From patchwork Mon Mar 11 03:57:15 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Allan Cady X-Patchwork-Id: 46948 Delivered-To: ffmpegpatchwork2@gmail.com Received: by 2002:a05:6a20:dc95:b0:1a1:738b:6bc0 with SMTP id ky21csp1001353pzb; Sun, 10 Mar 2024 20:57:35 -0700 (PDT) X-Forwarded-Encrypted: i=2; AJvYcCWt+kA0J5M7deLLna9U2gUn+f+AyjHYbz88AlrPzCsa/m/hFrsqd7VvrZuW9E5BvuZqPCi/Wy+uQMiI9MVsLZYSlhtZflcNw7LCYQ== X-Google-Smtp-Source: AGHT+IGlgT0t2wG6cWCKTq6G0/rl86E+hkZIkQYmTxSD76e0lHpRJ0tQTIcdpqnBSkll3lDdlHpH X-Received: by 2002:a17:907:76f1:b0:a44:e5ed:3d5d with SMTP id kg17-20020a17090776f100b00a44e5ed3d5dmr4156041ejc.9.1710129455016; Sun, 10 Mar 2024 20:57:35 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1710129455; cv=none; d=google.com; s=arc-20160816; b=roGalVODdjimZ5DM0RTYn9jy2MNUbDlNpqDaF5fTDVdKPY/lYpMkzQracUBH9zDccv FZwjKvsDRAqgNEIcy99JFk+AZj2RWn3YCVLN4xrxMV81Fp0etD+AUVyXR/dn5WNn2C2K u0fw3z6IUMY+MtlKaCMmkAbVOikQYacy4KET9BrGqLFwSOCr/HVaRU+3Srb5C50p9cvQ QcxVy9FtbWyaRcZnXe9ev63CrCGLri97umCPZqDqabeApji7r3hUlqEARDpKd6K9Pvqd SCvJeIodNTjI7XemdhiVgRWIZSuC/cuOw8WLPvG5h2fce/ewRFlp0d1ipeuHXXsW1A3e XCEA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=sender:errors-to:content-transfer-encoding:cc:reply-to:from :list-subscribe:list-help:list-post:list-archive:list-unsubscribe :list-id:precedence:subject:mime-version:references:in-reply-to :message-id:date:to:delivered-to; bh=RtLwVuHRc9eZdfGi3mdg2xOg6cSn0PaK/++mAk7JRfo=; fh=S/YeFcuJTzNpwnQtYNnkaO46vjyvP+066YP8Vbwnj3k=; b=lJxvkv9fjnBXvi2VpVdLlBdImOmdWeJSI2VSvMPPhenonnOCskllK4Ng6NhKUYUkVj SICH+zV+VAfRfiZcpc9is1QFKYPiOBYz3Ii8IdtDEVZ8XX8c1djLZsIuqO0+VU7LceNv JACGHxYv7GUclg/YG71JvJoffo1MnNK1I/FOBUJ1Sxf6pCUuW+Uv6Xglenbbjuf/GdCp tRSRYX047w3/vKrC8L1wb/n5tpOV07hh/RG2AYRcx0PqmYjzyIHqjlCdw5zW+j0GSNX/ 8DHKS58MiE2z8br+5LgRxjGMAletiUnjtVl10ZUK2uq8rG9KDrJnUY7EUgIIxsEoXWbj ZjIw==; dara=google.com ARC-Authentication-Results: i=1; mx.google.com; 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 Return-Path: Received: from ffbox0-bg.mplayerhq.hu (ffbox0-bg.ffmpeg.org. [79.124.17.100]) by mx.google.com with ESMTP id ay20-20020a170906d29400b00a3fb3bf4752si2095754ejb.545.2024.03.10.20.57.34; Sun, 10 Mar 2024 20:57:34 -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; 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 E672468CF78; Mon, 11 Mar 2024 05:57:30 +0200 (EET) X-Original-To: ffmpeg-devel@ffmpeg.org Delivered-To: ffmpeg-devel@ffmpeg.org Received: from sonic307-3.consmr.mail.bf2.yahoo.com (sonic307-3.consmr.mail.bf2.yahoo.com [74.6.134.42]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id 9A3C268C75C for ; Mon, 11 Mar 2024 05:57:23 +0200 (EET) X-SONIC-DKIM-SIGN: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s2048; t=1710129440; bh=ToT2CDeOJ1dsy4P/B9shIVKruxXTnvJ6tfrO7Z8blko=; h=X-Sonic-MF:From:To:Subject:Date:From:Subject; b=ZnmggCwCSmLN5EKBq4pzK39DFQ0/CxqsYTbIL66QEin1UK3HIGsOLnovvHenqhKDd+iceFtX1s/j/SMP9hBSpZgOqwsOPB4vCwgmm83ymwrq8RaR13BwedNQTkmrTGWd3i+3eWl50bhlz8W/+YnwdkhzEG1BqdCwhw5BT3beY3hvZCzS4IkP4DPbxl0CP1eWm4s5/KOyQaR7+w1+EEhD5ugxwjSUuRZDKb7IG4UItJBRTKb9fGC64SRjhtTbMwRQGBGWxxKqcQdCToEW9p8BAn7AdhqGsUYOgLRP2A4XwSvq0dLHtjnibHmaO9l0d9AV6/y5xVqOTLuyFN1617xU1Q== X-YMail-OSG: qAXf2GgVM1mnb8Ai_cs.2eoFrw9I8_r4TNqY7wQ0FxW1aBp5wmAZ36sG4Ulc8E3 xqvfsoGWJpt7UbokZmDA1Is89gULKiPv3I.2c5xGGlFmbGDy7aqc0qtSpXQmLjJWMqqxOzqMS8St xCG8WOVKCeGjmwb5SOMkOITFgVEXhhtXsyt9GPlogsz2sLv.NZjOgt.KDom57kWEAq8vLPLQE6.. DTDWNaTnWY66kmh4bpdTnQXmZfkCYJZ4hg5YNeLHqxr_XAGdGEBZfan870lGn7GM0TB3fh49T_Gz erdB9_ZMIJt10JpV8ixpXbfh1eEn61mWui2L2J4FcUB59qD94VoLa6qRfBp9JnOslfQtjwgS4YkU uAPx9cIx7YfZvedsMOISo4gobQwgoBoW8dvWicOcDJAOzZk7xki3hznQVjOQm8L5kYPZY_9qyNbT e6FpO39h0eN451W6qgTCOEV8IUXU6eopqMqmmGfi.YZwv2l8w5ap0uReIoCWODXL2rDW_xb6_GvK G4FTpEIqAZyzaEHxr5OI4Ih2PfRAL5LdVVD8oRaWPe4PydznaHYNndEh6xuscBnlmbDvasrxedd2 nIMnsgEbHivX7VuOTle2b9nJpu5AZDI3obdGIiwGmUs.dKJ1tk0WgKXxgpuNRguc2pDCFTEMqI63 Fit.xsR4fBeJLrgCe3Nr62.yU1HZO3H5ySTEbqZLAWKbGZnKL1phUuzeGOGpxHUWzaOinSReaIB. 83r6xFppS2TXSXd0gwGBMF0KjZa3TCtVEHoBBncHhyKQjVeYXEpjZzTiDRJrQ_GDgBCIAXfHB77r Etd.c77vrP3gbzKraSvupWmECnThXPHQoTzF4rehX4TFQGFZ7q0v0uUGfo1Dlv1QzP4XmJWdv.Si ICePHH3qOMUmahkpHnO0cGMh6fi1Zc8KfgtZwiU1of05dcAYkIlb42eKkfnYFVV0WD6twPDFLkr1 cPW3vsi6iB1aOhJz0Qud2na3y.8XNbqTbyYwSJPBosYGLohQUkE2Ra0TIoRftPj.jf83leWUzDQB Hlw24lyjnkaJrfNqD2yxOPSv4birmI4lKfe6FxAhKz9Y_zdsWsZ1uSIPy69buHg8bKSpDhCXfzMd EIpQaUayrFu4Gp5LvIaoWe8Pq_ic.8za2jz1_nVvfdG6Hh0IZE91s84EdyoZ3v6wyOnQiSOJO_ai UN0Gf1WgC_BSa7ymSCEEO2oDiPFAIGso0cQ4tXmxJoulC6vc8ZJvxz46iwSP.n7f1cjwogK0zh8p H894dVr0J60v6Shcui9hOeqMQN2AwyieuMuumvx9bAXv4p542Sv138dFN6m.FbMJwcUrEdqKeYo6 prskK4vz1YPf7HX0c7FsbAB5NnPNyk17kvCG6Jvax1o8VszCn7Gql9hJk6kaHcQYiFvm_.8DsuGR 1pX5TgSohsXkeVbC98UqFnHRbyNxk09t6xNBRrmAafmgu5hXTihDotuYSNGOcVIy5uavwRhPDn9k dB.b_VcZD9XGXHZAquLQKkp8fDegWjEHZtuidugDEstNn2pYOGvMHzwEXTG1ll0OK6.r8oQfY.Sg sjSb_e7EvYyKzzkrODxn2NCGYuMHHXWQY2BplRlKqlFL_.SweUn2xJAWjxu0w7JFZH2i9JdBEgpr NsTWLOxrUvQgnY8dOHSRld8YOJWYewz8UhoQ.WbQ1DTMOHjoGoykiGdi0fOTVJa6xk2SHRsXfP5i 2U.WaE9TSVQITBwzremWuzVss2IUGhelY0tR8y7t5Rs1AJAnPKjHAaVD3wKgnig6jmCmNDfUvUMt qEg898y2e2o3KSGzLXtkzokcVDm6go.o5oHCqcyOxmSCucugn3dDP3rP747zHWS4tOi3xNy9decX 69pQJPAPEEAfk2kVJK9lHnkvgDZfgA2NjRdsjkPaWQab5.MaQAQ6IBs_MyAyqjLo684_4V2i6t6q