Properly support interlaced video and signal it correctly in the caps and buffer flags

Cargo.toml

@@ -8,16 +8,20 @@ description = "NewTek NDI Plugin"
 
 [dependencies]
 glib = { version = "0.8.0", features = ["subclassing"] }
-gstreamer = { version = "0.14.0", features = ["subclassing"] }
+gstreamer = { version = "0.14.3", features = ["subclassing"] }
 gstreamer-base = { version = "0.14.0", features = ["subclassing"] }
 gstreamer-audio = "0.14.0"
-gstreamer-video = "0.14.0"
+gstreamer-video = "0.14.3"
 lazy_static = "1.1.0"
 byte-slice-cast = "0.2.0"
 
 [build-dependencies]
 gst-plugin-version-helper = "0.1"
 
+[features]
+default = ["interlaced-fields"]
+interlaced-fields = ["gstreamer/v1_16", "gstreamer-video/v1_16"]
+
 [lib]
 name = "gstndi"
 crate-type = ["cdylib"]

src/lib.rs

@@ -127,10 +127,13 @@ fn connect_ndi(
         source.ip_address(),
     );
 
+    // FIXME: Property for the name and bandwidth
+    // FIXME: Ideally we would use NDIlib_recv_color_format_fastest here but that seems to be
+    // broken with interlaced content currently
     let recv = RecvInstance::builder(&source, "Galicaster NDI Receiver")
         .bandwidth(NDIlib_recv_bandwidth_e::NDIlib_recv_bandwidth_highest)
         .color_format(NDIlib_recv_color_format_e::NDIlib_recv_color_format_UYVY_BGRA)
-        .allow_video_fields(false)
+        .allow_video_fields(true)
         .build();
     let recv = match recv {
         None => {

src/ndi.rs

@@ -360,13 +360,24 @@ impl<'a> VideoFrame<'a> {
     }
 
     pub fn data(&self) -> &[u8] {
+        // FIXME: Unclear if this is correct. Needs to be validated against an actual
+        // interlaced stream
+        let frame_size = if self.frame_format_type()
+            == NDIlib_frame_format_type_e::NDIlib_frame_format_type_field_0
+            || self.frame_format_type()
+                == NDIlib_frame_format_type_e::NDIlib_frame_format_type_field_1
+        {
+            self.yres() * self.line_stride_in_bytes() / 2
+        } else {
+            self.yres() * self.line_stride_in_bytes()
+        };
+
         unsafe {
             use std::slice;
             match self {
-                VideoFrame::Borrowed(ref frame, _) => slice::from_raw_parts(
-                    frame.p_data as *const u8,
-                    (frame.yres * frame.line_stride_in_bytes) as usize,
-                ),
+                VideoFrame::Borrowed(ref frame, _) => {
+                    slice::from_raw_parts(frame.p_data as *const u8, frame_size as usize)
+                }
             }
         }
     }

src/ndivideosrc.rs

@@ -9,6 +9,7 @@ use gst_base::prelude::*;
 use gst_base::subclass::prelude::*;
 
 use gst_video;
+use gst_video::prelude::*;
 
 use std::sync::Mutex;
 use std::{i32, u32};
@@ -148,6 +149,23 @@ impl ObjectSubclass for NdiVideoSrc {
             ],
         );
 
+        #[cfg(feature = "interlaced-fields")]
+        let caps = {
+            let mut tmp = caps.copy();
+            {
+                let tmp = tmp.get_mut().unwrap();
+                tmp.set_features_simple(Some(gst::CapsFeatures::new(&["format:Interlaced"])));
+            }
+
+            let mut caps = caps;
+            {
+                let caps = caps.get_mut().unwrap();
+                caps.append(tmp);
+            }
+
+            caps
+        };
+
         let src_pad_template = gst::PadTemplate::new(
             "src",
             gst::PadDirection::Src,
@@ -393,7 +411,48 @@ impl BaseSrcImpl for NdiVideoSrc {
         let par = gst::Fraction::approximate_f32(video_frame.picture_aspect_ratio()).unwrap()
             * gst::Fraction::new(video_frame.yres(), video_frame.xres());
 
