From patchwork Fri Jan 13 13:48:49 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ricardo Ribalda X-Patchwork-Id: 642366 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A901CC678D4 for ; Fri, 13 Jan 2023 13:52:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241859AbjAMNws (ORCPT ); Fri, 13 Jan 2023 08:52:48 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51044 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241482AbjAMNwU (ORCPT ); Fri, 13 Jan 2023 08:52:20 -0500 Received: from mail-ej1-x62f.google.com (mail-ej1-x62f.google.com [IPv6:2a00:1450:4864:20::62f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 156F668C84 for ; Fri, 13 Jan 2023 05:49:07 -0800 (PST) Received: by mail-ej1-x62f.google.com with SMTP id vm8so52445668ejc.2 for ; Fri, 13 Jan 2023 05:49:07 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=cc:to:in-reply-to:references:message-id:content-transfer-encoding :mime-version:subject:date:from:from:to:cc:subject:date:message-id :reply-to; bh=BIYSq+SG4WtbilzNOWYagt4DvEBoOwZmBVCbkxWrmdg=; b=Psf7tBaJ4kUzf0xvoPiWTIUp/xnmYxZevQ6ZlF2RYXkljmHGkAyZ+3rU/Ykwng7MeL GFT4jRKvJT/LUY5LDmcTukJ5b68E0ywQG+6EQDR6J4Rw9zbm2ROUc7by6meEkx+aOmTE /q17Fpsz/BPRntTDr6/imThxAf80cbNjjx+hs= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:in-reply-to:references:message-id:content-transfer-encoding :mime-version:subject:date:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=BIYSq+SG4WtbilzNOWYagt4DvEBoOwZmBVCbkxWrmdg=; b=LOPpLU1Xo3KKgX/anzBH8eMbXCkpRdFuFHcGSTxPaCsNjlDvrI9X2ffkyVnllkBKvi JmLGmmolBscTabxktBiHmKcTLeyvG6hqeaf7eiNTo0UQArXjNWFwFd8tLYkk7UO3Qf4O IcwCzzcUdsHU9FcIdUcWivTFiRz44wUg6yzhrt6OnhbbzvGjRcqxUNVSghSZUulahpQs 9PdqpbHkWrGgARR40fz5BFG4DZuG0clFWIIFx8UtdTf4+Eu3DZAoeHLKmfPnqvkakLX8 tmjZYypxqx/NG+vXUbD5bJoBnnJw10OviDK6scGVmakHv+NKkxF9S58N1koqwZK/PshU iiLA== X-Gm-Message-State: AFqh2krFY5FKdY6rqk+KRNJ25O9cKoPN80vZ1E7EAljZa0DNapZsaUpE pD4xVBgwesswdzsuN+reMFzcSg== X-Google-Smtp-Source: AMrXdXvVSF0aOYTYEszDFBVHm+AelHcJuzDS6lm5uyEPGb3LPwSyG+qOfiy2Gr75vPbH5JS4td16ZQ== X-Received: by 2002:a17:907:8b1a:b0:84d:34a4:46fd with SMTP id sz26-20020a1709078b1a00b0084d34a446fdmr3495226ejc.71.1673617745694; Fri, 13 Jan 2023 05:49:05 -0800 (PST) Received: from alco.roam.corp.google.com ([2620:0:1059:10:b023:4272:bddc:acf2]) by smtp.gmail.com with ESMTPSA id w23-20020a1709062f9700b0084d3bf44996sm7072888eji.142.2023.01.13.05.49.04 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 13 Jan 2023 05:49:05 -0800 (PST) From: Ricardo Ribalda Date: Fri, 13 Jan 2023 14:48:49 +0100 Subject: [PATCH v5 3/5] media: uvcvideo: Allow hw clock updates with buffers not full MIME-Version: 1.0 Message-Id: <20220920-resend-hwtimestamp-v5-3-660679c6e148@chromium.org> References: <20220920-resend-hwtimestamp-v5-0-660679c6e148@chromium.org> In-Reply-To: <20220920-resend-hwtimestamp-v5-0-660679c6e148@chromium.org> To: Mauro