dcW57SSdkzU6jy7UQDDfItSJUimcFFQn8bt.7696AWzVSx.n0J7p98v8JHHmY4UdfyMA2F4DyChS fqb7jTi7eoI6LfRYk0J8XkN5WWFirZvmB37Ry9xILgZSVTjN6HXxR.QAx8PuzlveegtZNQVI5DFt poYQ8mdqDwEsmIVz38kmtU89fI3qFECO9jSr6ZUccwRyf62ulhsR5xLxX3AOy3S1w.a8NGB9Ra4H eN3S3VtWE1lKL6TeITsSg1wKzM_gj5kQD1tl3QPlGqFK.emW.gVdnehc46jlkMCnfu8gXz.bIFFP 7oxpDXs5AJ1FUZI.CtIdbRYedDgAFRwceJo5l4YvU2Zprvw_QsefqTz3U X-Sonic-MF: X-Sonic-ID: 67f658d3-0a27-4a2f-883e-746b7e4423a7 Received: from sonic.gate.mail.ne1.yahoo.com by sonic307.consmr.mail.bf2.yahoo.com with HTTP; Mon, 11 Mar 2024 03:57:20 +0000 Received: by hermes--production-gq1-5c57879fdf-9nrfh (Yahoo Inc. Hermes SMTP Server) with ESMTPA ID 8c2d3a5142f52ab091710044a9cc6676; Mon, 11 Mar 2024 03:57:19 +0000 (UTC) To: ffmpeg-devel@ffmpeg.org Date: Sun, 10 Mar 2024 20:57:15 -0700 Message-Id: <20240311035715.3475488-1-allancady@yahoo.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: References: MIME-Version: 1.0 Subject: [FFmpeg-devel] [PATCH] libavutil/timestamp.h: Fix loss of precision in timestamps for silencedetect on long files 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: , X-Patchwork-Original-From: Allan Cady via ffmpeg-devel From: Allan Cady Reply-To: FFmpeg development discussions and patches Cc: Allan Cady Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" X-TUID: QpLwtwFnTZ14 When the silencedetect filter is run against long files, the output timestamps gradually lose precision as the scan proceeds further into the file. This is because the output is formatted (in libavutil/timestamp.h) as "%.6g", which limits the total field length. Eventually, for offsets greater than 100000 seconds (about 28 hours), fractions of a second disappear altogether, and the timestamps are logged as whole seconds. I propose changing the format to "%.6f", which will give microsecond precision for all timestamps, regardless of offset. Trailing zeros can be trimmed from the fraction, without losing precision. If the length of the fixed-precision formatted timestamp exceeds the length of the allocated buffer (AV_TS_MAX_STRING_SIZE, currently 32, less one for the terminating null), then we can fall back to scientific notation, though this seems almost certain to never occur, because 32 characters would allow a maximum timestamp value of (32 - 1 - 6 - 1) = 24 characters. By my calculation, 10^24 seconds is about six orders of magnitude greater than the age of the universe. The fix proposed here follows the following logic: 1) Try formatting the number of seconds using "%.6f". This will always result in a string with six decimal digits in the fraction, possibly including trailing zeros. (e.g. "897234.73200"). 