Is it possible to add a hidden string to an audio file (MP3, mid) via PHP?
I have an online music store and some of my customers resell the songs, and I want to hide his e-mail address in the audio file to identify them.
Audio Files
For real audio files (not MIDI, which is not really an audio file), the best method for this is to use audio watermarking. There are many algorithms and tools (such as AWT) that can be executed from your PHP script to handle this. They work by modifying the audio data in a way that cannot be perceived but can be decoded.
Most of these algorithms can encode the watermark in such a way that they survive re-encoding with other codecs. This is a critical difference from what you are asking for. If you simply were to add an ID3 tag, any tool could remove that. In fact, it's likely your tag would get removed just by tools that read and re-write your ID3 tags. With the information embedded in the actual audio itself however, it will survive. If someone decodes the file and re-encodes with another codec, depending on your watermarking algorithm, the watermark will still survive. Even if someone streams it within another stream, the watermark can survive.
and I want to hide his e-mail address in the audio file to identify them
Rather than embedding personally identifying information, you should store an ID or hash of an ID that you keep in your own database. It might be even better if you generate a new ID for each download so that should you need to find the user who re-sold your files, you can prove when they downloaded it and from what IP address, along with any other information you wish to keep in your database.
MIDI Files
For MIDI, you will have to embed your ID in the metadata of the file. This can be easily defeated, and may not be worth your time at all.
Related
I am currently developing a web solution in PHP 8.0 using Symfony 5.3.7 where I need to allow user to download a file with custom metadatas.
For example, I have on the server a file a.jpg and I created a metadata "Resume: John is looking to Marie", which is stored and linked to the file in database.
If a user click on a button to download the file, I need to set the metadata stored in database to the file before the user download it, then if he bring is a.jpg in USB key or whatever, the metadata is in it.
Does anyone knows how to do with Symfony or even native PHP?
I am thinking of create a download function to do this but I don't find how to write the metadata in the file.
The only thing I could find is this https://www.php.net/manual/fr/pharfileinfo.setmetadata.php, but I don't even understand how it works.
I need this for multiple file types : images, videos, audios and PDFs.
There is no universal way to add arbitrary metadata like this to a file, regardless of whether you're using PHP or anything else.
At its most basic, a file is just a series of bits, and the way we interpret those bits is what we call a "file format". Some file formats are very simple - the whole file is interpreted as a series of letters, or a series of coloured pixels; others are much more complex, with different sections interpreted as different types of information.
A JPEG image file, for instance, can have sections of data referred to as "EXIF information", which can store details about the image, including arbitrary text. Similarly, MP3 files can have sections called "ID3", which are used to store things like track and artist names to be displayed by media players. You can probably find tools or libraries for editing both of those formats, but you won't be able to use an EXIF editor on an MP3 file or an ID3 editor on a JPEG.
The function you found was for managing the metadata on PHAR files, which are PHP code archives. It's not going to be useful for editing images, PDFs, or anything else.
So, you need to identify the different types of file you want to edit, and then find out two things: firstly, does the file format have anywhere to put the metadata at all; and secondly, what tools can edit the metadata in that particular file type. You might find some libraries or tools which can manage metadata in multiple audio formats, or multiple image formats, but chances are you're going to need to integrate more than one to get the breadth of support you seem to want.
This is going to sound like an odd request.
I have a PHP script pulling a mp3 stream from SoundCloud and repeating the stream with the correct headers to allow WinAmp to play the file. But it only shows the local url I have the script running from. Before anyone asks, I am injecting ID3v1 into the file before echoing it.
Is there any way to provide WinAmp with the meta data from php?
Just to clarify, you are effectively proxying an MP3 file from SoundCloud, and you want to embed metadata into it?
Winamp will pick up ID3 tags in an HTTP-served MP3 file. However, if you are using ID3v1, those tags don't exist until the very end of the file. If you want the file to be identified without having to download the whole file, you must use ID3v2 which are typically located at the beginning of the file. (I actually recommend using both ID3v1 and ID3v2 for broader player compatibility, but almost everything supports ID3v2, so it is your choice.)
