Yeah, 

ffmpeg -i video_clip.3gp -vframes 1 -ss 00:00:01 -vf "transpose=1" output.jpg   
(the first frame is not good enough)
can give the right picture. but it is slow, cannot hold 200 cps with Xeon CPUs

And I explored the sample codes, and the guide line on the internet (most of 
them not up to date)

I know how to open a video file, but I don't know how to get the correct Key 
Frame and how to output to a JPG file.

so the progam like this:
Open the video file
Get the frame counts, and seek to a good key frame
Output to JPG buffer
Rotate it 
Save the buffer to file.

Would you please guide me to do it ?


Regards,
--------------------------------------------------------------------------------------------------------------------------------------
Freeman
Mobile: 13811178263
E-Mail: [email protected]


________________________________________
发件人: [email protected] [[email protected]] 代表 Carl 
Eugen Hoyos [[email protected]]
发送时间: 2013年3月23日 3:33
收件人: [email protected]
主题: Re: [Libav-user] How to extract a H264 video frame (container is    
3GPP/MP4) into a JPG File (with libavformat and libavcode) ?

张弘强 <zhanghongqiang@...> writes:

> Recently, I’m doing development to generate video clips’
> thumbnail pic file. But, it is hard without development
> guide, would you please show me some example code for it?

First confirm that ffmpeg (the command line application)
allows you to do what you want, then look into
doc/examples to learn how to use libavformat and libavcodec.

Carl Eugen

_______________________________________________
Libav-user mailing list
[email protected]
http://ffmpeg.org/mailman/listinfo/libav-user
_______________________________________________
Libav-user mailing list
[email protected]
http://ffmpeg.org/mailman/listinfo/libav-user

Reply via email to