Move ffmpeg to feature flag

Signed-off-by: trivernis <trivernis@protonmail.com>

Cargo.toml

@@ -4,7 +4,7 @@ readme = "README.md"
 license = "Apache-2.0"
 authors = ["trivernis <trivernis@protonmail.com>"]
 description = "An image thumbnail creation library"
-version = "0.2.2"
+version = "0.2.3"
 edition = "2018"
 repository = "https://github.com/Trivernis/thumbnailer"
 
@@ -14,8 +14,12 @@ repository = "https://github.com/Trivernis/thumbnailer"
 webp = "0.2.0"
 mime = "0.3.16"
 rayon = "1.5.1"
-ffmpeg-next = "4.4.0"
+ffmpeg-next = {version = "4.4.0", optional=true}
 tempfile = "3.2.0"
 
 [dependencies.image]
-version = "0.23.14"
+version = "0.23.14"
+
+[features]
+default = ["ffmpeg"]
+ffmpeg = ["ffmpeg-next"]

src/error.rs

@@ -17,6 +17,7 @@ pub enum ThumbError {
 
     NullVideo,
 
+    #[cfg(feature = "ffmpeg")]
     FFMPEG(ffmpeg_next::Error),
 }
 
@@ -28,6 +29,8 @@ impl Display for ThumbError {
             ThumbError::Decode => write!(f, "failed to decode image"),
             ThumbError::Unsupported(mime) => write!(f, "Unsupported media type {}", mime),
             ThumbError::NullVideo => write!(f, "no video data found in file"),
+
+            #[cfg(feature = "ffmpeg")]
             ThumbError::FFMPEG(e) => write!(f, "ffmpeg error: {}", e),
         }
     }
@@ -38,7 +41,10 @@ impl std::error::Error for ThumbError {
         match self {
             ThumbError::IO(e) => e.source(),
             ThumbError::Image(i) => i.source(),
+
+            #[cfg(feature = "ffmpeg")]
             ThumbError::FFMPEG(e) => e.source(),
+
             _ => None,
         }
     }
@@ -56,6 +62,7 @@ impl From<image::error::ImageError> for ThumbError {
     }
 }
 
+#[cfg(feature = "ffmpeg")]
 impl From<ffmpeg_next::Error> for ThumbError {
     fn from(e: ffmpeg_next::Error) -> Self {
         Self::FFMPEG(e)

src/formats/mod.rs

@@ -1,17 +1,21 @@
 use crate::error::{ThumbError, ThumbResult};
 use crate::formats::image_format::read_image;
-use crate::formats::video_format::get_video_frame;
 use image::DynamicImage;
 use mime::Mime;
 use std::io::{BufRead, Seek};
 
+#[cfg(feature = "ffmpeg")]
+use crate::formats::video_format::get_video_frame;
+
 pub mod image_format;
+#[cfg(feature = "ffmpeg")]
 pub mod video_format;
 
 /// Reads the buffer content into an image that can be used for thumbnail generation
 pub fn get_base_image<R: BufRead + Seek>(reader: R, mime: Mime) -> ThumbResult<DynamicImage> {
     match mime.type_() {
         mime::IMAGE => read_image(reader, mime),
+        #[cfg(feature = "ffmpeg")]
         mime::VIDEO => get_video_frame(reader, mime),
         _ => Err(ThumbError::Unsupported(mime)),
     }

tests/video_reading.rs

@@ -8,7 +8,7 @@ const VIDEO_BYTES: &'static [u8] = include_bytes!("assets/test.mp4");
 #[test]
 fn it_creates_thumbnails_for_mp4() {
     let reader = Cursor::new(VIDEO_BYTES);
-    create_thumbnails(
+    let result = create_thumbnails(
         reader,
         Mime::from_str("video/mp4").unwrap(),
         [
@@ -16,6 +16,10 @@ fn it_creates_thumbnails_for_mp4() {
             ThumbnailSize::Medium,
             ThumbnailSize::Large,
         ],
-    )
-    .unwrap();
+    );
+    #[cfg(feature = "ffmpeg")]
+    result.unwrap();
+
+    #[cfg(not(feature = "ffmpeg"))]
+    assert!(result.is_err())
 }