From 5f1f985dd05fc61ceb21554a08d22f2d3399b958 Mon Sep 17 00:00:00 2001
From: calzoneman <calzoneman@gmail.com>
Date: Tue, 19 May 2015 19:48:08 -0400
Subject: [PATCH] Rewrite ffmpeg module

---
 config.template.yaml |   3 +
 lib/config.js        |   3 +-
 lib/ffmpeg.js        | 256 ++++++++++++++++++++++++-------------------
 3 files changed, 150 insertions(+), 112 deletions(-)

diff --git a/config.template.yaml b/config.template.yaml
index 85ecd3d8..4da9d424 100644
--- a/config.template.yaml
+++ b/config.template.yaml
@@ -202,6 +202,9 @@ channel-blacklist: []
 #   * ffmpeg must be installed on the server
 ffmpeg:
   enabled: false
+# Executable name for ffprobe if it is not "ffprobe".  On Debian and Ubuntu (on which
+# libav is used rather than ffmpeg proper), this is "avprobe"
+  ffprobe-exec: 'ffprobe'
 
 link-domain-blacklist: []
 
diff --git a/lib/config.js b/lib/config.js
index d549fe0a..9f49afe1 100644
--- a/lib/config.js
+++ b/lib/config.js
@@ -100,7 +100,8 @@ var defaults = {
     },
     "channel-blacklist": [],
     ffmpeg: {
-        enabled: false
+        enabled: false,
+        "ffprobe-exec": "ffprobe"
     },
     "link-domain-blacklist": [],
     setuid: {
diff --git a/lib/ffmpeg.js b/lib/ffmpeg.js
index b2739fb7..b044b746 100644
--- a/lib/ffmpeg.js
+++ b/lib/ffmpeg.js
@@ -2,6 +2,8 @@ var Logger = require("./logger");
 var Config = require("./config");
 var spawn = require("child_process").spawn;
 
+var SUPPORTS_JSON = true;
+
 var acceptedCodecs = {
     "mov/h264": true,
     "flv/h264": true,
@@ -19,6 +21,124 @@ var audioOnlyContainers = {
     "mp3": true
 };
 
+function readOldFormat(buf) {
+    var lines = buf.split("\n");
+    var tmp = { tags: {} };
+    var data = {
+        streams: []
+    };
+
+    lines.forEach(function (line) {
+        if (line.match(/\[stream\]|\[format\]/i)) {
+            return;
+        } else if (line.match(/\[\/stream\]/i)) {
+            data.streams.push(tmp);
+            tmp = { tags: {} };
+        } else if (line.match(/\[\/format\]/i)) {
+            data.format = tmp;
+            tmp = { tags: {} };
+        } else {
+            var kv = line.split("=");
+            var key = kv[0].toLowerCase();
+            if (key.indexOf("tag:") === 0) {
+                tmp.tags[key.split(":")[1]] = kv[1];
+            } else {
+                tmp[key] = kv[1];
+            }
+        }
+    });
+
+    return data;
+}
+
+function reformatData(data) {
+    var reformatted = {};
+
+    var duration = parseInt(data.format.duration, 10);
+    if (isNaN(duration)) duration = "--:--";
+    reformatted.duration = Math.ceil(duration);
+
+    var bitrate = parseInt(data.format.bit_rate, 10) / 1000;
+    if (isNaN(bitrate)) bitrate = 0;
+    reformatted.bitrate = bitrate;
+
+    reformatted.title = data.format.tags.title;
+    var container = data.format.format_name.split(",")[0];
+
+    data.streams.forEach(function (stream) {
+        if (stream.codec_type === "video") {
+            reformatted.vcodec = stream.codec_name;
+            if (!reformatted.title) {
+                reformatted.title = stream.tags.title;
+            }
+        } else if (stream.codec_type === "audio") {
+            reformatted.acodec = stream.codec_name;
+        }
+    });
+
+    if (reformatted.vcodec && !(audioOnlyContainers.hasOwnProperty(container))) {
+        reformatted.type = [container, reformatted.vcodec].join("/");
+        reformatted.medium = "video";
+    } else if (reformatted.acodec) {
+        reformatted.type = [container, reformatted.acodec].join("/");
+        reformatted.medium = "audio";
+    }
+
+    return reformatted;
+}
+
+exports.ffprobe = function ffprobe(filename, cb) {
+    var childErr;
+    var args = ["-show_streams", "-show_format", filename];
+    if (SUPPORTS_JSON) args = ["-of", "json"].concat(args);
+    var child = spawn(Config.get("ffmpeg.ffprobe-exec"), args);
+    var stdout = "";
+    var stderr = "";
+
+    child.on("error", function (err) {
+        childErr = err;
+    });
+
+    child.stdout.on("data", function (data) {
+        stdout += data;
+    });
+
+    child.stderr.on("data", function (data) {
+        stderr += data;
+    });
+
+    child.on("close", function (code) {
+        if (code !== 0) {
+            if (stderr.match(/-of/)) {
+                Logger.errlog.log("Warning: ffprobe does not support -of json.  " +
+                                  "Assuming it will have old output format.");
+                SUPPORTS_JSON = false;
+                return ffprobe(filename, cb);
+            }
+
+            if (!childErr) childErr = new Error(stderr);
+            return cb(childErr);
+        }
+
+        var result;
+        if (SUPPORTS_JSON) {
+            try {
+                result = JSON.parse(stdout);
+            } catch (e) {
+                return cb(new Error("Unable to parse ffprobe output: " + e.message));
+            }
+        } else {
+            try {
+                result = readOldFormat(stdout);
+            } catch (e) {
+                return cb(new Error("Unable to parse ffprobe output: " + e.message));
+            }
+        }
+
+        return cb(null, result);
+    });
+}
+
 exports.query = function (filename, cb) {
     if (!Config.get("ffmpeg.enabled")) {
         return cb("Raw file playback is not enabled on this server");
@@ -29,56 +149,55 @@ exports.query = function (filename, cb) {
                   "or HTTPS");
     }
 
