cmd: add program for unwrapping MTS media to a local file

This is useful in the case that we want to playback media using players that don't support MPEG-TS eg. audacity for audio. Approved-by: Saxon Milton
2023-11-30 03:52:25 +00:00 · 2023-11-30 03:52:25 +00:00 · 19b696683b
parent 59bf9d15a8
commit 19b696683b
1 changed files with 142 additions and 0 deletions
--- a/exp/mts-unwrapper/main.go
+++ b/exp/mts-unwrapper/main.go
@ -0,0 +1,142 @@
+/*
+AUTHORS
+  Trek Hopton <trek@ausocean.org>
+
+LICENSE
+  Copyright (C) 2023 the Australian Ocean Lab (AusOcean)
+
+  It is free software: you can redistribute it and/or modify them
+  under the terms of the GNU General Public License as published by the
+  Free Software Foundation, either version 3 of the License, or (at your
+  option) any later version.
+
+  It is distributed in the hope that it will be useful, but WITHOUT
+  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+  FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+  for more details.
+
+  You should have received a copy of the GNU General Public License
+  in gpl.txt.  If not, see http://www.gnu.org/licenses.
+*/
+
+// mts-unwrapper will unwrap an MPEG-TS encoded file and output the data contained in the PES to a specified file.
+package main
+
+import (
+	"flag"
+	"fmt"
+	"log"
+	"os"
+
+	"bitbucket.org/ausocean/av/container/mts"
+	"bitbucket.org/ausocean/av/container/mts/meta"
+	"bitbucket.org/ausocean/av/container/mts/psi"
+
+	"github.com/Comcast/gots/packet"
+	"github.com/Comcast/gots/pes"
+)
+
+func main() {
+	const chunkSize = 16000
+	var (
+		inPath, outPath string
+		pid             int
+	)
+	flag.StringVar(&inPath, "in", "media.ts", "file path of input")
+	flag.StringVar(&outPath, "out", "media.raw", "file path of output data")
+	flag.IntVar(&pid, "pid", 210, "PID of encoded media; 210 is audio, 256 is h264 video")
+	flag.Parse()
+
+	clip, err := os.ReadFile(inPath)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	pmt, _, err := mts.FindPid(clip, mts.PmtPid)
+	if err != nil {
+		log.Fatal(err)
+	}
+	var metadata []byte
+	p := psi.PSIBytes(pmt)
+	p = p[4:]
+	_, metadata = p.HasDescriptor(psi.MetadataTag)
+
+	if metadata != nil {
+		v, err := meta.Get("codec", metadata[2:])
+		if err != nil {
+			log.Fatal(fmt.Errorf("unable to get MTS metadata: %v", err))
+		}
+		fmt.Println("codec:" + v)
+	} else {
+		fmt.Println("metadata nil")
+	}
+
+	// Get the first MTS packet to check.
+	var pkt packet.Packet
+	pesPacket := make([]byte, 0, chunkSize)
+	got := make([]byte, 0)
+	i := 0
+	if i+mts.PacketSize <= len(clip) {
+		copy(pkt[:], clip[i:i+mts.PacketSize])
+	}
+
+	// Loop through MTS packets until all the media data from PES packets has been retrieved.
+	for i+mts.PacketSize <= len(clip) {
+		// Check MTS packet.
+		if !(pkt.PID() == pid) {
+			i += mts.PacketSize
+			if i+mts.PacketSize <= len(clip) {
+				copy(pkt[:], clip[i:i+mts.PacketSize])
+			}
+			continue
+		}
+		if !pkt.PayloadUnitStartIndicator() {
+			i += mts.PacketSize
+			if i+mts.PacketSize <= len(clip) {
+				copy(pkt[:], clip[i:i+mts.PacketSize])
+			}
+		} else {
+			// Copy the first MTS payload.
+			payload, err := pkt.Payload()
+			if err != nil {
+				log.Fatal(fmt.Errorf("unable to get MTS payload: %v", err))
+			}
+			pesPacket = append(pesPacket, payload...)
+
+			i += mts.PacketSize
+			if i+mts.PacketSize <= len(clip) {
+				copy(pkt[:], clip[i:i+mts.PacketSize])
+			}
+
+			// Copy the rest of the MTS payloads that are part of the same PES packet.
+			for (!pkt.PayloadUnitStartIndicator()) && i+mts.PacketSize <= len(clip) {
+				payload, err = pkt.Payload()
+				if err != nil {
+					log.Fatal(fmt.Errorf("unable to get MTS payload: %v", err))
+				}
+				pesPacket = append(pesPacket, payload...)
+
+				i += mts.PacketSize
+				if i+mts.PacketSize <= len(clip) {
+					copy(pkt[:], clip[i:i+mts.PacketSize])
+				}
+			}
+		}
+		// Get the media data from the current PES packet.
+		pesHeader, err := pes.NewPESHeader(pesPacket)
+		if err != nil {
+			fmt.Println(fmt.Errorf("unable to read PES packet: %v", err))
+			continue
+		}
+		fmt.Printf("PTS: %v\n", pesHeader.PTS())
+		got = append(got, pesHeader.Data()...)
+		pesPacket = pesPacket[:0]
+	}
+
+	// Save media to file.
+	err = os.WriteFile(outPath, got, 0644)
+	if err != nil {
+		log.Fatal(err)
+	}
+	fmt.Println("Decoded and wrote", len(got), "bytes to file", outPath)
+}