Re: [rtcweb] H261/MPEG-1 video quality (was: I'd love it if patents evaporated)

Justin Uberti <juberti@google.com> Fri, 15 November 2013 22:01 UTC

Return-Path: <juberti@google.com>
X-Original-To: rtcweb@ietfa.amsl.com
Delivered-To: rtcweb@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id A5B0D11E81BD for <rtcweb@ietfa.amsl.com>; Fri, 15 Nov 2013 14:01:13 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -0.844
X-Spam-Level:
X-Spam-Status: No, score=-0.844 tagged_above=-999 required=5 tests=[AWL=0.533, BAYES_00=-2.599, FM_FORGED_GMAIL=0.622, HTML_MESSAGE=0.001, J_CHICKENPOX_45=0.6, NO_RELAYS=-0.001]
Received: from mail.ietf.org ([12.22.58.30]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id G22rgDR+htyk for <rtcweb@ietfa.amsl.com>; Fri, 15 Nov 2013 14:01:12 -0800 (PST)
Received: from mail-vb0-x22e.google.com (mail-vb0-x22e.google.com [IPv6:2607:f8b0:400c:c02::22e]) by ietfa.amsl.com (Postfix) with ESMTP id 6F08411E8164 for <rtcweb@ietf.org>; Fri, 15 Nov 2013 14:01:11 -0800 (PST)
Received: by mail-vb0-f46.google.com with SMTP id i3so1191531vbh.5 for <rtcweb@ietf.org>; Fri, 15 Nov 2013 14:01:10 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc:content-type; bh=BVVuRmLBivkNGm8z9OEP3DDve147cfd+weyE5bF9GZA=; b=U4plrW5wGFdUV3LPAsgWtOjGEm1TmkSgzIF0cbvZn83ShuzN6E44EawmxU3w/lMdax 57gN6ABs4uVznUGNEiTtXQ1pAKsYaiID4GVcfjQByV5ODiHRO1fkeY0w8LB7du3DQqO9 nGAvUA0o+1bIkP0jWiBS3nf/V3HwFI+bCxFv4C1NvBU2cX/Rm2M7GMpJAJu7zlXYLZnr 0sS7F8rkrwO6/GDzgwB8epGAb1NkKsih6oh8wZVrdslpW/QGEUNkFIrZc0dWAadCyvhf PEBurbEY8NYX0UTWLOfUztNF3x5g8RNu1OhD73CvxIk4XUgRpDyFoHjYYS/koN1RYJQh +R1g==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc:content-type; bh=BVVuRmLBivkNGm8z9OEP3DDve147cfd+weyE5bF9GZA=; b=d/prmYF9FO71RemcYExAghQrTY9SJLIq6daoIu/VLdCM6yYzf00f/+tFNxQH63siH5 hCn1ebKhOwVmFscqKPYjUjmXjhLuEljnvUioesuzfqk15P4fZEUqInRJeeeN8yPGUtxz fOiIUoRM44oD8qvdAiYZpF7DOeXab+Jns6zSgKUOT5USDJ1iRlyS9xdfuiotc/T0b9PC FAjipozaxznzK9AGADSXLecvTQRyi03O3a7QpGOwnq54zQmLWagn57YZlFeKdbWcbSUr u7tBnO44VqgZs9Mx3Va8As+Ik0aVdEplSYpJmdlz3U9HnL3g0/olP0XG9XJcstRKaX2p dkhA==
X-Gm-Message-State: ALoCoQkMsuJc4P40w274J+eyQ+7Vq0ZfATo47DeNStLucS+ssSTF2MnKq/z3ZE80qII9kf6TTpl2xM5zOskbR76Ifa7UbEd41+aXK9zNlioYdhxAilG2WJTbQ24nh4WiRuMGPPfQS2DRijF64XkhIitJf3e3MOnCrmCAJ1rbDhFMgMh7TkjsI6mOsnIxkU0FgWJMFxIbw77Z
X-Received: by 10.52.74.74 with SMTP id r10mr165319vdv.78.1384552870582; Fri, 15 Nov 2013 14:01:10 -0800 (PST)
MIME-Version: 1.0
Received: by 10.52.110.101 with HTTP; Fri, 15 Nov 2013 14:00:50 -0800 (PST)
In-Reply-To: <5286272B.5000005@bbs.darktech.org>
References: <5284AB73.5030505@googlemail.com> <5285209D.7020407@googlemail.com> <CAGgHUiSROwRznKZWD4kjn8Vu7SrUVwOnHN1EJ-PTgR=WQmcxAQ@mail.gmail.com> <CAOJ7v-2najyMhcVNC8r0Sg+8xgkgDwasBSz476zA0BEpi2X5Pg@mail.gmail.com> <528559E4.3020903@nostrum.com> <5286272B.5000005@bbs.darktech.org>
From: Justin Uberti <juberti@google.com>
Date: Fri, 15 Nov 2013 14:00:50 -0800
Message-ID: <CAOJ7v-3AT-5BHZAp2hvqm3Th20dk8Ec3orrj-voFMBwZroPdLA@mail.gmail.com>
To: cowwoc <cowwoc@bbs.darktech.org>
Content-Type: multipart/alternative; boundary=20cf307cff2006381b04eb3e5692
Cc: "rtcweb@ietf.org" <rtcweb@ietf.org>
Subject: Re: [rtcweb] H261/MPEG-1 video quality (was: I'd love it if patents evaporated)
X-BeenThere: rtcweb@ietf.org
X-Mailman-Version: 2.1.12
Precedence: list
List-Id: Real-Time Communication in WEB-browsers working group list <rtcweb.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/rtcweb>, <mailto:rtcweb-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/rtcweb>
List-Post: <mailto:rtcweb@ietf.org>
List-Help: <mailto:rtcweb-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/rtcweb>, <mailto:rtcweb-request@ietf.org?subject=subscribe>
X-List-Received-Date: Fri, 15 Nov 2013 22:01:13 -0000

