Transcoder: fix audio stream setting when demuxing without specified output profile
AvInputStream: remove audio codec block_align setting
No need to set it, FFmpeg do it for us
Pixel: add support of pixel formats 4:4:0, 4:1:1 and 4:1:0
Pixel: clean constructor from an AVPixelFormat
Profile: update value of constants avProfileIdentificator
Update README

Add sections:
   * What you need to know
   * How to use
Merge pull request #5 from valnoel/fix_some_audio_process

Fix block_align and audio demux without specified an output profile
Merge pull request #6 from cchampet/dev_add_support_pixelFormats

Supported chroma subsampling :
* 4:4:4
* 4:4:0
* 4:2:2
* 4:2:0
* 4:1:1
* 4:1:0
Merge pull request #7 from cchampet/dev_update_avProfileIdentificator

Update avProfileIdentificator value
mediaProperty: skip unnecessary functions for SWIG
Progress: into OutputFile, add getProgressDuration method to compute progress
Progress: update Transcoder progress computing
Progress: into OutputFile, remove unused getFormatContext method
Do not return FFmpeg dependant objects any more
mediaProperty: check if access of properties is possible

Throw exception if it's not possible and we can't return any value.
VideoProperties: clean
Merge pull request #9 from valnoel/fix_transcoder_progress_computing

Fix transcoder progress computing
OutputFile: make getProgressDuration method virtual
Merge pull request #11 from valnoel/develop

HotFix: make OutputFile::getProgressDuration() virtual
Transcoder: call init in process method

* No need to expect the user to call init() before process().
* Note: the init() method can be called several times with no side
effects.
* Update pyTest.
Transcoder: add private method getTotalDurationFromProcessMethod

In order to simplify process method.