| Message ID | 20240327222145.601148-2-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 |
On date Wednesday 2024-03-27 22:21:43 +0000, ffmpeg-devel Mailing List wrote: > The LC3 audio codec is the default codec of Bluetooth LE audio. > This is a wrapper over the liblc3 library (https://github.com/google/liblc3). > > Signed-off-by: Antoine Soulier <asoulier@google.com> > --- > doc/encoders.texi | 57 ++++++++++++ > doc/general_contents.texi | 11 ++- > libavcodec/Makefile | 2 + > libavcodec/allcodecs.c | 2 + > libavcodec/codec_desc.c | 7 ++ > libavcodec/codec_id.h | 1 + > libavcodec/liblc3dec.c | 135 +++++++++++++++++++++++++++ > libavcodec/liblc3enc.c | 190 ++++++++++++++++++++++++++++++++++++++ > 8 files changed, 404 insertions(+), 1 deletion(-) > create mode 100644 libavcodec/liblc3dec.c > create mode 100644 libavcodec/liblc3enc.c > > diff --git a/doc/encoders.texi b/doc/encoders.texi > index 7c223ed74c..66847191e1 100644 > --- a/doc/encoders.texi > +++ b/doc/encoders.texi > @@ -814,6 +814,63 @@ ffmpeg -i input.wav -c:a libfdk_aac -profile:a aac_he -b:a 64k output.m4a > @end example > @end itemize > > +@anchor{liblc3-enc} > +@section liblc3 > + > +liblc3 LC3 (Low Complexity Communication Codec) encoder wrapper. > + > +Requires the presence of the liblc3 headers and library during configuration. > +You need to explicitly configure the build with @code{--enable-liblc3}. > + > +This encoder has support for the Bluetooth SIG LC3 codec for the LE Audio > +protocol, and the following features of LC3plus: > +@itemize > +@item > +Frame duration of 2.5 and 5ms. > +@item > +High-Resolution mode, 48 KHz, and 96 kHz sampling rates. > +@end itemize > + > +For more information see the liblc3 project at > +@url{https://github.com/google/liblc3}. > + > +@subsection Options > + > +The following options are mapped on the shared FFmpeg codec options. > + > +@table @option > +@item b @var{bitrate} > +Set the bit rate in bits/s. This will determine the fixed size of the encoded > +frames, for a selected frame duration. > + > +@item ar @var{frequency} > +Set the audio sampling rate (in Hz). > + > +@item channels > +Set the number of audio channels. > + > +@item frame_duration > +Set the audio frame duration in milliseconds. Default value is 10ms. > +Allowed frame durations are 2.5ms, 5ms, 7.5ms and 10ms. > +LC3 (Bluetooth LE Audio), allows 7.5ms and 10ms; and LC3plus 2.5ms, 5ms > +and 10ms. > + > +The 10ms frame duration is available in LC3 and LC3 plus standard. > +In this mode, the produced bitstream can be referenced either as LC3 or LC3plus. > + > +@item high_resolution @var{boolean} > +Enable the high-resolution mode if set to 1. The high-resolution mode is > +available with all LC3plus frame durations and for a sampling rate of 48 KHz, > +and 96 KHz. > + > +The encoder automatically turns off this mode at lower sampling rates and > +activates it at 96 KHz. > + > +This mode should be preferred at high bitrates. In this mode, the audio > +bandwidth is always up to the Nyquist frequency, compared to LC3 at 48 KHz, > +which limits the bandwidth to 20 KHz. > +@end table > + > @anchor{libmp3lame} > @section libmp3lame > > diff --git a/doc/general_contents.texi b/doc/general_contents.texi > index f269cbd1a9..e7cf4f8239 100644 > --- a/doc/general_contents.texi > +++ b/doc/general_contents.texi > @@ -237,6 +237,14 @@ Go to @url{http://sourceforge.net/projects/opencore-amr/} and follow the > instructions for installing the library. > Then pass @code{--enable-libfdk-aac} to configure to enable it. > > +@subsection LC3 library > + > +FFmpeg can make use of the Google LC3 library for LC3 decoding & encoding. > + > +Go to @url{https://github.com/google/liblc3/} and follow the instructions for > +installing the library. > +Then pass @code{--enable-liblc3} to configure to enable it. > + > @section OpenH264 > > FFmpeg can make use of the OpenH264 library for H.264 decoding and encoding. > @@ -1300,7 +1308,8 @@ following image formats are supported: > @tab encoding and decoding supported through external library