-        let info =
+        #[cfg(feature = "interlaced-fields")]
+        let info = {
+            let mut builder = gst_video::VideoInfo::new(
+                format,
+                video_frame.xres() as u32,
+                video_frame.yres() as u32,
+            )
+            .fps(gst::Fraction::from(video_frame.frame_rate()))
+            .par(par)
+            .interlace_mode(match video_frame.frame_format_type() {
+                ndisys::NDIlib_frame_format_type_e::NDIlib_frame_format_type_progressive => {
+                    gst_video::VideoInterlaceMode::Progressive
+                }
+                ndisys::NDIlib_frame_format_type_e::NDIlib_frame_format_type_interleaved => {
+                    gst_video::VideoInterlaceMode::Interleaved
+                }
+                _ => gst_video::VideoInterlaceMode::Alternate,
+            });
+
+            /* Requires GStreamer 1.12 at least */
+            if video_frame.frame_format_type()
+                == ndisys::NDIlib_frame_format_type_e::NDIlib_frame_format_type_interleaved
+            {
+                builder = builder.field_order(gst_video::VideoFieldOrder::TopFieldFirst);
+            }
+
+            builder.build().unwrap()
+        };
+
+        #[cfg(not(feature = "interlaced-fields"))]
+        let info = if video_frame.frame_format_type()
+            != ndisys::NDIlib_frame_format_type_e::NDIlib_frame_format_type_progressive
+            && video_frame.frame_format_type()
+                != ndisys::NDIlib_frame_format_type_e::NDIlib_frame_format_type_interleaved
+        {
+            gst_element_error!(
+                element,
+                gst::StreamError::Format,
+                ["Separate field interlacing not supported"]
+            );
+            return Err(gst::FlowError::NotNegotiated);
+        } else {
             gst_video::VideoInfo::new(format, video_frame.xres() as u32, video_frame.yres() as u32)
                 .fps(gst::Fraction::from(video_frame.frame_rate()))
                 .par(par)
@@ -407,7 +466,8 @@ impl BaseSrcImpl for NdiVideoSrc {
                     },
                 )
                 .build()
-                .unwrap();
+                .unwrap()
+        };
 
         if state.info.as_ref() != Some(&info) {
             let caps = info.to_caps().unwrap();
@@ -425,8 +485,7 @@ impl BaseSrcImpl for NdiVideoSrc {
             pts
         );
 
-        let buff_size = (video_frame.yres() * video_frame.line_stride_in_bytes()) as usize;
-        let mut buffer = gst::Buffer::with_size(buff_size).unwrap();
+        let mut buffer = gst::Buffer::with_size(state.info.as_ref().unwrap().size()).unwrap();
         {
             let duration = gst::SECOND
                 .mul_div_floor(
@@ -437,6 +496,42 @@ impl BaseSrcImpl for NdiVideoSrc {
             let buffer = buffer.get_mut().unwrap();
             buffer.set_pts(pts);
             buffer.set_duration(duration);
+
+            #[cfg(feature = "interlaced-fields")]
+            {
+                match video_frame.frame_format_type() {
+                    ndisys::NDIlib_frame_format_type_e::NDIlib_frame_format_type_interleaved => {
+                        buffer.set_video_flags(
+                            gst_video::VideoBufferFlags::INTERLACED
+                                | gst_video::VideoBufferFlags::TFF,
+                        );
+                    }
+                    ndisys::NDIlib_frame_format_type_e::NDIlib_frame_format_type_field_0 => {
+                        buffer.set_video_flags(
+                            gst_video::VideoBufferFlags::INTERLACED
+                                | gst_video::VideoBufferFlags::TOP_FIELD,
+                        );
+                    }
+                    ndisys::NDIlib_frame_format_type_e::NDIlib_frame_format_type_field_1 => {
+                        buffer.set_video_flags(
+                            gst_video::VideoBufferFlags::INTERLACED
+                                | gst_video::VideoBufferFlags::BOTTOM_FIELD,
+                        );
+                    }
+                    _ => (),
+                };
+            }
+
+            #[cfg(not(feature = "interlaced-fields"))]
+            {
+                if video_frame.frame_format_type()
+                    == ndisys::NDIlib_frame_format_type_e::NDIlib_frame_format_type_interleaved
+                {
+                    buffer.set_video_flags(
+                        gst_video::VideoBufferFlags::INTERLACED | gst_video::VideoBufferFlags::TFF,
+                    );
+                }
+            }
         }
 
         let buffer = {