From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from int-mx1.corp.redhat.com (int-mx1.corp.redhat.com [172.16.44.254]) by listman.redhat.com (Postfix) with ESMTP id 07A9D3EAF6 for ; Mon, 19 Nov 2001 12:13:02 -0500 (EST) Received: from mail.redhat.com (mail.redhat.com [199.183.24.239]) by int-mx1.corp.redhat.com (8.11.6/8.11.6) with SMTP id fAJHD1p08776 for ; Mon, 19 Nov 2001 12:13:01 -0500 Received: (from mail@localhost) by mail.redhat.com (8.11.0/8.8.7) id fAJHD1a11260 for blinux-list@listman.redhat.com; Mon, 19 Nov 2001 12:13:01 -0500 Received: from xanadu.home (modemcable084.137-200-24.mtl.mc.videotron.ca [24.200.137.84]) by mail.redhat.com (8.11.0/8.8.7) with ESMTP id fAJHD1w11256 for ; Mon, 19 Nov 2001 12:13:01 -0500 Received: from localhost (nico@localhost) by xanadu.home (8.11.6/8.11.6) with ESMTP id fAJHD4c15290 for ; Mon, 19 Nov 2001 12:13:04 -0500 X-Authentication-Warning: xanadu.home: nico owned process doing -bs Date: Mon, 19 Nov 2001 12:13:04 -0500 (EST) From: Nicolas Pitre X-X-Sender: To: Subject: Re: Digital Talking Book Standard In-Reply-To: <20011119174322.D29158@stalin.acc.umu.se> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Loop: blinux-list@redhat.com Sender: blinux-list-admin@redhat.com Errors-To: blinux-list-admin@redhat.com X-BeenThere: blinux-list@redhat.com X-Mailman-Version: 2.0.1 Precedence: bulk Reply-To: blinux-list@redhat.com List-Help: List-Post: List-Subscribe: , List-Id: Linux for blind general discussion List-Unsubscribe: , List-Archive: On Mon, 19 Nov 2001, Peter Toneby wrote: > On Mon, Nov 19, 2001 at 11:35:59AM -0500, Nicolas Pitre wrote: > > On Mon, 19 Nov 2001, Peter Toneby wrote: > > > > > On Mon, Nov 19, 2001 at 11:14:39AM -0500, Janina Sajka wrote: > > > > What about freeamp? > > > > > > It does not support searches on timecode (at least I didn't see anything > > > about that while checking their pages, they only seem to have normal > > > seek in files, which is not enough). > > > > Well... It is enough with some extra processing. You need to find out the > > data bitrate, estimate the seek position in the audio file, resynchronize on > > a mpeg frame boundary, back a couple frames, compute the backed frames to > > restabilize the mpeg windowing factors without actually playing them then > > finally resume audio from the desired frame. > > The problem is VBR, I'm not sure how it works, but I suspect each frame > have it's own bitrate in that case, and if the stream use that, you need > to loop through all frames and calculate the current time :(, well, I'll > have a closer look at mad and see if I can do something for fixed > bitrates at least. No one can expect to use VBR in a talking book format and hope for snappy random seeks in the audio unless the indexing format now includes hard file offsets in bytes. Last time I had to deal with that it wasn't the case and therefore VBR wasn't used either. Nicolas