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 995314512E for ; Fri, 10 Feb 2023 00:04:14 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 921DE68BDC9; Fri, 10 Feb 2023 02:04:11 +0200 (EET) Received: from mail-pl1-f176.google.com (mail-pl1-f176.google.com [209.85.214.176]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id 560B868BD1E for ; Fri, 10 Feb 2023 02:04:05 +0200 (EET) Received: by mail-pl1-f176.google.com with SMTP id z1so4759741plg.6 for ; Thu, 09 Feb 2023 16:04:05 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=to:subject:message-id:date:from:in-reply-to:references:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=7xrxodYmg/dLxk0Ruy2FzWt5FI+G65v44WdnY24OQaw=; b=EcxG0Gxx8i5UZg0zab0eS7HCYEyeHe8cLFybadXXmXQt+iXQYRiRoGx7NGXGsx/hK9 ScXVXsVorrkUMxleaEA6vM3AVmbIhnbV7nC5oNptq2Ne7s37zgZEIkAgZJxoEt7MlQ72 8uF+Dec/9vsSbB3fhSIr1N0X7+t8ZUQ1RErui4hJGW78FOarUOs3pMHIOjAw1OdoGa25 I8wvFo6m0aFqjnI84uwqQX66zf4uqCjKN+Rgts8egRD4HmqJDZu7Tt5FA8dpXowIpUNR MGepjCjokoQmc5zDjadPIAnLAqmb0KzxlJhj1H+/0p23bX47/8DhMpOGNJqIinhYCBAe QAbg== X-Gm-Message-State: AO0yUKWF6nm4NwndCR/Ss60+zqa0osotfaaKAo9GEysxb8Em2nSQQd1O DKUkh0NRXRC3d2m2dUezQvjzKoXrGz+O731IUc8C6CiowaR8F4eMIZc= X-Google-Smtp-Source: AK7set87x2n6MbZarlnb+sKenenbFp4MvtvYeQ+byBEvW43PtBjfX+vM2x0FcTRM4RjL1uYH6i5aUFxwV2gRS9S3+K4= X-Received: by 2002:a17:90a:3f10:b0:22c:1179:3b8f with SMTP id l16-20020a17090a3f1000b0022c11793b8fmr1979290pjc.118.1675987442968; Thu, 09 Feb 2023 16:04:02 -0800 (PST) MIME-Version: 1.0 References: <20230209044058.2872534-1-marth64@proxyid.net> In-Reply-To: From: Marth64 Date: Thu, 9 Feb 2023 18:03:52 -0600 Message-ID: To: FFmpeg development discussions and patches X-Content-Filtered-By: Mailman/MimeDel 2.1.29 Subject: Re: [FFmpeg-devel] [PATCH] ffprobe/eac3/mlp/dca: add detection of spatial audio extensions 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: Hi, Thank you for your time and thoughts. Some of this I had wondered about the same. Re: Hendrik, Using profile > This was an original intention of mine but I changed course. I'm happy to do it, but felt too unsure for a first pass. My reasoning being that I'm not sure if the presence of extension metadata itself qualifies as a discrete profile. For DCA in particular, I was worried since DCA already expands to profiles (ES, XLL, etc.). I did not want to clutter those distinctions with a "somewhat profile of a profile, based on an educated guess without the reference docs" and break any existing integrations. Likewise, EAC3 and TrueHD didn't have profiles, so it felt tacked on for this case. So I settled with "extension" as the marker. That said, I wasn't too thrilled about adding to AVCodecContext either. I discovered and considered priv_data but then realized that this is a pattern across 3 codecs, maybe more in the future. So definitely open to guidance here. Profile is probably the next best bet. I had gone down the frame-level inspection road at some point, but came to a similar conclusion as you, it makes this less useful as a feature. I am open to other's interpretation. Will ponder this a little more. Re: Michael, show_bits_long > Will fix. I am trying to procure another IMAX DTS material to test the syncword better, so will push any of those changes together in the next 2 days. Thank you! On Thu, Feb 9, 2023 at 2:12 PM Hendrik Leppkes wrote: > On Thu, Feb 9, 2023 at 5:42 AM Marth64 wrote: > > > > Signed-off-by: Marth64 > > --- > > Adds detection of spatial/object-based audio extensions in E-AC-3, > > TrueHD, and DCA XLL (DTS). This includes Atmos, DTS:X, and IMAX formats. > > Please let me know what I could improve, I'm learning still. > > Thank you. > > > > The detection itself seems fine to me, however we should talk about > how the presence is communicated back to the user. > > A new flag in AVCodecContext goes against a variety of designs we try > to avoid - namely having codec-specific things in a global struct, as > well as having only one value, rather then per-frame values. > > So options that present themself to me: > (a) Use "profile". At least for DTS that would fit quite nicely, as it > already has profiles, and it seems like a logical extension. TrueHD > and eac3 do not have profiles, but it might still be sensible to put > it there. The advantage here is that it also automatically is conveyed > in AVCodecParameters after avformat opens a stream, so the information > is available early and lets players decide how to handle the stream. > (b) Use per-frame side data. The early-availability advantage is not > present here, so its not my favorite. side-data could be used in the > future to transport the actual object metadata, if needed. > > So from where I'm standing we should maybe define profiles to use for > these. In the past profiles were at least suggested for TrueHD Atmos > before, but there were some objections, so maybe a good time to > revisit and see where we go from here. > > - 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". > _______________________________________________ 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".