audiobookshelf/server/libs/fluentFfmpeg/ffprobe.js

262 lines
6.9 KiB
JavaScript

/*jshint node:true, laxcomma:true*/
'use strict';
var spawn = require('child_process').spawn;
function legacyTag(key) { return key.match(/^TAG:/); }
function legacyDisposition(key) { return key.match(/^DISPOSITION:/); }
function parseFfprobeOutput(out) {
var lines = out.split(/\r\n|\r|\n/);
lines = lines.filter(function (line) {
return line.length > 0;
});
var data = {
streams: [],
format: {},
chapters: []
};
function parseBlock(name) {
var data = {};
var line = lines.shift();
while (typeof line !== 'undefined') {
if (line.toLowerCase() == '[/'+name+']') {
return data;
} else if (line.match(/^\[/)) {
line = lines.shift();
continue;
}
var kv = line.match(/^([^=]+)=(.*)$/);
if (kv) {
if (!(kv[1].match(/^TAG:/)) && kv[2].match(/^[0-9]+(\.[0-9]+)?$/)) {
data[kv[1]] = Number(kv[2]);
} else {
data[kv[1]] = kv[2];
}
}
line = lines.shift();
}
return data;
}
var line = lines.shift();
while (typeof line !== 'undefined') {
if (line.match(/^\[stream/i)) {
var stream = parseBlock('stream');
data.streams.push(stream);
} else if (line.match(/^\[chapter/i)) {
var chapter = parseBlock('chapter');
data.chapters.push(chapter);
} else if (line.toLowerCase() === '[format]') {
data.format = parseBlock('format');
}
line = lines.shift();
}
return data;
}
module.exports = function(proto) {
/**
* A callback passed to the {@link FfmpegCommand#ffprobe} method.
*
* @callback FfmpegCommand~ffprobeCallback
*
* @param {Error|null} err error object or null if no error happened
* @param {Object} ffprobeData ffprobe output data; this object
* has the same format as what the following command returns:
*
* `ffprobe -print_format json -show_streams -show_format INPUTFILE`
* @param {Array} ffprobeData.streams stream information
* @param {Object} ffprobeData.format format information
*/
/**
* Run ffprobe on last specified input
*
* @method FfmpegCommand#ffprobe
* @category Metadata
*
* @param {?Number} [index] 0-based index of input to probe (defaults to last input)
* @param {?String[]} [options] array of output options to return
* @param {FfmpegCommand~ffprobeCallback} callback callback function
*
*/
proto.ffprobe = function() {
var input, index = null, options = [], callback;
// the last argument should be the callback
var callback = arguments[arguments.length - 1];
var ended = false
function handleCallback(err, data) {
if (!ended) {
ended = true;
callback(err, data);
}
};
// map the arguments to the correct variable names
switch (arguments.length) {
case 3:
index = arguments[0];
options = arguments[1];
break;
case 2:
if (typeof arguments[0] === 'number') {
index = arguments[0];
} else if (Array.isArray(arguments[0])) {
options = arguments[0];
}
break;
}
if (index === null) {
if (!this._currentInput) {
return handleCallback(new Error('No input specified'));
}
input = this._currentInput;
} else {
input = this._inputs[index];
if (!input) {
return handleCallback(new Error('Invalid input index'));
}
}
// Find ffprobe
this._getFfprobePath(function(err, path) {
if (err) {
return handleCallback(err);
} else if (!path) {
return handleCallback(new Error('Cannot find ffprobe'));
}
var stdout = '';
var stdoutClosed = false;
var stderr = '';
var stderrClosed = false;
// Spawn ffprobe
var src = input.isStream ? 'pipe:0' : input.source;
var ffprobe = spawn(path, ['-show_streams', '-show_format'].concat(options, src), {windowsHide: true});
if (input.isStream) {
// Skip errors on stdin. These get thrown when ffprobe is complete and
// there seems to be no way hook in and close stdin before it throws.
ffprobe.stdin.on('error', function(err) {
if (['ECONNRESET', 'EPIPE', 'EOF'].indexOf(err.code) >= 0) { return; }
handleCallback(err);
});
// Once ffprobe's input stream closes, we need no more data from the
// input
ffprobe.stdin.on('close', function() {
input.source.pause();
input.source.unpipe(ffprobe.stdin);
});
input.source.pipe(ffprobe.stdin);
}
ffprobe.on('error', callback);
// Ensure we wait for captured streams to end before calling callback
var exitError = null;
function handleExit(err) {
if (err) {
exitError = err;
}
if (processExited && stdoutClosed && stderrClosed) {
if (exitError) {
if (stderr) {
exitError.message += '\n' + stderr;
}
return handleCallback(exitError);
}
// Process output
var data = parseFfprobeOutput(stdout);
// Handle legacy output with "TAG:x" and "DISPOSITION:x" keys
[data.format].concat(data.streams).forEach(function(target) {
if (target) {
var legacyTagKeys = Object.keys(target).filter(legacyTag);
if (legacyTagKeys.length) {
target.tags = target.tags || {};
legacyTagKeys.forEach(function(tagKey) {
target.tags[tagKey.substr(4)] = target[tagKey];
delete target[tagKey];
});
}
var legacyDispositionKeys = Object.keys(target).filter(legacyDisposition);
if (legacyDispositionKeys.length) {
target.disposition = target.disposition || {};
legacyDispositionKeys.forEach(function(dispositionKey) {
target.disposition[dispositionKey.substr(12)] = target[dispositionKey];
delete target[dispositionKey];
});
}
}
});
handleCallback(null, data);
}
}
// Handle ffprobe exit
var processExited = false;
ffprobe.on('exit', function(code, signal) {
processExited = true;
if (code) {
handleExit(new Error('ffprobe exited with code ' + code));
} else if (signal) {
handleExit(new Error('ffprobe was killed with signal ' + signal));
} else {
handleExit();
}
});
// Handle stdout/stderr streams
ffprobe.stdout.on('data', function(data) {
stdout += data;
});
ffprobe.stdout.on('close', function() {
stdoutClosed = true;
handleExit();
});
ffprobe.stderr.on('data', function(data) {
stderr += data;
});
ffprobe.stderr.on('close', function() {
stderrClosed = true;
handleExit();
});
});
};
};