mirror of https://github.com/FFmpeg/FFmpeg.git
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>release/7.1
Antoine Soulier via ffmpeg-devel
9 months ago
committed by
Stefano Sabatini
parent
e3335e9e9e
commit
240fd04db2
10 changed files with 443 additions and 1 deletions
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/*
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* LC3 decoder wrapper |
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* Copyright (C) 2024 Antoine Soulier <asoulier@google.com> |
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* |
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* This file is part of FFmpeg. |
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* |
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* Permission to use, copy, modify, and/or distribute this software for any |
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* purpose with or without fee is hereby granted, provided that the above |
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* copyright notice and this permission notice appear in all copies. |
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* |
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES |
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR |
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN |
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF |
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
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*/ |
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#include <lc3.h> |
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#include "libavutil/intreadwrite.h" |
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#include "libavutil/mem.h" |
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#include "avcodec.h" |
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#include "codec.h" |
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#include "codec_internal.h" |
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#include "decode.h" |
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#include "internal.h" |
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#define DECODER_MAX_CHANNELS 2 |
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typedef struct LibLC3DecContext { |
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int frame_us, srate_hz, hr_mode; |
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void *decoder_mem; |
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lc3_decoder_t decoder[DECODER_MAX_CHANNELS]; |
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int64_t length; |
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} LibLC3DecContext; |
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static av_cold int liblc3_decode_init(AVCodecContext *avctx) |
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{ |
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LibLC3DecContext *liblc3 = avctx->priv_data; |
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int channels = avctx->ch_layout.nb_channels; |
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int ep_mode; |
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unsigned decoder_size; |
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if (avctx->extradata_size < 10) |
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return AVERROR_INVALIDDATA; |
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liblc3->frame_us = AV_RL16(avctx->extradata + 0) * 10; |
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liblc3->srate_hz = avctx->sample_rate; |
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ep_mode = AV_RL16(avctx->extradata + 2); |
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liblc3->hr_mode = AV_RL16(avctx->extradata + 4); |
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liblc3->length = AV_RL32(avctx->extradata + 6); |
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if (ep_mode != 0) { |
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av_log(avctx, AV_LOG_ERROR, |
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"Error protection mode is not supported.\n"); |
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return AVERROR(EINVAL); |
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} |
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av_log(avctx, AV_LOG_INFO, |
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"Decoding %.1f ms frames.\n", liblc3->frame_us / 1000.f); |
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if (liblc3->hr_mode) |
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av_log(avctx, AV_LOG_INFO, "High-resolution mode enabled.\n"); |
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decoder_size = lc3_hr_decoder_size( |
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liblc3->hr_mode, liblc3->frame_us, liblc3->srate_hz); |
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if (!decoder_size) |
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return AVERROR_INVALIDDATA; |
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liblc3->decoder_mem = av_malloc_array(channels, decoder_size); |
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if (!liblc3->decoder_mem) |
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return AVERROR(ENOMEM); |
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for (int ch = 0; ch < channels; ch++) { |
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liblc3->decoder[ch] = lc3_hr_setup_decoder( |
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liblc3->hr_mode, liblc3->frame_us, liblc3->srate_hz, 0, |
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(char *)liblc3->decoder_mem + ch * decoder_size); |
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} |
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avctx->sample_fmt = AV_SAMPLE_FMT_FLTP; |
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avctx->delay = lc3_hr_delay_samples( |
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liblc3->hr_mode, liblc3->frame_us, liblc3->srate_hz); |
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avctx->internal->skip_samples = avctx->delay; |
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return 0; |
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} |
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static av_cold int liblc3_decode_close(AVCodecContext *avctx) |
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{ |
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LibLC3DecContext *liblc3 = avctx->priv_data; |
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av_freep(&liblc3->decoder_mem); |
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return 0; |
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} |
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static int liblc3_decode(AVCodecContext *avctx, AVFrame *frame, |
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int *got_frame_ptr, AVPacket *avpkt) |
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{ |
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LibLC3DecContext *liblc3 = avctx->priv_data; |
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int channels = avctx->ch_layout.nb_channels; |
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uint8_t *in = avpkt->data; |
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int block_bytes, ret; |
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frame->nb_samples = av_rescale( |
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liblc3->frame_us, liblc3->srate_hz, 1000*1000); |
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if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) |
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return ret; |
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block_bytes = avpkt->size; |
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for (int ch = 0; ch < channels; ch++) { |
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int nbytes = block_bytes / channels + (ch < block_bytes % channels); |
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ret = lc3_decode(liblc3->decoder[ch], in, nbytes, |
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LC3_PCM_FORMAT_FLOAT, frame->data[ch], 1); |
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if (ret < 0) |
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return AVERROR_INVALIDDATA; |
