Re: [rtcweb] H261/MPEG-1 video quality

Maik Merten <maikmerten@googlemail.com> Sat, 16 November 2013 17:16 UTC

Return-Path: <maikmerten@googlemail.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 6529411E8150 for <rtcweb@ietfa.amsl.com>; Sat, 16 Nov 2013 09:16:06 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.999
X-Spam-Level:
X-Spam-Status: No, score=-1.999 tagged_above=-999 required=5 tests=[BAYES_00=-2.599, J_CHICKENPOX_45=0.6]
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 Ws22crbES-P8 for <rtcweb@ietfa.amsl.com>; Sat, 16 Nov 2013 09:16:05 -0800 (PST)
Received: from mail-ea0-x229.google.com (mail-ea0-x229.google.com [IPv6:2a00:1450:4013:c01::229]) by ietfa.amsl.com (Postfix) with ESMTP id 5445411E8106 for <rtcweb@ietf.org>; Sat, 16 Nov 2013 09:16:02 -0800 (PST)
Received: by mail-ea0-f169.google.com with SMTP id l9so1612012eaj.0 for <rtcweb@ietf.org>; Sat, 16 Nov 2013 09:16:01 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=20120113; h=message-id:date:from:user-agent:mime-version:to:subject:references :in-reply-to:content-type:content-transfer-encoding; bh=XP+LZPRCF9C3ZND9bNOH5RWDmhLzq/DAkKbyKYssNxE=; b=dFPxks+LXIAsLG6dP3KRiOQtSPlrYQrxI7o0BzMqg7xIo2rWowMhOvj/VymwWzDyZU PjjLrV1PfXL7twz6HAIe/s3tXQhtDlzXz9zhan7aGTpZliSzNSIqPF0Y88Y1eeXNifaG mtrBhpsXXGbDX0xnSpNLPZIgOTH43VbiiXFD6JnNwPMxy4eHoYIRDlAp1T3HcS4U1bgf IekkBl/in+l6JiXpudTNPo0FZW2zokHKEHrCLIgiS0Z2JVcsxo7etTHarU/CBIR7FZlH aF2jOnppP0P8kSL+eW2FqqGz3CRQzaPbk9dEc93KYFX2SnSAZev5ohJajBMrzu7islmc WZHw==
X-Received: by 10.14.199.1 with SMTP id w1mr703728een.13.1384622161449; Sat, 16 Nov 2013 09:16:01 -0800 (PST)
Received: from [192.168.2.109] (port-92-201-104-246.dynamic.qsc.de. [92.201.104.246]) by mx.google.com with ESMTPSA id 1sm18562391eeg.4.2013.11.16.09.15.59 for <rtcweb@ietf.org> (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Sat, 16 Nov 2013 09:16:00 -0800 (PST)
Message-ID: <5287A84B.1020404@googlemail.com>
Date: Sat, 16 Nov 2013 18:15:55 +0100
From: Maik Merten <maikmerten@googlemail.com>
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.1.0
MIME-Version: 1.0
To: rtcweb@ietf.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> <CAOJ7v-3AT-5BHZAp2hvqm3Th20dk8Ec3orrj-voFMBwZroPdLA@mail.gmail.com> <DUB127-W49A2377699D81E3A1EA912E0FB0@phx.gbl> <CAOJ7v-27XiBGFT8=i=8ZyWYPP4UE64Jo41Pe_i1GAAUWfhDBuA@mail.gmail.com>
In-Reply-To: <CAOJ7v-27XiBGFT8=i=8ZyWYPP4UE64Jo41Pe_i1GAAUWfhDBuA@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 8bit
Subject: Re: [rtcweb] H261/MPEG-1 video quality
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: Sat, 16 Nov 2013 17:16:07 -0000

I uploaded a set of H.261 encodes of the sign_irene sample, ranging from 
128 kbps to 1024 kbps. This is again done with ffmpeg, so please take my 
comments regarding its H.261 encoder into consideration.

https://drive.google.com/file/d/0B11N4VzriA21WWRoVGd6TWRwb3M/edit?usp=sharing

(btw, transmission of sign language is a nice example where "audio only" 
is not quite useful in case of video codec negotiation failure)


Maik


Am 16.11.2013 03:18, schrieb Justin Uberti:
> Thanks. Performance at 256 kbps is clearly unacceptable, 1933 kbps is
> pretty decent. Would be great to see a 512 kbps and 1024 kbps version to
> understand where things go from bad to good.
>
>
> On Fri, Nov 15, 2013 at 3:42 PM, Hervé W. <h_o_w_@hotmail.com
> <mailto:h_o_w_@hotmail.com>> wrote:
>
>     <http://ge.tt/2bp1Zrz><http://ge.tt/2bp1Zrz><http://ge.tt/2bp1Zrz>http://ge.tt/2bp1Zrz
>
>     options used:
>     mencoder.exe -ovc lavc -lavcopts vcodec=h261:vbitrate=256 -o
>     irene-256k.h261.avi sign_irene_cif.y4m
>
>     mencoder.exe -ovc lavc -lavcopts
>     vcodec=h261:vbitrate=256:last_pred=3:predia=2:dia=2:precmp=2:cmp=2:subcmp=2:preme=2:mbd=0
>     -o irene-256k.h261.miscoptions.avi sign_irene_cif.y4m
>
>     mencoder.exe -ovc lavc -lavcopts
>     vcodec=h261:vbitrate=15999:last_pred=3:predia=2:dia=2:precmp=2:cmp=2:subcmp=2:preme=2:mbd=0
>     -o irene-highbitrate.h261.avi sign_irene_cif.y4m
>
>     You can probably derive ffmpeg/avconv options from those.
>
>     Notes
>
>       * There's a ticket open about h261
>         <https://trac.ffmpeg.org/ticket/3143>https://trac.ffmpeg.org/ticket/3143
>       * 15999 kbps was not the bitrate irene-highbitrate ended up using;
>         that was more like 1933 kbps
>       * My untrained eye did not see any difference between
>         irene-256k.h261.avi and irene-256k.h261.miscoptions.avi but
>         maybe most of those options are (rightly) ignored for h261.
>
>
>     - Hervé
>
>     ------------------------------------------------------------------------
>     From: juberti@google.com <mailto:juberti@google.com>
>     Date: Fri, 15 Nov 2013 14:00:50 -0800
>     To: cowwoc@bbs.darktech.org <mailto:cowwoc@bbs.darktech.org>
>     CC: rtcweb@ietf.org <mailto:rtcweb@ietf.org>
>     Subject: Re: [rtcweb] H261/MPEG-1 video quality (was: I'd love it if
>     patents evaporated)
>
>
>      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
>     <mailto: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 list
>             rtcweb@ietf.org  <mailto:rtcweb@ietf.org>
>             https://www.ietf.org/mailman/listinfo/rtcweb
>
>
>
>         _______________________________________________
>         rtcweb mailing list
>         rtcweb@ietf.org <mailto:rtcweb@ietf.org>
>         https://www.ietf.org/mailman/listinfo/rtcweb
>
>
>
>     _______________________________________________ rtcweb mailing list
>     rtcweb@ietf.org <mailto:rtcweb@ietf.org>
>     https://www.ietf.org/mailman/listinfo/rtcweb
>
>
>
>
> _______________________________________________
> rtcweb mailing list
> rtcweb@ietf.org
> https://www.ietf.org/mailman/listinfo/rtcweb
>