Improved error reporting and other changes to make more Go idiomatic.

This commit is contained in:
Alan Noble 2017-09-21 13:36:54 +09:30
parent d0e796f47d
commit b54068e0a2
1 changed files with 81 additions and 116 deletions

View File

@ -40,6 +40,7 @@ import (
"math/rand"
"net"
"net/http"
"os"
"os/exec"
"strconv"
"strings"
@ -50,32 +51,23 @@ import (
"github.com/Comcast/gots/psi"
)
// program modes
const (
File = iota
HTTP
UDP
RTP
Dump
)
// defaults and networking consts
const (
defaultPid = 256
defaultPID = 256
defaultFrameRate = 25
defaultHTTPOutput = "http://localhost:8080?"
defaultUDPOutput = "udp://0.0.0.0:16384"
defaultRTPOutput = "rtp://0.0.0.0:16384"
mp2tPacketSize = 188 // MPEG-TS packet size
mp2tMaxPackets = 2016 // # first multiple of 7 and 8 greater than 2000
UDPPackets = 7 // # of UDP packets per ethernet frame (8 is the max)
RTPPackets = 7 // # of RTP packets per ethernet frame (7 is the max)
RTPHeaderSize = 12
RTPSSRC = 1 // any value will do
udpPackets = 7 // # of UDP packets per ethernet frame (8 is the max)
rtpPackets = 7 // # of RTP packets per ethernet frame (7 is the max)
rtpHeaderSize = 12
rtpSSRC = 1 // any value will do
ffmpegPath = "/usr/bin/ffmpeg"
)
// flags
// flag values
const (
filterFixPTS = 0x0001
filterDropAudio = 0x0002
@ -91,27 +83,25 @@ const (
// globals
var (
sendClip = sendClipToRTP
packetsPerFrame = RTPPackets
flags *int
frameRate *int
selectedPid *int
packetsPerFrame = rtpPackets
clipCount int
expectCC int
dumpCC int
dumpPcrBase uint64
dumpPCRBase uint64
RTPSequenceNum uint16
)
func main() {
var (
input = flag.String("i", "", "Input RTSP URL")
output = flag.String("o", "", "Output URL (HTTP, UDP or RTP)")
mode = flag.String("m", "r", "Mode: one of f,h,u,r or d")
)
flags = flag.Int("f", 0, "Flags: see readme for explanation")
frameRate = flag.Int("r", defaultFrameRate, "Input video frame rate (25fps by default)")
selectedPid = flag.Int("p", defaultPid, "Select packets with this packet ID (PID)")
// command-line flags
var (
input = flag.String("i", "", "Input RTSP URL")
output = flag.String("o", "", "Output URL (HTTP, UDP or RTP)")
mode = flag.String("m", "r", "Mode: one of f,h,u,r or d")
flags = flag.Int("f", 0, "Flags: see readme for explanation")
frameRate = flag.Int("r", defaultFrameRate, "Input video frame rate (25fps by default)")
selectedPID = flag.Int("p", defaultPID, "Select packets with this packet ID (PID)")
)
func main() {
flag.Parse()
if *input == "" {
@ -128,20 +118,20 @@ func main() {
}
case "u":
sendClip = sendClipToUDP
packetsPerFrame = UDPPackets
packetsPerFrame = udpPackets
if *output == "" {
*output = defaultUDPOutput
}
case "r":
sendClip = sendClipToRTP
packetsPerFrame = RTPPackets
packetsPerFrame = rtpPackets
if *output == "" {
*output = defaultRTPOutput
}
case "d":
sendClip = sendClipToStdout
default:
log.Fatal("Invalid mode %s\n", *mode)
log.Fatalf("Invalid mode %s\n", *mode)
}
if *flags&filterFixContinuity != 0 && *flags&dumpProgramInfo != 0 {
@ -149,9 +139,10 @@ func main() {
}
for {
_ = readWriteVideo(*input, *output)
fmt.Printf("Trying again in 10s\n")
time.Sleep(1e10 * time.Nanosecond)
err := readWriteVideo(*input, *output)
fmt.Fprintln(os.Stderr, err)
fmt.Fprintln(os.Stderr, "Trying again in 10s")
time.Sleep(10 * time.Second)
}
}
@ -160,78 +151,59 @@ func main() {
func readWriteVideo(input string, output string) error {
fmt.Printf("Reading video from %s\n", input)
var videoArg, audioArg [2]string
args := []string{
"-r", strconv.Itoa(*frameRate),
"-i", input,
}
if *flags&(filterFixPTS|filterScale640|filterScale320) == 0 {
videoArg[0] = "-vcodec"
videoArg[1] = "copy"
args = append(args, "-vcodec", "copy")
} else {
videoArg[0] = "-vf"
videoArg[1] = ""
vfArg := []string{}
if *flags&filterFixPTS != 0 {
videoArg[1] += "setpts='PTS-STARTPTS'" // start counting PTS from zero
