SRS5: Test: Support blackbox test by FFmpeg. v5.0.128 (#3355)

1. Enable blackbox test for each PR and push.
2. Refine Makefile and README for srs-bench.
3. Add blackbox using FFmpeg and ffprobe.
4. Add blackbox basic test for RTMP stream.
5. Add blackbox basic test for HTTP-FLV stream.
6. Fix utest rand seed issue.

PICK 2141d220b4

trunk/3rdparty/srs-bench/srs/srs_test.go

@@ -23,8 +23,10 @@ package srs
 import (
 	"github.com/ossrs/go-oryx-lib/logger"
 	"io/ioutil"
+	"math/rand"
 	"os"
 	"testing"
+	"time"
 )
 
 func TestMain(m *testing.M) {
@@ -41,5 +43,8 @@ func TestMain(m *testing.M) {
 		}()
 	}
 
+	// Init rand seed.
+	rand.Seed(time.Now().UnixNano())
+
 	os.Exit(m.Run())
 }