@@ -1,6 +1,10 @@
Entries are sorted chronologically from oldest to youngest within each release,
releases are sorted from youngest to oldest.
+version <next>:
+- LC3/LC3plus decoding/encoding using external library liblc3
+
+
version 7.0:
- DXV DXT1 encoder
- LEAD MCMP decoder
@@ -244,6 +244,7 @@ External library support:
--enable-libjxl enable JPEG XL de/encoding via libjxl [no]
--enable-libklvanc enable Kernel Labs VANC processing [no]
--enable-libkvazaar enable HEVC encoding via libkvazaar [no]
+ --enable-liblc3 enable LC3 de/encoding via liblc3 [no]
--enable-liblensfun enable lensfun lens correction [no]
--enable-libmodplug enable ModPlug via libmodplug [no]
--enable-libmp3lame enable MP3 encoding via libmp3lame [no]
@@ -1926,6 +1927,7 @@ EXTERNAL_LIBRARY_LIST="
libjxl
libklvanc
libkvazaar
+ liblc3
libmodplug
libmp3lame
libmysofa
@@ -3499,6 +3501,9 @@ libilbc_encoder_deps="libilbc"
libjxl_decoder_deps="libjxl libjxl_threads"
libjxl_encoder_deps="libjxl libjxl_threads"
libkvazaar_encoder_deps="libkvazaar"
+liblc3_decoder_deps="liblc3"
+liblc3_encoder_deps="liblc3"
+liblc3_encoder_select="audio_frame_queue"
libmodplug_demuxer_deps="libmodplug"
libmp3lame_encoder_deps="libmp3lame"
libmp3lame_encoder_select="audio_frame_queue mpegaudioheader"
@@ -6869,6 +6874,7 @@ enabled libjxl && require_pkg_config libjxl "libjxl >= 0.7.0" jxl/dec
require_pkg_config libjxl_threads "libjxl_threads >= 0.7.0" jxl/thread_parallel_runner.h JxlThreadParallelRunner
enabled libklvanc && require libklvanc libklvanc/vanc.h klvanc_context_create -lklvanc
enabled libkvazaar && require_pkg_config libkvazaar "kvazaar >= 2.0.0" kvazaar.h kvz_api_get
+enabled liblc3 && require_pkg_config liblc3 "lc3 >= 1.1.0" lc3.h lc3_hr_setup_encoder
enabled liblensfun && require_pkg_config liblensfun lensfun lensfun.h lf_db_create
if enabled libmfx && enabled libvpl; then
@@ -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
@@ -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
@@ -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
@@ -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;
@@ -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 */
{
@@ -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.
new file mode 100644
@@ -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),
+};
new file mode 100644
@@ -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> --- Changelog | 4 + configure | 6 ++ 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 ++++++++++++++++++++++++++++++++++++++ 10 files changed, 414 insertions(+), 1 deletion(-) create mode 100644 libavcodec/liblc3dec.c create mode 100644 libavcodec/liblc3enc.c