Carvalho Chehab , Laurent Pinchart Cc: "hn.chen" , linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, Ricardo Ribalda X-Mailer: b4 0.11.0-dev-696ae X-Developer-Signature: v=1; a=openpgp-sha256; l=1843; i=ribalda@chromium.org; h=from:subject:message-id; bh=ze5myykY7IWxFl+shu/B7fsc0sNffBzVSl+RqFnttm0=; b=owEBbQKS/ZANAwAKAdE30T7POsSIAcsmYgBjwWFJsRwW22gkHsLnSkRocTuSoJA32f8kqplaGddG N4YwKziJAjMEAAEKAB0WIQREDzjr+/4oCDLSsx7RN9E+zzrEiAUCY8FhSQAKCRDRN9E+zzrEiN9VD/ 0XTWp1wD61yuxVx7AJoIHnpjTRZO9X/JAVF2G2p0qj14/oeLVkL9YnLryvrkdYmxnPAIzJUtkroCiN X/eegUJgccziHt2GXqQVm7oBEcOehw2R5WKkoUT5WY7cXOv5rqfedIya76MxqGcpAQfa4KVkX4eBQm QqUvRqBKcBqKryviL9KXUA1zKfRx6PaMMIV/5/OXU2pztfzXjlFIKlntYu08rLeKVR/8upJlEdN0+1 XrfjPHP/PKM2qCY5bTV2siH7/y/QJJ68VFxFLkylkRWjIwgIZP3k0BAYiiTAStlQAz5Lqu7ia/Xg6p g+tc0xduyHVY1fOTWTf2TYdeaaPiBVFdP0R1m+8ubQ+23SNo56/0TEqywOgDkrgT6cIoZWE4XKyI/Y 0cEkwuMnBbL7rGmTi4HMFsNKapWZrtBZW2YRe9MhUNQEtl0UFt3SpQiCimuu1ECSX3N3hQkofgop8B DqOKbGlbhdoyeNgk/HSx1AX6/4Zn7NHUC4YYoFYw235Xr5NCItFs7aUESZl5U3r8nMPsubCpsWHjCV rZRpLurXrSJISxwTCX7OH32f45YY4ImJQWhKJlAQEBsBugv7ClLGfvi9nQybHr+VNTMZmJVUK5w4HO 1MZIksNsbbQ7l+iYvFa4z2exrsAbDlPWclFqxV0GCwCZI9ysjawGZrsZ3k9w== X-Developer-Key: i=ribalda@chromium.org; a=openpgp; fpr=9EC3BB66E2FC129A6F90B39556A0D81F9F782DA9 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org With UVC 1.5 we get as little as one clock sample per frame. Which means that it takes 32 frames to move from the software timestamp to the hardware timestamp method. This results in abrupt changes in the timestamping after 32 frames (~1 second), resulting in noticeable artifacts when used for encoding. With this patch we modify the update algorithm to work with whatever amount of values are available. Tested-by: HungNien Chen Signed-off-by: Ricardo Ribalda --- drivers/media/usb/uvc/uvc_video.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c index f4470f6df45c..21985598ff5b 100644 --- a/drivers/media/usb/uvc/uvc_video.c +++ b/drivers/media/usb/uvc/uvc_video.c @@ -747,10 +747,10 @@ void uvc_video_clock_update(struct uvc_streaming *stream, spin_lock_irqsave(&clock->lock, flags); - if (clock->count < clock->size) + if (clock->count < 2) goto done; - first = &clock->samples[clock->head]; + first = &clock->samples[(clock->head - clock->count) % clock->size]; last = &clock->samples[(clock->head - 1) % clock->size]; /* First step, PTS to SOF conversion. */ @@ -765,6 +765,15 @@ void uvc_video_clock_update(struct uvc_streaming *stream, if (y2 < y1) y2 += 2048 << 16; + /* + * Have at least 1/4 of a second of timestamps before we + * try to do any calculation. Otherwise we do not have enough + * precision. This value was determined by running Android CTS + * on different devices. + */ + if ((y2 - y1) < (256 << 16)) + goto done; + y = (u64)(y2 - y1) * (1ULL << 31) + (u64)y1 * (u64)x2 - (u64)y2 * (u64)x1; y = div_u64(y, x2 - x1);