wip: Do not emit pass data more than once

Author: lu-zero

src/api/context.rs

@@ -376,13 +376,15 @@ impl<T: Pixel> Context<T> {
   /// enum.EncoderStatus.html#variant.LimitReached
   ///
   /// It will return a `RcData::Summary` once the encoder is flushed.
-  pub fn rc_receive_pass_data(&mut self) -> RcData {
+  pub fn rc_receive_pass_data(&mut self) -> Option<RcData> {
     if self.inner.done_processing() && self.inner.rc_state.pass1_data_retrieved
     {
       let data = self.inner.rc_state.emit_summary();
-      RcData::Summary(data.to_vec().into_boxed_slice())
+      Some(RcData::Summary(data.to_vec().into_boxed_slice()))
+    } else if self.inner.rc_state.pass1_data_retrieved {
+      None
     } else if let Some(data) = self.inner.rc_state.emit_frame_data() {
-      RcData::Frame(data.to_vec().into_boxed_slice())
+      Some(RcData::Frame(data.to_vec().into_boxed_slice()))
     } else {
       unreachable!(
         "The encoder received more frames than its internal limit allows"

src/bin/rav1e.rs

@@ -204,7 +204,7 @@ fn process_frame<T: Pixel, D: Decoder>(
   if let Some(passfile) = pass1file.as_mut() {
     if emit_pass_data {
       match ctx.rc_receive_pass_data() {
-        RcData::Frame(outbuf) => {
+        Some(RcData::Frame(outbuf)) => {
           let len = outbuf.len() as u64;
           passfile.write_all(&len.to_be_bytes()).map_err(|e| {
             e.context("Unable to write to two-pass data file.")
@@ -214,7 +214,7 @@ fn process_frame<T: Pixel, D: Decoder>(
             e.context("Unable to write to two-pass data file.")
           })?;
         }
-        RcData::Summary(outbuf) => {
+        Some(RcData::Summary(outbuf)) => {
           // The last packet of rate control data we get is the summary data.
           // Let's put it at the start of the file.
           passfile.seek(std::io::SeekFrom::Start(0)).map_err(|e| {
@@ -230,6 +230,7 @@ fn process_frame<T: Pixel, D: Decoder>(
             e.context("Unable to write to two-pass data file.")
           })?;
         }
+        None => {}
       }
     }
   }

src/capi.rs

@@ -264,7 +264,7 @@ impl EncContext {
     }
   }
 
-  fn rc_receive_pass_data(&mut self) -> rav1e::RcData {
+  fn rc_receive_pass_data(&mut self) -> Option<rav1e::RcData> {
     match self {
       EncContext::U8(ctx) => ctx.rc_receive_pass_data(),
       EncContext::U16(ctx) => ctx.rc_receive_pass_data(),
@@ -873,6 +873,11 @@ pub enum RcDataKind {
   /// The information contained is required to encode its matching
   /// frame in a second pass encoding.
   Frame,
+  /// There is no pass data available for now
+  ///
+  /// This is emitted if rav1e_rc_receive_pass_data is called more
+  /// often than it should.
+  Empty,
 }
 
 /// Return the Rate Control Summary Packet size
@@ -900,8 +905,9 @@ pub unsafe extern fn rav1e_rc_receive_pass_data(
 ) -> RcDataKind {
   use crate::api::RcData::*;
   let (buf, kind) = match (*ctx).ctx.rc_receive_pass_data() {
-    Summary(data) => (data, RcDataKind::Summary),
-    Frame(data) => (data, RcDataKind::Frame),
+    Some(Summary(data)) => (data, RcDataKind::Summary),
+    Some(Frame(data)) => (data, RcDataKind::Frame),
+    None => return RcDataKind::Empty,
   };
 
   let mut full_buf = Vec::with_capacity(buf.len() + 8);