I&#39;ve been keeping the Dranger ffmpeg tutorials up to date here: https://github.com/mpenkov/ffmpeg-tutorial

I&#39;ve tried to keep the code changes minimal while fixing bugs and rewriting deprecated parts.

Here is the best one I have found so far.  It deals with a lot of the quirks of the API and shows you how to build a working video player using SDL and libavformat/libavcodec.

http://dranger.com/ffmpeg/

I created this wiki page so that it can try and keep updated: 

[Using libav*][1]


  [1]: http://ffmpeg.org/trac/ffmpeg/wiki/Using%20libav*

http://dranger.com/ffmpeg/ is great, but the source code is little dated. For updated code of the tutorial, please take a look here: https://github.com/phamquy/FFmpeg-tutorial-samples

If you&#39;re interested in writing your own ffmpeg format or codec, take a look here:

http://wiki.multimedia.cx/index.php?title=Category:FFmpeg_Tutorials

I need to define an &amp;lt;img&gt;&#39;s src attribute in CSS.  Is there a way to specify this attribute?

Define an &lt;img&gt;&#39;s src attribute in CSS

I&#39;ve inherited a load of Junit test, but these tests (apart from most not working) are a mixture of actual unit test and integration tests (requiring external systems, db etc).

So I&#39;m trying to think of a way to actually separate them out, so that I can run the unit test nice and quickly and the integration tests after that. 

The options are..

1. Split them into separate directories.

2. Move to Junit4 (from v3) and annotate the classes to separate them.

3. Use a file naming convention to tell what a class is , i.e. AdapterATest and 
AdapterAIntergrationTest.

3 has the issue that Eclipse has the option to &quot;Run all tests in the selected project/package or folder&quot;. So it would make it very hard to just run the integration tests.

2: runs the risk that developers might start writing integration tests in unit test classes and it just gets messy.

1: Seems like the neatest solution, but my gut says there must be a better solution out there.

So that is my question, how do you lot break apart integration tests and proper unit tests?



 


Junit: splitting integration test and Unit tests

I am trying to find documentation to use the FFmpeg C API. It seems that only command line documentation is available.

Is there any good documentation/tutorials/links available?

FFmpeg C API documentation/tutorial

<p>I am trying to find documentation to use the FFmpeg C API. It seems that only command line documentation is available.</p>
<p>Is there any good documentation/tutorials/links available?</p>


What is the difference between static and shared libraries?

I use Eclipse and there are several project types including Static Libraries and Shared Libraries? Does one have an advantage over the other?

Difference between static and shared libraries?

In my algorithm, I need to create an information output. I need to write a boolean matrix into a bmp file.
It must be a monocromic image, where pixels are white if the matrix on such element is true.
Main problem is the bmp header and how to write this.


Writing BMP image in pure c/c++ without other libraries

I&#39;m trying to detect the compiler used to compile my source code. I can easily find predefined macros to check for MSVC or GCC (see http://predef.sourceforge.net/ for example), but I cannot find any macro to check for clang.

Does someone know if clang defines a macro like `__CLANG__` in order to know what is currently compiling my code ?

What predefined macro can I use to detect clang?

&gt; **Possible Duplicates:**  
&gt; [What makes more sense - char* string or char *string?](https://stackoverflow.com/questions/558474/what-makes-more-sense-char-string-or-char-string)
[Pointer declarations in C++: placement of the asterisk](https://stackoverflow.com/questions/180401/pointer-declarations-in-c-placement-of-the-asterisk)  
&lt;!-- End of automatically inserted text --&gt;

I&#39;ve seen mixed versions of this in a lot of code. (This applies to C and C++, by the way.) People seem to declare pointers in one of two ways, and I have no idea which one is correct, of if it even matters.

The first way it to put the asterisk adjacent the type name, like so:

    someType* somePtr;

The second way is to put the asterisk adjacent the name of the variable, like so:

    someType *somePtr;

This has been driving me nuts for some time now. Is there any standard way of declaring pointers? Does it even matter how pointers are declared? I&#39;ve used both declarations before, and I know that the compiler doesn&#39;t care which way it is. However, the fact that I&#39;ve seen pointers declared in two different ways leads me to believe that there&#39;s a reason behind it. I&#39;m curious if either method is more readable or logical in some way that I&#39;m missing.

Declaring pointers; asterisk on the left or right of the space between the type and name?

How can I convert a mixed case string to a lowercase string in C?

How do I lowercase a string in C?

I often have problems reading AVI files with my TV&#39;s DVD player if they are not DivX or Xvid (e.g., DX50 is not readable).

I&#39;d like to make a fast script to determine the video codec of these files before burning them to CD-ROM or DVD.