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in += nbytes; |
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} |
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if (liblc3->length > 0) { |
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int64_t end_pts = liblc3->length + avctx->delay; |
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frame->nb_samples = FFMIN(frame->nb_samples, |
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FFMAX(end_pts - frame->pts, 0)); |
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} |
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*got_frame_ptr = 1; |
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return avpkt->size; |
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} |
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const FFCodec ff_liblc3_decoder = { |
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.p.name = "liblc3", |
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CODEC_LONG_NAME("LC3 (Low Complexity Communication Codec)"), |
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.p.type = AVMEDIA_TYPE_AUDIO, |
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.p.id = AV_CODEC_ID_LC3, |
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.p.capabilities = AV_CODEC_CAP_DR1, |
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.p.wrapper_name = "liblc3", |
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.priv_data_size = sizeof(LibLC3DecContext), |
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.caps_internal = FF_CODEC_CAP_INIT_CLEANUP, |
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.init = liblc3_decode_init, |
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.close = liblc3_decode_close, |
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FF_CODEC_DECODE_CB(liblc3_decode), |
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}; |
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@ -0,0 +1,211 @@ |
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/*
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* LC3 encoder wrapper |
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* Copyright (C) 2024 Antoine Soulier <asoulier@google.com> |
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* |
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* This file is part of FFmpeg. |
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* |
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* Permission to use, copy, modify, and/or distribute this software for any |
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* purpose with or without fee is hereby granted, provided that the above |
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* copyright notice and this permission notice appear in all copies. |
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* |
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES |
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR |
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN |
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF |
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
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*/ |
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#include <lc3.h> |
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#include "libavutil/intreadwrite.h" |
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#include "libavutil/opt.h" |
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#include "libavutil/mem.h" |
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#include "avcodec.h" |
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#include "codec.h" |
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#include "codec_internal.h" |
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#include "encode.h" |
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#define ENCODER_MAX_CHANNELS 2 |
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typedef struct LibLC3EncOpts { |
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float frame_duration; |
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int hr_mode; |
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} LibLC3EncOpts; |
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typedef struct LibLC3EncContext { |
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const AVClass *av_class; |
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LibLC3EncOpts opts; |
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int block_bytes; |
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void *encoder_mem; |
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lc3_encoder_t encoder[ENCODER_MAX_CHANNELS]; |
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int delay_samples; |
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int remaining_samples; |
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} LibLC3EncContext; |
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static av_cold int liblc3_encode_init(AVCodecContext *avctx) |
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{ |
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LibLC3EncContext *liblc3 = avctx->priv_data; |
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bool hr_mode = liblc3->opts.hr_mode; |
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int frame_us = liblc3->opts.frame_duration * 1000; |
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int srate_hz = avctx->sample_rate; |
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int channels = avctx->ch_layout.nb_channels; |
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int effective_bit_rate; |
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unsigned encoder_size; |
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if (frame_us != 2500 && frame_us != 5000 && |
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frame_us != 7500 && frame_us != 10000 ) { |
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av_log(avctx, AV_LOG_ERROR, |
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"Unsupported frame duration %.1f ms.\n", frame_us / 1000.f); |
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return AVERROR(EINVAL); |
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} |
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hr_mode |= srate_hz > 48000; |
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hr_mode &= srate_hz >= 48000; |
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if (frame_us == 7500 && hr_mode) { |
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av_log(avctx, AV_LOG_ERROR, |
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"High-resolution mode is not supported with 7.5 ms frames.\n"); |
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return AVERROR(EINVAL); |
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} |
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av_log(avctx, AV_LOG_INFO, "Encoding %.1f ms frames.\n", frame_us / 1000.f); |
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if (hr_mode) |
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av_log(avctx, AV_LOG_INFO, "High-resolution mode is enabled.\n"); |
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liblc3->block_bytes = lc3_hr_frame_block_bytes( |
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hr_mode, frame_us, srate_hz, channels, avctx->bit_rate); |
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effective_bit_rate = lc3_hr_resolve_bitrate( |
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hr_mode, frame_us, srate_hz, liblc3->block_bytes); |
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if (avctx->bit_rate != effective_bit_rate) |
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av_log(avctx, AV_LOG_WARNING, |
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"Bitrate changed to %d bps.\n", effective_bit_rate); |
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avctx->bit_rate = effective_bit_rate; |
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encoder_size = lc3_hr_encoder_size(hr_mode, frame_us, srate_hz); |
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if (!encoder_size) |
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return AVERROR(EINVAL); |
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liblc3->encoder_mem = av_malloc_array(channels, encoder_size); |
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if (!liblc3->encoder_mem) |
