| Message ID | 20240327222145.601148-3-asoulier@google.com |
|---|---|
| State | New |
| Headers | show |
| Series | [FFmpeg-devel,1/4] configure: Add option for enabling LC3/LC3plus wrapper | expand |
| Context | Check | Description |
|---|---|---|
| yinshiyou/make_loongarch64 | success | Make finished |
| yinshiyou/make_fate_loongarch64 | success | Make fate finished |
| andriy/make_x86 | success | Make finished |
| andriy/make_fate_x86 | success | Make fate finished |
This format actually supports seeking. The proposed solution here is sub-optimal. On Wed, Mar 27, 2024 at 11:22 PM Antoine Soulier via ffmpeg-devel < ffmpeg-devel@ffmpeg.org> wrote: > 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 <asoulier@google.com> > --- > doc/muxers.texi | 6 ++ > libavformat/Makefile | 2 + > libavformat/allformats.c | 2 + > libavformat/lc3dec.c | 135 +++++++++++++++++++++++++++++++++++++++ > libavformat/lc3enc.c | 102 +++++++++++++++++++++++++++++ > 5 files changed, 247 insertions(+) > create mode 100644 libavformat/lc3dec.c > create mode 100644 libavformat/lc3enc.c > > 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 e15d0fa6d7..e225354faf 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..9ca9825f1b > --- /dev/null > +++ b/libavformat/lc3dec.c > @@ -0,0 +1,135 @@ > +/* > + * LC3 demuxer > + * Copyright (C) 2024 Antoine Soulier <asoulier@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 position; > + int64_t length; > +} LC3DemuxContext; > + > +static int lc3_read_header(AVFormatContext *s) > +{ > + LC3DemuxContext *lc3 = s->priv_data; > + AVStream *st = NULL; > + uint16_t tag, hdr_size; > + uint16_t frame_us; > + 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_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); > + > + st = avformat_new_stream(s, NULL); > + if (!st) > + return AVERROR(ENOMEM); > + > + avpriv_set_pts_info(st, 32, 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, 6)) < 0) { > + av_log(s, AV_LOG_ERROR, "Could not allocate extradata\n"); > + return ret; > + } > + > + AV_WL16(st->codecpar->extradata + 0, frame_us); > + AV_WL16(st->codecpar->extradata + 2, ep_mode); > + AV_WL16(st->codecpar->extradata + 4, hr_mode); > + > + lc3->frame_samples = av_rescale(frame_us, srate_hz, 1000*1000); > + > + lc3->position = 0; > + lc3->length = st->duration + > + av_rescale(frame_us == 7500 ? 4000 : 2500, srate_hz, 1000*1000); > + > + return 0; > +} > + > +static int lc3_read_packet(AVFormatContext *s, AVPacket *pkt) > +{ > + LC3DemuxContext *lc3 = s->priv_data; > + AVIOContext *pb = s->pb; > + int ret; > + > + ret = av_get_packet(s->pb, pkt, avio_rl16(pb)); > + if (ret < 0) > + return ret; > + > + pkt->duration = lc3->frame_samples; > + lc3->position += lc3->frame_samples; > + if (lc3->position > lc3->length) { > + pkt->duration -= lc3->position - lc3->length; > + lc3->position = lc3->length; > + } > + > + 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_NOBINSEARCH | AVFMT_NOGENSEARCH | > AVFMT_NO_BYTE_SEEK | AVFMT_NOTIMESTAMPS, > + .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..a7e3e3f4f7 > --- /dev/null > +++ b/libavformat/lc3enc.c > @@ -0,0 +1,102 @@ > +/* > + * LC3 muxer > + * Copyright (C) 2024 Antoine Soulier <asoulier@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; > + uint16_t frame_us = 10000; > + int ep_mode = 0, hr_mode = 0; > + uint32_t nb_samples = av_rescale_q( > + st->duration, st->time_base, (AVRational){ 1, srate_hz }); > + > + if (st->codecpar->extradata_size >= 2) > + frame_us = AV_RL16(st->codecpar->extradata + 0); > + > + if (st->codecpar->extradata_size >= 6) { > + ep_mode = AV_RL16(st->codecpar->extradata + 2); > + hr_mode = AV_RL16(st->codecpar->extradata + 4); > + } > + > + 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, > +}; > -- > 2.44.0.478.gd926399ef9-goog > > _______________________________________________ > 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". >
