fix thumbnail transparency preservation and save things as bigger by default (#800)

Fixes: #798

Author: zkat

lib/banchan/workers/thumbnailer.ex

@@ -48,8 +48,8 @@ defmodule Banchan.Workers.Thumbnailer do
           Uploads.gen_pending(
             %User{id: upload.uploader_id},
             upload,
-            "image/jpeg",
-            Keyword.get(opts, :name, "thumbnail.jpg")
+            "image/png",
+            Keyword.get(opts, :name, "thumbnail.png")
           )
         )
         |> Ecto.Multi.run(:job, fn _repo, %{pending: pending} ->
@@ -58,9 +58,8 @@ defmodule Banchan.Workers.Thumbnailer do
               src: upload.id,
               dest: pending.id,
               opts: %{
-                target_size: Keyword.get(opts, :target_size),
-                format: Keyword.get(opts, :format, "jpeg"),
-                dimensions: Keyword.get(opts, :dimensions)
+                dimensions: Keyword.get(opts, :dimensions),
+                upscale: Keyword.get(opts, :upscale)
               }
             })
           )
@@ -106,15 +105,15 @@ defmodule Banchan.Workers.Thumbnailer do
       if Uploads.video?(src) do
         duration = FFprobe.duration(tmp_src)
 
-        output_src = Path.join([System.tmp_dir!(), src.key <> ".jpeg"])
+        output_src = Path.join([System.tmp_dir!(), src.key <> ".png"])
 
         command =
           FFmpex.new_command()
           |> add_global_option(option_y())
           |> add_input_file(tmp_src)
           |> add_output_file(output_src)
           |> add_file_option(option_f("image2"))
-          |> add_file_option(option_filter("scale=128:128"))
+          |> add_file_option(option_filter("scale=512:512"))
           |> add_file_option(option_ss(round(duration / 2)))
           |> add_file_option(option_vframes(1))
 

lib/banchan/works/works.ex

@@ -47,7 +47,7 @@ defmodule Banchan.Works do
             |> Enum.map(fn {%Upload{} = upload, index} ->
               preview_id =
                 if Uploads.media?(upload) do
-                  {:ok, %Upload{id: preview_id}} = Thumbnailer.thumbnail(upload)
+                  {:ok, %Upload{id: preview_id}} = Thumbnailer.thumbnail(upload, dimensions: 1024)
                   preview_id
                 end
 
@@ -487,7 +487,9 @@ defmodule Banchan.Works do
                 |> Enum.map(fn {%Upload{} = upload, index} ->
                   preview_id =
                     if Uploads.media?(upload) do
-                      {:ok, %Upload{id: preview_id}} = Thumbnailer.thumbnail(upload)
+                      {:ok, %Upload{id: preview_id}} =
+                        Thumbnailer.thumbnail(upload, dimensions: 1024)
+
                       preview_id
                     end