From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <ffmpeg-devel-bounces@ffmpeg.org>
Received: from ffbox0-bg.mplayerhq.hu (ffbox0-bg.ffmpeg.org [79.124.17.100])
	by master.gitmailbox.com (Postfix) with ESMTP id 608DF43050
	for <ffmpegdev@gitmailbox.com>; Sat, 17 Sep 2022 01:45:17 +0000 (UTC)
Received: from [127.0.1.1] (localhost [127.0.0.1])
	by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 436FD68BC47;
	Sat, 17 Sep 2022 04:45:16 +0300 (EEST)
Received: from mail.overt.org (mail.overt.org [157.230.92.47])
 by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id EE55268BC02
 for <ffmpeg-devel@ffmpeg.org>; Sat, 17 Sep 2022 04:45:09 +0300 (EEST)
Received: from authenticated-user (mail.overt.org [157.230.92.47])
 (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits))
 (No client certificate requested)
 by mail.overt.org (Postfix) with ESMTPSA id B1BC63F1DD
 for <ffmpeg-devel@ffmpeg.org>; Fri, 16 Sep 2022 20:45:08 -0500 (CDT)
DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=overt.org; s=mail;
 t=1663379109; bh=6xgxDqHf0fuEGG9r/Rm2IESbN5qsKySkDbTKUaLcM3w=;
 h=Date:From:To:Subject:In-Reply-To:References:From;
 b=c4QSugwOX4GZdCYSvswFL4w1i2SV5fmcLM2SOqAMZS8AxZlHuLF5Mc/AEttCB5B3/
 AJJyOnoZ3tUKD2M0WrIqvOWNtuC+eMMMdTxxU7YSjNMPL/edztLY8xFOeA2a6w1RGo
 wt0Pn2ofcY0qsqMhk4bGREe/LJqpy8g+NZi1p8J2u5LvQMLiTsfw/PsuD8OugPWV7g
 lq0awjPq6+vLIQGrESNyvyaXNm/IRU+ih/KPTazxMVTzSB1ulNHlYQaR8S4Mar2N0U
 K1NDYGWq/jk7ucMWW0olXEFiC8ceISPIAXN3bFPy+eatNDBJb7wFz+R8fI/4kRGjYi
 XDamqSceuwTJw==
Date: Fri, 16 Sep 2022 18:45:06 -0700
From: Philip Langdale <philipl@overt.org>
To: ffmpeg-devel@ffmpeg.org
Message-ID: <20220916184506.4e805fcb@fido7>
In-Reply-To: <20220915212554.GS2088045@pb2>
References: <20220914232002.325160-1-philipl@overt.org>
 <20220915212554.GS2088045@pb2>
MIME-Version: 1.0
Subject: Re: [FFmpeg-devel] [PATCH] v3: lavu/pixdesc: favour formats where
 depth and subsampling exactly match
X-BeenThere: ffmpeg-devel@ffmpeg.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: FFmpeg development discussions and patches <ffmpeg-devel.ffmpeg.org>
List-Unsubscribe: <https://ffmpeg.org/mailman/options/ffmpeg-devel>,
 <mailto:ffmpeg-devel-request@ffmpeg.org?subject=unsubscribe>
List-Archive: <https://ffmpeg.org/pipermail/ffmpeg-devel>
List-Post: <mailto:ffmpeg-devel@ffmpeg.org>
List-Help: <mailto:ffmpeg-devel-request@ffmpeg.org?subject=help>
List-Subscribe: <https://ffmpeg.org/mailman/listinfo/ffmpeg-devel>,
 <mailto:ffmpeg-devel-request@ffmpeg.org?subject=subscribe>
Reply-To: FFmpeg development discussions and patches <ffmpeg-devel@ffmpeg.org>
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Errors-To: ffmpeg-devel-bounces@ffmpeg.org
Sender: "ffmpeg-devel" <ffmpeg-devel-bounces@ffmpeg.org>
Archived-At: <https://master.gitmailbox.com/ffmpegdev/20220916184506.4e805fcb@fido7/>
List-Archive: <https://master.gitmailbox.com/ffmpegdev/>
List-Post: <mailto:ffmpegdev@gitmailbox.com>

On Thu, 15 Sep 2022 23:25:54 +0200
Michael Niedermayer <michael@niedermayer.cc> wrote:

> > +
> > +        if (dst_desc->log2_chroma_h < src_desc->log2_chroma_h) {
> > +            loss |= FF_LOSS_EXCESS_RESOLUTION;
> > +            score -= 32 << (src_desc->log2_chroma_h -
> > dst_desc->log2_chroma_h);
> > +        }  
> 
> with 16bit 4:2:0 
> to
> 14bit 4:2:0
> vs.
> 16bit 4:4:4
> 
> more data is preserved in the later but the 420->444 would have a
> loss of 64 i think and 16->14 i think 8. I didnt try this just
> reading the code so i may be missing something but i think the code
> would favor the lower bitdepth That may be unexpected

Yep. Another edge case :-)

I've posted a v4 that adjusts the excess resolution penalty to avoid
this.

Maybe I've got it right this time.

Thanks,

--phil
_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel

To unsubscribe, visit link above, or email
ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".