Read MP3 Tags with Silverlight got me started with reading id3 tags, but i realize that taglib# online deals with local file paths ?
Is there a way of reading this info from a remote file ?
I recently answered the same question for Ruby (see below) - I'm pretty sure you can do something similar.
The idea is:
use HTTP 1.1 protocol or higher, and a Range HTTP-request.
download the beginning section (100 bytes) of the ID3v2-tag
from the first few bytes downloaded, you can determine the correct length of the complete ID3v2 tag, e.g. N
download the first N bytes of the file (e.g. the complete ID3v2-tag)
parse the ID3v2 tag for your purposes
See:
Read ID3 Tags of Remote MP3 File in Ruby/Rails?
Tim Heuer has a good blog post on doing this. http://timheuer.com/blog/archive/2010/01/30/reading-mp3-id3-tags-with-silverlight-taglib.aspx
Like yourself, he also ran into the problem of TabLib# only using local paths.
One thing that TagLib# didn’t have was a stream input implementation. Most of the libraries, in fact, assumed a local file path. Luckily the library was written using a generic ‘File’ interface, so I just had to create my own StreamFileAbstraction. I chose to do this within my project rather than the base library. It was easy since the LocalFileAbstraction actually perfomed an Open on the file as it’s first task and set some public variables. My abstraction basically just hands the stream already and ready to go.
There is an example on the novell site that uses file abstraction.
http:// developer.novell.com/wiki/index.php/TagLib_Sharp:_Examples
Related
As my title says, is it possible? I am begginer at front-end and trying to teach myself reactJS right now. I learned some javascript before and I know it is impossible to read or write files with it. Mainly what I want to do is to get string from input and lets say write it into file.
Well the question is, where does that file live?
Node is able to write to files because the files exist on the server that node is running on.
React runs in browser so there is no shared file system to write to. You can read from a file because the contents of that file get bundled into the Javascript that gets served to the browser.
If you want to write to a file, you would need to send an API request from your browser / React to a server and have that server write to the file system.
Additionally, as pointed out by Huy Nguyen, it's possible to write to the clients file system from the browser but that is going to be private to that user.
Your question is a bit vague. In addition to what #Stretch0 said, it's possible to read/write files on a user's computer using the browser's native APIs. Here is a good tutorial.
My question is basically that I am new to this framework and I am looking at pointers to how to work with non-file sources in media foundation since the documentation in this front seems lacking in my mind. Below is some info on what I am doing and what approach I am working with right now but I have no idea if it is the correct way to use the framework.
I am currently trying to use Microsoft Media Foundation to decode audio that I'm getting over Bluetooth and then send it along as PCM audio. When looking at the documentation for ms media foundation it seems that almost all examples assume the source is a file.
Looking at the tutorial for decoding audio for example they use MFCreateSourceReaderFromURL, which I cannot use since my source is not a file.
As I wanted to follow the tutorial and change as little as possible Im thinking that I need only change how I create the source reader and the rest of the process would be the same. I looked at the other SourceReaders available and MFCreateSourceReaderFromByteStream sounds about right for my purposes.
Is there a chance that I only need to create a bytestream and continuously fill it with data that I get over the air as we go and the media source created by MFCreateSourceReaderFromByteStream handle this well? Or do I need to create a custom media source and do more manual work at the lower parts of the API to get something like this to work?
Or maybe a source reader is the wrong approach altogether when the source is not a file? In the main page about Source Reader here they have the following picture:
And this picture shows the media source within the source reader pointing to a source file only, is this a real limitation or simply and example?
Im writing this in plain c, but pointing to c++ documentation or examples is fine as its usually pretty straightforward to translate c++ to c and there seems to be no documentation for c anyways.
Edit:
Im adding a image on what kind of data Im getting, the red area being the chunks of data I refer to in comments below Source.
Non-file source is not a accurate description. Does it have a file structure, just not a file? Structured differently? Raw stream?
If you look at samples with source reader, they assume presence and usage of stream handler capable to parse incoming stream into elementary streams with known type and properties. Then you or Media Foundation could apply decoder or otherwise transform the data.
As you specified that the data come "in chunks", most likely that you are interested in an alternate option to use AAC Decoder explicitly. You can create an instance of it, initialize input and output types, then feed it with compressed audio and pull decoded PCM on the output. The decoder has MFT interface.
I used Sphinx4 for some time which really fits my needs. I load a recognizer, pass the audio data to it and use the recognized String in my application.
Right now I'm working on a C application (C++ is unfortunately not an option) where I need something similar and thought that I could use Sphinx3 which is written in C.
The problem is that I don't really know how it is used inside an application and there is no "Hello World"-example as Sphinx4 provides it.
I already compiled and installed sphinxbase and sphinx3 and now I can include the sphinx header files in my application.
Now to my questions:
Is there a "simple" and well documented example application that uses sphinx3 from a C environment?
How can I load up the sphinx3 engine and call a recognizer with my binary audio data?
OR: Do I need to start an application like "sphinx3_decode" and call it from my own application? If so, is there an example application for that?
Thank you in advance!
Best regards,
Robert
It's not recommended to use Sphinx3. From the website:
Sphinx-3 is CMU’s large vocabulary speech recognition system. It’s
older C based decoder that we continue to maintain. It’s planned to
make it obsolete in the future, it’s still most accurate decoder for
large vocabulary tasks. We are using it as a baseline to check the
recognizer accuracy. This decoder is only intended for researchers who
want to evaluate bleeding edge methods in ASR like tree search method.
