commit 751b779d8e7ce976d47f463ae36f64e9fe98c067
Author: Jan-Lukas Else <mail@jlelse.de>
Date:   Wed May 20 17:50:37 2020 +0200

    Initial commit

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..07706b4
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,3 @@
+/.idea
+bbb-download
+*.mp4
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diff --git a/README.md b/README.md
new file mode 100644
index 0000000..5442b9f
--- /dev/null
+++ b/README.md
@@ -0,0 +1,3 @@
+# bbb-download
+
+This is a downloader for BigBlueButton. It's based on [this code](https://github.com/zakcali/bbb-download) but with a few tweaks and support for downloading the screenshare (deskshare) recordings.
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diff --git a/bbb-download.go b/bbb-download.go
new file mode 100644
index 0000000..604a4cc
--- /dev/null
+++ b/bbb-download.go
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+package main
+
+import (
+	"bufio"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"log"
+	"math"
+	"net/http"
+	"os"
+	"os/exec"
+	"path"
+	"strconv"
+	"strings"
+)
+
+func main() {
+	fmt.Println("BigBlueButton video creator/downloader")
+
+	scanner := bufio.NewScanner(os.Stdin)
+
+	fmt.Print("Enter URL of recording: ")
+	scanner.Scan()
+	presentationUrl := scanner.Text()
+	result := strings.SplitAfter(presentationUrl, "?meetingId=")
+	presentationId := result[1]
+
+	fmt.Print("Name of recording: ")
+	scanner.Scan()
+	meetingName := scanner.Text()
+
+	result2 := strings.Split(result[0], "/playback/")
+	baseUrl := result2[0] + "/presentation/" + presentationId
+	fmt.Println("baseUrl= ", baseUrl)
+
+	//read duration of recording and meeting name from meta.xml
+	metaUrl := baseUrl + "/metadata.xml"
+	responseMeta, err := http.Get(metaUrl)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer func() {
+		_ = responseMeta.Body.Close()
+	}()
+
+	metaBody, err := ioutil.ReadAll(responseMeta.Body)
+	if err != nil {
+		log.Fatal(err)
+	}
+	//finding correct duration-ending of last slide
+	timeString := strings.SplitAfter(string(metaBody), "<duration>")
+	duration := strings.Split(timeString[1], "</duration>")
+	fmt.Println("duration of recording=", duration[0], "ms")
+
+	shapesUrl := baseUrl + "/shapes.svg"
+	webcamsWebmUrl := baseUrl + "/video/webcams.webm"
+	webcamsMp4Url := baseUrl + "/video/webcams.mp4"
+	deskshareWebmUrl := baseUrl + "/deskshare/deskshare.webm"
+	deskshareMp4Url := baseUrl + "/deskshare/deskshare.mp4"
+
+	//read content of the shapes.svg file, and assign shapes to it
+	responseShapes, err := http.Get(shapesUrl)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer func() {
+		_ = responseShapes.Body.Close()
+	}()
+
+	shapesBody, err := ioutil.ReadAll(responseShapes.Body)
+	if err != nil {
+		log.Fatal(err)
+	}
+	shapes := string(shapesBody)
+
+	fmt.Println("creating directory: ", presentationId)
+	if _, err := os.Stat(presentationId); os.IsNotExist(err) {
+		err = os.Mkdir(presentationId, 0700)
+		if err != nil {
+			fmt.Println("Failed to create temporary folder:", err.Error())
+		}
+	}
+
+	// Find and print slide timings, image Urls
+	durations := make(map[int]float64)
+	vidnames := make(map[int]string)
+	imgnames := make(map[int]string)
+	inValue, outValue, truncated := 0.0, 0.0, 0.0
+	inSrc, outSrc, pngSrc := "0.0", "10.5", "presentation/"
