DivX Decoder libraries? - cocoa

I saw, in an application from a major software vendor a dll called "DivXDecoder.dll" - which intrigued me as (a) it implies the existence of an easy to use divx library, and (b) I'd rather like to play divx compressed movies in a product I work on.
The DivX project itself seems to concentrate on making Codecs and tools for end users. Are there any C/C++ friendly projects that make playback of divx content in Win32 or Cocoa apps possible?

Look at mplayer sources - it uses the ffmpeg library that handles decoding from a number of formats.

DivX is a compressor that conforms to MPEG-4 Part 2. XviD and some versions of Windows Media are also implementations of the standard. So anything that can decompress MPEG-4 Part 2 should be able to handle things compressed with DivX.
As for actual decompression libraries, I'd recommend libavcodec. It's widely-used (= good support), cross-platform, and open-source (LGPL, so can be used in commercial apps). It's also fairly easy to use from it's C binding. It can open and play many different codecs (and with libavformat, handle many different wrappers i.e. avi, mkv, etc.).
If it's Windows-only, using the OS-provided Video For Windows might be a better option if you just want to play MPEG since you wouldn't need to ship it with your app and you avoid potential license issues. Be warned, though, that this requires the user to have certain codecs installed. On Win7 (and Vista I think) the MPEG codecs required to play DivX/XviD are installed by default, however they're not on XP...

Don't waste your time trying to implement DivX playback in a Cocoa application. Use QTKit. If someone wants to playback DivX content in your app they will install a DivX QuickTime plug-in.

Related

Proprietary codecs on Linux. What is legal?

So, assuming we got a distribution without proprietary codecs installed.
Let's take Linux Mint for example. I want to store and playback wav and ogg format sounds, either by using my own software, or by using another developer's software. So far so good right?
Imagine now that we have the following scenario. For some reason, I wanna playback a file that is either an mp4 or mp3 or mpeg or any other format, made by proprietary codecs. Instantly, I will need a codec for these formats.
I read somewhere that Fluendo sells solutions for "legal codec usage" for linux distros.
URL of fluendo: http://www.fluendo.com/en/
So here comes the questions:
Using VLC and ffmpeg is enough for me to convert a file to an ogg or ogv so I can playback a song or a video using an open format. You can also playback playback files made by proprietary formats. But are VLC and ffmpeg legal to use, to playback such files made by proprietary codecs? For example, ss VLC codecs okay to be used without paying anyone for mp4 playback? Is it okay to convert a file from mp4 to ogv?
If not, are there any legal and open source and free (as in freedom) codecs around that can solve the issue, or does someone have to pay a product, to be ethically correct, to the developers of the proprietaty codecs?
Note that I do not ask for Windows, since codec licenses are included to the price of the operating system. I ask exclusively for a free linux distribution.
Since #LordNeckbeard pointed me to the FAQ of FFmpeg, that I really can't believe I missed, it became clear to me that there is a problem in using proprietary codecs, thus there are some file formats that could be avoided to keep ourselves safe. Otherwise if someone can afford a license to use them too, that would be perfectly fine.
So mp3, mp4, mpeg and some more patented formats are to be avoided, if not licensed.
ffmpeg can be built so it can exclude support for such formats and if you need to use sound or video to your software ogg and ogv are nice and efficient formats as we all know.
Digging a little deeper Ι found that too.
https://www.fsf.org/resources/playogg_radiostation.pdf

Selecting a library / framework for video capture & recording

In one of the project that we have undertaken we are looking for a video capture & recording library. Our groundwork (based on google search) shows that vlc (libvlc), ffmpeg (libavcodec) and gstreamer are the three popular free and open source libraries / multimedia frameworks available for the same. How do these libraries compare on the following parameters:
Licensing policy to allow use within a commercial product without the need to open source any of the components of the product that is using the library
Ability to be used effectively in a multi-threaded environment (library should be inherently thread-safe)
Easy to use and maintain
Documentation: API should be well documented...this is relative...:)
Our primary intention is to be able to capture RTSP video streams (H.264/MPEG-2/MJPEG encoded), convert these streams to raw video / frames so that it can be used for analysis / processing and later on compress these frames and store it on the disk in the form of an MP4 file (using MPEG2 / H.264 encoding).
P.S. We understand that FFmpeg is also one of the components of vlc since vlc uses libavcodec library. Is the same true for gstreamer as well? Does it have any ffmpeg dependency?
Awaiting your responses.
Regards,
Saurabh Gandhi
I suggest you to use Gstreamer.
Gstremer is multimedia framework and it has so many plug-in for various task. Plugin are one type of library. And for Capturing rtsp , converting raw video , and muxing in mp4 all have i think you will easily find out the best plug-in in Gstermer. yOU just need to write one application for this.
1. Licensing policy to allow use within a commercial product without
the need to open source any of the components of the product that is
using the library
i dont know much about this
2. Ability to be used effectively in a multi-threaded environment
(library should be inherently thread-safe)
yea Gstremer internally take care for all threading.
3. Easy to use and maintain
yea Gstremer is easy to use and maintain
4. Documentation: API should be well documented...this is relative...:)
yea Gstremer has verry well managed documented API
No Gstermer framework has no dependency on ffmpeg.but Actualy gstremer has some plugin which are based on ffmpeg. that is gst-ffmpeg

