How to extract I-Frame from Mpeg-4?

[ahrouhi]

I am starting a research on video with H.264 (MPEG4/AVC) standard. I need to extract the I-frames from a stream video. Who can help me how can I achieve this purpose by programming or any high level software on windows.

[ahrouhi]

i would be pleased , if you let me know how can i extract i-frames of a video stream by ffmpeg.

[ronnylov]

ftp://linux4u.jinr.ru/pub/misc/video/mplayer/SVN/mplayer/libmpcodecs/vf_framestep.c

Seems like MPlayer can do it and I think it is available for Windows too.

[ahrouhi]

Thanks alot for your reply
I download the mplayer and the code referenced in c which you introduced. At the moment i focused on JM software which is the standard software recognised by ITO and ISO. As it is an approved software i guess it would be more reliable. the software accept input video in row format .yuv or .rgb and then convert it to MPEG4/10 latest edition. i use YUV-Tools software for creating raw video files, do you suggest any other free software?

[ronnylov]

I would suggest using x264 if you want to convert video to h.264.

[ahrouhi]

Hi
Thanks for x264 suggestion. but converting to H.264 is not my concern only. actually many video converter can do that. the research that i am doing is video copy detection. i have a proposed method for this goal and i should implement my method. so i need to extract some frames of any video that is in MPEG-4 AVC (H-264) format. i should extract the I-Frames and apply the algorithm on them so my 2wo most important concerns are:

1-How to extract I-Frames
2-What is the structure inside the I-Frame file.) because i should read the bits inside the file and extract my patterns from the file content)

if you help me in any of above request i would be gratefull.

[ronnylov]

Then you probably need to check the h.264 specification how the format is implemented.
You can find it for free on ITU-T.
http://www.itu.int/rec/T-REC-H.264-201003-I/en

You can also check open source implementations. The libavcodec library has a built-in avc decoder. FFMPEG is using libavcodec when decoding h.264. Since it is open source you can learn how they do it. If you copy any code you need to flollow the licenses and release your work as open source too.

[ahrouhi]

Thanks a lot for your explanation and introduced link. Actually it is for a long time that i am using ITU software and documents as one of the most reliable sources in MPEG. I could use JM software of ITU for extracting I-Frame. but my current struggle is to finding a bit by bit internal structure of extracted file to get the inside information among data file content. if you can help me i would be pleased.
Regards