I don't think it's "easy" seekable. We cannot move to an arbitrary position: - There is no start-code - The frame size can be variable (not generated by the proposed encoder implementation, but allowed). The only possibility I see is checking that the frame size looks valid for multiple frames. The range of valid frame sizes is large (20 to 625 Bytes), so I can only validate 6 bits for each 16 bits packet size read. This format is not really designed to be seekable. Do you think we will need it? On Thu, Mar 28, 2024 at 2:33 AM Paul B Mahol <onemda@gmail.com> wrote: > This format actually supports seeking. > > The proposed solution here is sub-optimal. > > On Wed, Mar 27, 2024 at 11:22 PM Antoine Soulier via ffmpeg-devel < > ffmpeg-devel@ffmpeg.org> wrote: > >> 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 <asoulier@google.com> >> --- >> doc/muxers.texi | 6 ++ >> libavformat/Makefile | 2 + >> libavformat/allformats.c | 2 + >> libavformat/lc3dec.c | 135 +++++++++++++++++++++++++++++++++++++++ >> libavformat/lc3enc.c | 102 +++++++++++++++++++++++++++++ >> 5 files changed, 247 insertions(+) >> create mode 100644 libavformat/lc3dec.c >> create mode 100644 libavformat/lc3enc.c >> >> 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 e15d0fa6d7..e225354faf 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..9ca9825f1b >> --- /dev/null >> +++ b/libavformat/lc3dec.c >> @@ -0,0 +1,135 @@ >> +/* >> + * LC3 demuxer >> + * Copyright (C) 2024 Antoine Soulier <asoulier@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 position; >> + int64_t length; >> +} LC3DemuxContext; >> + >> +static int lc3_read_header(AVFormatContext *s) >> +{ >> + LC3DemuxContext *lc3 = s->priv_data; >> + AVStream *st = NULL; >> + uint16_t tag, hdr_size; >> + uint16_t frame_us; >> + 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_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); >> + >> + st = avformat_new_stream(s, NULL); >> + if (!st) >> + return AVERROR(ENOMEM); >> + >> + avpriv_set_pts_info(st, 32, 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, 6)) < 0) { >> + av_log(s, AV_LOG_ERROR, "Could not allocate extradata\n"); >> + return ret; >> + } >> + >> + AV_WL16(st->codecpar->extradata + 0, frame_us); >> + AV_WL16(st->codecpar->extradata + 2, ep_mode); >> + AV_WL16(st->codecpar->extradata + 4, hr_mode); >> + >> + lc3->frame_samples = av_rescale(frame_us, srate_hz, 1000*1000); >> + >> + lc3->position = 0; >> + lc3->length = st->duration + >> + av_rescale(frame_us == 7500 ? 4000 : 2500, srate_hz, 1000*1000); >> + >> + return 0; >> +} >> + >> +static int lc3_read_packet(AVFormatContext *s, AVPacket *pkt) >> +{ >> + LC3DemuxContext *lc3 = s->priv_data; >> + AVIOContext *pb = s->pb; >> + int ret; >> + >> + ret = av_get_packet(s->pb, pkt, avio_rl16(pb)); >> + if (ret < 0) >> + return ret; >> + >> + pkt->duration = lc3->frame_samples; >> + lc3->position += lc3->frame_samples; >> + if (lc3->position > lc3->length) { >> + pkt->duration -= lc3->position - lc3->length; >> + lc3->position = lc3->length; >> + } >> + >> + 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_NOBINSEARCH | AVFMT_NOGENSEARCH | >> AVFMT_NO_BYTE_SEEK | AVFMT_NOTIMESTAMPS, >> + .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..a7e3e3f4f7 >> --- /dev/null >> +++ b/libavformat/lc3enc.c >> @@ -0,0 +1,102 @@ >> +/* >> + * LC3 muxer >> + * Copyright (C) 2024 Antoine Soulier <asoulier@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; >> + uint16_t frame_us = 10000; >> + int ep_mode = 0, hr_mode = 0; >> + uint32_t nb_samples = av_rescale_q( >> + st->duration, st->time_base, (AVRational){ 1, srate_hz }); >> + >> + if (st->codecpar->extradata_size >= 2) >> + frame_us = AV_RL16(st->codecpar->extradata + 0); >> + >> + if (st->codecpar->extradata_size >= 6) { >> + ep_mode = AV_RL16(st->codecpar->extradata + 2); >> + hr_mode = AV_RL16(st->codecpar->extradata + 4); >> + } >> + >> + 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, >> +}; >> -- >> 2.44.0.478.gd926399ef9-goog >> >> _______________________________________________ >> 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". >> >
On date Wednesday 2024-03-27 22:21:44 +0000, ffmpeg-devel Mailing List wrote: > 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 <asoulier@google.com> > --- > doc/muxers.texi | 6 ++ > libavformat/Makefile | 2 + > libavformat/allformats.c | 2 + > libavformat/lc3dec.c | 135 +++++++++++++++++++++++++++++++++++++++ > libavformat/lc3enc.c | 102 +++++++++++++++++++++++++++++ > 5 files changed, 247 insertions(+) > create mode 100644 libavformat/lc3dec.c > create mode 100644 libavformat/lc3enc.c Note: you might add an entry for muxing/demuxing support to the Changelog. Looks good to me otherwise.
