Stas, I don't really understand your question; do you want a CBR on the JPEG encoding? I can't instantly help you with that as I've only used VBR with JPEG as of now.. Try looking at some CBR encoders. I believe there is someting like a bitrate param in the encoder context. You should set that to a specific br I would guess.
Edwin On Thu, Apr 2, 2009 at 9:51 AM, Stas Oskin <[email protected]> wrote: > Hi. > > Thanks for hint, 2 quick questions: > > 1) I need to set some other flags to change from VBR to CBR (as seems to be > in this case?)? > 2) Any idea, how much it would be 80% in 1 - 100 scale? If we convert from > 100 to 31, it should be ~6, is it right? > > Thanks! > > 2009/4/2 Edwin van der Horst <[email protected]> > >> Clive, Stas, >> >> Without looking at the source you provided, >> you can specify the quality of outgoing JPEG 'stream' with qmin and >> qmax params: >> >> encContext->qmin = 1; // best quality >> encContext->qmax = 1; >> >> The lower, the better. >> >> Edwin >> >> On Thu, Apr 2, 2009 at 12:38 AM, Clive Taylor <[email protected]> wrote: >> > Thanks, Stas. >> > >> > This is more than I hoped for. >> > >> > Clive >> > >> > -----Original Message----- >> > From: [email protected] >> > [mailto:[email protected]] On Behalf Of Stas Oskin >> > Sent: 01 April 2009 19:31 >> > To: Libav* user questions and discussions >> > Subject: Re: [libav-user] Writing single frames to JPEG >> > >> > Hi. >> > >> > This code worked pretty well for me: >> > http://readlist.com/lists/mplayerhq.hu/ffmpeg-user/1/8128.html >> > >> > The only issue I had is that I'm unable to specify the outgoing quality. >> > >> > Can anyone comment on this? >> > >> > Regards. >> > >> > 2009/3/31 Clive Taylor <[email protected]> >> > >> >> Thank you, Edwin. I will give it a try. >> >> >> >> Clive >> >> >> >> -----Original Message----- >> >> From: [email protected] >> >> [mailto:[email protected]] On Behalf Of Edwin van der >> >> Horst >> >> Sent: 31 March 2009 09:01 >> >> To: Libav* user questions and discussions >> >> Subject: Re: [libav-user] Writing single frames to JPEG >> >> >> >> Clive, >> >> >> >> I still think using the MJPEG codec might work for you, as you can >> >> encode just a single frame using the codec, >> >> which essentially just works as an JPEG encoder, it only uses p-frames >> >> (in other words, full JPEG files frames as output >> >> decode the correct frame you wish to encode to jpeg, set the encoder >> >> parameters, and call the encode function. >> >> >> >> Good luck, >> >> >> >> Edwin >> >> >> >> >> >> On Tue, Mar 31, 2009 at 1:54 AM, Mark Heath <[email protected]> >> >> wrote: >> >> > >> >> > On 31/03/2009, at 10:47 AM, Clive Taylor wrote: >> >> >> >> >> > >> >> >> That's my new task. I'm already using libavformat, etc in my code >> > to >> >> >> read the frames, and I've adapted the frame accurate seek library >> >> code, >> >> >> too. The whole lot is running under Windows, but Linux and OS/X >> >> versions >> >> >> are needed. >> >> >> >> >> >> I thought the really hard part was solved until I tried to work out >> >> how >> >> >> to save a single frame as a JPEG. >> >> > >> >> > Maybe look at the jpeg library. >> >> > >> >> > http://www.ijg.org/ >> >> > >> >> > Mark >> >> > _______________________________________________ >> >> > 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 >> >> >> >> >> >> _______________________________________________ >> >> 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 >> > >> > >> > _______________________________________________ >> > 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 >> > _______________________________________________ > 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