The command

    ffmpeg -i file.avi

prints the &quot;container&quot; of the video stream (mpeg4, mpeg2, etc), not the codec.

Any hint?

Thanks


How to determine video codec of a file with FFmpeg

I have been meaning to install `ffmpeg` as an extension to my PHP setup. So before I can install it, I need to `phpize` it. I installed `php5-dev` by `sudo apt-get install php5-dev`. But now when I run `phpize` I get the following error : 

    phpize
    Cannot find config.m4. 
    Make sure that you run &#39;/usr/bin/phpize&#39; in the top level source directory of the module

The location of my php.ini is `/usr/local/zend/etc/php.ini`

From another online resource I tried this 

    sudo apt-get install autoconf automake libtool m4

But all of them are already installed. 

Locate config.m4 didn&#39;t return anything.

Any pointers here how I can get `phpize` and thus, `ffmpeg` up and running?


How to install and run phpize

Despite all the hype, in reality the HTML5 video tag has a bit of a problem. In order to use it and for it to be cross browser compatible, you have to include more than one format of the video. To target all supported browsers these formats are mp4 and ogg. 

I was searching around for optimum settings for each format but unfortunately I couldn&#39;t find any. I&#39;m using ffmpeg 0.6 which has the tagline &quot;Works with HTML5&quot;. I&#39;m no video expert so I was wondering if anyone could recommend decent settings for each format? 

ffmpeg settings for converting to mp4 and ogg for HTML5 video

I am using ffmpeg to tell me video info. Specifically:

    ffmpeg -i video.ext

I get the output:

    Stream #0.0[0x1e0]: Video: mpeg2video, yuv420p, 704x576 [PAR 12:11 DAR 4:3], 9578 kb/s, 25 tbr, 90k tbn, 50 tbc

Does anyone know what tbr, tbn and tbc are exactly? I have seen speculation on the net but nothing definitive?

Meaning of ffmpeg output (tbc, tbn, tbr)

I need to convert audio files to mp3 using ffmpeg.

When I write the command as `ffmpeg -i audio.ogg -acodec mp3 newfile.mp3`, I get the error:

    FFmpeg version 0.5.2, Copyright (c) 2000-2009 Fabrice Bellard, et al.
      configuration: 
      libavutil     49.15. 0 / 49.15. 0
      libavcodec    52.20. 1 / 52.20. 1
      libavformat   52.31. 0 / 52.31. 0
      libavdevice   52. 1. 0 / 52. 1. 0
      built on Jun 24 2010 14:56:20, gcc: 4.4.1
    Input #0, mp3, from &#39;ZHRE.mp3&#39;:
      Duration: 00:04:12.52, start: 0.000000, bitrate: 208 kb/s
        Stream #0.0: Audio: mp3, 44100 Hz, stereo, s16, 256 kb/s
    Output #0, mp3, to &#39;audio.mp3&#39;:
        Stream #0.0: Audio: 0x0000, 44100 Hz, stereo, s16, 64 kb/s
    Stream mapping:
      Stream #0.0 -&gt; #0.0
    Unsupported codec for output stream #0.0

I also ran this command:

     ffmpeg -formats | grep mp3

and got this in response:

    FFmpeg version 0.5.2, Copyright (c) 2000-2009 Fabrice Bellard, et al.
      configuration: 
      libavutil     49.15. 0 / 49.15. 0
      libavcodec    52.20. 1 / 52.20. 1
      libavformat   52.31. 0 / 52.31. 0
      libavdevice   52. 1. 0 / 52. 1. 0
      built on Jun 24 2010 14:56:20, gcc: 4.4.1
     DE mp3             MPEG audio layer 3
     D A    mp3             MP3 (MPEG audio layer 3)
     D A    mp3adu          ADU (Application Data Unit) MP3 (MPEG audio layer 3)
     D A    mp3on4          MP3onMP4
     text2movsub remove_extra noise mov2textsub mp3decomp mp3comp mjpegadump imxdump h264_mp4toannexb dump_extra

I guess that the mp3 codec isn&#39;t installed. Am I on the right track here?



Convert audio files to mp3 using ffmpeg

I am not able to find the offline docs for android. Can someone provide a link?

Android offline documentation and sample codes

Do you know if there is some sort of `&lt;code /&gt;` tag in JSDoc? I need to add pieces of code in my documentation like this:

    /**
     * This function does something see example below:
     *
     * var x = foo(&quot;test&quot;); //it will show &quot;test&quot; message
     *
     * @param {string} str: string argument that will be shown in message
     */
    function foo(str)
    {
       alert(str);
    }

I need the code in the comments to be displayed by JSDoc as code (if not syntax highlighted, at least like pre-formatted or something with grey background).