2) Check if that string would overflow the buffer. If it would, then format it using scientific notation ("%.8g"). 3) If the original fixed-point format fits, then trim any trailing zeros and decimal point, and return that result. Making this change broke two fate tests, filter-metadata-scdet, and filter-metadata-silencedetect. To correct this, I've modified tests/ref/fate/filter-metadata-scdet and tests/ref/fate/filter-metadata-silencedetect to match the new output. Signed-off-by: Allan Cady --- libavutil/timestamp.h | 53 +++++++++++++++++++- tests/ref/fate/filter-metadata-scdet | 12 ++--- tests/ref/fate/filter-metadata-silencedetect | 2 +- 3 files changed, 58 insertions(+), 9 deletions(-) diff --git a/libavutil/timestamp.h b/libavutil/timestamp.h index 2b37781eba..2f04f9bb2b 100644 --- a/libavutil/timestamp.h +++ b/libavutil/timestamp.h @@ -25,6 +25,7 @@ #define AVUTIL_TIMESTAMP_H #include "avutil.h" +#include #if defined(__cplusplus) && !defined(__STDC_FORMAT_MACROS) && !defined(PRId64) #error missing -D__STDC_FORMAT_MACROS / #define __STDC_FORMAT_MACROS @@ -53,6 +54,32 @@ static inline char *av_ts_make_string(char *buf, int64_t ts) */ #define av_ts2str(ts) av_ts_make_string((char[AV_TS_MAX_STRING_SIZE]){0}, ts) +/** + * Strip trailing zeros and decimal point from a string. Performed + * in-place on input buffer. For local use only by av_ts_make_time_string. + * + * e.g.: + * "752.378000" -> "752.378" + * "4.0" -> "4" + * "97300" -> "97300" + */ +static inline void av_ts_strip_trailing_zeros_and_decimal_point(char *str) { + if (strchr(str, '.')) + { + int i; + for (i = strlen(str) - 1; i >= 0 && str[i] == '0'; i--) { + str[i] = '\0'; + } + + // Remove decimal point if it's the last character + if (i >= 0 && str[i] == '.') { + str[i] = '\0'; + } + + // String was modified in place; no need for return value. + } +} + /** * Fill the provided buffer with a string containing a timestamp time * representation. @@ -65,8 +92,30 @@ static inline char *av_ts_make_string(char *buf, int64_t ts) static inline char *av_ts_make_time_string(char *buf, int64_t ts, const AVRational *tb) { - if (ts == AV_NOPTS_VALUE) snprintf(buf, AV_TS_MAX_STRING_SIZE, "NOPTS"); - else snprintf(buf, AV_TS_MAX_STRING_SIZE, "%.6g", av_q2d(*tb) * ts); + if (ts == AV_NOPTS_VALUE) + { + snprintf(buf, AV_TS_MAX_STRING_SIZE, "NOPTS"); + } + else + { + const int max_fraction_digits = 6; + + // Convert 64-bit timestamp to double, using rational timebase + double seconds = av_q2d(*tb) * ts; + + int length = snprintf(NULL, 0, "%.*f", max_fraction_digits, seconds); + if (length <= AV_TS_MAX_STRING_SIZE - 1) + { + snprintf(buf, AV_TS_MAX_STRING_SIZE, "%.