Now, there is another method but if you use this method the metadata won't be saved in the file when downloaded. You can use SHOUTcast-style metadata. Basically, Winamp and other clients (like VLC) send a request header, Icy-MetaData: 1. This tells the server that it supports SHOUTcast-style metadata. In your server response, you would insert metadata every 8KB or so. Basically, you want the reverse of what I have detailed here: https://stackoverflow.com/a/4914538/362536
In the end, simply adding ID3v2 tags will solve your problem in the best way, but I wanted to mention the alternative option in case you needed it for something else.
I am building a site similar to thefuture.fm. DJs are able to upload MP3 files and set if the file only can be streamed or streamed and downloaded.
Visitors to the site don't have to login to listen to music. They should be able to stream/download these MP3 songs depending on the users settings.
I am using the jPlayer to play songs. I have searched all over the web but can't find any solution. Does jPlayer have any facility like prevent downloading of MP3 files? Or is there any way I can prevent this?
It's actually impossible to prevent downloading. You can make it harder for somebody, but he still needs to download all the data to hear the song. So even if you use some encryption to send the data to a flash player you write yourself, the player will have to decrypt it and play the audio. And since you can decompile flash it wouldn't be to hard to find out the algorithm. He could also just record the music again when playing it (similar to the first DVD decrypt tools, who just took a screenshot 30 times/sec to pass million dollar security measurements)
So the goal is to make it harder, not impossible.
Personally I would go for temporary available links in combination with a cookie, so I can still use jplayer and don't have to reinvent the wheel. Also use some obfuscating to make it harder to read the URL.
When somebody request the main URL (where you show your player) generate a unique key and save it in a cookie. The unique key should link to the IP address and request time stored in session.
Now create a link to the music file like playfile.php?file=music.mp3 or whatever. Just make sure that PHP will handle the file request. If you obfuscate this link it will be a little harder to find it.
In playfile.php check for the unique code in the cookie and check if it matches the IP address in session and the request time is less then EG 15 seconds (any longer and music won't play anyway with slow internet connection). If it is, stream the file. If it's not, block it.
Now if somebody would write a program/script to download the music, he can. But if somebody has the knowledge and time to do that, nothing will stop him from downloading it.
This will prevent any normal user from downloading it.
Preventing hotlinking is a bit easier, since in general you'll have a referrer string to check. If this is present then you'll know not to serve the content. Here is a code example.
Preventing downloading on the other hand is much harder - the best approach would be for a Flash application to decrypt data in realtime - if you use a simple encryption scheme, most client hardware should be fast enough. I couldn't find much for this on the web, so I wonder whether you'd have to do some Flash/Flex development yourself: download MP3 data in chunks, apply decryption routines from a library, and send them to some sort of MP3 decoding buffer. I suspect the password would be hard-coded.
Addendum: I've found that in later versions of Flash you can play dynamically generated sounds from a buffer (see here). So, if you're willing to get stuck into some Flash/Flex development, a solution is in sight. I couldn't find anything that accesses low-level MP3 routines, but don't forget that files don't have to be MP3 as transmitted from your server - convert them to whatever your app needs.
What you are searching for can't be achieved with JavaScript solution. If you want javascript to play something, it has to download it and in order to download it, JavaScript needs a URL.
Most common way to tackle this problem is using Adobe Flash and making a player in it. You can make your player stream content (mp3 in your case) without explicitly exposing actual data location to user.
Put the file(s) in a location that isn't accessible from the browser and use PHP to stream them out as a series of chunks using HTTP/1.1 206 Partial Content. Then use a method like this to edit the context menu to add/remove the 'save as'.
Use a session var to eliminate direct linking.
