[ffmpeg] Complete filter graphs

Dynamically generate a list of supported filters and transmogrify the
typed out filter graph into a fish completion.

[ci skip]
This commit is contained in:
Mahmoud Al-Qudsi 2020-08-30 21:51:53 -05:00
parent 3d5e1a061c
commit 010db9e7be

View File

@ -2,6 +2,15 @@ function __fish_ffmpeg_last_arg
echo (commandline -co)[-1]
end
# Allow completions to match against an argument that includes a stream specifier, e.g. -c:v:2
function __fish_ffmpeg_complete_regex
set -l regex $argv[1]
set -l completions $argv[2..-1]
complete -x -c ffmpeg -n "__fish_ffmpeg_last_arg | string match -rq -- '^'$prefix'(\$|:)'" \
-a "$completions"
end
function __fish_ffmpeg_help_type
printf '%s\t%s\n' long "Print more options"
printf '%s\t%s\n' full "Print all options"
@ -57,6 +66,28 @@ function __fish_ffmpeg_pix_fmts
string replace -rf '^[IOHPB.]{5} (\S+) .*' '$1'
end
function __fish_ffmpeg_filters
# TODO: Figure out how to distinguish {audio,video} source and destination, because some filters
# can go cross those lines (e.g. showvolume, which generates a video representation of the input
# audio).
set -l filter '.'
switch $argv[1]
case video
set filter '[V]\S*->|->\S*[V]'
case audio
set filter '[A]\S*->|->\S*[A]'
case all
case '*'
set filter '.'
end
ffmpeg -hide_banner -loglevel quiet -filters |
string match -e -- '->' | # skip past the header
string match -er $filter |
string replace -rf '^ [TSC.]{3} +(\S+) +\S+->\S+ +(.*)' '$1\t$2'
end
complete -c ffmpeg -s i -d "Specify input file"
# Print help / information / capabilities
@ -130,8 +161,7 @@ complete -c ffmpeg -o bits_per_raw_sample -d "Set the number of bits per raw sam
complete -c ffmpeg -o vn -d "Disable video"
complete -c ffmpeg -o vcodec -o "codec:v" -o "c:v"
# Also list codecs when a particular stream is selected, e.g. -c:v:0
complete -x -c ffmpeg -n "__fish_ffmpeg_last_arg | string match -r '^-(vcodec|c(odec)?:v)(:\d+)?'" \
-a "(__fish_ffmpeg_codec_list video)" -d "Set video codec"
__fish_ffmpeg_complete_regex "-(vcodec|c(odec)?:v)" "(__fish_ffmpeg_codec_list video)"
complete -c ffmpeg -o timecode -d "Set initial TimeCode value"
complete -x -c ffmpeg -o pass -a "1 2 3" -d "Select the pass number"
complete -c ffmpeg -o vf -d "Set video filters"
@ -140,8 +170,7 @@ complete -c ffmpeg -s b -o "b:v" -d "Video bitrate"
complete -c ffmpeg -o dn -d "Disable data"
# Advanced video options
complete -c ffmpeg -o pix_fmt
complete -x -c ffmpeg -n "__fish_ffmpeg_last_arg | string match -rq -- '^-pix_fmt(\$|:)'" \
-a "(__fish_ffmpeg_pix_fmts)"
__fish_ffmpeg_complete_regex "-pix_fmt" "(__fish_ffmpeg_pix_fmts)"
# Audio options
complete -c ffmpeg -o aframes -d "Set the number of audio frames to output"
@ -150,9 +179,7 @@ complete -c ffmpeg -o ar -d "Set audio sampling rate"
complete -c ffmpeg -o ac -d "Set number of audio channels"
complete -c ffmpeg -o an -d "Disable audio"
complete -c ffmpeg -o acodec -o "codec:a" -o "c:a"
# Also list codecs when a particular stream is selected, e.g. -c:a:0
complete -x -c ffmpeg -n "__fish_ffmpeg_last_arg | string match -r '^-(acodec|c(odec)?:a)(:\d+)?'" \
-a "(__fish_ffmpeg_codec_list audio)" -d "Set audio codec"
__fish_ffmpeg_complete_regex '-(acodec|c(odec)?:a)' "(__fish_ffmpeg_codec_list audio)"
complete -c ffmpeg -o vol -d "Change audio volume"
complete -c ffmpeg -o af -d "Set audio filters"
@ -160,14 +187,94 @@ complete -c ffmpeg -o af -d "Set audio filters"
complete -c ffmpeg -s s -d "Set frame size"
complete -c ffmpeg -o sn -d "Disable subtitle"
complete -c ffmpeg -o scodec -o "codec:s" -o "c:s"
# Also list codecs when a particular stream is selected, e.g. -c:s:0
complete -x -c ffmpeg -n "__fish_ffmpeg_last_arg | string match -r '^-(scodec|c(odec)?:s)(:\d+)?'" \
-a "(__fish_ffmpeg_codec_list subtitle)" -d "Set subtitle codec"
__fish_ffmpeg_complete_regex '^-(scodec|c(odec)?:s)(:\d+)?' "(__fish_ffmpeg_codec_list subtitle)"
complete -c ffmpeg -o stag -d "Force subtitle tag/fourcc"
