Hi, There are two issues here.
1. For the beginning, I don't see anything obvious on our side, but lame's doc mentions some mandatory padding ( http://lame.sourceforge.net/tech-FAQ.txt ) which might explain the problem? 2. For the end, we effectively did not flush the encoder. I commited a patch ( https://github.com/savonet/liquidsoap/pull/68 ), which should hopefully integrated soon. ++ Sam. On Mon, Apr 29, 2013 at 12:40 AM, [email protected] <[email protected]> wrote: > As usual on these kind of forums, I will answer myself. > > It appears this issue is due to Lame. Depending on the type > of mp3 being generated,Lame will skip n samples at the > start and end of the pcm data it reads from the source file. > > Using Lame 3.99.3 and 3.99.5 alone at the command line > exhibits this behaviour (though it only introduces 50ms > of silence at the beginning and chops 30ms from the > end of the file). > > I note however, that Audacity is capable of using Lame to > encode mp3s without this issue. So an examination of > the Audacity code is in order, it looks like they have a > solution or workaround for this issue. > > > Apr 27, 2013 11:16:19 PM, [email protected] wrote: >> >>I am trying to manipulate sound files with liquidsoap and have >>everything pretty much working the way I want it, but... >> >>%mp3 and %external encodings are adding around 100ms of silence >>to the beginning of my output files and cutting about 60ms off the end >>of the output files. >> >>One can test this with the demonstration script "reencoding.liq" and >>just change the output encoding to %mp3. (%vorbis does not do this) >> >>I am running the native win32 builds posted. Both version 1.0.1 and >>version 1.1.1-beta1 show this behaviour. >> >>Is there some setting I have missed that will correct this or have I >>found a bug? I reviewed the ocaml-lame code but could not see >>anything obvious... (since the %external encoding also shows this >>problem the issue must lie elsewhere anyway) Also, setting the >>clock sync to true has no effect on this, the problem persists >>- don't know if that info helps any, but I tried it. >> >>Actually, when I use lame as an external encoder it still >>introduces ~100ms of silence at the start of the file, but >>chops less off the end of the file. >> >>Has anyone else encountered this or found a solution for it? >> > > ------------------------------------------------------------------------------ > Try New Relic Now & We'll Send You this Cool Shirt > New Relic is the only SaaS-based application performance monitoring service > that delivers powerful full stack analytics. Optimize and monitor your > browser, app, & servers with just a few lines of code. Try New Relic > and get this awesome Nerd Life shirt! http://p.sf.net/sfu/newrelic_d2d_apr > _______________________________________________ > Savonet-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/savonet-users ------------------------------------------------------------------------------ Try New Relic Now & We'll Send You this Cool Shirt New Relic is the only SaaS-based application performance monitoring service that delivers powerful full stack analytics. Optimize and monitor your browser, app, & servers with just a few lines of code. Try New Relic and get this awesome Nerd Life shirt! http://p.sf.net/sfu/newrelic_d2d_apr _______________________________________________ Savonet-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/savonet-users