vfArg = append(vfArg, "setpts='PTS-STARTPTS'") // start counting PTS from zero
}
if *flags&filterScale640 != 0 {
videoArg[1] += ", scale=640:352"
vfArg = append(vfArg, "scale=640:352")
} else if *flags&filterScale320 != 0 {
videoArg[1] += ", scale=320:176"
vfArg = append(vfArg, "scale=320:176")
}
args = append(args, "-vf", strings.Join(vfArg, ","))
}
if *flags&filterDropAudio == 0 {
audioArg[0] = "-acodec"
audioArg[1] = "copy"
args = append(args, "-acodec", "copy")
} else {
audioArg[0] = "-an"
audioArg[1] = ""
}
fmt.Printf("Executing: %s -r %d -i %s %s \"%s\" %s %s -f mpegts -\n",
ffmpegPath, *frameRate, input, videoArg[0], videoArg[1], audioArg[0], audioArg[1])
var cmd *exec.Cmd
if audioArg[1] == "" {
cmd = exec.Command(ffmpegPath,
"-r", strconv.Itoa(*frameRate),
"-i", input,
videoArg[0], videoArg[1],
audioArg[0],
"-f", "mpegts", "-")
} else {
cmd = exec.Command(ffmpegPath,
"-r", strconv.Itoa(*frameRate),
"-i", input,
videoArg[0], videoArg[1],
audioArg[0], audioArg[1],
"-f", "mpegts", "-")
args = append(args, "-an")
}
args = append(args, "-f", "mpegts", "-")
fmt.Printf("Executing: %s %s\n", ffmpegPath, strings.Join(args, " "))
cmd := exec.Command(ffmpegPath, args...)
stdout, err := cmd.StdoutPipe()
if err != nil {
fmt.Printf("Error creating pipe: %s\n", err)
return err
return fmt.Errorf("Error creating pipe: %s", err)
}
err = cmd.Start()
if err != nil {
fmt.Printf("Error starting pipe: %s\n", err)
return err
return fmt.Errorf("Error starting pipe: %s", err)
}
// (re)initialize globals
clipCount = 0
expectCC = -1
dumpCC = -1
dumpPcrBase = 0
dumpPCRBase = 0
RTPSequenceNum = uint16(rand.Intn(1 << 15))
// for UDP and RTP only dial once
var conn net.Conn
if strings.Index(output, "udp://") == 0 || strings.Index(output, "rtp://") == 0 {
if strings.HasPrefix(output, "udp://") || strings.HasPrefix(output, "rtp://") {
conn, err = net.Dial("udp", output[6:])
if err != nil {
fmt.Printf("Error dialing %s: %s\n", output, err)
return err
return fmt.Errorf("Error dialing %s: %s", output, err)
}
defer conn.Close()
}
@ -241,17 +213,17 @@ func readWriteVideo(input string, output string) error {
clip := make([]byte, mp2tMaxPackets*mp2tPacketSize)
clipSize := 0
packetCount := 0
prevTime := time.Now()
now := time.Now()
prevTime := now
fmt.Printf("Looping\n")
for {
_, err := io.ReadFull(br, pkt)
if err != nil {
fmt.Printf("Error reading from ffmpeg: %s\n", err)
return err
return fmt.Errorf("Error reading from ffmpeg: %s", err)
}
if *flags&filterFixContinuity != 0 && mp2tFixContinuity(pkt, packetCount, (uint16)(*selectedPid)) {
if *flags&filterFixContinuity != 0 && mp2tFixContinuity(pkt, packetCount, uint16(*selectedPID)) {
fmt.Printf("Packet #%d.%d fixed\n", clipCount, packetCount)
}
copy(clip[clipSize:], pkt)
@ -259,15 +231,16 @@ func readWriteVideo(input string, output string) error {
clipSize += mp2tPacketSize
// send if (1) our buffer is full or (2) 1 second has elapsed and we have % packetsPerFrame
now = time.Now()
if (packetCount == mp2tMaxPackets) ||
(time.Now().Sub(prevTime) > 1*time.Second && packetCount%packetsPerFrame == 0) {
(now.Sub(prevTime) > 1*time.Second && packetCount%packetsPerFrame == 0) {
clipCount++
if err = sendClip(clip[:clipSize], output, conn); err != nil {
return err
}
clipSize = 0
packetCount = 0
prevTime = time.Now()
prevTime = now
}
}
return nil
@ -279,40 +252,36 @@ func sendClipToFile(clip []byte, _ string, _ net.Conn) error {
fmt.Printf("Writing %s (%d bytes)\n", filename, len(clip))
err := ioutil.WriteFile(filename, clip, 0644)
if err != nil {
fmt.Printf("Error writing file %s: %s\n", filename, err)
return err
return fmt.Errorf("Error writing file %s: %s", filename, err)
}
return nil
}
// sendClipToHTPP posts a video clip via HTTP, using a new TCP connection each time.