Vorbis decoder for Windows Phone 7

Anyone know of a vorbis decoder library that can be used on Windows Phone 7?
The lack of native code interop make re-using any of the native code implementations difficult (impossible?) but if there are tricks to do that, I'm open to that as well.
There is a managed implementation for mono called csvorbis, it includes a sample which outputs a wav file this didn't need many changes to work with XNA's SoundEffect class. I did a whole track at once, this took a few seconds in the emulator so you may need to stream it using DynamicSoundEffect for better results. The mooncodecs folder has a codec for the desktop version based on csvorbis which may be worth a look aswell.
Ogg Vorbis is not a supported codec on Windows Phone 7 and the platform supports no way of adding support for custom codecs.
The options available are to write your own decoder/converter in managed code or to convert the original source files.
I suspect the second option will be easier.

Which video and audio format/codec should I use?

Environment: Windows XP/Vista, VS2008, C#/.NET 2.0, VideoGrabber.
Hi All,
I'm writing an app which captures cameras input and encodes them into a movie file (including sound).
My client suggests I encode the movie using the DivX codec. But it's not installed by default and it's not redistributable: Users would have to download, install and configure it themselves.
Is there a Codec available in default Windows (XP+) installations that I could use to encode video and sound? It must support compression. Ideally, I should be able to programmatically set basic configuration.
Note: I read this question but it doesn't actually address my needs.
TIA,
Is there a Codec available in default Windows (XP+) installations that I could use to encode video and sound?
About the best you can hope for is WMV2 (WMV v8). You may be able to encode it using qasf.dll.
The codecs you get for AVI in XP are all woeful efforts from the early days of ‘Multimedia PCs’: things like Cinepak and RLE, which are of zero use for modern full colour/resolution video, and Intel 4:2:0, which is only chroma subsampling, not really actual video compression.
If you need better than that you'll have to start embedding your own codecs, eg. from ffmpeg.
But it's not installed by default and it's not redistributable: Users would have to download, install and configure it themselves.
That's best anyway. Silently installing codecs onto a system is rather antisocial as there are often clashes between them and you could end up messing up other DirectShow applications. For example there are (at least) three different common DirectShow codecs that can handle “DivX” (which is really nothing more than MPEG-4 Advanced Simple Profile video plus MP3 audio in an AVI container): DivX, Xvid and ffdshow. Having more than one installed can be a recipe for bugs.
Not sure how useful this is to you, but I was trying to answer that very question just recently. This article suggests DIB, I420, or IYUV are supported on all platforms... at least in OpenCV. I had the least trouble with I420.

Installing just Quicktime libraries on Windows

There's Quicktime SDK for Windows, but any application that uses it needs quicktime runtime libraries to be installed on the system (SDK itself just has headers and library stubs, and not the actual DLLs).
If my application uses Quicktime, I'd like to install the necessary libraries with it's installer, thus not requiring user to install Quicktime separately. What I'm looking for is some sort of "quicktime redistributable".
As of now (quicktime 7.x), I can't find a way to do that. I could bundle whole quicktime installer (about 20 MiB), and launch it with MSI's silent/unattended flag. However, that way it has several side effects:
creates Quicktime player shortcut on desktop and in quick launch bar
hijacks file associations, (e.g. .mov becomes associated with Quicktime Player, even if it was associated with something else before)
installs some service/process (qttask) that presumably watches for Quicktime associations, or handles auto-updates.
installs Quicktime Player, which I don't need in fact.
Of the above, first three are quite bad.
Is there a way to "just install the libraries" for Quicktime?
In my application, I'd use Quicktime to import images, movies and audio files in various formats. If there is no sane way to install Quicktime runtime without side effects (changed file associations, extra icons, ...), then I should be seriously looking at alternative solutions (e.g. FreeImage to load images, perhaps DirectShow for video/audio).
If you need to redistribute QuickTime, see QuickTime Licensing for details. You're not allowed to redistribute any of the QuickTime libraries without a written agreement with Apple. Many CD-replication companies will actually request proof of this agreement before printing large numbers of CDs.
I would definitely not distribute "QuickTime Lite" without consulting with either a lawyer or your Apple licensing representative.
Your best bet, AFAIK, is to use the full QuickTime installer (all 20MB of it), and have your main installer run it with a "silent" flag. That, at least, will allow your users to install QuickTime without a half-dozen dialogs (and without those annoying pictures of surfers in bikinis). The people at Apple's licensing division seemed to think that using the "silent" flag was acceptable, at least when we consulted them.
One warning: If the user already has an older version of QuickTime 6 Pro (or earlier) installed, then installing QuickTime 7 silently will nuke their QuickTime Pro registration and they'll have to repurchase it. We actually detect this situation in our installer and display a warning during the installation process, much like Apple does.
Yes, this is a pain. After 6+ years of working with QuickTime, I'd honestly recommend looking at other video frameworks. We're currently evaluating Ogg Theora.
You could include, with your setup package, a program called Quicktime Lite. It comes with the same libraries as Quicktime uses, but is much, much smaller.
Here"s the link:
Download Quicktime Lite
Quicktime Alternative does what you want, but for the reasons others have stated here, its illegal. Apple probably is not going to let you do what you want.

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