From owner-freebsd-multimedia Mon Dec 22 09:21:27 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id JAA07434 for multimedia-outgoing; Mon, 22 Dec 1997 09:21:27 -0800 (PST) (envelope-from owner-freebsd-multimedia) Received: from whqvax.picker.com (whqvax.picker.com [144.54.1.1]) by hub.freebsd.org (8.8.7/8.8.7) with SMTP id JAA07422 for ; Mon, 22 Dec 1997 09:21:21 -0800 (PST) (envelope-from rhh@ct.picker.com) Received: from ct.picker.com by whqvax.picker.com with SMTP; Mon, 22 Dec 1997 12:20:13 -0500 (EST) Received: from elmer.ct.picker.com by ct.picker.com (4.1/SMI-4.1) id AA19663; Mon, 22 Dec 97 12:20:12 EST Received: by elmer.ct.picker.com (SMI-8.6/SMI-SVR4) id MAA12860; Mon, 22 Dec 1997 12:19:42 -0500 Message-Id: <19971222121942.13340@ct.picker.com> Date: Mon, 22 Dec 1997 12:19:42 -0500 From: Randall Hopper To: Luigi Rizzo Cc: hasty@rah.star-gate.com, multimedia@FreeBSD.ORG Subject: Re: MPEG audio/video sync & Re: These mtv video pauses are murder References: <19971221225947.08124@ct.picker.com> <199712220520.GAA01789@labinfo.iet.unipi.it> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.81 In-Reply-To: <199712220520.GAA01789@labinfo.iet.unipi.it>; from Luigi Rizzo on Mon, Dec 22, 1997 at 06:20:26AM +0100 Sender: owner-freebsd-multimedia@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk Luigi Rizzo: |I suppose the problem if any will be in the capture phase. We have a |way to timestamp (using the cpu clock) incoming video frames (do you |use that ?), but e.g. for audio you cannot rely on the sample rate I do store off a timestamp for each frame of data (video frame + accumulated audio to that point). This is used to know how many frames we missed, which is how many times the preceeding frame is replicated in the mpeg_encode input stream to normalize the video back up to the full FPS rate. Thanks, Randall