libilbc > @item IMC (Intel Music Coder) @tab @tab X > @item Interplay ACM @tab @tab X > -@item MACE (Macintosh Audio Compression/Expansion) 3:1 @tab @tab X > +@item LC3 @tab E @tab E > + @tab supported through external library liblc3 > @item MACE (Macintosh Audio Compression/Expansion) 6:1 @tab @tab X > @item Marian's A-pac audio @tab @tab X > @item MI-SC4 (Micronas SC-4 Audio) @tab @tab X > diff --git a/libavcodec/Makefile b/libavcodec/Makefile > index 9ce6d445c1..e70811dbd6 100644 > --- a/libavcodec/Makefile > +++ b/libavcodec/Makefile > @@ -1123,6 +1123,8 @@ OBJS-$(CONFIG_LIBILBC_ENCODER) += libilbc.o > OBJS-$(CONFIG_LIBJXL_DECODER) += libjxldec.o libjxl.o > OBJS-$(CONFIG_LIBJXL_ENCODER) += libjxlenc.o libjxl.o > OBJS-$(CONFIG_LIBKVAZAAR_ENCODER) += libkvazaar.o > +OBJS-$(CONFIG_LIBLC3_ENCODER) += liblc3enc.o > +OBJS-$(CONFIG_LIBLC3_DECODER) += liblc3dec.o > OBJS-$(CONFIG_LIBMP3LAME_ENCODER) += libmp3lame.o > OBJS-$(CONFIG_LIBOPENCORE_AMRNB_DECODER) += libopencore-amr.o > OBJS-$(CONFIG_LIBOPENCORE_AMRNB_ENCODER) += libopencore-amr.o > diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c > index 2386b450a6..f4705651fb 100644 > --- a/libavcodec/allcodecs.c > +++ b/libavcodec/allcodecs.c > @@ -776,6 +776,8 @@ extern const FFCodec ff_libilbc_encoder; > extern const FFCodec ff_libilbc_decoder; > extern const FFCodec ff_libjxl_decoder; > extern const FFCodec ff_libjxl_encoder; > +extern const FFCodec ff_liblc3_encoder; > +extern const FFCodec ff_liblc3_decoder; > extern const FFCodec ff_libmp3lame_encoder; > extern const FFCodec ff_libopencore_amrnb_encoder; > extern const FFCodec ff_libopencore_amrnb_decoder; > diff --git a/libavcodec/codec_desc.c b/libavcodec/codec_desc.c > index 3bab86db62..7dba61dc8b 100644 > --- a/libavcodec/codec_desc.c > +++ b/libavcodec/codec_desc.c > @@ -3425,6 +3425,13 @@ static const AVCodecDescriptor codec_descriptors[] = { > .long_name = NULL_IF_CONFIG_SMALL("QOA (Quite OK Audio)"), > .props = AV_CODEC_PROP_INTRA_ONLY | AV_CODEC_PROP_LOSSY, > }, > + { > + .id = AV_CODEC_ID_LC3, > + .type = AVMEDIA_TYPE_AUDIO, > + .name = "lc3", > + .long_name = NULL_IF_CONFIG_SMALL("LC3 (Low Complexity Communication Codec)"), > + .props = AV_CODEC_PROP_INTRA_ONLY | AV_CODEC_PROP_LOSSY, > + }, > > /* subtitle codecs */ > { > diff --git a/libavcodec/codec_id.h b/libavcodec/codec_id.h > index c8dc21da74..0ab1e34a61 100644 > --- a/libavcodec/codec_id.h > +++ b/libavcodec/codec_id.h > @@ -543,6 +543,7 @@ enum AVCodecID { > AV_CODEC_ID_AC4, > AV_CODEC_ID_OSQ, > AV_CODEC_ID_QOA, > + AV_CODEC_ID_LC3, > > /* subtitle codecs */ > AV_CODEC_ID_FIRST_SUBTITLE = 0x17000, ///< A dummy ID pointing at the start of subtitle codecs. > diff --git a/libavcodec/liblc3dec.c b/libavcodec/liblc3dec.c > new file mode 100644 > index 0000000000..f9c047c03f > --- /dev/null > +++ b/libavcodec/liblc3dec.c > @@ -0,0 +1,135 @@ > +/* > + * LC3 decoder wrapper > + * Copyright (C) 2024 Antoine Soulier <asoulier@google.com> > + * > + * This file is part of FFmpeg. > + * > + * Permission to use, copy, modify, and/or distribute this software for any > + * purpose with or without fee is hereby granted, provided that the above > + * copyright notice and this permission notice appear in all copies. > + * > + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES > + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF > + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR > + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES > + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN > + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF > + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. > + */ > + > +#include <lc3.h> > + > +#include "libavutil/intreadwrite.h" > + > +#include "avcodec.h" > +#include "codec.h" > +#include "codec_internal.h" > +#include "decode.h" > +#include "internal.h" > + > +#define DECODER_MAX_CHANNELS 2 > + > +typedef struct LibLC3DecContext { > + int frame_us, srate_hz; > + bool hr_mode; > + void *decoder_mem; > + lc3_decoder_t decoder[DECODER_MAX_CHANNELS]; > +} LibLC3DecContext; > + > +static