Can anyone explain me if is possible for the DLNA standard pass information of available external subtitles (.srt files) when playing media files (videos) without transcoding the video file.
If is possible then can anyone show me where this is explained in the DLNA standard? or how can this be implemented?
I'm trying to implement this using platinium library and don't know how to do it or if this is possible.
Thanks
Possible? Yes. Standardized? No. Reliable? Absolutely not. There is no specification of how to do subtitles right, neither in UPnP or DLNA. It ultimately is a question of how DMR wants the subtitles to be served by DMS, so it largely depends on the specific DMR you want to use. Some DMRs require a specific nonstandard DIDL-Lite field in media description (Samsung TVs seem to be promoting <sec:CaptionInfoEx>), some DMRs are happy with a somewhat standard-like <res protocolInfo="http-get:*:text/srt:*">. Both cases enclosing the URL of your SRT file, of course. It might be perfectly possible that your DMR does not support subtitles at all. There is no such requirement in either UPnP or DLNA (have i already said that?).
So Platinum does not have any subtitle support out of the box. You can create the <res> tag with existing logic - setting PLT_ProtocolInfo with ContentType of text/srt and assigning to PLT_MediaItemResource with m_Uri of your SRT file (served by your DMS).
Adding a new field is more tricky, PLT_Didl has a fixed set of fields which you must extend along with PLT_MediaObject::ToDidl which is pretty fixed in its operation. I consider this part of Platinum somewhat rushed, in comparison to the visible designing effort put in the rest of the framework.
In any case, your DMS must be also ready to act as HTTP server for your subtitles, which means giving the power to whatever class you have as implementation of PLT_MediaServerDelegate::ProcessFileRequest.
Related
I'm developing an engine for a 2D game in C ++ and for some days I've been looking for a way to protect the images and audio of my future game. I know there is no 100% protection and that someone would be able to open these files, but I mean the regular user who just installed the game, prevent it from modifying the sprites, change the sound, overwrite the xml files with game map data.
I downloaded some games made in Unity and noticed that a .assets extension is used, in Diablo 2 it is used .ma0, .mpq, .data, in FEZ .pak, in Super Meat Boy only a .tp file. In other words, you can not open and edit any of these files in a text editor or unzip with winrar, they offer a minimum level of protection. How is this done? Do I have to create my own binary file format or is there any program that makes it easier to work?
You can't.
That "minimum level of protection" is even more minimal than you think. You can open those files in a hex editor and hack away at them. This activity is something that has been commonplace for many decades.
You can encrypt the data, but since the key must be stored in your application and the user has a copy of your application, that can be extracted and/or changed too.
You can add a digital signature to prevent people from modifying the assets then using them ("modding") but, again, this can be altered in your application.
You can obfuscate the assets by shipping them in a proprietary format, but this is usually done purely for functional reasons because, again, someone will reverse engineer them.
Once a thing is on someone else's computer, you have lost control of that thing.
There are actually multiple questions here, iirc:
How can users be prevented from reading game assets?
How can users be prevented from manipulating game assets?
What file format can be used to store game assets?
If you're using an existing engine, it probably has some support for this, and if it is sufficient for your purposes you only need to learn how to use it.
If you need to roll your own, you need to define your requirements clearly and pick a solution which fulfills them. For asset storage, a ZIP based format is probably easiest to handle, all languages have some form of support for that. To protect integrity, you should use cryptographic algorithms: digital signatures to detect tampering, and encryption to prevent reading. These will probably slow down the opening of assets a little bit, but in most cases this should be acceptable.
These two links reference the ability, in ColdFusion, to get the name of an uploaded file using form.getPartsArray(). However I can not find ColdFusion documentation on it. I would like to use this but not if it has been deprecated or will be. Does anyone have more information on the origin and fate of this function?
ColdFusion: get the name of a file before uploading
http://www.stillnetstudios.com/get-filename-before-calling-cffile/
ColdFusion: get the name of a file before uploading
Ignoring the main question for a moment, can you elaborate on why you want to use it? Reason for asking is the title of the first question might give you a mistaken impression about what that method actually does. Form.getPartsArray() does not provide access to file information before the file is uploaded. The file is already on the server at that point, so in later versions of CF (with additional functionality) it does not necessarily buy you much over just using cffile action=upload.
