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 4E1B940AC4 for ; Sun, 26 Dec 2021 23:51:28 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 854B468B07F; Mon, 27 Dec 2021 01:51:26 +0200 (EET) Received: from relay9-d.mail.gandi.net (relay9-d.mail.gandi.net [217.70.183.199]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id EA5B768B037 for ; Mon, 27 Dec 2021 01:51:19 +0200 (EET) Received: from localhost (213-47-68-29.cable.dynamic.surfer.at [213.47.68.29]) (Authenticated sender: michael@niedermayer.cc) by relay9-d.mail.gandi.net (Postfix) with ESMTPSA id AA2BDFF805 for ; Sun, 26 Dec 2021 23:51:18 +0000 (UTC) Date: Mon, 27 Dec 2021 00:51:17 +0100 From: Michael Niedermayer To: FFmpeg development discussions and patches Message-ID: <20211226235117.GV2829255@pb2> References: <20211226160044.5913-1-ffmpeg@gyani.pro> MIME-Version: 1.0 In-Reply-To: <20211226160044.5913-1-ffmpeg@gyani.pro> Subject: Re: [FFmpeg-devel] [PATCH v3] avformat/mov: add option max_stts_delta 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: multipart/mixed; boundary="===============7425526161696234393==" Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Archived-At: List-Archive: List-Post: --===============7425526161696234393== Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="X6jspQRIhCX2/PVj" Content-Disposition: inline --X6jspQRIhCX2/PVj Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sun, Dec 26, 2021 at 09:30:44PM +0530, Gyan Doshi wrote: > Very high stts sample deltas may occasionally be intended but usually > they are written in error or used to store a negative value for dts corre= ction > when treated as signed 32-bit integers. >=20 > This option lets the user set an upper limit, beyond which the delta is c= lamped to 1. > Values greater than the limit if negative when cast to int32 are used to = adjust onward dts. >=20 > Unit is the track time scale. Default is UINT_MAX - 48000*10 which > allows upto a 10 second dts correction for 48 kHz audio streams while > accommodating 99.9% of uint32 range. > --- > v3 changes: >=20 > factored out loop > simplified correction logic this looks more sane now i guess this cannot be easily split into a seperate patch ? [...] > @@ -2965,11 +2967,34 @@ static int mov_read_stts(MOVContext *c, AVIOConte= xt *pb, MOVAtom atom) > sc->stts_data[i].count=3D sample_count; > sc->stts_data[i].duration=3D sample_duration; > =20 > - av_log(c->fc, AV_LOG_TRACE, "sample_count=3D%d, sample_duration= =3D%d\n", > + av_log(c->fc, AV_LOG_TRACE, "sample_count=3D%u, sample_duration= =3D%u\n", > sample_count, sample_duration); > =20 > - duration+=3D(int64_t)sample_duration*(uint64_t)sample_count; > - total_sample_count+=3Dsample_count; > + /* STTS sample offsets are uint32 but some files store it as int= 32 > + * with negative values used to correct DTS delays. > + There may be abnormally large values as well. */ > + if (sample_duration > c->max_stts_delta) { > + // assume high delta is a correction if negative when cast a= s int32 > + int32_t delta_magnitude =3D (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", > + sample_duration, i, sample_count, st->index); > + sc->stts_data[i].duration =3D 1; > + corrected_dts +=3D (delta_magnitude < 0 ? (int64_t)delta_mag= nitude : 1) * sample_count; > + } else { > + corrected_dts +=3D sample_duration * sample_count; > + } > + > + current_dts +=3D sc->stts_data[i].duration * sample_count; > + > + if (current_dts > corrected_dts) { > + int64_t drift =3D (current_dts - corrected_dts)/sample_count; division by 0 thx [...] --=20 Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB It is a danger to trust the dream we wish for rather than the science we have, -- Dr. Kenneth Brown --X6jspQRIhCX2/PVj Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iF0EABEIAB0WIQSf8hKLFH72cwut8TNhHseHBAsPqwUCYcj/7gAKCRBhHseHBAsP q+NCAJ9Zuc84Yxaly6hhWAEH91/tUZY21wCeIQJ1CrNsdTYo4APUlckM4FjwHJs= =Ox+f -----END PGP SIGNATURE----- --X6jspQRIhCX2/PVj-- --===============7425526161696234393== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ 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". --===============7425526161696234393==--