av_cold int liblc3_decode_init(AVCodecContext *avctx) > +{ > + LibLC3DecContext *liblc3 = avctx->priv_data; > + int channels = avctx->ch_layout.nb_channels; > + unsigned decoder_size; > + > + if (avctx->extradata_size < 2) > + return AVERROR_INVALIDDATA; > + > + liblc3->frame_us = AV_RL16(avctx->extradata + 0); > + liblc3->srate_hz = avctx->sample_rate; > + liblc3->hr_mode = avctx->extradata_size >= 6 && > + AV_RL16(avctx->extradata + 4); > + > + av_log(avctx, AV_LOG_INFO, > + "Decoding %.1f ms frames\n", liblc3->frame_us / 1000.f); > + if (liblc3->hr_mode) > + av_log(avctx, AV_LOG_INFO, "High-resolution mode enabled\n"); > + > + decoder_size = lc3_hr_decoder_size( > + liblc3->hr_mode, liblc3->frame_us, liblc3->srate_hz); > + if (!decoder_size) > + return AVERROR_INVALIDDATA; > + > + liblc3->decoder_mem = av_malloc_array(channels, decoder_size); > + if (!liblc3->decoder_mem) > + return AVERROR(ENOMEM); > + > + for (int ch = 0; ch < channels; ch++) { > + liblc3->decoder[ch] = lc3_hr_setup_decoder( > + liblc3->hr_mode, liblc3->frame_us, liblc3->srate_hz, 0, > + (char *)liblc3->decoder_mem + ch * decoder_size); > + } > + > + avctx->sample_fmt = AV_SAMPLE_FMT_FLTP; > + avctx->delay = lc3_hr_delay_samples( > + liblc3->hr_mode, liblc3->frame_us, liblc3->srate_hz); > + avctx->internal->skip_samples = avctx->delay; > + > + return 0; > +} > + > +static av_cold int liblc3_decode_close(AVCodecContext *avctx) > +{ > + LibLC3DecContext *liblc3 = avctx->priv_data; > + > + av_freep(&liblc3->decoder_mem); > + > + return 0; > +} > + > +static int liblc3_decode(AVCodecContext *avctx, AVFrame *frame, > + int *got_frame_ptr, AVPacket *avpkt) > +{ > + LibLC3DecContext *liblc3 = avctx->priv_data; > + int channels = avctx->ch_layout.nb_channels; > + uint8_t *in = avpkt->data; > + int block_bytes, ret; > + > + frame->nb_samples = av_rescale( > + liblc3->frame_us, liblc3->srate_hz, 1000*1000); > + if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) > + return ret; > + > + block_bytes = avpkt->size; > + for (int ch = 0; ch < channels; ch++) { > + int frame_bytes = block_bytes / channels > + + (ch < block_bytes % channels); > + > + ret = lc3_decode(liblc3->decoder[ch], in, frame_bytes, > + LC3_PCM_FORMAT_FLOAT, frame->data[ch], 1); nit++: weird indent (should be alignd to the first argument > + if (ret < 0) > + return AVERROR_INVALIDDATA; > + > + in += frame_bytes; > + } > + > + frame->nb_samples = FFMIN(frame->nb_samples, avpkt->duration); > + > + *got_frame_ptr = 1; > + > + return avpkt->size; > +} > + > +const FFCodec ff_liblc3_decoder = { > + .p.name = "liblc3", > + CODEC_LONG_NAME("LC3 (Low Complexity Communication Codec)"), > + .p.type = AVMEDIA_TYPE_AUDIO, > + .p.id = AV_CODEC_ID_LC3, > + .p.capabilities = AV_CODEC_CAP_DR1, > + .p.wrapper_name = "liblc3", > + .priv_data_size = sizeof(LibLC3DecContext), > + .caps_internal = FF_CODEC_CAP_INIT_CLEANUP, > + .init = liblc3_decode_init, > + .close = liblc3_decode_close, > + FF_CODEC_DECODE_CB(liblc3_decode), > +}; > diff --git a/libavcodec/liblc3enc.c b/libavcodec/liblc3enc.c > new file mode 100644 > index 0000000000..5ac45b8cd2 > --- /dev/null > +++ b/libavcodec/liblc3enc.c > @@ -0,0 +1,190 @@ > +/* > + * LC3 encoder wrapper > + * Copyright (C) 2024 Antoine Soulier <asoulier@google.com> > + * > + * This file is part of FFmpeg. > + * > + * Permission to use, copy, modify, and/or distribute this software for any > + * purpose with or without fee is hereby granted, provided that the above > + * copyright notice and this permission notice appear in all copies. > + * > + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES > + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF > + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR > + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES > + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN > + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF > + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. > + */ > + > +#include <lc3.h> > + > +#include "libavutil/intreadwrite.h" > +#include "libavutil/opt.h" > + > +#include "avcodec.h" > +#include "codec.h" > +#include "codec_internal.h" > +#include "encode.h" > + > +#define ENCODER_MAX_CHANNELS 2 > + > +typedef struct LibLC3EncOpts { > + float frame_duration; > + int hr_mode; > +} LibLC3EncOpts; > + > +typedef struct LibLC3EncContext { > + const AVClass *av_class; > + LibLC3EncOpts opts; > + int block_bytes; > + void *encoder_mem; > + lc3_encoder_t encoder[ENCODER_MAX_CHANNELS]; > +} LibLC3EncContext; > + > +static av_cold int liblc3_encode_init(AVCodecContext *avctx) > +{ > + LibLC3EncContext *liblc3 = avctx->priv_data; > + bool hr_mode = liblc3->opts.hr_mode; > + int frame_us = liblc3->opts.frame_duration * 1000; > + int srate_hz = avctx->sample_rate; > + int channels = avctx->ch_layout.nb_channels; > + int effective_bit_rate; > + unsigned encoder_size; > + > + if (frame_us != 2500 && frame_us != 5000 && > + frame_us != 7500 && frame_us != 10000 ) { > + av_log(avctx, AV_LOG_ERROR, > + "Unsupported frame duration %.1f ms\n", frame_us / 1000.f); nit++: weird indent > + return AVERROR(EINVAL); > + } > + > + hr_mode |= srate_hz > 48000; > + hr_mode &= srate_hz >= 48000; > + > + if (frame_us == 7500 && hr_mode) { > + av_log(avctx, AV_LOG_ERROR, > + "High-resolution mode not supported with 7.5 ms frames\n"); ditto > + return AVERROR(EINVAL); > + } > + > + av_log(avctx, AV_LOG_INFO, "Encoding %.1f ms frames\n", frame_us / 1000.f); > + if (hr_mode) > + av_log(avctx, AV_LOG_INFO, "High-resolution mode enabled\n"); > + > + liblc3->block_bytes = lc3_hr_frame_block_bytes( > + hr_mode, frame_us, srate_hz, channels, avctx->bit_rate); > + > + effective_bit_rate = lc3_hr_resolve_bitrate( > + hr_mode, frame_us, srate_hz, liblc3->block_bytes); > + > + if (avctx->bit_rate != effective_bit_rate) > + av_log(avctx, AV_LOG_WARNING, > + "Bitrate changed to %d bps\n", effective_bit_rate); > + avctx->bit_rate = effective_bit_rate; > + > + encoder_size = lc3_hr_encoder_size(hr_mode, frame_us, srate_hz); > + if (!encoder_size) > + return AVERROR(EINVAL); > + > + liblc3->encoder_mem = av_malloc_array(channels, encoder_size); > + if (!liblc3->encoder_mem) > + return AVERROR(ENOMEM); > + > + for (int ch = 0; ch < channels; ch++) { > + liblc3->encoder[ch] = > + lc3_hr_setup_encoder(hr_mode, frame_us, srate_hz, 0, > + (char *)liblc3->encoder_mem + ch * encoder_size); > + } > + > + avctx->extradata = av_mallocz(6 + AV_INPUT_BUFFER_PADDING_SIZE); > + if (!avctx->extradata) > + return AVERROR(ENOMEM); > + > + AV_WL16(avctx->extradata + 0, frame_us); > + AV_WL16(avctx->extradata + 2, 0); > + AV_WL16(avctx->extradata + 4, hr_mode); > + avctx->extradata_size = 6; > + > + avctx->frame_size = av_rescale(frame_us, srate_hz, 1000*1000); > + > + return 0; > +} > + > +static av_cold int liblc3_encode_close(AVCodecContext *avctx) > +{ > + LibLC3EncContext *liblc3 = avctx->priv_data; > + > + av_freep(&liblc3->encoder_mem); > + > + return 0; > +} > + > +static int liblc3_encode(AVCodecContext *avctx, AVPacket *avpkt, > + const AVFrame *av_frame, int *got_packet_ptr) > +{ > + LibLC3EncContext *liblc3 = avctx->priv_data; > + int block_bytes = liblc3->block_bytes; > + int channels = avctx->ch_layout.nb_channels; > + uint8_t *data_ptr; > + int ret; > + > + if ((ret = ff_get_encode_buffer(avctx, avpkt, block_bytes, 0)) < 0) > + return ret; > + > + data_ptr = avpkt->data; > + for (int ch = 0; ch < channels; ch++) { > + int frame_bytes = block_bytes / channels > + + (ch < block_bytes % channels); > + > + lc3_encode(liblc3->encoder[ch], > + LC3_PCM_FORMAT_FLOAT, av_frame->data[ch], 1, > + frame_bytes, data_ptr); > + > + data_ptr += frame_bytes; > + } > + > + *got_packet_ptr = 1; > + > + return 0; > +} > + > +#define OFFSET(x) offsetof(LibLC3EncContext, opts.x) > +#define FLAGS AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_ENCODING_PARAM > +static const AVOption options[] = { > + { "frame_duration", "Duration of a frame in milliseconds", > + OFFSET(frame_duration), AV_OPT_TYPE_FLOAT, > + { .dbl = 10.0 }, 2.5, 10.0, FLAGS }, > + { "high_resolution", "Enable High-Resolution mode (48 KHz or 96 KHz)", > + OFFSET(hr_mode), AV_OPT_TYPE_BOOL, > + { .i64 = 0 }, 0, 1, FLAGS }, > + { NULL } > +}; > + > +static const AVClass class = { > + .class_name = "liblc3 encoder", > + .item_name = av_default_item_name, > + .option = options, > + .version = LIBAVUTIL_VERSION_INT, > +}; > + > +const FFCodec ff_liblc3_encoder = { > + .p.name = "liblc3", > + CODEC_LONG_NAME("LC3 (Low Complexity Communication Codec)"), > + .p.type = AVMEDIA_TYPE_AUDIO, > + .p.id = AV_CODEC_ID_LC3, > + .p.capabilities = AV_CODEC_CAP_DR1, > + .p.ch_layouts = (const AVChannelLayout[]) > + { { AV_CHANNEL_ORDER_UNSPEC, 1 }, > + { AV_CHANNEL_ORDER_UNSPEC, 2 }, { 0 } }, > + .p.supported_samplerates = (const int []) > + { 96000, 48000, 32000, 24000, 16000, 8000, 0 }, > + .p.sample_fmts = (const enum AVSampleFormat[]) > + { AV_SAMPLE_FMT_FLTP, AV_SAMPLE_FMT_NONE }, > + .p.priv_class = &class, > + .p.wrapper_name = "liblc3", > + .priv_data_size = sizeof(LibLC3EncContext), > + .init = liblc3_encode_init, > + .close = liblc3_encode_close, > + FF_CODEC_ENCODE_CB(liblc3_encode), > +}; > -- > 2.44.0.478.gd926399ef9-goog No more comments from me, it looks good to me apart for the nits.
diff --git a/doc/encoders.texi b/doc/encoders.texi index 7c223ed74c..66847191e1 100644 --- a/doc/encoders.texi +++ b/doc/encoders.texi @@ -814,6 +814,63 @@ ffmpeg -i input.wav -c:a libfdk_aac -profile:a aac_he -b:a 64k output.m4a @end example @end itemize +@anchor{liblc3-enc} +@section liblc3 + +liblc3 LC3 (Low Complexity Communication Codec) encoder wrapper. + +Requires the presence of the liblc3 headers and library during configuration. +You need to explicitly configure the build with @code{--enable-liblc3}. + +This encoder has support for the Bluetooth SIG LC3 codec for the LE Audio +protocol, and the following features of LC3plus: +@itemize +@item +Frame duration of 2.5 and 5ms. +@item +High-Resolution mode, 48 KHz, and 96 kHz sampling rates. +@end itemize + +For more information see the liblc3 project at +@url{https://github.com/google/liblc3}. + +@subsection Options + +The following options are mapped on the shared FFmpeg codec options. + +@table @option +@item b @var{bitrate} +Set the bit rate in bits/s. This will determine the fixed size of the encoded +frames, for a selected frame duration. + +@item ar @var{frequency} +Set the audio sampling rate (in Hz). + +@item channels +Set the number of audio channels. + +@item frame_duration +Set the audio frame duration in milliseconds. Default value is 10ms. +Allowed frame durations are 2.5ms, 5ms, 7.5ms and 10ms. +LC3 (Bluetooth LE Audio), allows 7.5ms and 10ms; and LC3plus 2.5ms, 5ms +and 10ms. + +The 10ms frame duration is available in LC3 and LC3 plus standard. +In this mode, the produced bitstream can be referenced either as LC3 or LC3plus. + +@item high_resolution @var{boolean} +Enable the high-resolution mode if set to 1. The high-resolution mode is +available with all LC3plus frame durations and for a sampling rate of 48 KHz, +and 96 KHz. + +The encoder automatically turns off this mode at lower sampling rates and +activates it at 96 KHz. + +This mode should be preferred at high bitrates. In this mode, the audio +bandwidth is always up to the Nyquist frequency, compared to LC3 at 48 KHz, +which limits the bandwidth to 20 KHz. +@end table + @anchor{libmp3lame} @section libmp3lame diff --git a/doc/general_contents.texi b/doc/general_contents.texi index f269cbd1a9..e7cf4f8239 100644 --- a/doc/general_contents.texi +++ b/doc/general_contents.texi @@ -237,6 +237,14 @@ Go to @url{http://sourceforge.net/projects/opencore-amr/} and follow the instructions for installing the library. Then pass @code{--enable-libfdk-aac} to configure to enable it. +@subsection LC3 library + +FFmpeg can make use of the Google LC3 library for LC3 decoding & encoding. + +Go to @url{https://github.com/google/liblc3/} and follow the instructions for +installing the library. +Then pass @code{--enable-liblc3} to configure to enable it. + @section OpenH264 FFmpeg can