switch to playbin, improve public api, performance

Author: jazzfool

README.md

@@ -13,7 +13,7 @@ Features:
 - Video buffering when streaming on a network.
 - Audio support.
 - Programmatic control.
-- Capture thumbnails from a set of timestamps.
+- Can capture thumbnails from a set of timestamps.
 - Good performance (i.e., comparable to other video players). GStreamer (with the right plugins) will perform hardware-accelerated decoding, and the color space (YUV to RGB) is converted on the GPU whilst rendering the frame.
 
 Limitations (hopefully to be fixed):

examples/minimal.rs

@@ -64,7 +64,7 @@ impl App {
             Message::SeekRelease => {
                 self.dragging = false;
                 self.video
-                    .seek(Duration::from_secs_f64(self.position))
+                    .seek(Duration::from_secs_f64(self.position), false)
                     .expect("seek");
                 self.video.set_paused(false);
             }

src/shader.wgsl

@@ -54,5 +54,10 @@ fn fs_main(in: VertexOutput) -> @location(0) vec4<f32> {
     rgb.y = dot(yuv, yuv2g);
     rgb.z = dot(yuv, yuv2b);
 
-    return vec4<f32>(pow(rgb, vec3<f32>(2.2)), 1.0);
+    let threshold = rgb <= vec3<f32>(0.04045);
+    let hi = pow((rgb + vec3<f32>(0.055)) / vec3<f32>(1.055), vec3<f32>(2.4));
+    let lo = rgb * vec3<f32>(1.0 / 12.92);
+    rgb = select(hi, lo, threshold);
+
+    return vec4<f32>(rgb, 1.0);
 }