complete -c ffmpeg -o fix_sub_duration -d "Fix subtitles duration"
complete -c ffmpeg -o canvas_size -d "Set canvas size"
complete -c ffmpeg -o spre -d "Set the subtitle options to the indicated preset"
# Indeterminate options, may be used e.g. when only one stream exists
complete -x -c ffmpeg -n "__fish_ffmpeg_last_arg | string match -r '^-(codec|c(odec)?)(:\d+)?'" \
-a "(__fish_ffmpeg_codec_list all)" -d "Set codec"
__fish_ffmpeg_complete_regex '^-(codec|c(odec)?)(:\d+)?' "(__fish_ffmpeg_codec_list all)"
# Filters
#
# fish completions are not designed to take the current argument being completed as an input,
# and if introspected it is normally used to filter/constrain the completions generated. ffmpeg's
# command line syntax is extremely nasty and in addition to using stringification for all arguments,
# relies on special characters to delimit separate subarguments (rather than, e.g., concatenating
# repeated invocations of the same switch), meaning the typical way of generating fish completions
# would only allow us to generate the very first subargument in a complex argument payload.
#
# We hack around this in a ridiculously ugly fashion by always generating completions that are
# prepended with a prefix of the current value of the payload in question.
#
# Top-level ffmpeg filters are comma separated, but take optional arguments that might themselves
# take optional subarguments. While = is a key=value delimiter, it is also a prefix for the first
# argument to a filter, e.g. filter_name=opt1 and filter_name=opt1=opt_value, and in the case that
# a filter takes more than one argument, filter arguments are delimited with :
#
# A complete example:
#
# ffmpeg .... -filter:v filter1,filter2=f2_arg1=f2_arg1_val:f2_arg2
function __fish_ffmpeg_split_filter_graph
set -l filters (string split , $argv[1])
printf "%s\n" $filters
end
# Given a single filter expression, emits the filter name on the first line and then each key=value
# pair of arguments to the filter on each subsequent line.
function __fish_ffmpeg_decompose_filter
set -l parts (string split -m 1 = "$argv")
echo $parts[1] # the filter name
set -l arguments (string split : $parts[2])
printf "%s\n" $arguments
end
function __fish_ffmpeg_concat_filters
string join -- , $argv
end
function __fish_ffmpeg_concat_filter_args
string join -- : $argv
end
function __fish_ffmpeg_complete_filter
set -l filter_type "all"
if string match -rq -- '^-(vf(ilter)?|f(ilter)?:v)' (__fish_ffmpeg_last_arg)
set filter_type "video"
else if string match -rq -- '^-(af(ilter)?|f(ilter)?:a' (__fish_ffmpeg_last_arg)
set filter_type "audio"
end
# echo -e "\n **** $filter_type **** \n" > /dev/tty
set -l filters_arg (commandline -o)[-1]
if string match -rq -- '^-' $filters_arg
# No filter name started
__fish_ffmpeg_filters $filter_type
return
end
set -l filters (__fish_ffmpeg_split_filter_graph $filters_arg)
# We are completing only the last filter (in case there are multiple)
set -l filter $filters[-1]
# Remove it from the list of passed-through filters
set -e filters[-1]
# `ffmpeg -h filter=FILTER` exposes information that can be used to dynamically complete not
# only the name of the filter but also the name of its individual options. We currently only
# support completing the name of the filter.
set -l decomposed (__fish_ffmpeg_decompose_filter $filter)
set -l filter_name $decomposed[1]
set -l filter_args (__fish_ffmpeg_concat_filter_args $decomposed[2..-1])
# Emit the mutated filter graph, with permutations of the final filter name offered as
# completions.
for known_filter in (__fish_ffmpeg_filters $filter_type)
set -l modified_filter (string join = $known_filter $filter_args)
__fish_ffmpeg_concat_filters $filters $modified_filter
end
end
complete -x -c ffmpeg -o filter -o filter:v -o filter:s -o filter:a -o vf -o af \
-a "(__fish_ffmpeg_complete_filter)"