check the ffmpeg tutorial 1. 2010/7/22 Michael Chisholm <[email protected]>
> Decoded data in libav* is stored in an AVFrame structure. In the case of > video, this is a complete frame of video. You create one of those, and fill > out its data, and encode it with avcodec_encode_video. For the purposes of > encoding an image, you're really just creating a "video" with one frame. > (Similarly, for decoding, you treat the jpeg file as a "video" with one > frame.) > > The output-example.c example shows how to create the AVFrame and encode it. > There is another sample app in libavcodec/api-example.c in the source > distribution to look at too. If you need to convert between pixel formats > (e.g. rgb to yuv), see the sws_scale() function. (The frame given to the > codec to encode has to have a pixel format compatible with the codec. I use > PIX_FMT_YUVJ420P for jpeg. Those constants are in libavutil/pixfmt.h.) > > Study the sample code, and I would also generate doxygen docs of the libav* > source to help you navigate around and familiarize yourself with the APIs > and how they work. > > Andy > > > On 7/22/2010 11:15 AM, Denis Gottardello wrote: > >> Alle giovedì 22 luglio 2010, Michael Chisholm ha scritto: >> >>> You ought to be able to decode and encode jpegs with libav's builtin jpeg >>> codec. I've done both before with the "mjpeg" codec. I didn't need >>> libjpeg. It's not C++ though. You'd have to either use C from within a >>> C++ >>> app, or find some other library. From the looks of things, libjpeg isn't >>> C++ either... >>> >>> >> >> Ignoring the language which is the rigth way to use the ffmpeg libraries >> to >> transalte a just in memory rgb (or yuv) image to jpeg image? >> >> >> > > _______________________________________________ > libav-user mailing list > [email protected] > https://lists.mplayerhq.hu/mailman/listinfo/libav-user > _______________________________________________ libav-user mailing list [email protected] https://lists.mplayerhq.hu/mailman/listinfo/libav-user