If you need to use a decoder you should use pocketsphinx. You can find the tutorial and the API documentation on the website
http://cmusphinx.sourceforge.net/wiki/tutorialpocketsphinx
http://cmusphinx.sourceforge.net/api/pocketsphinx/pocketsphinx_8h.html
I Recently worked on an Intregated Project on Punjabi Language.
Here are some steps that we used...
First we recorded the punjabi audio data in a vaccumed room in 16000 hz sample rate.
Then we took the recorded data and segmented it using Praat Software into small wav and raw files of 2 to 30 sec and saved them in a folder named train.
Then we took a system having Linux ie. Ubuntu and installed the required plug in like autoconfig, automake etc and untarred Sphinx 3 along with 4 packages that are cmuclmtk, pocketsphinx, sphinxbase, sphinxtrain.
Then according to the small wav files we made many files like transcription, dic, phone, filler, file id, ccs etc.
Then we opened the terminal and typed –"sphinx_fe” to check the whether the sphinx is functional or not.
Then we created an folder named “man” and then in terminal wrote its path.
Then we run the command- “sphinxtrain –t man setup”. By running this command an folder named “etc” will be formed in “man” folder containing files “feat_paramas” & ”config”.
Changes were made in the in the config file according to our data.
Then we moved all the files that we created before ie. transcription, dic in the etc folder in that is located in man folder.
Then we placed ‘lang1.sh” script in etc folder and remaining 4 scripts in man folder.
Then we opened the path for etc folder in terminal and run command- “lang1.sh”
Then we run series of commands in terminal – “mfcgen2.sh” then “verify3.sh” then “hmm4.sh” and at last “end-test.sh” to get the final result.
Rest if you have worked on Sphinx 4 then you may know about the files that are mentioned above in the steps. I hope this helps you.
Is there any archive format that offers the following:
be digitally sign-able with a digital certificate from a trusted source like Verisign - for preventing changes to the file (I am not referring to read only, but in case the file was changed it should no longer be signed telling the user this is not the original file)
be stream-able - be able to be opened even if not all of the content has been transferred (also not strictly linearly)
be "readable" - be able to read the data without extracting to a temporary folder (AFAIK if you open a file in a zip archive it is extracted first, and this stays true even for zip based formats like OOXML. This is not what I want)
be portable - support on at least Windows, Linux and Mac OS X is a must, or at least future support
be free of patents - Be open source - also preferably a license that allows commercial use(as far as i know GPL a share-alike license so it doesn't allow commercial use, BSD on the other hand allows it)
Note: Though it may come in handy eventually I can not think right now of a scenario that would require both point 1 and point 2 simultaneously. Or lets leave it a be able to check the signature only when the whole file was downloaded.
I am not interested in:
being able to be compressed
being supported on legacy systems
Does any existing archive format fit this description (tar evolutions like DAR and pax come to mind) ?
If there is, are there programing libraries available for the above mentioned OSs?
If not, would it be hard to create such a thing?
Usage scenario:
I want to use this to create a new media container.
Current media containers contain the audio, video and subtitle streams directly.
Matroska, currently the most advanced container, has supplementary features like attachments and menus.
The menu functionality however is not implemented and very limited.
What I want to create is one level higher.
I want to create a file similar in a way to OOXML.
Also all of the menuing should be done in web technologies like HTML5 (as it is now the tag allows for any kind of codec to be used) and CSS.
Also just like you have holograms on dvds to prove the authenticity I want to create a sign-able file
Research notes:
Before asking this question I stumbled uppon this:
Whats the best way digitally sign a zip file for download using .Net
While detached signing would be feasable for the individual files contained in this archive it is not an ellegant solution for the archive file. Not end user friendly.End users should be able to doubleclick the file to open it in a media player like VLC, and see a message that the file is legit (just like you see in a browser if the page is transmitted with SSL through HTTPS or not)
EDIT: clarified point 5
EDIT 2: added a note to clarify point 1 and 2
EDIT 3: added usage scenario
EDIT 4: added research notes section
P.S.: This is my first question on StackOverflow
I doubt that you find such format out of the box. I understand how such solution can be built with help of our SolFS, but SolFS doesn't have built-in signing (you can add signing easily).
In C following this article (http://blogs.msdn.com/oldnewthing/archive/2006/12/21/1340571.aspx), we have succesfully been able to grab the file version information out of windows files however there are some files that seem to have a different mechanism for storing the version information that is not addressed in the article and was wondering if anyone had any ideas here.
One example of a file would be system32/oledlg.dll. Going through the file byte by byte we come to a chunk where the version information SHOULD be stored:
F^#i^#l^#e^#V^#e^#r^#s^#i^#o^#n^#^#^#^#^1.0 (x^#p^#s^#p^#.^#0^#8^#0^#4^#1^#3
^#-^#2^#1^#0^#8^#)^#^#^#^#^#.^#^G^#^A^#I^#n^#t^#e^#r^#n^#a^#l^#N^#a^#m^#e
That we can see is 1.0. However, when you look at the file information in windows the version is actually 5.1.2600.5512. The method in the article works for most files but there are a few instances I have come across where I am running into the above problem. Anyone have any experience with this? I only have access to standard C.
Based on the follow up article posted in the comment, does that mean there is no way to grab the actual file version from a file with a corrupted file info block?
I should also add that I am grabbing the files from a windows box, and then examining them on linux with a C program to grab the file info.
IT turns out the wrong peice of info for that file was being used to get the version, didn't actually need the File Version block but the "VS_VERSION_INFO" block.