Remove static binding to ffmpeg and use command instead

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

Cargo.toml

@@ -4,22 +4,16 @@ readme = "README.md"
 license = "Apache-2.0"
 authors = ["trivernis <trivernis@protonmail.com>"]
 description = "An image thumbnail creation library"
-version = "0.3.0"
+version = "0.4.0"
 edition = "2018"
 repository = "https://github.com/Trivernis/thumbnailer"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-webp = "^0.2.1"
-mime = "^0.3.16"
-rayon = "^1.5.1"
-ffmpeg-next = {version = "^4.4.0", optional=true}
-tempfile = "^3.3.0"
-
-[dependencies.image]
-version = "^0.24.0"
-
-[features]
-default = ["ffmpeg"]
-ffmpeg = ["ffmpeg-next"]
+webp = "0.2.1"
+mime = "0.3.16"
+rayon = "1.5.1"
+tempfile = "3.3.0"
+image= "0.24.0"
+lazy_static = "1.4.0"

src/error.rs

@@ -17,8 +17,7 @@ pub enum ThumbError {
 
     NullVideo,
 
-    #[cfg(feature = "ffmpeg")]
-    FFMPEG(ffmpeg_next::Error),
+    FFMPEG(String),
 }
 
 impl Display for ThumbError {
@@ -29,8 +28,6 @@ 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),
         }
     }
@@ -41,10 +38,6 @@ 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,
         }
     }
@@ -61,10 +54,3 @@ impl From<image::error::ImageError> for ThumbError {
         Self::Image(e)
     }
 }
-
-#[cfg(feature = "ffmpeg")]
-impl From<ffmpeg_next::Error> for ThumbError {
-    fn from(e: ffmpeg_next::Error) -> Self {
-        Self::FFMPEG(e)
-    }
-}

src/formats/mod.rs

@@ -4,18 +4,15 @@ 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)),
     }

src/formats/video_format.rs

@@ -1,17 +1,19 @@
 use crate::error::{ThumbError, ThumbResult};
-use ffmpeg_next::codec::decoder::Video as VideoDecoder;
-use ffmpeg_next::filter;
-use ffmpeg_next::filter::Graph;
-use ffmpeg_next::frame::Video;
-use ffmpeg_next::media::Type as MediaType;
-use ffmpeg_next::threading::Config;
-use image::{DynamicImage, RgbaImage};
+use crate::utils::ffmpeg_cli::{get_png_frame, is_ffmpeg_installed};
+use image::io::Reader as ImageReader;
+use image::{DynamicImage, ImageFormat};
 use mime::Mime;
 use std::fs;
-use std::io::{BufRead, Seek};
+use std::io::{BufRead, Cursor, Seek};
 use std::path::PathBuf;
 
 pub fn get_video_frame<R: BufRead + Seek>(mut reader: R, mime: Mime) -> ThumbResult<DynamicImage> {
+    lazy_static::lazy_static! { static ref FFMPEG_INSTALLED: bool = is_ffmpeg_installed(); }
+
+    if !*FFMPEG_INSTALLED {
+        return Err(ThumbError::Unsupported(mime));
+    }
+
     let tempdir = tempfile::tempdir()?;
     tempdir.path();
     let path = PathBuf::from(tempdir.path())
@@ -22,112 +24,16 @@ pub fn get_video_frame<R: BufRead + Seek>(mut reader: R, mime: Mime) -> ThumbRes
     reader.read_to_end(&mut buf)?;
     fs::write(&path, buf)?;
 
-    let img = extract_frame_from_video(&path)?;
+    let mut buf = Vec::new();
+    reader.read_to_end(&mut buf)?;
+
+    let png_bytes = get_png_frame(
+        path.to_str()
+            .expect("path to tmpdir contains invalid characters"),
+        16,
+    )?; // take the 16th frame
     tempdir.close()?;
+    let img = ImageReader::with_format(Cursor::new(png_bytes), ImageFormat::Png).decode()?;
 