func sendClipToHTTP(clip []byte, output string, _ net.Conn) error {
URL := output + strconv.Itoa(len(clip)) // NB: append the size to the output
fmt.Printf("Posting %s (%d bytes)\n", URL, len(clip))
resp, err := http.Post(URL, "video/mp2t", bytes.NewReader(clip)) // lighter than NewBuffer
url := output + strconv.Itoa(len(clip)) // NB: append the size to the output
fmt.Printf("Posting %s (%d bytes)\n", url, len(clip))
resp, err := http.Post(url, "video/mp2t", bytes.NewReader(clip)) // lighter than NewBuffer
if err != nil {
fmt.Printf("Error posting to %s: %s\n", output, err)
return err
return fmt.Errorf("Error posting to %s: %s", output, err)
}
defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
if err == nil {
fmt.Printf(string(body) + "\n")
fmt.Printf("%s\n", body)
}
return err
}
// sendClipToUDP sends a video clip over UDP.
func sendClipToUDP(clip []byte, _ string, conn net.Conn) error {
size := UDPPackets * mp2tPacketSize
size := udpPackets * mp2tPacketSize
fmt.Printf("Sending %d UDP packets of size %d (%d bytes)\n", len(clip)/size, size, len(clip))
for offset := 0; offset < len(clip); offset += size {
pkt := clip[offset : offset+size]
_, err := conn.Write(pkt)
if err != nil {
fmt.Printf("UDP write error %s. Is your player listening?\n", err)
return err
return fmt.Errorf("UDP write error %s. Is your player listening?", err)
}
}
return nil
@ -320,16 +289,15 @@ func sendClipToUDP(clip []byte, _ string, conn net.Conn) error {
// sendClipToRTP sends a video clip over RTP.