*f", max_fraction_digits, seconds); + av_ts_strip_trailing_zeros_and_decimal_point(buf); + } + else + { + snprintf(buf, AV_TS_MAX_STRING_SIZE, "%.8g", seconds); + } + + } + return buf; } diff --git a/tests/ref/fate/filter-metadata-scdet b/tests/ref/fate/filter-metadata-scdet index ca5dbaaefc..d385920fcd 100644 --- a/tests/ref/fate/filter-metadata-scdet +++ b/tests/ref/fate/filter-metadata-scdet @@ -1,11 +1,11 @@ pts=1620|tag:lavfi.scd.score=59.252|tag:lavfi.scd.mafd=60.175|tag:lavfi.scd.time=2.7 pts=4140|tag:lavfi.scd.score=36.070|tag:lavfi.scd.mafd=44.209|tag:lavfi.scd.time=6.9 -pts=5800|tag:lavfi.scd.score=55.819|tag:lavfi.scd.mafd=55.819|tag:lavfi.scd.time=9.66667 +pts=5800|tag:lavfi.scd.score=55.819|tag:lavfi.scd.mafd=55.819|tag:lavfi.scd.time=9.666667 pts=6720|tag:lavfi.scd.score=18.580|tag:lavfi.scd.mafd=22.505|tag:lavfi.scd.time=11.2 pts=8160|tag:lavfi.scd.score=49.240|tag:lavfi.scd.mafd=49.444|tag:lavfi.scd.time=13.6 -pts=9760|tag:lavfi.scd.score=51.497|tag:lavfi.scd.mafd=51.801|tag:lavfi.scd.time=16.2667 -pts=14080|tag:lavfi.scd.score=34.165|tag:lavfi.scd.mafd=34.337|tag:lavfi.scd.time=23.4667 -pts=15700|tag:lavfi.scd.score=58.310|tag:lavfi.scd.mafd=58.315|tag:lavfi.scd.time=26.1667 -pts=18500|tag:lavfi.scd.score=16.504|tag:lavfi.scd.mafd=19.603|tag:lavfi.scd.time=30.8333 +pts=9760|tag:lavfi.scd.score=51.497|tag:lavfi.scd.mafd=51.801|tag:lavfi.scd.time=16.266667 +pts=14080|tag:lavfi.scd.score=34.165|tag:lavfi.scd.mafd=34.337|tag:lavfi.scd.time=23.466667 +pts=15700|tag:lavfi.scd.score=58.310|tag:lavfi.scd.mafd=58.315|tag:lavfi.scd.time=26.166667 +pts=18500|tag:lavfi.scd.score=16.504|tag:lavfi.scd.mafd=19.603|tag:lavfi.scd.time=30.833333 pts=20040|tag:lavfi.scd.score=13.764|tag:lavfi.scd.mafd=19.060|tag:lavfi.scd.time=33.4 -pts=21760|tag:lavfi.scd.score=64.451|tag:lavfi.scd.mafd=64.551|tag:lavfi.scd.time=36.2667 +pts=21760|tag:lavfi.scd.score=64.451|tag:lavfi.scd.mafd=64.551|tag:lavfi.scd.time=36.266667 diff --git a/tests/ref/fate/filter-metadata-silencedetect b/tests/ref/fate/filter-metadata-silencedetect index bc53fea047..e66ffe5fdd 100644 --- a/tests/ref/fate/filter-metadata-silencedetect +++ b/tests/ref/fate/filter-metadata-silencedetect @@ -1,5 +1,5 @@ pts=0|tag:lavfi.silence_duration=0.523107|tag:lavfi.silence_end=0.690023|tag:lavfi.silence_start=0.736417 -pts=46080|tag:lavfi.silence_start=1.27626|tag:lavfi.silence_end=1.80751|tag:lavfi.silence_duration=0.531247 +pts=46080|tag:lavfi.silence_start=1.276259|tag:lavfi.silence_end=1.807506|tag:lavfi.silence_duration=0.531247 pts=92160 pts=138240 pts=184320