rename read-codec and publish-codec examples into read-track and publish-track

examples/client-read-track-h264/main.go

@@ -0,0 +1,105 @@
+package main
+
+import (
+	"log"
+
+	"github.com/aler9/gortsplib"
+	"github.com/aler9/gortsplib/pkg/url"
+)
+
+// This example shows how to
+// 1. connect to a RTSP server and read all tracks on a path
+// 2. check if there's an H264 track
+// 3. decode H264 into RGBA frames
+
+// This example requires the ffmpeg libraries, that can be installed in this way:
+// apt install -y libavformat-dev libswscale-dev gcc pkg-config
+
+func main() {
+	c := gortsplib.Client{}
+
+	// parse URL
+	u, err := url.Parse("rtsp://localhost:8554/mystream")
+	if err != nil {
+		panic(err)
+	}
+
+	// connect to the server
+	err = c.Start(u.Scheme, u.Host)
+	if err != nil {
+		panic(err)
+	}
+	defer c.Close()
+
+	// find published tracks
+	tracks, baseURL, _, err := c.Describe(u)
+	if err != nil {
+		panic(err)
+	}
+
+	// find the H264 track
+	track := func() *gortsplib.TrackH264 {
+		for _, track := range tracks {
+			if track, ok := track.(*gortsplib.TrackH264); ok {
+				return track
+			}
+		}
+		return nil
+	}()
+	if track == nil {
+		panic("H264 track not found")
+	}
+
+	// setup RTP/H264->H264 decoder
+	rtpDec := track.CreateDecoder()
+
+	// setup H264->raw frames decoder
+	h264RawDec, err := newH264Decoder()
+	if err != nil {
+		panic(err)
+	}
+	defer h264RawDec.close()
+
+	// if SPS and PPS are present into the SDP, send them to the decoder
+	sps := track.SafeSPS()
+	if sps != nil {
+		h264RawDec.decode(sps)
+	}
+	pps := track.SafePPS()
+	if pps != nil {
+		h264RawDec.decode(pps)
+	}
+
+	// called when a RTP packet arrives
+	c.OnPacketRTP = func(ctx *gortsplib.ClientOnPacketRTPCtx) {
+		// convert RTP packets into NALUs
+		nalus, _, err := rtpDec.Decode(ctx.Packet)
+		if err != nil {
+			return
+		}
+
+		for _, nalu := range nalus {
+			// convert NALUs into RGBA frames
+			img, err := h264RawDec.decode(nalu)
+			if err != nil {
+				panic(err)
+			}
+
+			// wait for a frame
+			if img == nil {
+				continue
+			}
+
+			log.Printf("decoded frame with size %v", img.Bounds().Max)
+		}
+	}
+
+	// setup and read the H264 track only
+	err = c.SetupAndPlay(gortsplib.Tracks{track}, baseURL)
+	if err != nil {
+		panic(err)
+	}
+
+	// wait until a fatal error
+	panic(c.Wait())
+}