func sendClipToRTP(clip []byte, _ string, conn net.Conn) error {
size := RTPPackets * mp2tPacketSize
size := rtpPackets * mp2tPacketSize
fmt.Printf("Sending %d RTP packets of size %d (%d bytes)\n",
len(clip)/size, size+RTPHeaderSize, len(clip))
pkt := make([]byte, RTPHeaderSize+RTPPackets*mp2tPacketSize)
len(clip)/size, size+rtpHeaderSize, len(clip))
pkt := make([]byte, rtpHeaderSize+rtpPackets*mp2tPacketSize)
for offset := 0; offset < len(clip); offset += size {
RTPEncapsulate(clip[offset:offset+size], pkt)
_, err := conn.Write(pkt)
if err != nil {
fmt.Printf("RTP write error %s. Is your player listening?\n", err)
return err
return fmt.Errorf("RTP write error %s. Is your player listening?", err)
}
}
return nil
@ -351,11 +319,11 @@ func sendClipToStdout(clip []byte, _ string, _ net.Conn) error {
packetCount++
pkt := clip[offset : offset+mp2tPacketSize]
pktPid, err := packet.Pid(pkt)
pktPID, err := packet.Pid(pkt)
if err != nil {
return err
}
if pktPid != (uint16)(*selectedPid) {
if pktPID != uint16(*selectedPID) {
continue
}
@ -391,14 +359,14 @@ func sendClipToStdout(clip []byte, _ string, _ net.Conn) error {
// adaptation field, followed by payload
afl := adaptationfield.Length(pkt)
if adaptationfield.HasPCR(pkt) {
pcrBase, pcrExt, _ := mp2tGetPcr(pkt)
pcrBase, pcrExt, _ := mp2tGetPCR(pkt)
if *flags&dumpPacketHeader != 0 {
fmt.Printf("\t\tAFL=%d, PCRbase=%d, PCRext=%d\n", afl, pcrBase, pcrExt)
}
if pcrBase < dumpPcrBase {
if pcrBase < dumpPCRBase {
fmt.Printf("Warning: PCRbase went backwards!\n")
}
dumpPcrBase = pcrBase
dumpPCRBase = pcrBase
} else if *flags&dumpPacketHeader != 0 {
fmt.Printf("\t\tAFL=%d\n", afl)
}
@ -422,13 +390,11 @@ func mp2tDumpProgram(clip []byte) error {
_, err := packet.Sync(reader)
if err != nil {
fmt.Println("Warning: Bad MPEG-TS sync byte")
return err
return fmt.Errorf("Error reading sync byte: %s", err)
}
pat, err := psi.ReadPAT(reader)
if err != nil {
fmt.Printf("ReadPAT error: %s\n", err)
return err
return fmt.Errorf("Error reading PAT: %s", err)
}
mp2tDumpPat(pat)
@ -437,8 +403,7 @@ func mp2tDumpProgram(clip []byte) error {
for pn, pid := range pm {
pmt, err := psi.ReadPMT(reader, pid)
if err != nil {
fmt.Printf("ReadPMT error: %s\n", err)
return err
return fmt.Errorf("Error reading PMT: %s", err)
}
pmts = append(pmts, pmt)
mp2tDumpPmt(pn, pmt)
@ -458,7 +423,7 @@ func mp2tDumpPmt(pn uint16, pmt psi.PMT) {
fmt.Printf("\tPIDs %v\n", pmt.Pids())
fmt.Printf("\tElementary Streams")
for _, es := range pmt.ElementaryStreams() {
fmt.Printf("\t\tPid %v : StreamType %v\n", es.ElementaryPid(), es.StreamType())
fmt.Printf("\t\tPID %v : StreamType %v\n", es.ElementaryPid(), es.StreamType())
for _, d := range es.Descriptors() {
fmt.Printf("\t\t\t%+v\n", d)
}
@ -475,7 +440,7 @@ func mp2tFixContinuity(pkt []byte, packetCount int, pid uint16) bool {
if !hasPayload {
return false
}
if pktPid, _ := packet.Pid(pkt); pktPid != pid {
if pktPID, _ := packet.Pid(pkt); pktPID != pid {
return false
}
fixed := false
@ -491,8 +456,8 @@ func mp2tFixContinuity(pkt []byte, packetCount int, pid uint16) bool {
return fixed
}
// Mp2tGetPcr extracts the Program Clock Reference (PCR) from an MPEG-TS packet (if any)
func mp2tGetPcr(pkt []byte) (uint64, uint32, bool) {
// Mp2tGetPCR extracts the Program Clock Reference (PCR) from an MPEG-TS packet (if any)
func mp2tGetPCR(pkt []byte) (uint64, uint32, bool) {
if !adaptationfield.HasPCR(pkt) {
return 0, 0, false
}
@ -523,8 +488,8 @@ func RTPEncapsulate(mp2tPacket []byte, pkt []byte) {
timestamp := uint32(time.Now().UnixNano() / 1e6) // ms timestamp
binary.BigEndian.PutUint32(pkt[4:8], timestamp)
// bytes 8,9,10&11: SSRC
binary.BigEndian.PutUint32(pkt[8:12], RTPSSRC)
binary.BigEndian.PutUint32(pkt[8:12], rtpSSRC)
// payload follows
copy(pkt[RTPHeaderSize:RTPHeaderSize+RTPPackets*mp2tPacketSize], mp2tPacket)
copy(pkt[rtpHeaderSize:rtpHeaderSize+rtpPackets*mp2tPacketSize], mp2tPacket)
}