for video codec check

codec_check.js

#!/usr/bin/env node

const path 	= require('path')
const http	= require('http')
const https	= require('https')
const spawn	= require('child_process').spawn;
const fs 	= require('fs');
const os 	= require('fs');

function path_resove(uri, file){
	return path.dirname(uri) + '/' + file
}

function pase_m3u8(uri, format){	
	var prot = /^http/.test(uri) ? http: 
				/^https/.test(uri) ? https :
				null
	if(!prot){
		return Promise.reject(new Error('Does not support this protocol.'))
	}			
	return new Promise(function(resolve, reject){
		prot.get(uri, function(res){
			res.resume();
			if(res.statusCode !== 200){
				return reject(new Error('Resource not found.'))
			}
			var data = '';
			res.setEncoding('utf8');
			res.on('data', (chunk) => {
				data += chunk
			});
			res.on('end', function(){
			 	var s = data.match(/^.+\.ts$/mg)
				if(s && s.length){
			    		return resolve(path_resove(uri,s[0]))
			    	}
				reject(new Error('Resource not found.'))
			});

		}).on('error', (e) => {
		  reject(e)
		})
	});
}


function parse(data){
	var arr = data.split(/\[\/STREAM\]/g);
	var item = {
		audio: {},
		video: {}
	}
	if(!arr && arr.length){
		return null;
	}
	for(var i = 0; i < 2; i++){
		var n = arr[i];
		if(/channels/.test(n)){
			item.audio.channels = /^channels=(.+)$/mg.exec(n)[1]
			item.audio.codec_name = /^codec_name=(.+)$/mg.exec(n)[1]
			item.audio.profile = /^profile=(.+)$/mg.exec(n)[1]
			item.audio.sample_rate = /^sample_rate=(.+)$/mg.exec(n)[1]
		}else{
			item.video.codec_name = /^codec_name=(.+)$/mg.exec(n)[1]
			item.video.profile = /^profile=(.+)$/mg.exec(n)[1]
			item.video.level = /^level=(.+)$/mg.exec(n)[1]
		}
	}
	return item;
}

function exec(file){
	file = file.trim();
	return new Promise(function(resolve, reject){

		if(/\.m3u8$/.test(file)){
			return pase_m3u8(file)
				.then(function(result){
					exec(result).then(function(item){
						resolve(item)
					})
				})
		}

		if(!file.match(/http[s]?/) && !fs.existsSync(file)){
			return reject(new Error('File does not exist'));
		}
		
		var proc = os.platform === 'win32' ? 'ffprobe.exe' : 'ffprobe';
		
		var ffprobe = spawn(proc, ['-show_streams', file]);
		ffprobe.on('error', function(err){
			return reject(err);
		});

		var result = '';
		ffprobe.stdout.on('data', function(data){
			result += data;
		});

		ffprobe.on('close', function(code){
			if(code !== 0){
				return reject(new Error('Exec ffprobe error, exit code: ' + code));
			}else{
				resolve(parse(result))
			}
		})
	})
}

function audio_code(item){
	// need to see ietf document
	if(item.audio.codec_name === 'aac'){
		return 'mp4a.40.2'
	}
	var codec_name = ['aac', '']
	var profile = ['LC']
}

function video_code(item){
	var codec_names = {h264: 'avc1'}
	var profiles = {Baseline :66, Main : 77, High : 100}
	var exts = {Baseline: 'E0', Main: '40', High: '00'}
	var res = [];
	var res1 = []
	var code_name = item.video.codec_name
		, profile =  item.video.profile 
		, level = item.video.level;

	if(code_name === 'h264'){
		res.push(codec_names[code_name])
		res.push('.')
		res1.push(codec_names[code_name])
		profile = profiles[profile]
		var p = profile && parseInt(profile)
		res.push(p.toString(16))
		res1.push(p)
		res.push(exts[item.video.profile])
		level = parseInt(level)
		res.push(level.toString(16))
		res1.push(level)
	}
	return [res1.join('.'),res.join('')]
}


if(process.argv.length < 3){
	return console.log('node codec_check.js <file or url>')
}

process.argv.slice(2).forEach(function(file){
	exec(file).then(function(result){	
		var a = audio_code(result)
		var v = video_code(result)
		result.codec = []
		for(var i = 0 ; i < v.length; i++){
			result.codec.push(v[i] + ', ' + a)
		}
		console.log(file)
		console.dir(result)
	}).catch(function(err){
		console.error(err);
	})
})