From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andy Lo A Foe Date: Wed, 27 Oct 1999 14:02:22 +0000 Subject: Re: mp3 seeking Message-Id: List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-sound@vger.kernel.org On Tue, 26 Oct 1999 est@hyperreal.org wrote: > First, I must thank you for alsaplayer since I'm using an adaptation > of your adaptation of the mpg123 code in the next major release of > oolaboola. I'm encapsulating it in a separate process (called > mp3serv) to get re-entrancy. I may move to the xing decoder but the > process interface will remain the same. Very interesting. I'm thinking about a similar solution for doing reentrancy with plugins that don't support it, something like a proxy plugin interface with IPC and shared memory. Where can I get the latest version of oolaboola? > My understanding was that it *may* take more than 3 frames of priming > to resynchronize. One of the xing/freemap people got me the logic but > I haven't implemented it yet. I'm using 3 right now. You need a bit more for lower bitrates it seems. I've never really looked into the encoding algorithm so... :) > Another issue is how to find a given frame in the first place. Given > that each frame may have an extra byte of padding, a multiplication is > (audibly!) unreliable. I've implemented a table-of-contents mechanism > to deal with this. Yes, if you want 100% correct seeking the best thing you can do is to store the frame start positions while decoding. It is a bit slow though. Is that what you're doing? (for VBR encoded files I don't see any other (simple) method to support seeking BTW)... Regs, Andy -- AlsaPlayer, http://www.alsa-project.org/~andy/