-    ffprobe(filename, function (err, meta) {
+    exports.ffprobe(filename, function (err, data) {
         if (err) {
-            if (meta && meta.stderr && meta.stderr.match(/Protocol not found/)) {
+            if (err.message && err.message.match(/protocol not found/i)) {
                 return cb("Link uses a protocol unsupported by this server's ffmpeg");
             } else if (err.code && err.code === "ENOENT") {
-                return cb("Server is missing ffprobe");
+                return cb("Failed to execute `ffprobe`.  Set ffmpeg.ffprobe-exec to " +
+                          "the correct name of the executable in config.yaml.  If " +
+                          "you are using Debian or Ubuntu, it is probably avprobe.");
             } else {
                 Logger.errlog.log(err.stack || err);
                 return cb("Unable to query file data with ffmpeg");
             }
         }
 
-        meta = parse(meta);
-        if (meta == null) {
-            return cb("Unknown error");
+        try {
+            data = reformatData(data);
+        } catch (e) {
+            Logger.errlog.log(err.stack || err);
+            return cb("Unable to query file data with ffmpeg");
         }
 
-        if (isVideo(meta)) {
-            var codec = meta.container + "/" + meta.vcodec;
-
-            if (!(codec in acceptedCodecs)) {
-                return cb("Unsupported video codec " + codec);
+        if (data.medium === "video") {
+            if (!acceptedCodecs.hasOwnProperty(data.type)) {
+                return cb("Unsupported video codec " + data.type);
             }
 
-            var data = {
-                title: meta.title || "Raw Video",
-                duration: Math.ceil(meta.seconds) || "--:--",
-                bitrate: meta.bitrate,
-                codec: codec
+            data = {
+                title: data.title || "Raw Video",
+                duration: data.duration,
+                bitrate: data.bitrate,
+                codec: data.type
             };
 
             cb(null, data);
-        } else if (isAudio(meta)) {
+        } else if (data.medium === "audio") {
             var codec = meta.acodec;
 
-            if (!(codec in acceptedAudioCodecs)) {
-                return cb("Unsupported audio codec " + codec);
+            if (!acceptedAudioCodecs.hasOwnProperty(data.type)) {
+                return cb("Unsupported audio codec " + data.type);
             }
 
-            var data = {
-                title: meta.title || "Raw Audio",
-                duration: Math.ceil(meta.seconds) || "--:--",
-                bitrate: meta.bitrate,
+            data = {
+                title: data.title || "Raw Audio",
+                duration: data.duration,
+                bitrate: data.bitrate,
                 codec: codec
             };
 
             cb(null, data);
-        } else if (data.ffmpegErr.match(/Protocol not found/)) {
-            return cb("This server is unable to load videos over the " +
-                      filename.split(":")[0] + " protocol.");
         } else {
             return cb("Parsed metadata did not contain a valid video or audio stream.  " +
                       "Either the file is invalid or it has a format unsupported by " +
@@ -86,88 +205,3 @@ exports.query = function (filename, cb) {
         }
     });
 };
-
-function isVideo(meta) {
-    return meta.vcodec && !(meta.container in audioOnlyContainers);
-}
-
-function isAudio(meta) {
-    return meta.acodec;
-}
-
-function parse(meta) {
-    if (meta == null) {
-        return null;
-    }
-
-    if (!meta.format) {
-        return null;
-    }
-
-    var data = {};
-    meta.streams.forEach(function (s) {
-        if (s.codec_type === "video") {
-            data.vcodec = s.codec_name;
-        } else if (s.codec_type === "audio") {
-            data.acodec = s.codec_name;
-        }
-    });
-
-    data.container = meta.format.format_name.split(",")[0];
-    data.bitrate = parseInt(meta.format.bit_rate) / 1000;
-    if (meta.format["tag:title"]) {
-        data.title = meta.format["tag:title"];
-    }
-    data.seconds = Math.ceil(parseFloat(meta.format.duration));
-    return data;
-}
-
-function ffprobe(filename, cb) {
-    var err;
-    var ff = spawn("ffprobe", ["-show_streams", "-show_format", filename]);
-    ff.on("error", function (err_) {
-        err = err_;
-    });
-
-    var outbuf = "";
-    var errbuf = "";
-    ff.stdout.on("data", function (data) {
-        outbuf += data;
-    });
-    ff.stderr.on("data", function (data) {
-        errbuf += data;
-    });
-
-    ff.on("close", function (code) {
-        if (code !== 0) {
-            if (!err) {
-                err = "ffprobe exited with nonzero exit code";
-            }
-            return cb(err, { stderr: errbuf });
-        }
-
-        var lines = outbuf.split("\n");
-        var streams = [];
-        var format = {};
-        var data = {};
-        lines.forEach(function (line) {
-            if (line.match(/\[stream\]|\[format\]/i)) {
-                return;
-            } else if (line.match(/\[\/stream\]/i)) {
-                streams.push(data);
-                data = {};
-            } else if (line.match(/\[\/format\]/i)) {
-                format = data;
-                data = {};
-            } else {
-                var kv = line.split("=");
-                data[kv[0].toLowerCase()] = kv[1];
-            }
-        });
-
-        cb(null, {
-            streams: streams,
-            format: format
-        });
-    });
-}