spc-pleroma/lib/pleroma/helpers/media_helper.ex

163 lines
3.8 KiB
Elixir

# Pleroma: A lightweight social networking server
# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
# SPDX-License-Identifier: AGPL-3.0-only
defmodule Pleroma.Helpers.MediaHelper do
@moduledoc """
Handles common media-related operations.
"""
alias Pleroma.HTTP
require Logger
def missing_dependencies do
Enum.reduce([imagemagick: "convert", ffmpeg: "ffmpeg"], [], fn {sym, executable}, acc ->
if Pleroma.Utils.command_available?(executable) do
acc
else
[sym | acc]
end
end)
end
def image_resize(url, options) do
with executable when is_binary(executable) <- System.find_executable("convert"),
{:ok, args} <- prepare_image_resize_args(options),
{:ok, env} <- HTTP.get(url, [], pool: :media),
{:ok, fifo_path} <- mkfifo() do
args = List.flatten([fifo_path, args])
run_fifo(fifo_path, env, executable, args)
else
nil -> {:error, {:convert, :command_not_found}}
{:error, _} = error -> error
end
end
defp prepare_image_resize_args(
%{max_width: max_width, max_height: max_height, format: "png"} = options
) do
quality = options[:quality] || 85
resize = Enum.join([max_width, "x", max_height, ">"])
args = [
"-resize",
resize,
"-quality",
to_string(quality),
"png:-"
]
{:ok, args}
end
defp prepare_image_resize_args(%{max_width: max_width, max_height: max_height} = options) do
quality = options[:quality] || 85
resize = Enum.join([max_width, "x", max_height, ">"])
args = [
"-interlace",
"Plane",
"-resize",
resize,
"-quality",
to_string(quality),
"jpg:-"
]
{:ok, args}
end
defp prepare_image_resize_args(_), do: {:error, :missing_options}
# Note: video thumbnail is intentionally not resized (always has original dimensions)
def video_framegrab(url) do
with executable when is_binary(executable) <- System.find_executable("ffmpeg"),
{:ok, env} <- HTTP.get(url, [], pool: :media),
{:ok, fifo_path} <- mkfifo(),
args = [
"-y",
"-i",
fifo_path,
"-vframes",
"1",
"-f",
"mjpeg",
"-loglevel",
"error",
"-"
] do
run_fifo(fifo_path, env, executable, args)
else
nil -> {:error, {:ffmpeg, :command_not_found}}
{:error, _} = error -> error
end
end
defp run_fifo(fifo_path, env, executable, args) do
pid =
Port.open({:spawn_executable, executable}, [
:use_stdio,
:stream,
:exit_status,
:binary,
args: args
])
fifo = Port.open(to_charlist(fifo_path), [:eof, :binary, :stream, :out])
fix = Pleroma.Helpers.QtFastStart.fix(env.body)
true = Port.command(fifo, fix)
:erlang.port_close(fifo)
loop_recv(pid)
after
File.rm(fifo_path)
end
defp mkfifo do
path = Path.join(System.tmp_dir!(), "pleroma-media-preview-pipe-#{Ecto.UUID.generate()}")
case System.cmd("mkfifo", [path]) do
{_, 0} ->
spawn(fifo_guard(path))
{:ok, path}
{_, err} ->
{:error, {:fifo_failed, err}}
end
end
defp fifo_guard(path) do
pid = self()
fn ->
ref = Process.monitor(pid)
receive do
{:DOWN, ^ref, :process, ^pid, _} ->
File.rm(path)
end
end
end
defp loop_recv(pid) do
loop_recv(pid, <<>>)
end
defp loop_recv(pid, acc) do
receive do
{^pid, {:data, data}} ->
loop_recv(pid, acc <> data)
{^pid, {:exit_status, 0}} ->
{:ok, acc}
{^pid, {:exit_status, status}} ->
{:error, status}
after
5000 ->
:erlang.port_close(pid)
{:error, :timeout}
end
end
end