     Ok(img)
 }
-
-fn extract_frame_from_video(path: &PathBuf) -> ThumbResult<DynamicImage> {
-    let mut input = ffmpeg_next::format::input(path)?;
-    let stream = input
-        .streams()
-        .best(MediaType::Video)
-        .ok_or_else(|| ThumbError::NullVideo)?;
-
-    let mut decoder = stream.codec().decoder().video()?;
-    decoder.set_threading(Config::count(1));
-
-    let mut filter = get_format_filter(&mut decoder)?;
-
-    let stream_index = stream.index();
-
-    let packets = input
-        .packets()
-        .filter(|(s, _)| s.index() == stream_index)
-        .map(|(_, p)| p);
-
-    let mut frame = Video::empty();
-    let mut output_frame = Video::empty();
-    let mut count = 0;
-
-    for packet in packets {
-        decoder.send_packet(&packet)?;
-        while let Err(ffmpeg_next::Error::DecoderNotFound) = decoder.receive_frame(&mut frame) {}
-
-        if decode_single_frame(&mut filter, &mut frame, &mut output_frame).is_ok() {
-            count += 1;
-        }
-        if count > 2 {
-            // take the second frame because the first one often is just blank
-            break;
-        }
-    }
-    decoder.send_eof()?;
-
-    convert_frame_to_image(&decoder, output_frame)
-}
-
-fn get_format_filter(decoder: &mut VideoDecoder) -> ThumbResult<Graph> {
-    let args = format!(
-        "width={w}:height={h}:video_size={w}x{h}:pix_fmt={fmt}:time_base={base}",
-        w = decoder.width(),
-        h = decoder.height(),
-        fmt = decoder
-            .format()
-            .descriptor()
-            .ok_or_else(|| ThumbError::NullVideo)?
-            .name(),
-        base = decoder.time_base(),
-    );
-    let mut filter = Graph::new();
-    filter.add(
-        &filter::find("buffer").ok_or_else(|| ThumbError::NullVideo)?,
-        "in",
-        &args,
-    )?;
-    filter.add(
-        &filter::find("buffersink").ok_or_else(|| ThumbError::NullVideo)?,
-        "out",
-        "",
-    )?;
-    filter
-        .output("in", 0)?
-        .input("out", 0)?
-        .parse("format=rgba")?;
-    filter.validate()?;
-
-    Ok(filter)
-}
-
-fn decode_single_frame(
-    filter: &mut Graph,
-    frame: &mut Video,
-    mut output_frame: &mut Video,
-) -> ThumbResult<()> {
-    filter
-        .get("in")
-        .ok_or_else(|| ThumbError::NullVideo)?
-        .source()
-        .add(&frame)?;
-    let mut ctx = filter.get("out").ok_or_else(|| ThumbError::NullVideo)?;
-    let mut out = ctx.sink();
-    out.frame(&mut output_frame)?;
-
-    Ok(())
-}
-
-fn convert_frame_to_image(
-    decoder: &VideoDecoder,
-    output_frame: Video,
-) -> ThumbResult<DynamicImage> {
-    let image = RgbaImage::from_raw(
-        decoder.width(),
-        decoder.height(),
-        output_frame.data(0).to_vec(),
-    )
-    .ok_or_else(|| ThumbError::NullVideo)?;
-    let image = DynamicImage::ImageRgba8(image);
-
-    Ok(image)
-}

src/lib.rs

@@ -34,6 +34,7 @@ pub use size::ThumbnailSize;
 pub mod error;
 mod formats;
 mod size;
+pub(crate) mod utils;
 
 #[derive(Clone, Debug)]
 pub struct Thumbnail {

src/utils/ffmpeg_cli.rs

@@ -0,0 +1,58 @@
+use crate::error::ThumbError;
+use crate::ThumbResult;
+use std::ffi::OsStr;
+use std::io::ErrorKind;
+use std::process::{Command, Stdio};
+
+const FFMPEG: &str = "ffmpeg";
+
+/// Runs ffmpeg to retrieve a png video frame
+pub fn get_png_frame(video_file: &str, index: usize) -> ThumbResult<Vec<u8>> {
+    ffmpeg([
+        "-loglevel",
+        "panic",
+        "-i",
+        video_file,
+        "-vf",
+        format!("select=eq(n\\,{})", index).as_str(),
+        "-vframes",
+        "1",
+        "-c:v",
+        "png",
+        "-movflags",
+        "empty_moov",
+        "-f",
+        "image2pipe",
+        "pipe:1",
+    ])
+}
+
+/// Runs ffmpeg with the given args
+fn ffmpeg<I: IntoIterator<Item = S>, S: AsRef<OsStr>>(args: I) -> ThumbResult<Vec<u8>> {
+    let child = Command::new(FFMPEG)
+        .args(args)
+        .stdout(Stdio::piped())
+        .spawn()?;
+
+    let output = child.wait_with_output()?;
+    if output.status.success() && output.stdout.len() > 0 {
+        Ok(output.stdout)
+    } else {
+        Err(ThumbError::FFMPEG(
+            String::from_utf8_lossy(&output.stderr[..]).to_string(),
+        ))
+    }
+}
+
+pub fn is_ffmpeg_installed() -> bool {
+    match Command::new("ffmpeg").args(["-loglevel", "quiet"]).spawn() {
+        Ok(_) => true,
+        Err(e) => {
+            if let ErrorKind::NotFound = e.kind() {
+                false
+            } else {
+                true
+            }
+        }
+    }
+}

src/utils/mod.rs

@@ -0,0 +1 @@
+pub mod ffmpeg_cli;

tests/video_reading.rs

@@ -1,6 +1,9 @@
+extern crate core;
+
 use mime::Mime;
 use std::io::Cursor;
 use std::str::FromStr;
+use thumbnailer::error::ThumbError;
 use thumbnailer::{create_thumbnails, ThumbnailSize};
 
 const VIDEO_BYTES: &'static [u8] = include_bytes!("assets/test.mp4");
@@ -17,9 +20,18 @@ fn it_creates_thumbnails_for_mp4() {
             ThumbnailSize::Large,
         ],
     );
-    #[cfg(feature = "ffmpeg")]
-    result.unwrap();
 
-    #[cfg(not(feature = "ffmpeg"))]
-    assert!(result.is_err())
+    match result {
+        Ok(_) => {
+            assert!(true)
+        }
+        Err(e) => match e {
+            ThumbError::Unsupported(_) => {
+                assert!(true, "ffmpeg is not installed");
+            }
+            e => {
+                panic!("failed to create thumbnails {}", e);
+            }
+        },
+    }
 }