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 AD58047900 for ; Tue, 26 Dec 2023 22:30:59 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 035EF68CD0C; Wed, 27 Dec 2023 00:30:57 +0200 (EET) Received: from relay8-d.mail.gandi.net (relay8-d.mail.gandi.net [217.70.183.201]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id 14AA168CA49 for ; Wed, 27 Dec 2023 00:30:51 +0200 (EET) Received: by mail.gandi.net (Postfix) with ESMTPSA id 59F311BF206 for ; Tue, 26 Dec 2023 22:30:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=niedermayer.cc; s=gm1; t=1703629850; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=jqdlwn0ghgxj5hfHysejOso/qo1OBiNoBoKdJ+1w6Rk=; b=ScLO3t7exxsCfZP+Sk/aXR30mcqgnhchzWGdB+ngr3KP9Ak4PrreXg2X4uLDHqfvITtbdk gYfkkiXNaMKD68j88+LDnKK7TgjV7tm2taF2O+GAGwxjYNjF+KuYViZ+R1RGUx6U6a5a0J lu/cgY+mrSuDrYE+tjL4sOO5XW8iyxZ1kT40bIGh13bpBLxLs6jv7nFGhQ/gHsTI9zLE6M c5LPiKQVpBcvg8Hqd2uRMQoEXrhlU9ouLNEMW5PoB61cLIdKfmcVtJv2wpPY1B531cpQTb g9DXmQDJvFKco1QekqP03qK+Nu44/G/E6Xdo1Gm9ohLBIBnD90ugAZ7nDSSxRQ== Date: Tue, 26 Dec 2023 23:30:49 +0100 From: Michael Niedermayer To: FFmpeg development discussions and patches Message-ID: <20231226223049.GU6420@pb2> References: MIME-Version: 1.0 In-Reply-To: X-GND-Sasl: michael@niedermayer.cc Subject: Re: [FFmpeg-devel] [PATCH 3/6] Add CRYO APC muxer 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="===============1940004431572163355==" Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Archived-At: List-Archive: List-Post: --===============1940004431572163355== Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="95xjieIIiUQImiTX" Content-Disposition: inline --95xjieIIiUQImiTX Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi On Tue, Dec 26, 2023 at 04:52:47PM +0100, Tomas H=E4rdin wrote: >=20 [...] > + > +static int apc_write_header(AVFormatContext *s) > +{ > + AVIOContext *pb =3D s->pb; > + AVCodecParameters *par; > + AVStream *st; > + > + if (s->nb_streams !=3D 1) { > + av_log(s, AV_LOG_ERROR, "Must have exactly one stream\n"); > + return AVERROR(EINVAL); > + } > + > + st =3D s->streams[0]; > + par =3D st->codecpar; > + > + if (par->ch_layout.nb_channels <=3D 0 || par->ch_layout.nb_channels = > 2) { > + av_log(s, AV_LOG_ERROR, "Must be mono or stereo\n"); > + return AVERROR(EINVAL); > + } > + > + if (par->extradata_size !=3D 0 && par->extradata_size !=3D 8) { > + av_log(s, AV_LOG_ERROR, > + "Must have exactly 0 or 8 bytes of extradata, got %i\n", > + par->extradata_size); > + return AVERROR(EINVAL); > + } > + > + ffio_wfourcc(pb, "CRYO"); > + ffio_wfourcc(pb, "_APC"); > + ffio_wfourcc(pb, "1.20"); > + avio_wl32(pb, 0); // number or samples please add to the comment "updated in apc_write_trailer()" > + avio_wl32(pb, par->sample_rate); > + > + // write extradata if we have it (remuxing) > + // else write dummy values and wait for AV_PKT_DATA_NEW_EXTRADATA (e= ncoding) > + if (par->extradata_size) { > + avio_write(pb, par->extradata, par->extradata_size); > + } else { > + avio_wl64(pb, 0); > + } > + > + avio_wl32(pb, par->ch_layout.nb_channels - 1); > + avpriv_set_pts_info(st, 64, 1, par->sample_rate); > + return 0; > +} > + > +static int apc_write_packet(AVFormatContext *s, AVPacket *pkt) > +{ > + size_t extradata_size =3D 0; > + const uint8_t *extradata =3D av_packet_get_side_data( > + pkt, AV_PKT_DATA_NEW_EXTRADATA, &extradata_size); > + > + if (extradata_size =3D=3D 8) { > + // we got predictors from encoder > + // try to seek back end write them > + int64_t pos =3D avio_tell(s->pb), err; > + if ((err =3D avio_seek(s->pb, 20, SEEK_SET)) >=3D 0) { > + avio_write(s->pb, extradata, extradata_size); > + avio_seek(s->pb, pos, SEEK_SET); > + } else { > + av_log(s, AV_LOG_ERROR, "Got predictors from encoder but cou= ldn't seek back to write them\n"); > + // fail since we should always be able to do this within the= avio cache > + // unless the encoder gave us predictors way too late for so= me reason > + return err; > + } > + } I think the encoder should buffer data or use 2 passes if it needs future data. seeking back in the muxer is a bit odd. if it becomes available always in teh first packet then maybe the whole header could be written in the first packet I would suggest, you add APC support to nut. Thats a good test to ensure the packet and extradata is set at the right ti= me for a generic muxer > + > + avio_write(s->pb, pkt->data, pkt->size); > + return 0; > +} > + > +static int apc_write_trailer(AVFormatContext *s) > +{ > + int64_t file_size =3D avio_tell(s->pb); > + > + // write length, if we're able to seek back > + if (avio_seek(s->pb, 12, SEEK_SET) >=3D 0) { > + if (file_size - APC_HEADER_SIZE > > + UINT32_MAX * s->streams[0]->codecpar->ch_layout.nb_chann= els / 2) { > + av_log(s, AV_LOG_ERROR, "File too large\n"); > + return AVERROR(EINVAL); > + } > + > + avio_wl32(s->pb, (file_size - APC_HEADER_SIZE) * > + 2 / s->streams[0]->codecpar->ch_layout.nb_ch= annels); I think something like this is slightly cleaner: int64_t number_of_samples =3D (file_size - APC_HEADER_SIZE) * 2 / s->streams[0]->codecpar->ch_layout.nb_chann= els; if (number_of_samples > UINT32_MAX) ... [...] thx -- Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB Avoid a single point of failure, be that a person or equipment. --95xjieIIiUQImiTX Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iF0EABEIAB0WIQSf8hKLFH72cwut8TNhHseHBAsPqwUCZYtUEgAKCRBhHseHBAsP q44/AKCVZQ4yWuk/8q9Al109ndDFtGdk0ACfUEP2XHwfKuvNyRsPoOgk/APMB6M= =jnY3 -----END PGP SIGNATURE----- --95xjieIIiUQImiTX-- --===============1940004431572163355== 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". --===============1940004431572163355==--