Add ability to create summary clips of existing videos

src/video/ffmpeg.rs

@@ -5,13 +5,19 @@ use log::{debug, error, info, trace, warn};
 use std::future::Future;
 use std::io::{Result, Stdout};
 use std::process::{Output, Stdio};
+use std::time::Instant;
 use tokio::process::Command;
 
 pub struct Ffmpeg;
 
+pub enum GifType {
+    Overview,
+    OverviewVideo { duration: u32 },
+}
+
 impl Ffmpeg {
     async fn _generate_playlist(&self, input_file: &str, output_file: &str) -> Result<String> {
-        let ffmpeg_result: Result<Output> = tokio::process::Command::new("ffmpeg")
+        let ffmpeg_result: Result<Output> = Command::new("ffmpeg")
             .arg("-i")
             .arg(input_file)
             .arg("-c:v")
@@ -41,7 +47,7 @@ impl Ffmpeg {
         ffmpeg_result.map(|_| output_file.to_string())
     }
 
-    async fn get_video_duration(&self, input_file: &str) -> Result<String> {
+    async fn get_video_duration(&self, input_file: &str) -> Result<u32> {
         Command::new("ffprobe")
             .args(["-i", input_file])
             .args(["-show_entries", "format=duration"])
@@ -51,16 +57,24 @@ impl Ffmpeg {
             .await
             .map(|out| String::from_utf8_lossy(&out.stdout).trim().to_string())
             .inspect(|duration| debug!("Found video duration: {:?}", duration))
+            .and_then(|duration| {
+                duration
+                    .parse::<f32>()
+                    .map(|duration| duration as u32)
+                    .map_err(|e| std::io::Error::new(std::io::ErrorKind::Other, e.to_string()))
+            })
+            .inspect(|duration| debug!("Found video duration: {:?}", duration))
     }
-
     pub async fn generate_video_gif(
         &self,
         input_file: &str,
         output_file: &str,
-        duration_sec: u32,
+        gif_type: GifType,
     ) -> Result<String> {
         info!("Creating gif for: '{}'", input_file);
 
+        match gif_type {
+            GifType::Overview => {
                 let temp_dir = tempfile::tempdir()?;
                 let temp_path = temp_dir
                     .path()
@@ -110,7 +124,34 @@ impl Ffmpeg {
                         error!("Error creating gif for '{}': {:?}", input_file, e);
                     }
                 }
+            }
+            GifType::OverviewVideo { duration } => {
+                let start = Instant::now();
 
+                match self
+                    .get_video_duration(input_file)
+                    .and_then(|input_duration| {
+                        Command::new("ffmpeg")
+                            .args(["-i", input_file])
+                            .args([
+                                "-vf",
+                                // Grab 1 second of frames equally spaced to create a 'duration' second long video scaled to 720px on longest side
+                                &format!(
+                                    "select='lt(mod(t,{}),1)',setpts=N/FRAME_RATE/TB,scale='if(gt(iw,ih),720,-2)':'if(gt(ih,iw),720,-2)",
+                                    input_duration / duration
+                                ),
+                            ])
+                            .arg("-an")
+                            .arg(output_file)
+                            .status()
+                    })
+                    .await
+                {
+                    Ok(out) => info!("Finished clip '{}' with code {:?} in {:?}", output_file, out.code(), start.elapsed()),
+                    Err(e) => error!("Error creating video overview: {}", e),
+                }
+            }
+        }
         Ok(output_file.to_string())
     }
 
@@ -126,10 +167,11 @@ impl Ffmpeg {
                 "[0:v]scale=480:-1:flags=lanczos,crop='min(in_w,in_h)':'min(in_w,in_h)':(in_w-out_w)/2:(in_h-out_h)/2, paletteuse",
             ])
             .args(["-loop", "0"]) // loop forever
+            .args(["-final_delay", "75"])
             .arg(output_file)
             .stderr(Stdio::null())
             .status()
-            .map_ok(|out| out.code().unwrap_or( -1))
+            .map_ok(|out| out.code().unwrap_or(-1))
             .inspect_ok(|output| debug!("ffmpeg gif create exit code: {:?}", output))
             .await
     }