Hello, I have figured out most things needed. MP4 Source was big help because it does some things very similar than FFMPEG. Seeking should be mostly ok (It has to be confirmed but mostly) FFMPEG have come long way in these years. Biggest problem currently is reading samples.. I have to work couple things out. Let's see if i can't get it working next week. What is the right thing to do? Post a patch (against trunk) or branch a devel tree?
Lainaus RJ Ryan <rr...@mixxx.org>: > Hi Tuukka, > > I attempted this a few years ago but could not figure out how to use FFMPEG > correctly. I'm happy that you're investigating! > > In general, here is what you must satisfy to make a SoundSource: > > * Seeking to a particular sample must be 100% accurate. The main problem I > had with FFMPEG is that I could not seek to a particular sample, I could > only seek to a rough stream time. > * Data must be output in 2-channel, 16-bit samples (even if the source file > is mono or multi-channel, you must convert to stereo) > > If you look at the mess that is SoundSourceMp3 you'll find that we build a > seek-tree which record what sample each MP3 frame corresponds to. This way > we can rapidly jump to the closest frame, decode it, and discard the > appropriate number of samples to get to the exact sample we desire from the > seek. > > It would be excellent if you made progress on this. I'd love to discard > almost all of our SoundSources in favor of FFMPEG. > > Best regards, > RJ Ryan > > On Thu, Aug 30, 2012 at 5:22 AM, Tuukka Pasanen > <tuukka.pasa...@ilmi.fi>wrote: > >> Hello, >> I've doing a little bit coding with mixxx and ffmpeg lately (works with >> newest ffmpeg). I get ffmpeg soundsource in shape (compiling and almost >> working sound) but because I don't really yet understand all the inner >> things in Mixxx I ask these guestions: >> >> I understand that soundsource I asked some amount of 16 bit PCM data but >> ffmpeg doesn't fit in. Decoded data >> doesn't go as smooth as Mixxx wants. If anybody know what should I do. >> Just drop fewer amount of data or do as >> in mp3 little bit hackery.. that I didn't quite get yet ;). >> >> Where to add more formats: like wma and aac that works with ffmpeg just >> fine? Documents say that method that is supposed >> to tell what format are supported is evil. >> >> Is this even wanted hacking? I've though it would be good to have ffmpeg >> in soundsource because of formats it supports. >> I can't yet see if all the seeking things are fixed. I've been also >> wondering if MLT or Gstreamer would be way to go >> in Soundsource because ffmpeg is kinda diffucult to make work but >> Gstreamer is easier (and support all the formats >> that ffmpeg with plugin) same goes to MLT. >> >> Sorry about not having patch but in the current state of code (because >> playing it's not working correct).. if someone wants it i'll send it.. >> >> Thanks, >> Tuukka >> >> >> ------------------------------------------------------------------------------ >> Live Security Virtual Conference >> Exclusive live event will cover all the ways today's security and >> threat landscape has changed and how IT managers can respond. Discussions >> will include endpoint security, mobile security and the latest in malware >> threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ >> _______________________________________________ >> Get Mixxx, the #1 Free MP3 DJ Mixing software Today >> http://mixxx.org >> >> >> Mixxx-devel mailing list >> Mixxx-devel@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/mixxx-devel >> > -- Tuukka Pasanen Producer Manager tuukka.pasa...@ilmi.fi +358 40 7303 216 ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Get Mixxx, the #1 Free MP3 DJ Mixing software Today http://mixxx.org Mixxx-devel mailing list Mixxx-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mixxx-devel