make use of the OpenH264 library for H.264 decoding and encoding. @@ -1300,7 +1308,8 @@ following image formats are supported: @tab encoding and decoding supported through external library libilbc @item IMC (Intel Music Coder) @tab @tab X @item Interplay ACM @tab @tab X -@item MACE (Macintosh Audio Compression/Expansion) 3:1 @tab @tab X +@item LC3 @tab E @tab E + @tab supported through external library liblc3 @item MACE (Macintosh Audio Compression/Expansion) 6:1 @tab @tab X @item Marian's A-pac audio @tab @tab X @item MI-SC4 (Micronas SC-4 Audio) @tab @tab X diff --git a/libavcodec/Makefile b/libavcodec/Makefile index 9ce6d445c1..e70811dbd6 100644 --- a/libavcodec/Makefile +++ b/libavcodec/Makefile @@ -1123,6 +1123,8 @@ OBJS-$(CONFIG_LIBILBC_ENCODER) += libilbc.o OBJS-$(CONFIG_LIBJXL_DECODER) += libjxldec.o libjxl.o OBJS-$(CONFIG_LIBJXL_ENCODER) += libjxlenc.o libjxl.o OBJS-$(CONFIG_LIBKVAZAAR_ENCODER) += libkvazaar.o +OBJS-$(CONFIG_LIBLC3_ENCODER) += liblc3enc.o +OBJS-$(CONFIG_LIBLC3_DECODER) += liblc3dec.o OBJS-$(CONFIG_LIBMP3LAME_ENCODER) += libmp3lame.o OBJS-$(CONFIG_LIBOPENCORE_AMRNB_DECODER) += libopencore-amr.o OBJS-$(CONFIG_LIBOPENCORE_AMRNB_ENCODER) += libopencore-amr.o diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c index 2386b450a6..f4705651fb 100644 --- a/libavcodec/allcodecs.c +++ b/libavcodec/allcodecs.c @@ -776,6 +776,8 @@ extern const FFCodec ff_libilbc_encoder; extern const FFCodec ff_libilbc_decoder; extern const FFCodec ff_libjxl_decoder; extern const FFCodec ff_libjxl_encoder; +extern const FFCodec ff_liblc3_encoder; +extern const FFCodec ff_liblc3_decoder; extern const FFCodec ff_libmp3lame_encoder; extern const FFCodec ff_libopencore_amrnb_encoder; extern const FFCodec ff_libopencore_amrnb_decoder; diff --git a/libavcodec/codec_desc.c b/libavcodec/codec_desc.c index 3bab86db62..7dba61dc8b 100644 --- a/libavcodec/codec_desc.c +++ b/libavcodec/codec_desc.c @@ -3425,6 +3425,13 @@ static const AVCodecDescriptor codec_descriptors[] = { .long_name = NULL_IF_CONFIG_SMALL("QOA (Quite OK Audio)"), .props = AV_CODEC_PROP_INTRA_ONLY | AV_CODEC_PROP_LOSSY, }, + { + .id = AV_CODEC_ID_LC3, + .type = AVMEDIA_TYPE_AUDIO, + .name = "lc3", + .long_name = NULL_IF_CONFIG_SMALL("LC3 (Low Complexity Communication Codec)"), + .props = AV_CODEC_PROP_INTRA_ONLY | AV_CODEC_PROP_LOSSY, + }, /* subtitle codecs */ { diff --git a/libavcodec/codec_id.h b/libavcodec/codec_id.h index c8dc21da74..0ab1e34a61 100644 --- a/libavcodec/codec_id.h +++ b/libavcodec/codec_id.h @@ -543,6 +543,7 @@ enum AVCodecID { AV_CODEC_ID_AC4, AV_CODEC_ID_OSQ, AV_CODEC_ID_QOA, + AV_CODEC_ID_LC3, /* subtitle codecs */ AV_CODEC_ID_FIRST_SUBTITLE = 0x17000, ///< A dummy ID pointing at the start of subtitle codecs. diff --git a/libavcodec/liblc3dec.c b/libavcodec/liblc3dec.c new file mode 100644 index 0000000000..f9c047c03f --- /dev/null +++ b/libavcodec/liblc3dec.c @@ -0,0 +1,135 @@ +/* + * LC3 decoder wrapper + * Copyright (C) 2024 Antoine Soulier <asoulier@google.com> + * + * This file is part of FFmpeg. + * + * Permission to use, copy, modify, and/or distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#include <lc3.h> + +#include "libavutil/intreadwrite.h" + +#include "avcodec.h" +#include "codec.h" +#include "codec_internal.h" +#include "decode.h" +#include "internal.h" + +#define DECODER_MAX_CHANNELS 2 + +typedef struct LibLC3DecContext { + int frame_us, srate_hz; + bool hr_mode; + void *decoder_mem; + lc3_decoder_t decoder[DECODER_MAX_CHANNELS]; +} LibLC3DecContext; + +static av_cold int liblc3_decode_init(AVCodecContext *avctx) +{ + LibLC3DecContext *liblc3 = avctx->priv_data; + int channels = avctx->ch_layout.nb_channels; + unsigned decoder_size; + + if (avctx->extradata_size < 2) + return AVERROR_INVALIDDATA; + + liblc3->frame_us = AV_RL16(avctx->extradata + 0); + liblc3->srate_hz = avctx->sample_rate; + liblc3->hr_mode = avctx->extradata_size >= 6 && + AV_RL16(avctx->extradata + 4); + + av_log(avctx, AV_LOG_INFO, + "Decoding %.1f ms frames\n", liblc3->frame_us / 1000.f); + if (liblc3->hr_mode) + av_log(avctx, AV_LOG_INFO, "High-resolution mode enabled\n"); + + decoder_size = lc3_hr_decoder_size( + liblc3->hr_mode, liblc3->frame_us, liblc3->srate_hz); + if (!decoder_size) + return AVERROR_INVALIDDATA; + + liblc3->decoder_mem = av_malloc_array(channels, decoder_size); + if (!liblc3->decoder_mem) + return AVERROR(ENOMEM); + + for (int ch = 0; ch < channels; ch++) { + liblc3->decoder[ch] = lc3_hr_setup_decoder( + liblc3->hr_mode, liblc3->frame_us, liblc3->srate_hz, 0, + (char *)liblc3->decoder_mem + ch * decoder_size); + } + + avctx->sample_fmt = AV_SAMPLE_FMT_FLTP; + avctx->delay = lc3_hr_delay_samples( + liblc3->hr_mode, liblc3->frame_us, liblc3->srate_hz); + avctx->internal->skip_samples = avctx->delay; + + return 0; +} + +static av_cold int liblc3_decode_close(AVCodecContext *avctx) +{ + LibLC3DecContext *liblc3 = avctx->priv_data; + + av_freep(&liblc3->decoder_mem); + + return 0; +} + +static int liblc3_decode(AVCodecContext *avctx, AVFrame *frame, + int *got_frame_ptr, AVPacket *avpkt) +{ + LibLC3DecContext *liblc3 = avctx->priv_data; + int channels = avctx->ch_layout.nb_channels; + uint8_t *in = avpkt->data; + int block_bytes, ret; + + frame->nb_samples = av_rescale( + liblc3->frame_us, liblc3->srate_hz, 1000*1000); + if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) + return ret; + + block_bytes = avpkt->size; + for (int ch = 0; ch < channels; ch++) { + int frame_bytes = block_bytes / channels + + (ch < block_bytes % channels); + + ret = lc3_decode(liblc3->decoder[ch], in, frame_bytes, + LC3_PCM_FORMAT_FLOAT, frame->data[ch], 1); + if (ret < 0) + return AVERROR_INVALIDDATA; + + in += frame_bytes; + } + + frame->nb_samples = FFMIN(frame->nb_samples, avpkt->duration); + + *got_frame_ptr = 1; + + return avpkt->size; +} + +const FFCodec ff_liblc3_decoder = { + .p.name = "liblc3", + CODEC_LONG_NAME("LC3 (Low Complexity Communication Codec)"), + .p.type = AVMEDIA_TYPE_AUDIO, + .p.id = AV_CODEC_ID_LC3, + .p.capabilities = AV_CODEC_CAP_DR1, + .p.wrapper_name = "liblc3", + .priv_data_size = sizeof(LibLC3DecContext), + .caps_internal = FF_CODEC_CAP_INIT_CLEANUP, + .init = liblc3_decode_init, + .close = liblc3_decode_close, + FF_CODEC_DECODE_CB(liblc3_decode), +}; diff --git a/libavcodec/liblc3enc.c b/libavcodec/liblc3enc.c new file mode 100644 index 0000000000..5ac45b8cd2 --- /dev/null +++ b/libavcodec/liblc3enc.c @@ -0,0 +1,190 @@ +/* + * LC3 encoder wrapper + * Copyright (C) 2024 Antoine Soulier <asoulier@google.com> + * + * This file is part of FFmpeg. + * + * Permission to use, copy, modify, and/or distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#include <lc3.h> + +#include "libavutil/intreadwrite.h" +#include "libavutil/opt.h" + +#include "avcodec.h" +#include "codec.h" +#include "codec_internal.h" +#include "encode.h" + +#define ENCODER_MAX_CHANNELS 2 + +typedef struct LibLC3EncOpts { + float frame_duration; + int hr_mode; +} LibLC3EncOpts; + +typedef struct LibLC3EncContext { + const AVClass *av_class; + LibLC3EncOpts opts; + int block_bytes; + void *encoder_mem; + lc3_encoder_t encoder[ENCODER_MAX_CHANNELS]; +} LibLC3EncContext; + +static av_cold int liblc3_encode_init(AVCodecContext *avctx) +{ + LibLC3EncContext *liblc3 = avctx->priv_data; + bool hr_mode = liblc3->opts.hr_mode; + int frame_us = liblc3->opts.frame_duration * 1000; + int srate_hz = avctx->sample_rate; + int channels = avctx->ch_layout.nb_channels; + int effective_bit_rate; + unsigned encoder_size; + + if (frame_us != 2500 && frame_us != 5000 && + frame_us != 7500 && frame_us != 10000 ) { + av_log(avctx, AV_LOG_ERROR, + "Unsupported frame duration %.1f ms\n", frame_us / 1000.f); + return AVERROR(EINVAL); + } + + hr_mode |= srate_hz > 48000; + hr_mode &= srate_hz >= 48000; + + if (frame_us == 7500 && hr_mode) { + av_log(avctx, AV_LOG_ERROR, + "High-resolution mode not supported with 7.5 ms frames\n"); + return AVERROR(EINVAL); + } + + av_log(avctx, AV_LOG_INFO, "Encoding %.1f ms frames\n", frame_us / 1000.f); + if (hr_mode) + av_log(avctx, AV_LOG_INFO, "High-resolution mode