From patchwork Wed Mar 15 21:52:29 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mateusz Brzostek X-Patchwork-Id: 2941 Delivered-To: ffmpegpatchwork@gmail.com Received: by 10.103.50.79 with SMTP id y76csp482925vsy; Wed, 15 Mar 2017 14:54:28 -0700 (PDT) X-Received: by 10.223.173.76 with SMTP id p70mr4722101wrc.168.1489614868632; Wed, 15 Mar 2017 14:54:28 -0700 (PDT) Return-Path: Received: from ffbox0-bg.mplayerhq.hu (ffbox0-bg.ffmpeg.org. [79.124.17.100]) by mx.google.com with ESMTP id 5si1970049wmu.47.2017.03.15.14.54.28; Wed, 15 Mar 2017 14:54:28 -0700 (PDT) Received-SPF: pass (google.com: domain of ffmpeg-devel-bounces@ffmpeg.org designates 79.124.17.100 as permitted sender) client-ip=79.124.17.100; Authentication-Results: mx.google.com; dkim=neutral (body hash did not verify) header.i=@msystem.waw.pl; spf=pass (google.com: domain of ffmpeg-devel-bounces@ffmpeg.org designates 79.124.17.100 as permitted sender) smtp.mailfrom=ffmpeg-devel-bounces@ffmpeg.org Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 4097E680D07; Wed, 15 Mar 2017 23:54:09 +0200 (EET) X-Original-To: ffmpeg-devel@ffmpeg.org Delivered-To: ffmpeg-devel@ffmpeg.org Received: from s36a.hekko.net.pl (s36a.hekko.net.pl [188.116.19.94]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id 6823D680A9D for ; Wed, 15 Mar 2017 23:54:02 +0200 (EET) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=msystem.waw.pl; s=x; h=Content-Type:MIME-Version:Date:Message-ID:Subject: From:To:Sender:Reply-To:Cc:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:In-Reply-To:References:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=ipXUTOxqD4LJe3lOybXSbgqyd1Dj1EmhvuGu09qCuOg=; b=yba9N3d0uAkJC3yULQpINlQRY0 mxmi1rUB0BsjaZZVlPjUMIo1o69ntn5Msx4LUjvHm+zO37tAip07UmVn4iVwkCnP2SJnncgnx+6hN s1TnwjgY9kQ0USYvYHKXDXwODTWQU4jiReM7vW+lH/bOn0fO0OhN2xpNXl9ssWt/VMMxgKTaj33kr wjL3G/NWdeYFMWEjNLvEGK18zszuDHeFJWSSaSLjbHJR5nW+iwDWyqQg6bnXgwKO95tCsDlC4IPW1 P0wWb2yef0X/lrkn2NvwJarjdpO+y7NmBdPtGzl5YVSYdIWQ+KNbOMSnIgcor56aNJU0kZ7KMLkN1 OT6/F0aQ==; Received: from aayv181.neoplus.adsl.tpnet.pl ([83.6.133.181] helo=[192.168.1.3]) by s36.hekko.net.pl with esmtpsa (TLSv1.2:DHE-RSA-AES128-SHA:128) (Exim 4.87) (envelope-from ) id 1coGs5-0004kZ-MG for ffmpeg-devel@ffmpeg.org; Wed, 15 Mar 2017 22:54:18 +0100 To: ffmpeg-devel@ffmpeg.org From: Mateusz Brzostek Message-ID: <5de4b4a8-767b-5ddb-1b5b-78cb913e32d0@msystem.waw.pl> Date: Wed, 15 Mar 2017 22:52:29 +0100 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 X-HEKKO: 83.6.133.181:mateusz@msystem.waw.pl Subject: [FFmpeg-devel] [PATCH] libswscale/swscale_unscaled: fix DITHER_COPY macro X-BeenThere: ffmpeg-devel@ffmpeg.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: FFmpeg development discussions and patches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: FFmpeg development discussions and patches Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Hello! There are 3 problems with DITHER_COPY macro in libswscale/swscale_unscaled.c: 1) there is overflow in dithering from 12-bit to 10-bit (output value > 1023); 2) for limit range the lower limit is not respected, for example from 10-bit to 8-bit value 64 is converted to 15; 3) for many iteration of downscale/upscale of the same image the 200th iteration is significantly darker. The first bug is due to wrong dithers table (now it is OK only for 8-bit destination), fix is: - const uint8_t *dither= dithers[src_depth-9][i&7];\ + const uint8_t *dither= dithers[src_depth-dst_depth-1][i&7];\ For bugs 2) and 3) it is needed formula that do not make images darker (in attachment). So please review. Mateusz diff --git a/libswscale/swscale_unscaled.c