From patchwork Tue Dec 28 16:43:47 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gyan Doshi X-Patchwork-Id: 32935 Delivered-To: ffmpegpatchwork2@gmail.com Received: by 2002:a6b:cd86:0:0:0:0:0 with SMTP id d128csp11348244iog; Tue, 28 Dec 2021 08:44:24 -0800 (PST) X-Google-Smtp-Source: ABdhPJzgqB93DUkTFIWqOF+s03mj4eUd+fFjXb7EfPUjky4fMnmxI6mrldq1galluqiKd1n4i/uQ X-Received: by 2002:a17:906:ca44:: with SMTP id jx4mr18066007ejb.135.1640709864240; Tue, 28 Dec 2021 08:44:24 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1640709864; cv=none; d=google.com; s=arc-20160816; b=aK0vGrheiyC9m7zpyBeTnCSnkodcg72hTGDWHY/8uvpMhpjvJXinPqnPvpOPDnv6+9 3oJe6BpijHydB1WnjD5DRKWbJwbLAkOp2+itGEz/dkpZbTQFYTJ1F69qnkwiPPUaW0oZ 0CvRwtUc1sYDMfawgmfQfP/GJYm1DbsMrJyYJ1ZmjZAcaxWHK/DFIMrY4zz3LMFWAbtQ Yb/Ag86nLmwwXJPaJ3m+bkKlMYHV1OSTesFN9Lympd59V7zCb3MOZXvBLGm8Vh9E7N3a X6ZMQusTdl+WLfOyfmqFFgxh0YgN+gr4vFcEXUEr0QMYV1dUclTL4og5n2E9DvEgYcHz T1nA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=sender:errors-to:content-transfer-encoding:reply-to:list-subscribe :list-help:list-post:list-archive:list-unsubscribe:list-id :precedence:subject:mime-version:message-id:date:to:from :delivered-to; bh=BJ+TlCZApvPzdYQ7j2qeAMnB9XnKcJfXQEhwnMxMCKU=; b=aY8O8T/bBpmdYUWYFpLkjc12/D4ZUQdCXUTgzZbSQHm47P1TFvYpXf1XfddXvT429D IHq9hLFdbGBYOmHpML+MH7K+Gr3oVcq80LF5vLA96FfPe0kGK7Sk3lldMu7L33vMgrhp Y3+0THcXw3idaDKMNy42h2dbuXza+U4N2WROZYr0l2RXfJkZ7Bim9gg24GWW+MJUC2zr qSeFpuIa5cc4Op31+T8IhjHSNHQdn1Pjk2JLxF/Hpsw4JV70QuQyUjocsHObgx0G4FSx HKpV2d72PHfdS3hHlURN/sWxLqcPuvTb5ViGTnTSrDiqjcmRm4Q+qp/BTzXXuqBgPJVI qykw== 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 c18si7853505ejj.325.2021.12.28.08.44.23; Tue, 28 Dec 2021 08:44:24 -0800 (PST) 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 DB71C68AE56; Tue, 28 Dec 2021 18:44:21 +0200 (EET) X-Original-To: ffmpeg-devel@ffmpeg.org Delivered-To: ffmpeg-devel@ffmpeg.org Received: from mout-p-101.mailbox.org (mout-p-101.mailbox.org [80.241.56.151]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id 15CEC68AE3E for ; Tue, 28 Dec 2021 18:44:15 +0200 (EET) Received: from smtp202.mailbox.org (smtp202.mailbox.org [80.241.60.245]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-384) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mout-p-101.mailbox.org (Postfix) with ESMTPS id 4JNgNZ4x86zQlMZ for ; Tue, 28 Dec 2021 17:44:14 +0100 (CET) X-Virus-Scanned: amavisd-new at heinlein-support.de From: Gyan Doshi To: ffmpeg-devel@ffmpeg.org Date: Tue, 28 Dec 2021 22:13:47 +0530 Message-Id: <20211228164347.632-1-ffmpeg@gyani.pro> MIME-Version: 1.0 Subject: [FFmpeg-devel] [PATCH v2] avformat/mov: adjust 0 values in stts 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 Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" X-TUID: EJi99Zjn9MuF As per ISO 14496-12, sample duration of 0 is invalid except for the last entry. However, some files may use it to stall dts progress in order to recover from a desync. In addition, catch and fix 0 value for sample count. --- v2: adjust dts if 0 duration is encountered libavformat/mov.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/libavformat/mov.c b/libavformat/mov.c index 351ecde770..7e90e24bd5 100644 --- a/libavformat/mov.c +++ b/libavformat/mov.c @@ -2970,16 +2970,22 @@ static int mov_read_stts(MOVContext *c, AVIOContext *pb, MOVAtom atom) av_log(c->fc, AV_LOG_TRACE, "sample_count=%u, sample_duration=%u\n", sample_count, sample_duration); + if (!sample_count) { + av_log(c->fc, AV_LOG_WARNING, "invalid sample count of 0 in stts for st %d at entry %u; changing to 1.\n", + c->fc->nb_streams-1, i); + sc->stts_data[i].count = sample_count = 1; + } + /* STTS sample offsets are uint32 but some files store it as int32 * with negative values used to correct DTS delays. There may be abnormally large values as well. */ - if (sample_duration > c->max_stts_delta) { + if (sample_duration > c->max_stts_delta || !sample_duration) { // assume high delta is a correction if negative when cast as int32 int32_t delta_magnitude = (int32_t)sample_duration; - av_log(c->fc, AV_LOG_WARNING, "Too large sample offset %u in stts entry %u with count %u in st:%d. Clipping to 1.\n", + av_log(c->fc, AV_LOG_WARNING, "Too large or zero sample offset %u in stts entry %u with count %u in st:%d. Setting to 1.\n", sample_duration, i, sample_count, st->index); sc->stts_data[i].duration = 1; - corrected_dts += (delta_magnitude < 0 ? (int64_t)delta_magnitude : 1) * sample_count; + corrected_dts += (delta_magnitude <= 0 ? (int64_t)delta_magnitude : 1) * sample_count; } else { corrected_dts += sample_duration * sample_count; } @@ -2987,7 +2993,7 @@ static int mov_read_stts(MOVContext *c, AVIOContext *pb, MOVAtom atom) current_dts += sc->stts_data[i].duration * sample_count; if (current_dts > corrected_dts) { - int64_t drift = (current_dts - corrected_dts)/FFMAX(sample_count, 1); + int64_t drift = (current_dts - corrected_dts)/sample_count; uint32_t correction = (sc->stts_data[i].duration > drift) ? drift : sc->stts_data[i].duration - 1; current_dts -= correction * sample_count; sc->stts_data[i].duration -= correction;