In a previous patch, I modified the duration of the packet. But since, we now support seeking, I don't know how to obtain the pts of the packet (or sample position since start), without an implementation of a `read_seek()` function. Can you help me on how I can derive the pts of the packet? Thanks.
On Thu, Apr 4, 2024, 9:30 AM Andreas Rheinhardt < andreas.rheinha...@outlook.com> wrote: > Antoine Soulier via ffmpeg-devel: > > A file format is described in Bluetooth SIG LC3 and ETSI TS 103 634, for > > test purpose. This is the format implemented here. > > > > Signed-off-by: Antoine Soulier <asoul...@google.com> > > --- > > Changelog | 1 + > > doc/muxers.texi | 6 ++ > > libavformat/Makefile | 2 + > > libavformat/allformats.c | 2 + > > libavformat/lc3dec.c | 127 +++++++++++++++++++++++++++++++++++++++ > > libavformat/lc3enc.c | 100 ++++++++++++++++++++++++++++++ > > 6 files changed, 238 insertions(+) > > create mode 100644 libavformat/lc3dec.c > > create mode 100644 libavformat/lc3enc.c > > > > diff --git a/Changelog b/Changelog > > index 83a4cf7888..08c200a41d 100644 > > --- a/Changelog > > +++ b/Changelog > > @@ -2,6 +2,7 @@ Entries are sorted chronologically from oldest to > youngest within each release, > > releases are sorted from youngest to oldest. > > > > version <next>: > > +- LC3/LC3plus demuxer and muxer > > - LC3/LC3plus decoding/encoding using external library liblc3 > > > > > > diff --git a/doc/muxers.texi b/doc/muxers.texi > > index a10a8e216f..9687746c30 100644 > > --- a/doc/muxers.texi > > +++ b/doc/muxers.texi > > @@ -2612,6 +2612,12 @@ WebDAV server every second: > > ffmpeg -f x11grab -framerate 1 -i :0.0 -q:v 6 -update 1 -protocol_opts > method=PUT http://example.com/desktop.jpg > > @end example > > > > +@section lc3 > > +Bluetooth SIG Low Complexity Communication Codec audio (LC3), or > > +ETSI TS 103 634 Low Complexity Communication Codec plus (LC3plus). > > + > > +This muxer accepts a single @code{lc3} audio stream. > > + > > @section matroska > > > > Matroska container muxer. > > diff --git a/libavformat/Makefile b/libavformat/Makefile > > index 44aa485029..4961c42852 100644 > > --- a/libavformat/Makefile > > +++ b/libavformat/Makefile > > @@ -332,6 +332,8 @@ OBJS-$(CONFIG_KVAG_DEMUXER) += kvag.o > > OBJS-$(CONFIG_KVAG_MUXER) += kvag.o rawenc.o > > OBJS-$(CONFIG_LAF_DEMUXER) += lafdec.o > > OBJS-$(CONFIG_LATM_MUXER) += latmenc.o rawenc.o > > +OBJS-$(CONFIG_LC3_DEMUXER) += lc3dec.o > > +OBJS-$(CONFIG_LC3_MUXER) += lc3enc.o > > OBJS-$(CONFIG_LMLM4_DEMUXER) += lmlm4.o > > OBJS-$(CONFIG_LOAS_DEMUXER) += loasdec.o rawdec.o > > OBJS-$(CONFIG_LUODAT_DEMUXER) += luodatdec.o > > diff --git a/libavformat/allformats.c b/libavformat/allformats.c > > index 9df42bb87a..0b36a7c3eb 100644 > > --- a/libavformat/allformats.c > > +++ b/libavformat/allformats.c > > @@ -252,6 +252,8 @@ extern const FFInputFormat ff_kvag_demuxer; > > extern const FFOutputFormat ff_kvag_muxer; > > extern const FFInputFormat ff_laf_demuxer; > > extern const FFOutputFormat ff_latm_muxer; > > +extern const FFInputFormat ff_lc3_demuxer; > > +extern const FFOutputFormat ff_lc3_muxer; > > extern const FFInputFormat ff_lmlm4_demuxer; > > extern const FFInputFormat ff_loas_demuxer; > > extern const FFInputFormat ff_luodat_demuxer; > > diff --git a/libavformat/lc3dec.c b/libavformat/lc3dec.c > > new file mode 100644 > > index 0000000000..7232e9847e > > --- /dev/null > > +++ b/libavformat/lc3dec.c > > @@ -0,0 +1,127 @@ > > +/* > > + * LC3 demuxer > > + * Copyright (C) 2024 Antoine Soulier <asoul...