MODULE FOR I, P FRAME
in [Python]
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From: DANNY on 11 Feb 2010 14:31 Hello! I am currently developing a simple video player in python, and my problem is that i can't find a module which has a function that can determine if frame(image) is I or P coded (MPEG coding). I have been using PIL but I couldnt find anything that could help me with that problem. Thanks for sugestions!
From: Rhodri James on 11 Feb 2010 18:32 On Thu, 11 Feb 2010 19:31:52 -0000, DANNY <danijel.gvero(a)gmail.com> wrote: > Hello! > > I am currently developing a simple video player in python, and my > problem is that i can't find a module which has a function that can > determine if frame(image) is I or P coded (MPEG coding). I have been > using PIL but I couldnt find anything that could help me with that > problem. How are you reading the video? PIL doesn't claim to do more than identify MPEG files. Also, which MPEG encoding, in which container format? If you aren't just putting a wrapper around something like ffmpeg, I rather suspect you'll have to decode the bitstream yourself. That could be rather painful if you're talking about MPEG-4/10. -- Rhodri James *-* Wildebeeste Herder to the Masses
From: DANNY on 14 Feb 2010 05:07 Hy, first thanks for your response! Well I am thinkin on coding in MPEG4/10, but I would just encode the video in that encoding, then stream it with VLC and save the video file on my disc. Then I would play it with my player....I was thinking on using the image iterator in PIL...because I would encode the video in GoP of 10 (one I and 9P), and then I would manipulate it within the sequence...so I dont have to have a special decoder, because the VLC would already decode it.
From: Rhodri James on 15 Feb 2010 17:53 On Sun, 14 Feb 2010 10:07:35 -0000, DANNY <danijel.gvero(a)gmail.com> wrote: > Hy, first thanks for your response! > Well I am thinkin on coding in MPEG4/10, but I would just encode the > video in that encoding, > then stream it with VLC and save the video file on my disc. Then I > would play it with my player.... I think you're misunderstanding what VLC does here. Saving the video file should preserve format by default; you may be able save it out in YUV format (I don't have a copy on this machine to check), but that will take up ludicrous amounts of disc space and you'd still have to write a byte reader for it. If you do do that, you have lost any chance of knowing whether a frame was an I or P frame in the original format, not that it matters anyway by that point. MPEG-4/10 is hard to write efficient decoders for, and I have to admit I wouldn't do it in Python. You'd be better off writing a wrapper for one of the existing MP4 libraries. -- Rhodri James *-* Wildebeeste Herder to the Masses
From: DANNY on 16 Feb 2010 02:14
On Feb 16, 12:53 am, "Rhodri James" <rho...(a)wildebst.demon.co.uk> wrote: > On Sun, 14 Feb 2010 10:07:35 -0000, DANNY <danijel.gv...(a)gmail.com> wrote: > > Hy, first thanks for your response! > > Well I am thinkin on coding in MPEG4/10, but I would just encode the > > video in that encoding, > > then stream it with VLC and save the video file on my disc. Then I > > would play it with my player.... > > I think you're misunderstanding what VLC does here. Saving the video file > should preserve format by default; you may be able save it out in YUV > format (I don't have a copy on this machine to check), but that will take > up ludicrous amounts of disc space and you'd still have to write a byte > reader for it. If you do do that, you have lost any chance of knowing > whether a frame was an I or P frame in the original format, not that it > matters anyway by that point. > > MPEG-4/10 is hard to write efficient decoders for, and I have to admit I > wouldn't do it in Python. You'd be better off writing a wrapper for one > of the existing MP4 libraries. > > -- > Rhodri James *-* Wildebeeste Herder to the Masses Hm, well I see that and now I am thinking of using reference software for MPEG4/10 which is written in c++ http://iphome.hhi.de/suehring/tml/ just to use it as a decoder on my client side, save the file in that format and then play it in my player using pyffmpeg http://code.google.com/p/pyffmpeg/ and just manipulate frames in that clip-I think that could be possible....am I right? Thanks for your help! |