refactor: use decoder name from ctx

examples/main.rs

@@ -48,7 +48,6 @@ unsafe fn decode_input(demuxer: Demuxer, info: DemuxerInfo) {
             .setup_decoder(stream, None)
             .expect("decoder setup failed");
     }
-    info!("{}", decoder);
     loop_decoder(demuxer, decoder);
 }
 

src/decode.rs

@@ -35,9 +35,9 @@ impl DecoderCodecContext {
 
     /// Get the codec name
     pub fn codec_name(&self) -> String {
-        let codec_name = unsafe { rstr!(avcodec_get_name((*self.codec).id)) };
+        let codec_name = unsafe { rstr!((*(*self).codec).name) };
         if self.hw_config.is_null() {
-            codec_name.to_string()
+            format!("{}", codec_name)
         } else {
             let hw = unsafe { rstr!(av_hwdevice_get_type_name((*self.hw_config).device_type)) };
             format!("{}_{}", codec_name, hw)

src/lib.rs

@@ -38,7 +38,11 @@ macro_rules! cstr {
 #[macro_export]
 macro_rules! rstr {
     ($str:expr) => {
-        core::ffi::CStr::from_ptr($str).to_str().unwrap()
+        if !$str.is_null() {
+            core::ffi::CStr::from_ptr($str).to_str().unwrap()
+        } else {
+            ""
+        }
     };
 }