[feature] support processing of (many) more media types (#3090)

* initial work replacing our media decoding / encoding pipeline with ffprobe + ffmpeg

* specify the video codec to use when generating static image from emoji

* update go-storage library (fixes incompatibility after updating go-iotools)

* maintain image aspect ratio when generating a thumbnail for it

* update readme to show go-ffmpreg

* fix a bunch of media tests, move filesize checking to callers of media manager for more flexibility

* remove extra debug from error message

* fix up incorrect function signatures

* update PutFile to just use regular file copy, as changes are file is on separate partition

* fix remaining tests, remove some unneeded tests now we're working with ffmpeg/ffprobe

* update more tests, add more code comments

* add utilities to generate processed emoji / media outputs

* fix remaining tests

* add test for opus media file, add license header to utility cmds

* limit the number of concurrently available ffmpeg / ffprobe instances

* reduce number of instances

* further reduce number of instances

* fix envparsing test with configuration variables

* update docs and configuration with new media-{local,remote}-max-size variables

cmd/process-media/main.go

@@ -0,0 +1,124 @@
+// GoToSocial
+// Copyright (C) GoToSocial Authors admin@gotosocial.org
+// SPDX-License-Identifier: AGPL-3.0-or-later
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package main
+
+import (
+	"context"
+	"io"
+	"os"
+	"os/signal"
+	"syscall"
+
+	"codeberg.org/gruf/go-storage/memory"
+	"github.com/superseriousbusiness/gotosocial/internal/config"
+	"github.com/superseriousbusiness/gotosocial/internal/db/bundb"
+	"github.com/superseriousbusiness/gotosocial/internal/log"
+	"github.com/superseriousbusiness/gotosocial/internal/media"
+	"github.com/superseriousbusiness/gotosocial/internal/state"
+	"github.com/superseriousbusiness/gotosocial/internal/storage"
+)
+
+func main() {
+	ctx := context.Background()
+	ctx, cncl := signal.NotifyContext(ctx, syscall.SIGTERM, syscall.SIGINT)
+	defer cncl()
+
+	if len(os.Args) != 4 {
+		log.Panic(ctx, "Usage: go run ./cmd/process-media <input-file> <output-processed> <output-thumbnail>")
+	}
+
+	var st storage.Driver
+	st.Storage = memory.Open(10, true)
+
+	var state state.State
+	state.Storage = &st
+
+	state.Caches.Init()
+
+	var err error
+
+	config.SetHost("example.com")
+	config.SetStorageBackend("disk")
+	config.SetStorageLocalBasePath("/tmp/gotosocial")
+	config.SetDbType("sqlite")
+	config.SetDbAddress(":memory:")
+
+	state.DB, err = bundb.NewBunDBService(ctx, &state)
+	if err != nil {
+		log.Panic(ctx, err)
+	}
+
+	if err := state.DB.CreateInstanceAccount(ctx); err != nil {
+		log.Panicf(ctx, "error creating instance account: %s", err)
+	}
+
+	if err := state.DB.CreateInstanceInstance(ctx); err != nil {
+		log.Panicf(ctx, "error creating instance instance: %s", err)
+	}
+
+	if err := state.DB.CreateInstanceApplication(ctx); err != nil {
+		log.Panicf(ctx, "error creating instance application: %s", err)
+	}
+
+	account, err := state.DB.GetInstanceAccount(ctx, "")
+	if err != nil {
+		log.Panic(ctx, err)
+	}
+
+	mgr := media.NewManager(&state)
+
+	processing, err := mgr.CreateMedia(ctx,
+		account.ID,
+		func(ctx context.Context) (reader io.ReadCloser, err error) {
+			return os.Open(os.Args[1])
+		},
+		media.AdditionalMediaInfo{},
+	)
+	if err != nil {
+		log.Panic(ctx, err)
+	}
+
+	media, err := processing.Load(ctx)
+	if err != nil {
+		log.Panic(ctx, err)
+	}
+
+	copyFile(ctx, &st, media.File.Path, os.Args[2])
+	copyFile(ctx, &st, media.Thumbnail.Path, os.Args[3])
+}
+
+func copyFile(ctx context.Context, st *storage.Driver, key string, path string) {
+	rc, err := st.GetStream(ctx, key)
+	if err != nil {
+		log.Panic(ctx, err)
+	}
+	defer rc.Close()
+
+	_ = os.Remove(path)
+
+	output, err := os.Create(path)
+	if err != nil {
+		log.Panic(ctx, err)
+	}
+	defer output.Close()
+
+	_, err = io.Copy(output, rc)
+	if err != nil {
+		log.Panic(ctx, err)
+	}
+}