+	i := 1 // number of png pictures for slide
+
+	//parse for in= out= href= from /shapes.svg
+	ins := strings.Split(shapes, "in=\"")
+	outs := strings.Split(shapes, "out=\"")
+	pngs := strings.Split(shapes, "xlink:href=\"")
+
+	for k := 1; k < len(ins); k++ {
+		intext := strings.SplitAfter(ins[k], "\"")
+		realin := strings.Split(intext[0], "\"")
+		inSrc = realin[0]
+
+		outtext := strings.SplitAfter(outs[k], "\"")
+		realout := strings.Split(outtext[0], "\"")
+		outSrc = realout[0]
+
+		imgtext := strings.SplitAfter(pngs[k], "\"")
+		realpng := strings.Split(imgtext[0], "\"")
+		pngSrc = realpng[0]
+
+		inValue, _ = strconv.ParseFloat(inSrc, 64)
+		outValue, _ = strconv.ParseFloat(outSrc, 64)
+		truncated = (outValue*10 - inValue*10) / 10
+		durations[i] = truncated
+		imgnames[i] = "s" + strconv.Itoa(i) + ".png"
+		vidnames[i] = "v" + strconv.Itoa(i) + ".mp4"
+
+		imgUrl := baseUrl + "/" + pngSrc
+
+		if err := DownloadFile(path.Join(presentationId+"/"+imgnames[i]), imgUrl); err != nil {
+			panic(err)
+		}
+		i++
+	}
+
+	//correct duration of last slide
+	outValue, _ = strconv.ParseFloat(duration[0], 64)
+	outValue = outValue / 1000
+	outValue = math.Round(outValue*100) / 100
+	fmt.Println("ending of presentation=", outValue)
+	truncated = (outValue*10 - inValue*10) / 10
+	durations[i-1] = math.Round(truncated*100) / 100
+	fmt.Println("Duration of last slide according to meta.xml is: ", durations[i-1])
+
+	// create mp4 files from png files
+	fmt.Println("Creating videos from slide pictures, duration is given as seconds")
+	for j := 1; j < i; j++ {
+		fmt.Println(imgnames[j], " ", vidnames[j], " ", durations[j])
+		cmd := exec.Command("ffmpeg",
+			"-loop", "1",
+			"-framerate", "1",
+			"-i", path.Join(presentationId, imgnames[j]),
+			"-t", fmt.Sprint(durations[j]),
+			"-pix_fmt", "yuv420p",
+			"-vf", "scale=-1:720",
+			path.Join(presentationId, vidnames[j]))
+		err = cmd.Run()
+		if err != nil {
+			fmt.Println("Failed to create video from slide:", err.Error())
+			return
+		}
+	}
+
+	//create video_list.txt file to cancat with ffmpeg
+	f, err := os.Create("video_list.txt")
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+	for j := 1; j < i; j++ {
+		_, err := f.WriteString("file " + path.Join(presentationId, vidnames[j]) + "\n")
+		if err != nil {
+			fmt.Println(err)
+			_ = f.Close()
+			return
+		}
+	}
+	err = f.Close()
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+
+	// concat slide videos to create one piece of video file: slides.mp4
+	fmt.Println("merging slide videos to create: slides.mp4")
+	cmd := exec.Command("ffmpeg",
+		"-f", "concat",
+		"-safe", "0",
+		"-i", "video_list.txt",
+		"-c", "copy",
+		path.Join(presentationId, "slides.mp4"))
+	err = cmd.Run()
+	if err != nil {
+		fmt.Println("Failed to merge slide videos:", err.Error())
+		return
+	}
+	fmt.Println("slide videos merged")
+
+	// download webcams
+	fmt.Println("downloading webcams")
+	err = DownloadFile(path.Join(presentationId, "webcams.webm"), webcamsWebmUrl)
+	if err != nil {
+		err = DownloadFile(path.Join(presentationId, "orig-webcams.mp4"), webcamsMp4Url)
+		if err != nil {
+			fmt.Println("Failed to download webcams:", err.Error())
+			return
+		}
+		cmd = exec.Command("ffmpeg",
+			"-i", path.Join(presentationId, "orig-webcams.mp4"),
+			"-framerate", "1",
+			"-q:a", "0",
+			"-q:v", "0",
+			"-vf", "scale=-1:720",
