[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

2 files changed, 37 insertions, 23 deletions

diff --git a/internal/processing/media/create.go b/internal/processing/media/create.go
index 0dbe997de..b3a7d6052 100644
--- a/internal/processing/media/create.go
+++ b/internal/processing/media/create.go
@@ -19,10 +19,13 @@ package media
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"io"
 
+	"codeberg.org/gruf/go-iotools"
 	apimodel "github.com/superseriousbusiness/gotosocial/internal/api/model"
+	"github.com/superseriousbusiness/gotosocial/internal/config"
 	"github.com/superseriousbusiness/gotosocial/internal/gtserror"
 	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
 	"github.com/superseriousbusiness/gotosocial/internal/media"
@@ -30,21 +33,39 @@ import (
 
 // Create creates a new media attachment belonging to the given account, using the request form.
 func (p *Processor) Create(ctx context.Context, account *gtsmodel.Account, form *apimodel.AttachmentRequest) (*apimodel.Attachment, gtserror.WithCode) {
-	data := func(_ context.Context) (io.ReadCloser, int64, error) {
-		f, err := form.File.Open()
-		return f, form.File.Size, err
+
+	// Get maximum supported local media size.
+	maxsz := config.GetMediaLocalMaxSize()
+
+	// Ensure media within size bounds.
+	if form.File.Size > int64(maxsz) {
+		text := fmt.Sprintf("media exceeds configured max size: %s", maxsz)
+		return nil, gtserror.NewErrorBadRequest(errors.New(text), text)
 	}
 
+	// Parse focus details from API form input.
 	focusX, focusY, err := parseFocus(form.Focus)
 	if err != nil {
-		err := fmt.Errorf("could not parse focus value %s: %s", form.Focus, err)
-		return nil, gtserror.NewErrorBadRequest(err, err.Error())
+		text := fmt.Sprintf("could not parse focus value %s: %s", form.Focus, err)
+		return nil, gtserror.NewErrorBadRequest(errors.New(text), text)
+	}
+
+	// Open multipart file reader.
+	mpfile, err := form.File.Open()
+	if err != nil {
+		err := gtserror.Newf("error opening multipart file: %w", err)
+		return nil, gtserror.NewErrorInternalError(err)
 	}
 
+	// Wrap the multipart file reader to ensure is limited to max.
+	rc, _, _ := iotools.UpdateReadCloserLimit(mpfile, int64(maxsz))
+
 	// Create local media and write to instance storage.
 	attachment, errWithCode := p.c.StoreLocalMedia(ctx,
 		account.ID,
-		data,
+		func(ctx context.Context) (reader io.ReadCloser, err error) {
+			return rc, nil
+		},
 		media.AdditionalMediaInfo{
 			Description: &form.Description,
 			FocusX:      &focusX,
diff --git a/internal/processing/media/getfile_test.go b/internal/processing/media/getfile_test.go
index f0517b339..34f5d99a2 100644
--- a/internal/processing/media/getfile_test.go
+++ b/internal/processing/media/getfile_test.go
@@ -18,7 +18,6 @@
 package media_test
 
 import (
-	"bytes"
 	"context"
 	"io"
 	"path"
@@ -87,9 +86,9 @@ func (suite *GetFileTestSuite) TestGetRemoteFileUncached() {
 		MediaSize: string(media.SizeOriginal),
 		FileName:  fileName,
 	})
-
 	suite.NoError(errWithCode)
 	suite.NotNil(content)
+
 	b, err := io.ReadAll(content.Content)
 	suite.NoError(err)
 	suite.NoError(content.Content.Close())
@@ -111,7 +110,7 @@ func (suite *GetFileTestSuite) TestGetRemoteFileUncached() {
 	suite.True(*dbAttachment.Cached)
 
 	// the file should be back in storage at the same path as before
-	refreshedBytes, err := suite.storage.Get(ctx, testAttachment.File.Path)
+	refreshedBytes, err := suite.storage.Get(ctx, dbAttachment.File.Path)
 	suite.NoError(err)
 	suite.Equal(suite.testRemoteAttachments[testAttachment.RemoteURL].Data, refreshedBytes)
 }
@@ -139,32 +138,26 @@ func (suite *GetFileTestSuite) TestGetRemoteFileUncachedInterrupted() {
 		MediaSize: string(media.SizeOriginal),
 		FileName:  fileName,
 	})
-
 	suite.NoError(errWithCode)
 	suite.NotNil(content)
 
-	// only read the first kilobyte and then stop
-	b := make([]byte, 0, 1024)
-	if !testrig.WaitFor(func() bool {
-		read, err := io.CopyN(bytes.NewBuffer(b), content.Content, 1024)
-		return err == nil && read == 1024
-	}) {
-		suite.FailNow("timed out trying to read first 1024 bytes")
-	}
+	_, err = io.CopyN(io.Discard, content.Content, 1024)
+	suite.NoError(err)
 
-	// close the reader
-	suite.NoError(content.Content.Close())
+	err = content.Content.Close()
+	suite.NoError(err)
 
 	// the attachment should still be updated in the database even though the caller hung up
+	var dbAttachment *gtsmodel.MediaAttachment
 	if !testrig.WaitFor(func() bool {
-		dbAttachment, _ := suite.db.GetAttachmentByID(ctx, testAttachment.ID)
+		dbAttachment, _ = suite.db.GetAttachmentByID(ctx, testAttachment.ID)
 		return *dbAttachment.Cached
 	}) {
 		suite.FailNow("timed out waiting for attachment to be updated")
 	}
 
 	// the file should be back in storage at the same path as before
-	refreshedBytes, err := suite.storage.Get(ctx, testAttachment.File.Path)
+	refreshedBytes, err := suite.storage.Get(ctx, dbAttachment.File.Path)
 	suite.NoError(err)
 	suite.Equal(suite.testRemoteAttachments[testAttachment.RemoteURL].Data, refreshedBytes)
 }
@@ -196,9 +189,9 @@ func (suite *GetFileTestSuite) TestGetRemoteFileThumbnailUncached() {
 		MediaSize: string(media.SizeSmall),
 		FileName:  fileName,
 	})
-
 	suite.NoError(errWithCode)
 	suite.NotNil(content)
+
 	b, err := io.ReadAll(content.Content)
 	suite.NoError(err)
 	suite.NoError(content.Content.Close())