>From what I understand, the clip from this thread was encoded using MPEG-1,
not H.261. Aside from http://www-mobile.ecs.soton.ac.uk/peter/h261/, I
don't think we have seen any samples of actual H.261 output that give a
good indication of its suitability.


On Fri, Nov 15, 2013 at 5:52 AM, cowwoc <cowwoc@bbs.darktech.org>; wrote:

>
> Excellent work Adam. I can't speak for others, but at 254 kbps (corrected
> figure from your follow-up post) H.261 is definitely "good enough" and
> better than an audio-only connection.
>
> Gili
>
>
> On 14/11/2013 6:16 PM, Adam Roach wrote:
>
> I sent a reply to this earlier, but just now realized that it went only to
> Justin, not to the list.
>
>
>  On 11/14/13 13:59, Justin Uberti wrote:
>
> Thanks, this is interesting. Is the ffmpeg 261 encoder limited to
> CIF/QCIF, or can you specify arbitrary sizes?
>
>
> It looks like the ffmpeg mpeg-1 coder works for arbitrary sizes. I'm not
> sure what the difference between mpeg-1 and H.261 are, though, so we could
> be talking apples and oranges (or at least apples and pears) here. I'll
> note that mpeg-1 came out in 1991, which is a good 22 years in the past.
> I'm not drawing IPR conclusions for you, but invite you to ponder the
> implications yourself.
>
> Following Maik's lead with the mpeg-1 js decoder, I put this together:
>
> https://dl.dropboxusercontent.com/u/53717247/mpg/maven.html
>
> ...with this commandline:
>
>   ffmpeg -i maven.mp4 -f mpeg1video -flags qprd -mbd rd -cmp rd -subcmp rd
> -mbcmp rd -precmp rd -trellis 2 -g 100 -vb 256k maven.mpg
>
> I don't really understand most of those options (I just cribbed them from
> Maik's example) or whether any of them would introduce more latency than is
> reasonable for a real-time conversation, but I will observe:
>
>    1. The encoder claims that it was performing on the order of 90 - 100
>    fps on my (admittedly modern) system;
>     2. The resolution is 640x360 (somewhat larger than DCIF);
>    3. The video is not, to my eye, unusable (draw your own conclusions,
>    as it's clearly not as nice as modern codecs);
>     4. At 74 seconds and 4.7 MBytes (i.e., 37.6 Mbits), this encoding
>    works out to 508 kbits/second total.
>
>
>  Source video here, and NASA is acknowledged as the source of the material
> contained therein: http://www.youtube.com/watch?v=ijAO0FFExx0
>
> /a
>
>
>
> _______________________________________________
> rtcweb mailing listrtcweb@ietf.orghttps://www.ietf.org/mailman/listinfo/rtcweb
>
>
>
> _______________________________________________
> rtcweb mailing list
> rtcweb@ietf.org
> https://www.ietf.org/mailman/listinfo/rtcweb
>
>