Does anyone have more information on the origin and fate of this
function?
However, to answer your other question - it is an undocumented feature last I checked. (It was more useful in earlier versions of CF, which lacked some of the newer features relating to form fields and uploads.)
Internally, most form data can be handled using standard request objects, ie HttpServletRequest. However, those do not support multipart requests, ie file uploads. So a special handler is needed. Macromedia/Adobe chose to use the com.oreilly.servlet library for their internal implementation. That is what you are accessing when using FORM.getPartsArray().
The O'Reilly stuff has been bundled with CF since (at least) CF8, which is a good indicator. However, using any internal feature always comes with the risk the implementation will change and break your application. Also, if you move to another engine, the code may not be supported/compatible. So "You pays your money, you takes your choice".
CF8 / Form Scope
I'm writing a C++ library for an existing networking protocol (one with an document specifying the exact packet layout). As there are a considerable number of packet definitions, rather than writing all the serialization/de-serialization methods manually, are there any serialization libraries which are capable of specifying a packet layout specifically?
I've been looking at things like Google Protobuf and Apache Thrift, but they seem to be focused towards developing a server and client in tandem, where the packet layout does not matter along as it is consistent across a single release of the software. I need to serialize to an existing specification, so need to determine the field ordering, length, endianness, etc. explicitly. Is there anything that can help make this less of a chore?
There is a library/tools called PADS which should be ideal for this. See this SO answer here, the project home page here, some GitHub-ish stuff here. There seems to be some Haskell related stuff here. I've just tried and succeeded in downloading PADS/C from the homepage (note that the download server's username and password are given at the bottom of their license agreement).
It's a bit like writing a Google Protocol Buffer schema, except you're specifying bits/bytes in an arbitrary data stream, which is what you have.
I tried to get PADS/ML downloaded from https://github.com/yitzhakm/PADS-ML working some time ago, but ran into a lot of trouble and ultimately failed.
As you're interested in C (which is about as close to C++ as you're going to get) you might try the PADS/C library.
I am currently developping a windows application who test railroad equipments to find any defaults.
Utility A => OK
Utility B => NOK
...
This application will check the given equipment and generate a report.
This report needs to be written once, and no further modifications are allowed since this file can be used as working proof for the equipment.
My first idea was ta use pdf files (haru lib looks great), but pdf can also be modified.
I told myself that I could obsfuscate the report, and implement a homemade reader inside my application, but whatever way I store it, the file would always be possibly accessed and modified right?
So I'm running out of ideas.
Sorry if my approach and my problem appear naive but it's an intership.
Thanks for any help.
Edit: I could also add checksums for files after I generated them, and keep a "checksums record file", and implement a checksums comparison tool for verification? just thought about this.
I believe the answer to your question is to use any format whatosever, and use a digital signature anybody can verify, e.g., create a gnupg, get that key signed by the people who require to check your documents, upload it to one of the key servers, and use it to sign the documents. You can publish the documents, and have a link to your public key available for verification; for critical cases someone verifying must be trust your signature (i.e., trust somebody who signed your key).
People's lives depend on the state of train inspections. Therefore, I find it hard to believe that someone expects you to solve this problem only using free-as-in-beer components.
Adobe supports a strong digital signature model. If you buy into their technology base, you can create PDF's that are digitally signed, and are therefore tamper-evident, as the consumer can check for the signature.
You can, as someone else pointed out, use GNUpg, or for that matter OpenSSL, to implement your own signature scheme, but railroad regulators are somewhat less likely to figure out how to work with it.
I would store reports in an encrypted/protected datastore.
When a user accesses a report (requests a copy, the original is of course always in the database and cannot be modified), it includes the text "Report #XXXXX". If you want to validate the report, retrive a new copy from the system using the Report ID.
Given I have description of say product x in multiple languages along with its price and availability dictated by region/locale, how do I go about telling django to render the most appropriate variant of the content based on region of request origin? Amazon would be a good example of what I am trying to achieve.
Is is best to store each variant in the database, and afterwards look at request header to serve the most appropriate content, or is there a best practise way to achieve this.
I was struggling with the same problem. The localeurl library seems to handle these cases, so you don't have to write the logic by yourself. I still haven't tested the library, but at first glance it seems to be exactly what we need. You can read more about it here