Pylibdv

WikiStart » Historikk » Revisjon 26

Revisjon 25 (Niels Petter Rasch-Olsen, 11.05.2006 16:17) → Revisjon 26/27 (Christian Skarby, 07.04.2011 12:04)

 h1. Welcome to pylibdv-0.1 






 

 [[PageOutline]] 




 h2. Background 

 

 pylibdv is a project for one of my university courses; "INF5660 - Advanced problem solving with high level languages":http://www.uio.no/studier/emner/matnat/ifi/INF5660/index-eng.xml. 

 pylibdv is a python wrapper for "libdv":http://libdv.sourceforge.net/. 

 

 From libdv home page: "libdv is a software codec for DV video, the encoding format used by most digital camcorders, typically those that support the IEEE 1394 Firewire or i.Link) interface. Libdv was developed according to the official standards for DV video: IEC 61834 and SMPTE 314M." 


 


 h2. Download 

 

 You can find the project as pylibdv-0.1.tar.gz here: "download":https://dev.interhost.no/pylibdv/browser/download/pylibdv-0.1.tar.gz?format=raw 

 

 h2. Overview of package 

 

 <pre> 
 
 pylibdv-0.1/src/pylibdv.c 
 pylibdv-0.1/src/pylibdv.h 
 pylibdv-0.1/frame_viewer/frame-viewer.py 
 pylibdv-0.1/example/parse_decode.py 
 pylibdv-0.1/dv/test.dv 
 pylibdv-0.1/testing.py 
 pylibdv-0.1/setup.py 
 pylibdv-0.1/README 
 </pre> 


 


 h2. Setup 

 

 use setup.py to install package. 
 Please note! If you can't get root acces, but want to build, and try the examples (frame-viewer.py and parse_decode.py) simply copy the .so file into those folder after building. 
 <pre> 
 
 pylibdv-0.1/python setup.py build (will create a build directory, inside the arcitecthure directory you will find the shared object file pylibdv.so) 
 pylibdv-0.1/python setup.py install (requires root) 
 </pre> 


 


 h2. Testing 

 

 To run the tests simply use pylibdv-0.1/python testing.py 

 Uses "doctest":http://docs.python.org/lib/module-doctest.html. It will search for pieces of text that look like interactive Python sessions, and then executes those sessions to verify that they work exactly as shown. See "Known Bugs":https://dev.interhost.no/pylibdv/wiki/WikiStart#Knownbugs for more information. 


 


 h2. Requirements 

 

 libdv 1.4 (works with debian package 0.104-2 from debian repository) 

 

 python >= 2.4 (testing.py won't work with 2.3, doctest will fail due to a bug in 2.3) 

 

 gcc 



 



 h2. Known bugs 

 

 libdv seg-faults on some versions of the libdv library. There seems to be a bug in the asm-optimization, so a quick work-around if this occurs is to turn off asm-optimization. 

 The doctest suite doesn't seem to find the two tests belonging to the Decoder, only the pylibdv tests are performed. 


 


 h2. Progress 

 

 So far the following is available: 


 


 pylibdv: 
   Constants: 
     DV_QUALITY_BEST 

     

     DV_QUALITY_FASTEST 

     

     DV_QUALITY_COLOR 

     

     DV_QUALITY_DC 

     

     DV_QUALITY_AC_1 

     

     DV_QUALITY_AC_2 

     

     DV_QUALITY_AC_MASK 

     

     e_dv_color_rgb 

     

     e_dv_color_yuv 

     

     e_dv_color_bgr0 

   

   Object: 
     Decoder 

       

       Methods: 
         parse_header() 

         

         decode_full_frame() 

       

       Data: 
         frame_size (read only) 

         

         width (read only) 

         

         length (read only) 

         

         quality (read & write) 



 



 This project is ongoing and most functions will be wrapped by the end of the summer (depending on need). 




 




 h2. Simple example 

 

 <pre> 
 
 import pylibdv 

 decoder = pylibdv.Decoder(ignored=1, clamp_luma=1, clamp_chroma=1)  

 file = open("somedvfile.dv,"r") 
 framebuffer = file.read(120000) # Just enough to make sure 

 decoder.parse_header(framebuffer) 

 # Now we can get some information about the video 
 frame_size = decoder.frame_size 
 width = decoder.width 
 height = decoder.height 

 file.seek(0) #Back to start 
 framebuffer = file.read(frame_size) 
 rgb_buffer = decoder.decode_full_frame(framebuffer) 
 #Now the rgb buffer can be drawn to screen, check out gtk package 
 </pre> 


 


 Enjoy!  

 "Niels  

 [mailto:nielsr@ifi.uio.no Niels Petter Rasch-Olsen":mailto:nielsr@ifi.uio.no Rasch-Olsen]