b/libswscale/swscale_unscaled.c index ba3d688..429c98c 100644 --- a/libswscale/swscale_unscaled.c +++ b/libswscale/swscale_unscaled.c @@ -110,24 +110,6 @@ DECLARE_ALIGNED(8, static const uint8_t, dithers)[8][8][8]={ { 112, 16,104, 8,118, 22,110, 14,}, }}; -static const uint16_t dither_scale[15][16]={ -{ 2, 3, 3, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,}, -{ 2, 3, 7, 7, 13, 13, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25,}, -{ 3, 3, 4, 15, 15, 29, 57, 57, 57, 113, 113, 113, 113, 113, 113, 113,}, -{ 3, 4, 4, 5, 31, 31, 61, 121, 241, 241, 241, 241, 481, 481, 481, 481,}, -{ 3, 4, 5, 5, 6, 63, 63, 125, 249, 497, 993, 993, 993, 993, 993, 1985,}, -{ 3, 5, 6, 6, 6, 7, 127, 127, 253, 505, 1009, 2017, 4033, 4033, 4033, 4033,}, -{ 3, 5, 6, 7, 7, 7, 8, 255, 255, 509, 1017, 2033, 4065, 8129,16257,16257,}, -{ 3, 5, 6, 8, 8, 8, 8, 9, 511, 511, 1021, 2041, 4081, 8161,16321,32641,}, -{ 3, 5, 7, 8, 9, 9, 9, 9, 10, 1023, 1023, 2045, 4089, 8177,16353,32705,}, -{ 3, 5, 7, 8, 10, 10, 10, 10, 10, 11, 2047, 2047, 4093, 8185,16369,32737,}, -{ 3, 5, 7, 8, 10, 11, 11, 11, 11, 11, 12, 4095, 4095, 8189,16377,32753,}, -{ 3, 5, 7, 9, 10, 12, 12, 12, 12, 12, 12, 13, 8191, 8191,16381,32761,}, -{ 3, 5, 7, 9, 10, 12, 13, 13, 13, 13, 13, 13, 14,16383,16383,32765,}, -{ 3, 5, 7, 9, 10, 12, 14, 14, 14, 14, 14, 14, 14, 15,32767,32767,}, -{ 3, 5, 7, 9, 11, 12, 14, 15, 15, 15, 15, 15, 15, 15, 16,65535,}, -}; - static void fillPlane(uint8_t *plane, int stride, int width, int height, int y, uint8_t val) @@ -1485,22 +1467,22 @@ static int packedCopyWrapper(SwsContext *c, const uint8_t *src[], } #define DITHER_COPY(dst, dstStride, src, srcStride, bswap, dbswap)\ - uint16_t scale= dither_scale[dst_depth-1][src_depth-1];\ - int shift= src_depth-dst_depth + dither_scale[src_depth-2][dst_depth-1];\ + int scale= 31-src_depth, shift= 31-dst_depth;\ for (i = 0; i < height; i++) {\ - const uint8_t *dither= dithers[src_depth-9][i&7];\ + const uint8_t *dither= dithers[src_depth-dst_depth-1][i&7];\ for (j = 0; j < length-7; j+=8){\ - dst[j+0] = dbswap((bswap(src[j+0]) + dither[0])*scale>>shift);\ - dst[j+1] = dbswap((bswap(src[j+1]) + dither[1])*scale>>shift);\ - dst[j+2] = dbswap((bswap(src[j+2]) + dither[2])*scale>>shift);\ - dst[j+3] = dbswap((bswap(src[j+3]) + dither[3])*scale>>shift);\ - dst[j+4] = dbswap((bswap(src[j+4]) + dither[4])*scale>>shift);\ - dst[j+5] = dbswap((bswap(src[j+5]) + dither[5])*scale>>shift);\ - dst[j+6] = dbswap((bswap(src[j+6]) + dither[6])*scale>>shift);\ - dst[j+7] = dbswap((bswap(src[j+7]) + dither[7])*scale>>shift);\ + int32_t tmp = (bswap(src[j+0]) + (unsigned)dither[0])<>31)) & 0x7FFFFFFF; dst[j+0] = dbswap(tmp>>shift);\ + tmp = (bswap(src[j+1]) + (unsigned)dither[1])<>31)) & 0x7FFFFFFF; dst[j+1] = dbswap(tmp>>shift);\ + tmp = (bswap(src[j+2]) + (unsigned)dither[2])<>31)) & 0x7FFFFFFF; dst[j+2] = dbswap(tmp>>shift);\ + tmp = (bswap(src[j+3]) + (unsigned)dither[3])<>31)) & 0x7FFFFFFF; dst[j+3] = dbswap(tmp>>shift);\ + tmp = (bswap(src[j+4]) + (unsigned)dither[4])<>31)) & 0x7FFFFFFF; dst[j+4] = dbswap(tmp>>shift);\ + tmp = (bswap(src[j+5]) + (unsigned)dither[5])<>31)) & 0x7FFFFFFF; dst[j+5] = dbswap(tmp>>shift);\ + tmp = (bswap(src[j+6]) + (unsigned)dither[6])<>31)) & 0x7FFFFFFF; dst[j+6] = dbswap(tmp>>shift);\ + tmp = (bswap(src[j+7]) + (unsigned)dither[7])<>31)) & 0x7FFFFFFF; dst[j+7] = dbswap(tmp>>shift);\ + }\ + for (; j < length; j++){\ + int32_t tmp = (bswap(src[j]) + (unsigned)dither[j&7])<>31)) & 0x7FFFFFFF; dst[j] = dbswap(tmp>>shift);\ }\ - for (; j < length; j++)\ - dst[j] = dbswap((bswap(src[j]) + dither[j&7])*scale>>shift);\ dst += dstStride;\ src += srcStride;\ }