use gstreamer::{prelude::*, PadLinkError}; use gstreamer::{Element, ElementFactory, Pipeline}; use gstreamer_app::AppSink; use gtk::glib::BoolError; use snafu::prelude::*; use std::str::FromStr; use std::sync::{Arc, Mutex}; pub const JPEG_QUALITY: i32 = 40; #[derive(Debug)] pub struct WebcamPipeline { pub pipeline: Pipeline, pub sink_paintable: Element, pub sink_frame: Arc>, } impl WebcamPipeline { pub fn new() -> Result { let pipeline = Pipeline::with_name("webcam_pipeline"); // All of the following errors are unrecoverable let source = ElementFactory::make("mfvideosrc") .build() .context(BuildSnafu { element: "mfvideosrc", })?; let convert = ElementFactory::make("videoconvert") .build() .context(BuildSnafu { element: "videoconvert", })?; let rate = ElementFactory::make("videorate") .build() .context(BuildSnafu { element: "videorate", })?; let tee = ElementFactory::make("tee") .build() .context(BuildSnafu { element: "tee" })?; let queue_app = ElementFactory::make("queue") .property("max-size-time", 1u64) .property("max-size-buffers", 0u32) .property("max-size-bytes", 0u32) .build() .context(BuildSnafu { element: "paintable queue", })?; let sink_paintable = ElementFactory::make("gtk4paintablesink") .name("gtk4_output") .build() .context(BuildSnafu { element: "gtkpaintablesink", })?; // queue.connect_closure("overrun", false, glib::closure!(|queue: Element| { // println!("The queue is full!"); // })); let appsink_queue = ElementFactory::make("queue") .property("max-size-time", 1u64) .property("max-size-buffers", 0u32) .property("max-size-bytes", 0u32) .build() .context(BuildSnafu { element: "appsink queue", })?; let resize = ElementFactory::make("videoscale") .build() .context(BuildSnafu { element: "videoscale", })?; let jpeg_enc = ElementFactory::make("jpegenc") .property("quality", JPEG_QUALITY) .build() .context(BuildSnafu { element: "jpegenc" })?; let caps_string = "image/jpeg,width=640,height=640"; let appsrc_caps = gstreamer::Caps::from_str(caps_string).context(BuildSnafu { element: "appsink caps", })?; let sink_frame = AppSink::builder() .name("frame_appsink") .sync(false) .max_buffers(3u32) .drop(true) .caps(&appsrc_caps) .build(); sink_frame.set_property("caps", &appsrc_caps.to_value()); pipeline .add_many(&[ &source, &convert, &rate, &tee, &queue_app, &sink_paintable, &appsink_queue, &resize, &jpeg_enc, &sink_frame.upcast_ref(), ]) .context(LinkSnafu { from: "all", to: "pipeline", })?; Element::link_many(&[&source, &convert, &rate]).context(LinkSnafu { from: "source et. al.", to: "rate", })?; // -- BEGIN PAINTABLE SINK PIPELINE let tee_caps = // gstreamer::caps::Caps::from_str("video/x-raw,framerate=15/1").context(BuildSnafu { gstreamer::caps::Caps::from_str("video/x-raw").context(BuildSnafu { element: "tee caps", })?; rate.link_filtered(&tee, &tee_caps).context(LinkSnafu { from: "videorate", to: "tee", })?; let tee_src_1 = tee .request_pad_simple("src_%u") .ok_or(PipelineError::PadRequestError { element: "tee pad 1".to_string(), })?; let paintable_queue_sinkpad = queue_app .static_pad("sink") .ok_or(PipelineError::PadRequestError { element: "gtk4 sink".to_string(), })?; tee_src_1 .link(&paintable_queue_sinkpad) .context(PadLinkSnafu { from: "tee src pad", to: "gtk4 paintable queue", })?; queue_app.link(&sink_paintable).context(LinkSnafu { from: "gtk4 paintable queue", to: "gtk4 paintable", })?; // -- END PAINTABLE SINK PIPELINE // -- BEGIN APPSINK PIPELINE let tee_src_2 = tee .request_pad_simple("src_%u") .ok_or(PipelineError::PadRequestError { element: "tee pad 2".to_string(), })?; let appsink_queue_sinkpad = appsink_queue .static_pad("sink") .ok_or(PipelineError::PadRequestError { element: "appsink queue".to_string(), })?; tee_src_2 .link(&appsink_queue_sinkpad) .context(PadLinkSnafu { from: "tee src pad 2", to: "appsink queue sinkpad", })?; appsink_queue.link(&resize).context(LinkSnafu { from: "appsink_queue", to: "resize", })?; let resize_caps = gstreamer::caps::Caps::from_str("video/x-raw,format=RGB,width=640,height=640") .context(BuildSnafu { element: "resize_caps", })?; resize .link_filtered(&jpeg_enc, &resize_caps) .context(LinkSnafu { from: "jpeg_enc", to: "resize_caps", })?; Element::link_many(&[&jpeg_enc, &sink_frame.upcast_ref()]).context(LinkSnafu { from: "jpeg_enc", to: "appsink", })?; Ok(WebcamPipeline { pipeline, sink_paintable, sink_frame: Arc::new(Mutex::new(sink_frame)), }) } } #[derive(Debug, Snafu)] pub enum PipelineError { #[snafu(display("Error during element linking"))] LinkError { source: BoolError, from: String, to: String, }, #[snafu(display("Error linking pads"))] PadLinkError { source: PadLinkError, from: String, to: String, }, #[snafu(display("Error creating element"))] BuildError { source: BoolError, element: String }, #[snafu(display("Error getting pad from element"))] PadRequestError { element: String }, }