@google.com> > > + * > > + * This file is part of FFmpeg. > > + * > > + * FFmpeg is free software; you can redistribute it and/or > > + * modify it under the terms of the GNU Lesser General Public > > + * License as published by the Free Software Foundation; either > > + * version 2.1 of the License, or (at your option) any later version. > > + * > > + * FFmpeg is distributed in the hope that it will be useful, > > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > > + * Lesser General Public License for more details. > > + * > > + * You should have received a copy of the GNU Lesser General Public > > + * License along with FFmpeg; if not, write to the Free Software > > + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA > 02110-1301 USA > > + */ > > + > > +/** > > + * @file > > + * Based on the file format specified by : > > + * > > + * - Bluetooth SIG - Low Complexity Communication Codec Test Suite > > + * > https://www.bluetooth.org/docman/handlers/downloaddoc.ashx?doc_id=502301 > > + * 3.2.8.2 Reference LC3 Codec Bitstream Format > > + * > > + * - ETSI TI 103 634 V1.4.1 - Low Complexity Communication Codec plus > > + * > https://www.etsi.org/deliver/etsi_ts/103600_103699/103634/01.04.01_60/ts_103634v010401p.pdf > > + * LC3plus conformance script package > > + */ > > + > > +#include "libavcodec/packet.h" > > +#include "libavutil/intreadwrite.h" > > + > > +#include "avformat.h" > > +#include "avio.h" > > +#include "demux.h" > > +#include "internal.h" > > + > > +typedef struct LC3DemuxContext { > > + int frame_samples; > > +} LC3DemuxContext; > > + > > +static int lc3_read_header(AVFormatContext *s) > > +{ > > + LC3DemuxContext *lc3 = s->priv_data; > > + AVStream *st = NULL; > > + uint16_t tag, hdr_size; > > + uint16_t frame_10us; > > + uint32_t length; > > + int ep_mode, hr_mode; > > + int srate_hz, channels, bit_rate; > > + int num_extra_params, ret; > > + > > + tag = avio_rb16(s->pb); > > + hdr_size = avio_rl16(s->pb); > > + > > + if (tag != 0x1ccc || hdr_size < 9 * sizeof(uint16_t)) > > + return AVERROR_INVALIDDATA; > > + > > + num_extra_params = hdr_size / sizeof(uint16_t) - 9; > > + > > + srate_hz = avio_rl16(s->pb) * 100; > > + bit_rate = avio_rl16(s->pb) * 100; > > + channels = avio_rl16(s->pb); > > + frame_10us = avio_rl16(s->pb); > > + ep_mode = avio_rl16(s->pb) != 0; > > + length = avio_rl32(s->pb); > > + hr_mode = num_extra_params >= 1 && avio_rl16(s->pb); > > + > > + st = avformat_new_stream(s, NULL); > > + if (!st) > > + return AVERROR(ENOMEM); > > + > > + avpriv_set_pts_info(st, 64, 1, srate_hz); > > + st->duration = length; > > + > > + st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO; > > + st->codecpar->codec_id = AV_CODEC_ID_LC3; > > + st->codecpar->sample_rate = srate_hz; > > + st->codecpar->bit_rate = bit_rate; > > + st->codecpar->ch_layout.nb_channels = channels; > > + > > + if ((ret = ff_alloc_extradata(st->codecpar, 10)) < 0) { > > + av_log(s, AV_LOG_ERROR, "Could not allocate extradata.\n"); > > Still pointless error message. > > > + return ret; > > + } > > + > > + AV_WL16(st->codecpar->extradata + 0, frame_10us); > > + AV_WL16(st->codecpar->extradata + 2, ep_mode); > > + AV_WL16(st->codecpar->extradata + 4, hr_mode); > > + AV_WL32(st->codecpar->extradata + 6, length); > > + > > + lc3->frame_samples = av_rescale(frame_10us, srate_hz, 100*1000); > > + > > + return 0; > > +} > > + > > +static int lc3_read_packet(AVFormatContext *s, AVPacket *pkt) > > +{ > > + LC3DemuxContext *lc3 = s->priv_data; > > + AVIOContext *pb = s->pb; > > + int64_t pos = avio_tell(pb); > > + int ret; > > + > > + ret = av_get_packet(s->pb, pkt, avio_rl16(pb)); > > + if (ret < 0) > > + return ret; > > + > > + pkt->pos = pos; > > + pkt->duration = lc3->frame_samples; > > This should set AV_PKT_DATA_SKIP_SAMPLES side data to the packet that > crosses the number of samples specified in the header. > > > + > > + return 0; > > +} > > + > > +const FFInputFormat ff_lc3_demuxer = { > > + .p.name = "lc3", > > + .p.long_name = NULL_IF_CONFIG_SMALL("LC3 (Low Complexity > Communication Codec)"), > > + .p.extensions = "lc3", > > + .p.flags = AVFMT_GENERIC_INDEX, > > + .priv_data_size = sizeof(LC3DemuxContext), > > + .read_header = lc3_read_header, > > + .read_packet = lc3_read_packet, > > +}; > > diff --git a/libavformat/lc3enc.c b/libavformat/lc3enc.c > > new file mode 100644 > > index 0000000000..e768212f63 > > --- /dev/null > > +++ b/libavformat/lc3enc.c > > @@ -0,0 +1,100 @@ > > +/* > > + * LC3 muxer > > + * Copyright (C) 2024 Antoine Soulier <asoul...