On date Saturday 2024-04-06 21:08:19 +0000, ffmpeg-devel Mailing List wrote: > From: Antoine SOULIER <asoul...@google.com> > > A file format is described in Bluetooth SIG LC3 and ETSI TS 103 634, for > test purpose. This is the format implemented here. > --- > Changelog | 1 + > doc/muxers.texi | 6 ++ > libavformat/Makefile | 2 + > libavformat/allformats.c | 2 + > libavformat/lc3dec.c | 173 +++++++++++++++++++++++++++++++++++++++ > libavformat/lc3enc.c | 114 ++++++++++++++++++++++++++ > 6 files changed, 298 insertions(+) > create mode 100644 libavformat/lc3dec.c > create mode 100644 libavformat/lc3enc.c > > diff --git a/Changelog b/Changelog > index 18e83b99a1..02ed7831ec 100644 > --- a/Changelog > +++ b/Changelog > @@ -4,6 +4,7 @@ releases are sorted from youngest to oldest. > version <next>: > - Raw Captions with Time (RCWT) closed caption demuxer > - LC3/LC3plus decoding/encoding using external library liblc3 > +- LC3/LC3plus demuxer and muxer > > > version 7.0: > diff --git a/doc/muxers.texi b/doc/muxers.texi > index d8a1f83309..ed4144f6d1 100644 > --- a/doc/muxers.texi > +++ b/doc/muxers.texi > @@ -2700,6 +2700,12 @@ computer-generated compositions. > > This muxer accepts a single audio stream containing PCM data. > > +@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 9981799cc9..027d0cdae5 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 ae925dcf60..305fa46532 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..371e9242d5 > --- /dev/null > +++ b/libavformat/lc3dec.c > @@ -0,0 +1,173 @@ > +/* > + * 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; > + int64_t end_dts; > +} LC3DemuxContext; > + > +static int lc3_read_probe(const AVProbeData *p) > +{ > + int frame_us, srate_hz; > + > + if (p->buf_size < 12) > + return 0; > + > + if (AV_RB16(p->buf + 0) != 0x1ccc || > + AV_RL16(p->buf + 2) < 9 * sizeof(uint16_t)) > + return 0; > + > + srate_hz = AV_RL16(p->buf + 4) * 100; > + if (srate_hz != 8000 && srate_hz != 16000 && srate_hz != 24000 && > + srate_hz != 32000 && srate_hz != 48000 && srate_hz != 96000) > + return 0; > + > + frame_us = AV_RL16(p->buf + 10) * 10; > + if (frame_us != 2500 && frame_us != 5000 && > + frame_us != 7500 && frame_us != 10000) > + return 0; > + > + return AVPROBE_SCORE_MAX; > +} > + > +static int lc3_read_header(AVFormatContext *s) > +{ > + LC3DemuxContext *lc3 = s->priv_data; > + AVStream *st = NULL; > + uint16_t tag, hdr_size; > + uint32_t length; > + int srate_hz, frame_us, channels, bit_rate; > + int ep_mode, hr_mode; > + int num_extra_params; > + int delay, 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_us = avio_rl16(s->pb) * 10; > + ep_mode = avio_rl16(s->pb) != 0; > + length = avio_rl32(s->pb); > + hr_mode = num_extra_params >= 1 && avio_rl16(s->pb); > +
> + if (srate_hz != 8000 && srate_hz != 16000 && srate_hz != 24000 && > + srate_hz != 32000 && srate_hz != 48000 && srate_hz != 96000) { > + av_log(s, AV_LOG_ERROR, "Incompatible LC3 sample rate: %d Hz.\n", > + srate_hz); > + return AVERROR_INVALIDDATA; > + } > + > + if (frame_us != 2500 && frame_us != 5000 && > + frame_us != 7500 && frame_us != 10000) { > + av_log(s, AV_LOG_ERROR, "Incompatible LC3 frame duration: %.1f > ms.\n", > + frame_us / 1000.f); > + return AVERROR_INVALIDDATA; > + } This data and logic is repeated three times in the code. To avoid the code duplication I suggest two possible solutions: 1. store an ff_lc3_check_sample_rate() and ff_lc3_check_frame_size() function in a common lc3.[hc] file and header (see for example caf.*) 2. put the shared utils, muxer, and demuxer in the same module (see for example codec2.c) with conditional compilation guards Possibly solution #2 should be simpler. [...] Thanks. _______________________________________________ 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".