metadata processing

src/demux/flv.rs

@@ -86,12 +86,29 @@ pub fn new_reader(stdin: io::Stdin) -> Result<FLVReader, Box<dyn Error>> {
 }
 
 fn process_metadata(mut data: Vec<u8>) -> Result<util::Metadata, Box<dyn Error>> {
+    let mut metadata = util::Metadata { ..Default::default() };
     data.drain(..13);
     let ecma_sync_byte = data.drain(..1).next().unwrap();
     if ecma_sync_byte != 8 {
         return Err(Box::new(util::DemuxerError::FLVMetadataSyncFail));
     }
-    let arr_len = u32::fetch_amf_val(&mut data);
+    let arr_len = u32::fetch_amf_val(&mut data) as usize;
+    for _ in 0..arr_len {
+        let key = String::fetch_amf_val(&mut data);
+        let amf_marker = u8::fetch_amf_val(&mut data);
+        if !handle_relevant_keys(key, &mut data, &amf_marker, &mut metadata) {
+            match amf_marker {
+                0 => {let _ = f64::fetch_amf_val(&mut data);},
+                1 => {let _ = bool::fetch_amf_val(&mut data);},
+                2 => {let _ = String::fetch_amf_val(&mut data);},
+                _ => {return Err(Box::new(util::DemuxerError::FLVMetadataAMFMarkerError));}
+            }
+        }
+    }
+    return Ok(metadata);
+}
+
+fn handle_relevant_keys(key: String, data: &mut Vec<u8>, marker: &u8, metadata: &mut util::Metadata) -> bool {
     todo!();
 }
 
@@ -118,6 +135,13 @@ impl FetchAMFVal for u16 {
     }
 }
 
+impl FetchAMFVal for u8 {
+    type Primitive = u8;
+    fn fetch_amf_val(data: &mut Vec<u8>) -> Self::Primitive {
+        return data.drain(..1).next().unwrap();
+    }
+}
+
 impl FetchAMFVal for f64 {
     type Primitive = f64;
     fn fetch_amf_val(data: &mut Vec<u8>) -> Self::Primitive {

src/util/mod.rs

@@ -3,6 +3,7 @@ use std::fmt;
 
 // Data structs/enums
 
+#[derive(Default)]
 pub struct VideoMetadata {
     pub width: u32,
     pub height: u32,
@@ -14,6 +15,7 @@ pub enum VideoCodec {
     H264,
 }
 
+#[derive(Default)]
 pub struct AudioMetadata {
     pub samplerate: u32,
     pub channels: u8,
@@ -24,6 +26,7 @@ pub enum AudioCodec {
     AAC,
 }
 
+#[derive(Default)]
 pub struct Metadata {
     pub video: VideoMetadata,
     pub audio: AudioMetadata,
@@ -62,6 +65,7 @@ pub enum DemuxerError {
     FLVCheckFail,
     FLVPacketNotMetadata,
     FLVMetadataSyncFail,
+    FLVMetadataAMFMarkerError,
 }
 
 impl Error for DemuxerError {}
@@ -74,6 +78,7 @@ impl fmt::Debug for DemuxerError {
             DemuxerError::FLVCheckFail => write!(f, "Input does not contain assumed FLV signature"),
             DemuxerError::FLVPacketNotMetadata => write!(f, "Did not find expected metadata tag"),
             DemuxerError::FLVMetadataSyncFail => write!(f, "ECMA array not where expected"),
+            DemuxerError::FLVMetadataAMFMarkerError => write!(f, "Marker value not recognized/implemented"),
             _ => write!(f, "Error not described yet")
         }
     }