+			path.Join(presentationId, "webcams.mp4"))
+		err = cmd.Run()
+		if err != nil {
+			fmt.Println("Failed to convert orig-webcams.mp4 to MP4:", err.Error())
+			return
+		}
+	} else {
+		// Successful download, convert to MP4
+		fmt.Println("webcams.webm file is downloaded")
+		fmt.Println("converting webcams.webm to webcams.mp4")
+		cmd = exec.Command("ffmpeg",
+			"-i", path.Join(presentationId, "webcams.webm"),
+			"-framerate", "1",
+			"-q:a", "0",
+			"-q:v", "0",
+			"-vf", "scale=-1:720",
+			path.Join(presentationId, "webcams.mp4"))
+		err = cmd.Run()
+		if err != nil {
+			fmt.Println("Failed to convert webcams.webm to MP4:", err.Error())
+			return
+		}
+	}
+
+	// download deskshare
+	deskshare := true
+	fmt.Println("downloading deskshare")
+	err = DownloadFile(path.Join(presentationId, "deskshare.webm"), deskshareWebmUrl)
+	if err != nil {
+		err = DownloadFile(path.Join(presentationId, "orig-deskshare.mp4"), deskshareMp4Url)
+		if err != nil {
+			fmt.Println("No deskshare")
+			deskshare = false
+		} else {
+			cmd = exec.Command("ffmpeg",
+				"-i", path.Join(presentationId, "orig-deskshare.mp4"),
+				"-framerate", "1",
+				"-q:a", "0",
+				"-q:v", "0",
+				"-vf", "scale=-1:720",
+				path.Join(presentationId, "deskshare.mp4"))
+			err = cmd.Run()
+			if err != nil {
+				fmt.Println("Failed to convert orig-deskshare.mp4 to MP4:", err.Error())
+				return
+			}
+		}
+	} else {
+		// Successful download, convert to MP4
+		fmt.Println("deskshare.webm file is downloaded")
+		fmt.Println("converting deskshare.webm to deskshare.mp4")
+		cmd = exec.Command("ffmpeg",
+			"-i", path.Join(presentationId, "deskshare.webm"),
+			"-framerate", "1",
+			"-q:a", "0",
+			"-q:v", "0",
+			"-vf", "scale=-1:720",
+			path.Join(presentationId, "deskshare.mp4"))
+		err = cmd.Run()
+		if err != nil {
+			fmt.Println("Failed to convert deskshare.webm to MP4:", err.Error())
+			return
+		}
+	}
+
+	fmt.Println("merging slides, webcams and deskshare side by side")
+	cmd = exec.Command("ffmpeg",
+		"-i", path.Join(presentationId, "slides.mp4"),
+		"-i", path.Join(presentationId, "webcams.mp4"),
+		"-i", path.Join(presentationId, "deskshare.mp4"),
+		"-framerate", "1",
+		"-filter_complex", "hstack=inputs=3",
+		meetingName+".mp4")
+	if !deskshare {
+		cmd = exec.Command("ffmpeg",
+			"-i", path.Join(presentationId, "slides.mp4"),
+			"-i", path.Join(presentationId, "webcams.mp4"),
+			"-framerate", "1",
+			"-filter_complex", "hstack=inputs=2",
+			meetingName+".mp4")
+	}
+	err = cmd.Run()
+	if err != nil {
+		fmt.Println("Failed to merge slides and webcams:", err.Error())
+		return
+	}
+
+	fmt.Println("Name of the final video is: ", meetingName)
+
+	_ = os.RemoveAll(presentationId + "/")
+	_ = os.Remove("video_list.txt")
+}
+
+// DownloadFile will download a url to a local file.
+func DownloadFile(filepath string, url string) error {
+	// Get the data
+	resp, err := http.Get(url)
+	if err != nil {
+		return err
+	} else if resp.StatusCode != 200 {
+		return errors.New("Response status code: " + strconv.Itoa(resp.StatusCode))
+	}
+	defer func() {
+		_ = resp.Body.Close()
+	}()
+	// Create the file
+	out, err := os.Create(filepath)
+	if err != nil {
+		return err
+	}
+	defer func() {
+		_ = out.Close()
+	}()
+	// Write the body to file
+	_, err = io.Copy(out, resp.Body)
+	return err
+}