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return AVERROR(ENOMEM); |
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for (int ch = 0; ch < channels; ch++) { |
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liblc3->encoder[ch] = lc3_hr_setup_encoder( |
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hr_mode, frame_us, srate_hz, 0, |
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(char *)liblc3->encoder_mem + ch * encoder_size); |
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} |
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avctx->extradata = av_mallocz(6 + AV_INPUT_BUFFER_PADDING_SIZE); |
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if (!avctx->extradata) |
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return AVERROR(ENOMEM); |
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AV_WL16(avctx->extradata + 0, frame_us / 10); |
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AV_WL16(avctx->extradata + 2, 0); |
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AV_WL16(avctx->extradata + 4, hr_mode); |
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avctx->extradata_size = 6; |
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avctx->frame_size = av_rescale(frame_us, srate_hz, 1000*1000); |
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liblc3->delay_samples = lc3_hr_delay_samples(hr_mode, frame_us, srate_hz); |
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liblc3->remaining_samples = 0; |
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return 0; |
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} |
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static av_cold int liblc3_encode_close(AVCodecContext *avctx) |
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{ |
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LibLC3EncContext *liblc3 = avctx->priv_data; |
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av_freep(&liblc3->encoder_mem); |
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return 0; |
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} |
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static int liblc3_encode(AVCodecContext *avctx, AVPacket *pkt, |
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const AVFrame *frame, int *got_packet_ptr) |
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{ |
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LibLC3EncContext *liblc3 = avctx->priv_data; |
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int block_bytes = liblc3->block_bytes; |
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int channels = avctx->ch_layout.nb_channels; |
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void *zero_frame = NULL; |
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uint8_t *data_ptr; |
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int ret; |
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if ((ret = ff_get_encode_buffer(avctx, pkt, block_bytes, 0)) < 0) |
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return ret; |
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if (frame) { |
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int padding = frame->nb_samples - frame->duration; |
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liblc3->remaining_samples = FFMAX(liblc3->delay_samples - padding, 0); |
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} else { |
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if (!liblc3->remaining_samples) |
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return 0; |
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liblc3->remaining_samples = 0; |
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zero_frame = av_mallocz(avctx->frame_size * sizeof(float)); |
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if (!zero_frame) |
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return AVERROR(ENOMEM); |
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} |
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data_ptr = pkt->data; |
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for (int ch = 0; ch < channels; ch++) { |
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const float *pcm = zero_frame ? zero_frame : frame->data[ch]; |
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int nbytes = block_bytes / channels + (ch < block_bytes % channels); |
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lc3_encode(liblc3->encoder[ch], |
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LC3_PCM_FORMAT_FLOAT, pcm, 1, nbytes, data_ptr); |
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data_ptr += nbytes; |
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} |
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if (zero_frame) |
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av_free(zero_frame); |
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*got_packet_ptr = 1; |
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return 0; |
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} |
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#define OFFSET(x) offsetof(LibLC3EncContext, opts.x) |
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#define FLAGS AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_ENCODING_PARAM |
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static const AVOption options[] = { |
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{ "frame_duration", "Duration of a frame in milliseconds", |
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OFFSET(frame_duration), AV_OPT_TYPE_FLOAT, |
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{ .dbl = 10.0 }, 2.5, 10.0, FLAGS }, |
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{ "high_resolution", "Enable High-Resolution mode (48 KHz or 96 KHz)", |
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OFFSET(hr_mode), AV_OPT_TYPE_BOOL, |
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{ .i64 = 0 }, 0, 1, FLAGS }, |
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{ NULL } |
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}; |
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static const AVClass class = { |
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.class_name = "liblc3 encoder", |
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.item_name = av_default_item_name, |
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.option = options, |
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.version = LIBAVUTIL_VERSION_INT, |
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}; |
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const FFCodec ff_liblc3_encoder = { |
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.p.name = "liblc3", |
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CODEC_LONG_NAME("LC3 (Low Complexity Communication Codec)"), |
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.p.type = AVMEDIA_TYPE_AUDIO, |
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.p.id = AV_CODEC_ID_LC3, |
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.p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_DELAY, |
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.p.ch_layouts = (const AVChannelLayout[]) |
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{ { AV_CHANNEL_ORDER_UNSPEC, 1 }, |
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{ AV_CHANNEL_ORDER_UNSPEC, 2 }, { 0 } }, |
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.p.supported_samplerates = (const int []) |
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{ 96000, 48000, 32000, 24000, 16000, 8000, 0 }, |
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.p.sample_fmts = (const enum AVSampleFormat[]) |
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{ AV_SAMPLE_FMT_FLTP, AV_SAMPLE_FMT_NONE }, |
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.p.priv_class = &class, |
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.p.wrapper_name = "liblc3", |
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.priv_data_size = sizeof(LibLC3EncContext), |
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.init = liblc3_encode_init, |
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.close = liblc3_encode_close, |
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FF_CODEC_ENCODE_CB(liblc3_encode), |
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}; |
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