enabled\n"); + + liblc3->block_bytes = lc3_hr_frame_block_bytes( + hr_mode, frame_us, srate_hz, channels, avctx->bit_rate); + + effective_bit_rate = lc3_hr_resolve_bitrate( + hr_mode, frame_us, srate_hz, liblc3->block_bytes); + + if (avctx->bit_rate != effective_bit_rate) + av_log(avctx, AV_LOG_WARNING, + "Bitrate changed to %d bps\n", effective_bit_rate); + avctx->bit_rate = effective_bit_rate; + + encoder_size = lc3_hr_encoder_size(hr_mode, frame_us, srate_hz); + if (!encoder_size) + return AVERROR(EINVAL); + + liblc3->encoder_mem = av_malloc_array(channels, encoder_size); + if (!liblc3->encoder_mem) + return AVERROR(ENOMEM); + + for (int ch = 0; ch < channels; ch++) { + liblc3->encoder[ch] = + lc3_hr_setup_encoder(hr_mode, frame_us, srate_hz, 0, + (char *)liblc3->encoder_mem + ch * encoder_size); + } + + avctx->extradata = av_mallocz(6 + AV_INPUT_BUFFER_PADDING_SIZE); + if (!avctx->extradata) + return AVERROR(ENOMEM); + + AV_WL16(avctx->extradata + 0, frame_us); + AV_WL16(avctx->extradata + 2, 0); + AV_WL16(avctx->extradata + 4, hr_mode); + avctx->extradata_size = 6; + + avctx->frame_size = av_rescale(frame_us, srate_hz, 1000*1000); + + return 0; +} + +static av_cold int liblc3_encode_close(AVCodecContext *avctx) +{ + LibLC3EncContext *liblc3 = avctx->priv_data; + + av_freep(&liblc3->encoder_mem); + + return 0; +} + +static int liblc3_encode(AVCodecContext *avctx, AVPacket *avpkt, + const AVFrame *av_frame, int *got_packet_ptr) +{ + LibLC3EncContext *liblc3 = avctx->priv_data; + int block_bytes = liblc3->block_bytes; + int channels = avctx->ch_layout.nb_channels; + uint8_t *data_ptr; + int ret; + + if ((ret = ff_get_encode_buffer(avctx, avpkt, block_bytes, 0)) < 0) + return ret; + + data_ptr = avpkt->data; + for (int ch = 0; ch < channels; ch++) { + int frame_bytes = block_bytes / channels + + (ch < block_bytes % channels); + + lc3_encode(liblc3->encoder[ch], + LC3_PCM_FORMAT_FLOAT, av_frame->data[ch], 1, + frame_bytes, data_ptr); + + data_ptr += frame_bytes; + } + + *got_packet_ptr = 1; + + return 0; +} + +#define OFFSET(x) offsetof(LibLC3EncContext, opts.x) +#define FLAGS AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_ENCODING_PARAM +static const AVOption options[] = { + { "frame_duration", "Duration of a frame in milliseconds", + OFFSET(frame_duration), AV_OPT_TYPE_FLOAT, + { .dbl = 10.0 }, 2.5, 10.0, FLAGS }, + { "high_resolution", "Enable High-Resolution mode (48 KHz or 96 KHz)", + OFFSET(hr_mode), AV_OPT_TYPE_BOOL, + { .i64 = 0 }, 0, 1, FLAGS }, + { NULL } +}; + +static const AVClass class = { + .class_name = "liblc3 encoder", + .item_name = av_default_item_name, + .option = options, + .version = LIBAVUTIL_VERSION_INT, +}; + +const FFCodec ff_liblc3_encoder = { + .p.name = "liblc3", + CODEC_LONG_NAME("LC3 (Low Complexity Communication Codec)"), + .p.type = AVMEDIA_TYPE_AUDIO, + .p.id = AV_CODEC_ID_LC3, + .p.capabilities = AV_CODEC_CAP_DR1, + .p.ch_layouts = (const AVChannelLayout[]) + { { AV_CHANNEL_ORDER_UNSPEC, 1 }, + { AV_CHANNEL_ORDER_UNSPEC, 2 }, { 0 } }, + .p.supported_samplerates = (const int []) + { 96000, 48000, 32000, 24000, 16000, 8000, 0 }, + .p.sample_fmts = (const enum AVSampleFormat[]) + { AV_SAMPLE_FMT_FLTP, AV_SAMPLE_FMT_NONE }, + .p.priv_class = &class, + .p.wrapper_name = "liblc3", + .priv_data_size = sizeof(LibLC3EncContext), + .init = liblc3_encode_init, + .close = liblc3_encode_close, + FF_CODEC_ENCODE_CB(liblc3_encode), +};
The LC3 audio codec is the default codec of Bluetooth LE audio. This is a wrapper over the liblc3 library (https://github.com/google/liblc3). Signed-off-by: Antoine Soulier <asoulier@google.com> --- doc/encoders.texi | 57 ++++++++++++ doc/general_contents.texi | 11 ++- libavcodec/Makefile | 2 + libavcodec/allcodecs.c | 2 + libavcodec/codec_desc.c | 7 ++ libavcodec/codec_id.h | 1 + libavcodec/liblc3dec.c | 135 +++++++++++++++++++++++++++ libavcodec/liblc3enc.c | 190 ++++++++++++++++++++++++++++++++++++++ 8 files changed, 404 insertions(+), 1 deletion(-) create mode 100644 libavcodec/liblc3dec.c create mode 100644 libavcodec/liblc3enc.c