JSDoc adding real code in documentation

I&#39;m writing a lightweight class whose attributes are intended to be publicly accessible, and only sometimes overridden in specific instantiations.  There&#39;s no provision in the Python language for creating docstrings for class attributes, or any sort of attributes, for that matter.  What is the expected and supported way, should there be one, to document these attributes?  Currently I&#39;m doing this sort of thing:

    class Albatross(object):
        &quot;&quot;&quot;A bird with a flight speed exceeding that of an unladen swallow.

        Attributes:
        &quot;&quot;&quot;
    
        flight_speed = 691
        __doc__ += &quot;&quot;&quot;
            flight_speed (691)
              The maximum speed that such a bird can attain.
        &quot;&quot;&quot;
    
        nesting_grounds = &quot;Raymond Luxury-Yacht&quot;
        __doc__ += &quot;&quot;&quot;
            nesting_grounds (&quot;Raymond Luxury-Yacht&quot;)
              The locale where these birds congregate to reproduce.
        &quot;&quot;&quot;
    
        def __init__(self, **keyargs):
            &quot;&quot;&quot;Initialize the Albatross from the keyword arguments.&quot;&quot;&quot;
            self.__dict__.update(keyargs)

This will result in the class&#39;s docstring containing the initial standard docstring section, as well as the lines added for each attribute via augmented assignment to `__doc__`.

Although this style doesn&#39;t seem to be expressly forbidden in the [docstring style guidelines][1], it&#39;s also not mentioned as an option.  The advantage here is that it provides a way to document attributes alongside their definitions, while still creating a presentable class docstring, and avoiding having to write comments that reiterate the information from the docstring.  I&#39;m still kind of annoyed that I have to actually write the attributes twice; I&#39;m considering using the string representations of the values in the docstring to at least avoid duplication of the default values.

Is this a heinous breach of the ad hoc community conventions?  Is it okay?  Is there a better way?  For example, it&#39;s possible to create a dictionary containing values and docstrings for the attributes and then add the contents to the class `__dict__` and docstring towards the end of the class declaration; this would alleviate the need to type the attribute names and values twice.  **edit**: this last idea is, I think, not actually possible, at least not without dynamically building the entire class from data, which seems like a really bad idea unless there&#39;s some other reason to do that.

I&#39;m pretty new to python and still working out the details of coding style, so unrelated critiques are also welcome.


  [1]: http://www.python.org/dev/peps/pep-0257/

How to document class attributes in Python?

Edit: This is technically a 2 part question. I&#39;ve chosen the best answer that covers the question in general and linked to the answer that handles the specific question.

What is the best way to document anonymous objects and functions with jsdoc?

    /**
     * @class {Page} Page Class specification
     */
    var Page = function() {
   
        /**
         * Get a page from the server
         * @param {PageRequest} pageRequest Info on the page you want to request
         * @param {function} callback Function executed when page is retrieved
         */
        this.getPage = function(pageRequest, callback) {
        }; 
    };

Neither the `PageRequest` object or the `callback` exist in code. They will be provided to `getPage()` at runtime. But I would like to be able to define what the object and function are.

I can get away with creating the `PageRequest` object to document that:

    /**
     * @namespace {PageRequest} Object specification
     * @property {String} pageId ID of the page you want.
     * @property {String} pageName Name of the page you want.
     */
    var PageRequest = {
        pageId : null,
        pageName : null
    };

And that&#39;s fine (though I&#39;m open to better ways to do this).

What is the best way to document the `callback` function? I want to make it know in the document that, for example, the callback function is in the form of:

    callback: function({PageResponse} pageResponse, {PageRequestStatus} pageRequestStatus)

Any ideas how to do this? 

Best way to document anonymous objects and functions with jsdoc

The help for Mogenerator is very minimal. What do all the parameters do?

Content Type	Original Author	Original Content on Stackoverflow
Question	fvisticot	View Question on Stackoverflow
Solution 1 - C	mpenkov	View Answer on Stackoverflow
Solution 2 - C	Jason B	View Answer on Stackoverflow
Solution 3 - C	rogerdpack	View Answer on Stackoverflow
Solution 4 - C	jAckOdE	View Answer on Stackoverflow
Solution 5 - C	jeff7	View Answer on Stackoverflow

FFmpeg C API documentation/tutorial

C Problem Overview

C Solutions

Solution 1 - C

Solution 2 - C

Solution 3 - C

Solution 4 - C

Solution 5 - C

Junit: splitting integration test and Unit tests

Define an <img>'s src attribute in CSS

Attributions