From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ffbox0-bg.mplayerhq.hu (ffbox0-bg.ffmpeg.org [79.124.17.100]) by master.gitmailbox.com (Postfix) with ESMTP id AB2D8437F3 for ; Wed, 29 Jun 2022 04:34:32 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 447E068B641; Wed, 29 Jun 2022 07:34:30 +0300 (EEST) Received: from mail-lf1-f49.google.com (mail-lf1-f49.google.com [209.85.167.49]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id 9F24468B467 for ; Wed, 29 Jun 2022 07:34:23 +0300 (EEST) Received: by mail-lf1-f49.google.com with SMTP id j21so25926037lfe.1 for ; Tue, 28 Jun 2022 21:34:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to; bh=aL11M3wM45sELBVpOlJmk6SHdBEFrikaHAG4kU+KL10=; b=WIYDKyEBMjh5h10Dcy9dgo0qwhTMXozWdiDFXrc/eATOtFsOosELTkeyGTQHudgB+y oTx11fPKp7Qmfgea26g2/b4gkBUHhkeyR2mWjf8/FGkk2nEY+aditvqN9k+DpkPdTPAV Mc2lQgP8ffR8luRqqJZU8yAZaw7LnYDyb7aXYJ4N1Skd23W6VVIoRng75pcnMz+5sXln FPnJabKiSFRSlFAEKD0D0N/oavK/NgnouyAyebubYeg3pIRHw9Gw7yYZYPnxDkgYDJBr DjcnSXwHZ+5E/eNgSMy3K+IgpsoHLv8kIzZxXhQi4JIeGztKa0uhqxvXb0fIfngqIuAA B6BQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to; bh=aL11M3wM45sELBVpOlJmk6SHdBEFrikaHAG4kU+KL10=; b=xtgmc8VwbBRMiIYZhlOdF3TV6dKAOuQKpEUE65Bi9EBgYEoaggqHkkqqzeQLnoLVlJ ZwBp1sH829SzvbGz/Z2fW/Ks7AXGUjkeBw2+GZ1rwZiW7h5hWiNBcdFjRUddvFtvhqQL vaqAkPlWTxIeXf/GJNTKl2h7en6vVkhcln88Uf8ZtF+ubxpTPOeVFUw7lzimxL9LC8qn UBnhNkxErojbJXLUDhjSyyBjWKYi8JhvpaAeuQsdf3ves+Z72pTC/l6dR8n/CdBY3yN4 1eYojG5y++PckqG6hFvKwvHoznMHSIvgAPMn8zWmG0KCOweQOpCrkcTcjJ9R2adIXNY4 PCBA== X-Gm-Message-State: AJIora+9xfPmRuM+zdkKmE1fm5ks+O/VB9t2C0es8AqWtXrMj3cswc+i m0L9kCGDT6s0SvmrZV5bUFKWFTEsy7lbe/oaZrSQwZFJ2HI= X-Google-Smtp-Source: AGRyM1v0ndRmUCyj/Zsh5mUQVIvWgRlp0ztvQ6+dRzNmGGlHPSr46Jb10CXJgST4tTeKNpkCnzPgfBsccrLgIb6bTd8= X-Received: by 2002:a05:6512:1295:b0:481:1a61:8d21 with SMTP id u21-20020a056512129500b004811a618d21mr785520lfs.500.1656477261603; Tue, 28 Jun 2022 21:34:21 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Hendrik Leppkes Date: Wed, 29 Jun 2022 06:34:09 +0200 Message-ID: To: FFmpeg development discussions and patches Subject: Re: [FFmpeg-devel] [RFC] Bug in colorspace.c X-BeenThere: ffmpeg-devel@ffmpeg.org X-Mailman-Version: 2.1.29 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 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Archived-At: List-Archive: List-Post: On Tue, Jun 28, 2022 at 11:38 PM Soft Works wrote: > > Hi, > > in colorspace.c, there are two functions with contradicting behavior > regarding reading/writing the max_luminance value from/to > AVMasteringDisplayMetadata. The code seems to be unchanged since > 3 years: > > > 1. ff_determine_signal_peak() > > sd = av_frame_get_side_data(in, AV_FRAME_DATA_MASTERING_DISPLAY_METADATA); > if (!peak && sd) { > AVMasteringDisplayMetadata *metadata = (AVMasteringDisplayMetadata *)sd->data; > if (metadata->has_luminance) > peak = av_q2d(metadata->max_luminance) / REFERENCE_WHITE; > } > > > 2. ff_update_hdr_metadata() > > sd = av_frame_get_side_data(in, AV_FRAME_DATA_MASTERING_DISPLAY_METADATA); > if (sd) { > AVMasteringDisplayMetadata *metadata = (AVMasteringDisplayMetadata *)sd->data; > if (metadata->has_luminance) > metadata->max_luminance = av_d2q(peak * REFERENCE_WHITE, 10000); > } > > > The latter function writes the value as an AVRational with a denominator of > 10000, but the former function doesn't multiply the value by 10000. > These two calls round-trip just fine. The 10000 is not a forced denominator, divisor, or multiplier, it is the maximum denominator it is allowed to use to convert the floating point value to a rational. av_d2q will ensure the value is properly scaled. - Hendrik _______________________________________________ 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".