Subject: Re: AAC Constant Bit Rate coding From: =?UTF-8?B?UMOhZHJhaWcgS2l0dGVyaWNr?= <=?UTF-8?B?UMOhZHJhaWcgS2l0dGVyaWNr?=> Date: Wed, 16 Nov 2011 11:24:31 +0000 List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>This is a multi-part message in MIME format. --------------040103080301010801010706 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable To set the bitrate, you may want to try: ffmpeg -i input.wav -b:a 128k output.m4a ffmpeg will auto-select whichever aac encoder is available when the=20 output file has the extension m4a. P=C3=A1draig On 15/11/2011 15:44, John O'Connell wrote: > Hi, > > You could try ffmpeg: www.ffmpeg.org <http://www.ffmpeg.org> > > Open source and handles pretty much anything you throw at it. > > This line should convert a wav to aac. > > ffmpeg -i file.wav -ab 128k -acodec libfaac test.mp4 > > It seems to ignore the audio bit-rate flag though (-ab 128k) - perhaps=20 > for reasons mentioned previously > > This is what I get inside test.mp4: Audio: aac, 44100 Hz, stereo, s16,=20 > 141 kb/s > > Cheers, > > John > > 2011/11/15 Warren Bakay <warren@xxxxxxxx <mailto:warren@xxxxxxxx>> > > I use xld to encode to aac. It uses core audio to do the encoding. > > > On Tue, Nov 15, 2011 at 1:07 PM, fabien gouyon > <fgouyon@xxxxxxxx <mailto:fgouyon@xxxxxxxx>> wrote: > > Dear list, > > Could somebody recommend a free software, or even better some > open-source code, for converting audio from WAV to AAC with > *constant* > bit rate (and not variable bit rate). > > Any help would be much appreciated. > Best, > > -- > Fabien Gouyon, PhD > Senior Research Scientist, INESC Porto > Invited Assistant Professor, Engineering Faculty, University > of Porto > http://www.inescporto.pt/~fgouyon > <http://www.inescporto.pt/%7Efgouyon> > http://smc.inescporto.pt/ > > > --=20 P=C3=A1draig Kitterick Post-Doctoral Research Fellow Department of Psychology University of York Heslington York YO10 5DD UK Tel: +44 (0) 1904 32 2911 Email: p.kitterick@xxxxxxxx Web: http://psych.york.ac.uk/aphhc --------------040103080301010801010706 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable <html> <head> <meta content=3D"text/html; charset=3DUTF-8" http-equiv=3D"Content-Ty= pe"> </head> <body bgcolor=3D"#FFFFFF" text=3D"#000000"> To set the bitrate, you may want to try:<br> <br> ffmpeg -i input.wav -b:a 128k output.m4a<br> <br> ffmpeg will auto-select whichever aac encoder is available when the output file has the extension m4a.<br> <br> P=C3=A1draig<br> <br> On 15/11/2011 15:44, John O'Connell wrote: <blockquote cite=3D"mid:26039_1321381076_4EC2ACD4_26039_140_1_CACW2ap8p818iy_weOdh0GR= -DX8hatHD2tyd=3DjFJV19Y4E2ciMg@xxxxxxxx" type=3D"cite">Hi,<br> <br> You could try ffmpeg: <a moz-do-not-send=3D"true" href=3D"http://www.ffmpeg.org">www.ffmpeg.org</a><br> <br> Open source and handles pretty much anything you throw at it.<br> <br> This line should convert a wav to aac. <br> <br> ffmpeg -i file.wav -ab 128k -acodec libfaac test.mp4<br> <br> It seems to ignore the audio bit-rate flag though (-ab 128k) - perhaps for reasons mentioned previously <br> <br> This is what I get inside test.mp4: Audio: aac, 44100 Hz, stereo, s16, 141 kb/s<br> <br> Cheers,<br> <br> John<br> <br> <div class=3D"gmail_quote">2011/11/15 Warren Bakay <span dir=3D"ltr= "><<a moz-do-not-send=3D"true" href=3D"mailto:warren@xxxxxxxx">warr= en@xxxxxxxx</a>></span><br> <blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"> I use xld to encode to aac. It uses core audio to do the encoding. <div class=3D"HOEnZb"> <div class=3D"h5"><br> <br> <div class=3D"gmail_quote">On Tue, Nov 15, 2011 at 1:07 PM, fabien gouyon <span dir=3D"ltr"><<a moz-do-not-send=3D"true" href=3D"mailto:fgouyon@xxxxxxxx" target=3D"_blan= k">fgouyon@xxxxxxxx</a>></span> wrote:<br> <blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Dear list,<br> <br> Could somebody recommend a free software, or even better some<br> open-source code, for converting audio from WAV to AAC with *constant*<br> bit rate (and not variable bit rate).<br> <br> Any help would be much appreciated.<br> Best,<br> <font color=3D"#888888"><br> --<br> Fabien Gouyon, PhD<br> Senior Research Scientist, INESC Porto<br> Invited Assistant Professor, Engineering Faculty, University of Porto<br> <a moz-do-not-send=3D"true" href=3D"http://www.inescporto.pt/%7Efgouyon" target=3D"_blank">http://www.inescporto.pt/~fgouyon= </a><br> <a moz-do-not-send=3D"true" href=3D"http://smc.inescporto.pt/" target=3D"_blank= ">http://smc.inescporto.pt/</a><br> <br> </font></blockquote> </div> <br> </div> </div> </blockquote> </div> <br> </blockquote> <br> <br> <pre class=3D"moz-signature" cols=3D"72">--=20 P=C3=A1draig Kitterick Post-Doctoral Research Fellow Department of Psychology University of York Heslington York YO10 5DD UK Tel: +44 (0) 1904 32 2911 Email: <a class=3D"moz-txt-link-abbreviated" href=3D"mailto:p.kitterick@xxxxxxxx= sych.york.ac.uk">p.kitterick@xxxxxxxx</a> Web: <a class=3D"moz-txt-link-freetext" href=3D"http://psych.york.ac.uk= /aphhc">http://psych.york.ac.uk/aphhc</a></pre> </body> </html> --------------040103080301010801010706--