 4 and set up 4 routes that
swap channel 0 and channel 1 and leave channel 2 and 3 intact.
Observe that if media containing two channels were played back,
channels 2 and 3 would contain silence but 0 and 1 would still be
swapped.
``mpv --af=channels=6:[0-0,0-1,0-2,0-3] media.avi``
Would change the number of channels to 6 and set up 4 routes that
copy channel 0 to channels 0 to 3. Channel 4 and 5 will contain
silence.
.. note::
You should probably not use this filter. If you want to change the
output channel layout, try the ``format`` filter, which can make mpv
automatically up- and downmix standard channel layouts.
``format=format:srate:channels:out-format:out-srate:out-channels``
Does not do any format conversion itself. Rather, it may cause the
filter system to insert necessary conversion filters before or after this
@@ -205,107 +130,6 @@ Available filters are:
used to do conversion itself, unlike this one which lets the filter system
handle the conversion.
``volume[=<volumedb>[:...]]``
Implements software volume control. Use this filter with caution since it
can reduce the signal to noise ratio of the sound. In most cases it is
best to use the *Master* volume control of your sound card or the volume
knob on your amplifier.
*WARNING*: This filter is deprecated. Use the top-level options like
``--volume`` and ``--replaygain...`` instead.
*NOTE*: This filter is not reentrant and can therefore only be enabled
once for every audio stream.
``<volumedb>``
Sets the desired gain in dB for all channels in the stream from -200 dB
to +60 dB, where -200 dB mutes the sound completely and +60 dB equals a
gain of 1000 (default: 0).
``replaygain-track``
Adjust volume gain according to the track-gain replaygain value stored
in the file metadata.
``replaygain-album``
Like replaygain-track, but using the album-gain value instead.
``replaygain-preamp``
Pre-amplification gain in dB to apply to the selected replaygain gain
(default: 0).
``replaygain-clip=yes|no``
Prevent clipping caused by replaygain by automatically lowering the
gain (default). Use ``replaygain-clip=no`` to disable this.
``replaygain-fallback``
Gain in dB to apply if the file has no replay gain tags. This option
is always applied if the replaygain logic is somehow inactive. If this
is applied, no other replaygain options are applied.
``softclip``
Turns soft clipping on. Soft-clipping can make the
sound more smooth if very high volume levels are used. Enable this
option if the dynamic range of the loudspeakers is very low.
*WARNING*: This feature creates distortion and should be considered a
last resort.
``s16``
Force S16 sample format if set. Lower quality, but might be faster
in some situations.
``detach``
Remove the filter if the volume is not changed at audio filter config
time. Useful with replaygain: if the current file has no replaygain
tags, then the filter will be removed if this option is enabled.
(If ``--softvol=yes`` is used and the player volume controls are used
during playback, a different volume filter will be inserted.)
.. admonition:: Example
``mpv --af=volume=10.1 media.avi``
Would amplify the sound by 10.1 dB and hard-clip if the sound level
is too high.
``pan=n:[<matrix>]``
Mixes channels arbitrarily. Basically a combination of the volume and the
channels filter that can be used to down-mix many channels to only a few,
e.g. stereo to mono, or vary the "width" of the center speaker in a
surround sound system. This filter is hard to use, and will require some
tinkering before the desired result is obtained. The number of options for
this filter depends on the number of output channels. An example how to
downmix a six-channel file to two channels with this filter can be found
in the examples section near the end.
``<n>``
Number of output channels (1-8).
``<matrix>``
A list of values ``[L00,L01,L02,...,L10,L11,L12,...,Ln0,Ln1,Ln2,...]``,
where each element ``Lij`` means how much of input channel i is mixed
into output channel j (range 0-1). So in principle you first have n
numbers saying what to do with the first input channel, then n numbers
that act on the second input channel etc. If you do not specify any
numbers for some input channels, 0 is assumed.
Note that the values are separated by ``,``, which is already used
by the option parser to separate filters. This is why you must quote
the value list with ``[...]`` or similar.
.. admonition:: Examples
``mpv --af=pan=1:[0.5,0.5] media.avi``
Would downmix from stereo to mono.
``mpv --af=pan=3:[1,0,0.5,0,1,0.5] media.avi``
Would give 3 channel output leaving channels 0 and 1 intact, and mix
channels 0 and 1 into output channel 2 (which could be sent to a
subwoofer for example).
.. note::
If you just want to force remixing to a certain output channel layout,
it is easier to use the ``format`` filter. For example,
``mpv '--af=format=channels=5.1' '--audio-channels=5.1'`` would always force
remixing audio to 5.1 and output it like this.
This filter supports the following ``af-command`` commands:
``set-matrix``
Set the ``<matrix>`` argument dynamically. This can be used to change
the mixing matrix at runtime, without reinitializing the entire filter
chain.
``scaletempo[=option1:option2:...]``
Scales audio tempo without altering pitch, optionally synced to playback
speed (default).