Add example to convert AVI frame to RGB24 frame

examples/avi-to-ppm.rs

@@ -0,0 +1,58 @@
+extern crate ffmpeg_next as ffmpeg;
+
+use ffmpeg::format::{input, Pixel};
+use ffmpeg::media::Type;
+use ffmpeg::software::scaling::{context::Context, flag::Flags};
+use ffmpeg::util::frame::video::Video;
+use std::env;
+use std::fs::File;
+use std::io::prelude::*;
+
+fn main() -> Result<(), ffmpeg::Error> {
+    ffmpeg::init().unwrap();
+
+    if let Ok(mut ictx) = input(&env::args().nth(1).expect("Cannot open file.")) {
+        let input = ictx
+            .streams()
+            .best(Type::Video)
+            .ok_or_else(|| ffmpeg::Error::StreamNotFound)?;
+
+        let mut decoder = input.codec().decoder().video()?;
+
+        let mut scaler = Context::get(
+            decoder.format(),
+            decoder.width(),
+            decoder.height(),
+            Pixel::RGB24,
+            decoder.width(),
+            decoder.height(),
+            Flags::BILINEAR,
+        )?;
+
+        for (i, (_, p)) in ictx.packets().enumerate() {
+            let mut frame = Video::empty();
+            match decoder.decode(&p, &mut frame) {
+                Ok(_) => {
+                    let mut rgb_frame = Video::empty();
+                    scaler.run(&frame, &mut rgb_frame)?;
+                    match save_file(&rgb_frame, i) {
+                        Ok(_) => {}
+                        Err(e) => println!("Error occurred during file writing - {}", e),
+                    }
+                }
+                _ => {
+                    println!("Error occurred while decoding packet.");
+                }
+            }
+        }
+    }
+
+    Ok(())
+}
+
+fn save_file(frame: &Video, index: usize) -> std::result::Result<(), std::io::Error> {
+    let mut file = File::create(format!("frame{}.ppm", index))?;
+    file.write_all(format!("P6\n{} {}\n255\n", frame.width(), frame.height()).as_bytes())?;
+    file.write_all(frame.data(0))?;
+    Ok(())
+}