feat: use slimbox + add example

examples/main.rs

@@ -0,0 +1,54 @@
+use ffmpeg_rs_raw::{Decoder, Demuxer};
+use ffmpeg_sys_the_third::{av_frame_free, av_packet_free};
+use std::env::args;
+use std::fs::File;
+use std::io::Read;
+use std::path::PathBuf;
+
+struct DropTest {
+    inner: File,
+}
+
+impl Read for DropTest {
+    fn read(&mut self, buf: &mut [u8]) -> std::io::Result<usize> {
+        self.inner.read(buf)
+    }
+}
+
+impl Drop for DropTest {
+    fn drop(&mut self) {
+        println!("Dropped!");
+    }
+}
+
+fn main() {
+    let name = args().next().unwrap_or("main".to_string());
+    let path = if let Some(path) = args().skip(1).next() {
+        PathBuf::from(path)
+    } else {
+        eprintln!("Usage: {} <path>", name);
+        std::process::exit(1);
+    };
+
+    let file = File::open(path).unwrap();
+    let mut demuxer = Demuxer::new_custom_io(DropTest { inner: file });
+    unsafe {
+        let info = demuxer.probe_input().expect("demuxer failed");
+        println!("{}", info);
+
+        let mut decoder = Decoder::new();
+        loop {
+            let (mut pkt, stream) = demuxer.get_packet().expect("demuxer failed");
+            if pkt.is_null() {
+                break; // EOF
+            }
+            if let Ok(frames) = decoder.decode_pkt(pkt, stream) {
+                for (mut frame, stream) in frames {
+                    // do nothing but decode entire stream
+                    av_frame_free(&mut frame);
+                }
+            }
+            av_packet_free(&mut pkt);
+        }
+    }
+}