On Thu, Mar 28, 2024 at 5:40 PM Antoine Soulier <asoulier@google.com> wrote: > I don't think it's "easy" seekable. > We cannot move to an arbitrary position: > - There is no start-code > Not relevant. > - The frame size can be variable (not generated by the proposed encoder > implementation, but allowed). > Not relevant. > > The only possibility I see is checking that the frame size looks valid for > multiple frames. > Not relevant, the only needed feature is known stored number of samples in each packet for proper pts/timestamp generation. The range of valid frame sizes is large (20 to 625 Bytes), so I can only > validate 6 bits for each 16 bits packet size read. > > This format is not really designed to be seekable. > Do you think we will need it? > I cant force you do to correct implementation. Seeking is possible, just you are not aware of actual solution. Hint: see other demuxers. > > > On Thu, Mar 28, 2024 at 2:33 AM Paul B Mahol <onemda@gmail.com> wrote: > >> This format actually supports seeking. >> >> The proposed solution here is sub-optimal. >> >> On Wed, Mar 27, 2024 at 11:22 PM Antoine Soulier via ffmpeg-devel < >> ffmpeg-devel@ffmpeg.org> wrote: >> >>> 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 <asoulier@google.com> >>> --- >>> doc/muxers.texi | 6 ++ >>> libavformat/Makefile | 2 + >>> libavformat/allformats.c | 2 + >>> libavformat/lc3dec.c | 135 +++++++++++++++++++++++++++++++++++++++ >>> libavformat/lc3enc.c | 102 +++++++++++++++++++++++++++++ >>> 5 files changed, 247 insertions(+) >>> create mode 100644 libavformat/lc3dec.c >>> create mode 100644 libavformat/lc3enc.c >>> >>> 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 e15d0fa6d7..e225354faf 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..9ca9825f1b >>> --- /dev/null >>> +++ b/libavformat/lc3dec.c >>> @@ -0,0 +1,135 @@ >>> +/* >>> + * LC3 demuxer >>> + * Copyright (C) 2024 Antoine Soulier <asoulier@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 position; >>> + int64_t length; >>> +} LC3DemuxContext; >>> + >>> +static int lc3_read_header(AVFormatContext *s) >>> +{ >>> + LC3DemuxContext *lc3 = s->priv_data; >>> + AVStream *st = NULL; >>> + uint16_t tag, hdr_size; >>> + uint16_t frame_us; >>> + 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_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); >>> + >>> + st = avformat_new_stream(s, NULL); >>> + if (!st) >>> + return AVERROR(ENOMEM); >>> + >>> + avpriv_set_pts_info(st, 32, 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, 6)) < 0) { >>> + av_log(s, AV_LOG_ERROR, "Could not allocate extradata\n"); >>> + return ret; >>> + } >>> + >>> + AV_WL16(st->codecpar->extradata + 0, frame_us); >>> + AV_WL16(st->codecpar->extradata + 2, ep_mode); >>> + AV_WL16(st->codecpar->extradata + 4, hr_mode); >>> + >>> + lc3->frame_samples = av_rescale(frame_us, srate_hz, 1000*1000); >>> + >>> + lc3->position = 0; >>> + lc3->length = st->duration + >>> + av_rescale(frame_us == 7500 ? 4000 : 2500, srate_hz, 1000*1000); >>> + >>> + return 0; >>> +} >>> + >>> +static int lc3_read_packet(AVFormatContext *s, AVPacket *pkt) >>> +{ >>> + LC3DemuxContext *lc3 = s->priv_data; >>> + AVIOContext *pb = s->pb; >>> + int ret; >>> + >>> + ret = av_get_packet(s->pb, pkt, avio_rl16(pb)); >>> + if (ret < 0) >>> + return ret; >>> + >>> + pkt->duration = lc3->frame_samples; >>> + lc3->position += lc3->frame_samples; >>> + if (lc3->position > lc3->length) { >>> + pkt->duration -= lc3->position - lc3->length; >>> + lc3->position = lc3->length; >>> + } >>> + >>> + 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_NOBINSEARCH | AVFMT_NOGENSEARCH | >>> AVFMT_NO_BYTE_SEEK | AVFMT_NOTIMESTAMPS, >>> + .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..a7e3e3f4f7 >>> --- /dev/null >>> +++ b/libavformat/lc3enc.c >>> @@ -0,0 +1,102 @@ >>> +/* >>> + * LC3 muxer >>> + * Copyright (C) 2024 Antoine Soulier <asoulier@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; >>> + uint16_t frame_us = 10000; >>> + int ep_mode = 0, hr_mode = 0; >>> + uint32_t nb_samples = av_rescale_q( >>> + st->duration, st->time_base, (AVRational){ 1, srate_hz }); >>> + >>> + if (st->codecpar->extradata_size >= 2) >>> + frame_us = AV_RL16(st->codecpar->extradata + 0); >>> + >>> + if (st->codecpar->extradata_size >= 6) { >>> + ep_mode = AV_RL16(st->codecpar->extradata + 2); >>> + hr_mode = AV_RL16(st->codecpar->extradata + 4); >>> + } >>> + >>> + 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, >>> +}; >>> -- >>> 2.44.0.478.gd926399ef9-goog >>> >>> _______________________________________________ >>> 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". >>> >>
You're right, I was not aware at all. I have pushed a patch that does the job. PTAL, thanks.
