From owner-freebsd-hackers@FreeBSD.ORG Mon Jun 18 18:22:10 2012 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id DD3C6106566B; Mon, 18 Jun 2012 18:22:10 +0000 (UTC) (envelope-from user.vdr@gmail.com) Received: from mail-gh0-f182.google.com (mail-gh0-f182.google.com [209.85.160.182]) by mx1.freebsd.org (Postfix) with ESMTP id 705A48FC0C; Mon, 18 Jun 2012 18:22:10 +0000 (UTC) Received: by ghbz22 with SMTP id z22so4542005ghb.13 for ; Mon, 18 Jun 2012 11:22:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; bh=XBl0VTnm5U8RucdQJOBT3a9noH2XT2ahcyN6+5P3Uc0=; b=XFf9ODtOE8duA1fpfvhzDwkpYgBOj8x7VhEvYK8GwQqcUOOUwtH4pEYRv4WxNaA4er DgKQ9eCYJKyX+pbFh+p+4OkTPHDq4O4Gd9Wwt1+ysoqGq5cKZXMUV4GF++DlSuJyCdKt ytfZ1/OtqtgLM13tU992w3n6Sl9e9vEO3VJ4nPaBSF9+hcW/sIX03OCU3TMJ3pa09npw rONWAiP4WMgLB9Ruy6FMO4f54huWixkDklB4XWd3TxcPbVo74KcnhUrzVd5t060DeGFT k33MKpWQ3bnDCoSTbyGEmMrRfHs7XQOPEP4m4ubc/KuBMaVsna+imJK0cwn22LHzBzm2 34GA== MIME-Version: 1.0 Received: by 10.50.100.169 with SMTP id ez9mr9362807igb.44.1340043728827; Mon, 18 Jun 2012 11:22:08 -0700 (PDT) Received: by 10.231.189.201 with HTTP; Mon, 18 Jun 2012 11:22:08 -0700 (PDT) In-Reply-To: <20120618172144.303410@gmx.com> References: <20120618172144.303410@gmx.com> Date: Mon, 18 Jun 2012 11:22:08 -0700 Message-ID: From: VDR User To: Dieter BSD Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Mailman-Approved-At: Mon, 18 Jun 2012 18:51:22 +0000 Cc: freebsd-multimedia@freebsd.org, freebsd-hackers@freebsd.org Subject: Re: how to turn my computer into a TV X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 18 Jun 2012 18:22:11 -0000 On Mon, Jun 18, 2012 at 10:21 AM, Dieter BSD wrote= : > user.vdr writes: >> Recording doesn't require any compression unless you are transcoding >> in real-time. There's no difference between recording ATSC, NTSC, PAL, >> etc, and it's actually irrelevant what the stream is. > > This is incorrect. =C2=A0ATSC is compressed before broadcast, so > you receive the data already compresed. =C2=A0NTSC and PAL are > broadcast in analog. =C2=A0The tuner performs A-to-D which gives > an uncompressed data stream. =C2=A0Have fun trying to store that. > As a practical matter, you have to compress the data in real time. > Some, not all, tuners include hardware compression. All consumer digital broadcasts are compressed typically with mpeg2 or mpeg= 4. With very very very few exceptions, all analog NTSC broadcasts have been switched to digital, by the FCC mandated deadline of June 12, 2009. Tuners perform demodulation, not decompression. There are a few "premium" or "full-featured" devices which have an on-board decoder such as a Hauppauge Nexus-s or the TechnoTrend S2-6400. You absolutely do NOT have to reencode a stream unless you want to alter the resolution, bitrate, or compression method. Tuners do NOT provide raw audio/video to the system in any case. >> Lastly, it's possible to save a single channel or the entire stream >> which usually contains several channels. Even when saving the full >> stream, it likely uses far less bandwidth than your media offers so >> there's no problem there. > > This appariently refers to ATSC. =C2=A0Yes, modern disks have plenty > of bandwidth to store the entire ATSC stream. =C2=A0The main reason > to filter PIDs is to save disk *space*. =C2=A0Also, some software > can't select which program to decode. It refers to ANY multiplex. Again, the standard used for broadcast is irrelevant. Also, any program that can tune a channel has the ability to filter the pids, otherwise it would be impossible to tune a channel. > Wojciech writes: >> most people vastly underestimate power of modern CPUs. > > Many people overestimate the "moderness" of most people's CPUs. An old Pentium 4 3ghz can decode HD with plenty of cpu resources to spare so unless a person using something older than that, they've certainly got "modern" cpu power.