Actually, there is a player that DOES scramble the url and it works pretty good. We used it because of this excellent feature. It is not impossible to download/save the audio, but at least it is not a matter of just opening the inspector and copying the url. It also prevents from sharing to outside sources by URL. So, contrary to the above, it IS possible and it IS available :)
Check the plugin out here:
https://wordpress.org/plugins/mp3-jplayer/
I run a website which serves videos to monthly subscribers who can download them. The majority of the videos are WMV and MP4. Is there a PHP or Linux library which would inject metadata or text into the video files without re-encoding the entire file?
My problem is that the videos are pirated and shared on other sites; we are losing money. So, I want to inject the downloader's username so that we can catch the pirates.
I cannot have the movies being re-rendendered/re-encoded for every download because it would put a lot of stress on the server.
I'm looking for some solution that will fopen and fwrite this data to the file.
Any ideas on how to accomplish that or is there any library that can do this?
As Pekka mentioned, inserting meta data won't help you fight piracy. The minute the pirate re-encodes the file, the meta data is lost. In addition, there is software (e.g. TigoTago) which edits meta-data.
A better approach would be to:
Don't allow downloads. Instead, use encrypted streaming.
Allow downloads, but chase down the pirated content; whenever you find the videos on Rapidshare and other file sharing sites, file a complaint.
Because punishing the pirate won't do much. They'll just sign up again with a different name, a different email, and a different prepaid credit card.
If you're still unsure about it; take a look at iTunes. The file which you download cannot be played on any computer which is not authorized (if the file is protected). But, the minute a user converts the file or re-encodes it, the file can be played any where on anything.
edit
And anyways, most pirate shares and torrents are uploaded as MKV or AVI. So most likely, the pirates will be converting and re-encoding it before they upload it; rendering the metadata useless.
I'm sorry if the question is ambiguous, I'll try to explain.
I'm working on an existing PHP download script for videos and some parts of it are broken. There's code in there that's supposed to place a specific member code inside the video file before download, but it doesn't work. Here's the code:
//embed user's code in video file
$fpTarget = fopen($filename, "a");
fwrite($fpTarget, $member_code);
fclose($fpTarget);
$member_code is a random 6-character code.
Now, this would make sense to me if it were a text file, but since it's a video file, how could this possibly work and what is it supposed to do? If the member code is somehow added to the video, how can I see it after download it? I have no experience with video files, so any help is appreciated (a modification of the available code or new code would be equally welcome).
I'm sorry I can't give a more precise description of what the code is supposed to do, I'm trying to figure that out myself.
It may work, depending on the format/type of the video. MPG files are fairly tolerant of "noise" in a file and players would skip over your code because it doesn't look like valid video frame data.
Other formats/players may puke, because the format requires certain data be at specific offsets relative to the end of the file, which you've now shifted by 6 characters.
Your best bet is to figure see if whatever format you're serving up has provisions for metadata in its specifications. e.g. there might be support for a comment field somewhere that you can simply slap the code into.
However, if you're doing all this for 'security' or tracking unauthorized sharing of the video, then simply writing the number into a header is fairly easy to bypass. A better bet would be to watermark the video somehow so that the code is embedded in the actual video data, so that "This video belongs to member XYZ only" is displayed while playing.
You don't write to the content of the file directly, not like you would with a text file. As you've noticed, this effectively corrupts the video and you have no way of reasonably reading the information.
For audio/video files, you write to meta-data that's packaged with the file. How this is packaged and what you can do with it generally depends heavily on the container format used for the file. (Remember that container and codec are two different things. The codec is the format used to encode the audio/video, the container is the file format in which that data stream is stored.)
A library like getID3 might be a good place to start. I've never used it, but it seems to be what you're looking for. What you would essentially do is write a value to the meta-data in the container (either a pre-defined value for that container or maybe a custom key/value pair, etc.) which would be part of the file. Then, when reading the file, you can get that data. (Now, that last part depends heavily on what's reading the file. The data is there, but not every player cares about it. You'll want to match up what you're writing to with what you usually see/read from the file's internal meta-data.)