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 e15d0fa6d7..e225354faf 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..9ca9825f1b --- /dev/null +++ b/libavformat/lc3dec.c @@ -0,0 +1,135 @@ +/* + * LC3 demuxer + * Copyright (C) 2024 Antoine Soulier <asoulier@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 position; + int64_t length; +} LC3DemuxContext; + +static int lc3_read_header(AVFormatContext *s) +{ + LC3DemuxContext *lc3 = s->priv_data; + AVStream *st = NULL; + uint16_t tag, hdr_size; + uint16_t frame_us; + 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_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); + + st = avformat_new_stream(s, NULL); + if (!st) + return AVERROR(ENOMEM); + + avpriv_set_pts_info(st, 32, 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, 6)) < 0) { + av_log(s, AV_LOG_ERROR, "Could not allocate extradata\n"); + return ret; + } + + AV_WL16(st->codecpar->extradata + 0, frame_us); + AV_WL16(st->codecpar->extradata + 2, ep_mode); + AV_WL16(st->codecpar->extradata + 4, hr_mode); + + lc3->frame_samples = av_rescale(frame_us, srate_hz, 1000*1000); + + lc3->position = 0; + lc3->length = st->duration + + av_rescale(frame_us == 7500 ? 4000 : 2500, srate_hz, 1000*1000); + + return 0; +} + +static int lc3_read_packet(AVFormatContext *s, AVPacket *pkt) +{ + LC3DemuxContext *lc3 = s->priv_data; + AVIOContext *pb = s->pb; + int ret; + + ret = av_get_packet(s->pb, pkt, avio_rl16(pb)); + if (ret < 0) + return ret; + + pkt->duration = lc3->frame_samples; + lc3->position += lc3->frame_samples; + if (lc3->position > lc3->length) { + pkt->duration -= lc3->position - lc3->length; + lc3->position = lc3->length; + } + + 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_NOBINSEARCH | AVFMT_NOGENSEARCH | AVFMT_NO_BYTE_SEEK | AVFMT_NOTIMESTAMPS, + .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..a7e3e3f4f7 --- /dev/null +++ b/libavformat/lc3enc.c @@ -0,0 +1,102 @@ +/* + * LC3 muxer + * Copyright (C) 2024 Antoine Soulier <asoulier@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; + uint16_t frame_us = 10000; + int ep_mode = 0, hr_mode = 0; + uint32_t nb_samples = av_rescale_q( + st->duration, st->time_base, (AVRational){ 1, srate_hz }); + + if (st->codecpar->extradata_size >= 2) + frame_us = AV_RL16(st->codecpar->extradata + 0); + + if (st->codecpar->extradata_size >= 6) { + ep_mode = AV_RL16(st->codecpar->extradata + 2); + hr_mode = AV_RL16(st->codecpar->extradata + 4); + } + + 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, +};
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 <asoulier@google.com> --- doc/muxers.texi | 6 ++ libavformat/Makefile | 2 + libavformat/allformats.c | 2 + libavformat/lc3dec.c | 135 +++++++++++++++++++++++++++++++++++++++ libavformat/lc3enc.c | 102 +++++++++++++++++++++++++++++ 5 files changed, 247 insertions(+) create mode 100644 libavformat/lc3dec.c create mode 100644 libavformat/lc3enc.c