@google.com> > > + * > > + * This file is part of FFmpeg. > > + * > > + * FFmpeg is free software; you can redistribute it and/or > > + * modify it under the terms of the GNU Lesser General Public > > + * License as published by the Free Software Foundation; either > > + * version 2.1 of the License, or (at your option) any later version. > > + * > > + * FFmpeg is distributed in the hope that it will be useful, > > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > > + * Lesser General Public License for more details. > > + * > > + * You should have received a copy of the GNU Lesser General Public > > + * License along with FFmpeg; if not, write to the Free Software > > + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA > 02110-1301 USA > > + */ > > + > > +/** > > + * @file > > + * Based on the file format specified by : > > + * > > + * - Bluetooth SIG - Low Complexity Communication Codec Test Suite > > + * > https://www.bluetooth.org/docman/handlers/downloaddoc.ashx?doc_id=502301 > > + * 3.2.8.2 Reference LC3 Codec Bitstream Format > > + * > > + * - ETSI TI 103 634 V1.4.1 - Low Complexity Communication Codec plus > > + * > https://www.etsi.org/deliver/etsi_ts/103600_103699/103634/01.04.01_60/ts_103634v010401p.pdf > > + * LC3plus conformance script package > > + */ > > + > > +#include "libavutil/intreadwrite.h" > > + > > +#include "avformat.h" > > +#include "avio.h" > > +#include "mux.h" > > +#include "internal.h" > > + > > +static av_cold int lc3_init(AVFormatContext *s) > > +{ > > + if (s->nb_streams != 1) { > > + av_log(s, AV_LOG_ERROR, "This muxer only supports a single > stream.\n"); > > + return AVERROR(EINVAL); > > + } > > + > > + return 0; > > +} > > + > > +static int lc3_write_header(AVFormatContext *s) > > +{ > > + AVStream *st = s->streams[0]; > > + int channels = st->codecpar->ch_layout.nb_channels; > > + int srate_hz = st->codecpar->sample_rate; > > + int bit_rate = st->codecpar->bit_rate; > > + int frame_us, ep_mode, hr_mode; > > + uint32_t nb_samples = av_rescale_q( > > + st->duration, st->time_base, (AVRational){ 1, srate_hz }); > > + > > + if (st->codecpar->extradata_size < 6) > > + return AVERROR_INVALIDDATA; > > + > > + frame_us = AV_RL16(st->codecpar->extradata + 0) * 10; > > + ep_mode = AV_RL16(st->codecpar->extradata + 2) != 0; > > + hr_mode = AV_RL16(st->codecpar->extradata + 4) != 0; > > + > > + avio_wb16(s->pb, 0x1ccc); > > + avio_wl16(s->pb, (9 + hr_mode) * sizeof(uint16_t)); > > + avio_wl16(s->pb, srate_hz / 100); > > + avio_wl16(s->pb, bit_rate / 100); > > + avio_wl16(s->pb, channels); > > + avio_wl16(s->pb, frame_us / 10); > > + avio_wl16(s->pb, ep_mode); > > + avio_wl32(s->pb, nb_samples); > > + if (hr_mode) > > + avio_wl16(s->pb, hr_mode); > > + > > + return 0; > > +} > > + > > +static int lc3_write_packet(AVFormatContext *s, AVPacket *pkt) > > +{ > > + avio_wl16(s->pb, pkt->size); > > + avio_write(s->pb, pkt->data, pkt->size); > > + return 0; > > +} > > + > > +const FFOutputFormat ff_lc3_muxer = { > > + .p.name = "lc3", > > + .p.long_name = NULL_IF_CONFIG_SMALL("LC3 (Low Complexity > Communication Codec)"), > > + .p.extensions = "lc3", > > + .p.audio_codec = AV_CODEC_ID_LC3, > > + .p.video_codec = AV_CODEC_ID_NONE, > > + .p.flags = AVFMT_NOTIMESTAMPS, > > + .init = lc3_init, > > + .write_header = lc3_write_header, > > + .write_packet = lc3_write_packet, > > +}; > > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel > > To unsubscribe, visit link above, or email > ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe". > _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
