yading@10: /*
yading@10:  * Opus encoder using libopus
yading@10:  * Copyright (c) 2012 Nathan Caldwell
yading@10:  *
yading@10:  * This file is part of FFmpeg.
yading@10:  *
yading@10:  * FFmpeg is free software; you can redistribute it and/or
yading@10:  * modify it under the terms of the GNU Lesser General Public
yading@10:  * License as published by the Free Software Foundation; either
yading@10:  * version 2.1 of the License, or (at your option) any later version.
yading@10:  *
yading@10:  * FFmpeg is distributed in the hope that it will be useful,
yading@10:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@10:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@10:  * Lesser General Public License for more details.
yading@10:  *
yading@10:  * You should have received a copy of the GNU Lesser General Public
yading@10:  * License along with FFmpeg; if not, write to the Free Software
yading@10:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@10:  */
yading@10: 
yading@10: #include <opus.h>
yading@10: #include <opus_multistream.h>
yading@10: 
yading@10: #include "libavutil/opt.h"
yading@10: #include "avcodec.h"
yading@10: #include "bytestream.h"
yading@10: #include "internal.h"
yading@10: #include "libopus.h"
yading@10: #include "vorbis.h"
yading@10: #include "audio_frame_queue.h"
yading@10: 
yading@10: typedef struct LibopusEncOpts {
yading@10:     int vbr;
yading@10:     int application;
yading@10:     int packet_loss;
yading@10:     int complexity;
yading@10:     float frame_duration;
yading@10:     int packet_size;
yading@10:     int max_bandwidth;
yading@10: } LibopusEncOpts;
yading@10: 
yading@10: typedef struct LibopusEncContext {
yading@10:     AVClass *class;
yading@10:     OpusMSEncoder *enc;
yading@10:     int stream_count;
yading@10:     uint8_t *samples;
yading@10:     LibopusEncOpts opts;
yading@10:     AudioFrameQueue afq;
yading@10: } LibopusEncContext;
yading@10: 
yading@10: static const uint8_t opus_coupled_streams[8] = {
yading@10:     0, 1, 1, 2, 2, 2, 2, 3
yading@10: };
yading@10: 
yading@10: /* Opus internal to Vorbis channel order mapping written in the header */
yading@10: static const uint8_t opus_vorbis_channel_map[8][8] = {
yading@10:     { 0 },
yading@10:     { 0, 1 },
yading@10:     { 0, 2, 1 },
yading@10:     { 0, 1, 2, 3 },
yading@10:     { 0, 4, 1, 2, 3 },
yading@10:     { 0, 4, 1, 2, 3, 5 },
yading@10:     { 0, 4, 1, 2, 3, 5, 6 },
yading@10:     { 0, 6, 1, 2, 3, 4, 5, 7 },
yading@10: };
yading@10: 
yading@10: /* libavcodec to libopus channel order mapping, passed to libopus */
yading@10: static const uint8_t libavcodec_libopus_channel_map[8][8] = {
yading@10:     { 0 },
yading@10:     { 0, 1 },
yading@10:     { 0, 1, 2 },
yading@10:     { 0, 1, 2, 3 },
yading@10:     { 0, 1, 3, 4, 2 },
yading@10:     { 0, 1, 4, 5, 2, 3 },
yading@10:     { 0, 1, 5, 6, 2, 4, 3 },
yading@10:     { 0, 1, 6, 7, 4, 5, 2, 3 },
yading@10: };
yading@10: 
yading@10: static void libopus_write_header(AVCodecContext *avctx, int stream_count,
yading@10:                                  int coupled_stream_count,
yading@10:                                  const uint8_t *channel_mapping)
yading@10: {
yading@10:     uint8_t *p   = avctx->extradata;
yading@10:     int channels = avctx->channels;
yading@10: 
yading@10:     bytestream_put_buffer(&p, "OpusHead", 8);
yading@10:     bytestream_put_byte(&p, 1); /* Version */
yading@10:     bytestream_put_byte(&p, channels);
yading@10:     bytestream_put_le16(&p, avctx->delay); /* Lookahead samples at 48kHz */
yading@10:     bytestream_put_le32(&p, avctx->sample_rate); /* Original sample rate */
yading@10:     bytestream_put_le16(&p, 0); /* Gain of 0dB is recommended. */
yading@10: 
yading@10:     /* Channel mapping */
yading@10:     if (channels > 2) {
yading@10:         bytestream_put_byte(&p, channels <= 8 ? 1 : 255);
yading@10:         bytestream_put_byte(&p, stream_count);
yading@10:         bytestream_put_byte(&p, coupled_stream_count);
yading@10:         bytestream_put_buffer(&p, channel_mapping, channels);
yading@10:     } else {
yading@10:         bytestream_put_byte(&p, 0);
yading@10:     }
yading@10: }
yading@10: 
yading@10: static int libopus_configure_encoder(AVCodecContext *avctx, OpusMSEncoder *enc,
yading@10:                                      LibopusEncOpts *opts)
yading@10: {
yading@10:     int ret;
yading@10: 
yading@10:     if (avctx->global_quality) {
yading@10:         av_log(avctx, AV_LOG_ERROR,
yading@10:                "Quality-based encoding not supported, "
yading@10:                "please specify a bitrate and VBR setting.\n");
yading@10:         return AVERROR(EINVAL);
yading@10:     }
yading@10: 
yading@10:     ret = opus_multistream_encoder_ctl(enc, OPUS_SET_BITRATE(avctx->bit_rate));
yading@10:     if (ret != OPUS_OK) {
yading@10:         av_log(avctx, AV_LOG_ERROR,
yading@10:                "Failed to set bitrate: %s\n", opus_strerror(ret));
yading@10:         return ret;
yading@10:     }
yading@10: 
yading@10:     ret = opus_multistream_encoder_ctl(enc,
yading@10:                                        OPUS_SET_COMPLEXITY(opts->complexity));
yading@10:     if (ret != OPUS_OK)
yading@10:         av_log(avctx, AV_LOG_WARNING,
yading@10:                "Unable to set complexity: %s\n", opus_strerror(ret));
yading@10: 
yading@10:     ret = opus_multistream_encoder_ctl(enc, OPUS_SET_VBR(!!opts->vbr));
yading@10:     if (ret != OPUS_OK)
yading@10:         av_log(avctx, AV_LOG_WARNING,
yading@10:                "Unable to set VBR: %s\n", opus_strerror(ret));
yading@10: 
yading@10:     ret = opus_multistream_encoder_ctl(enc,
yading@10:                                        OPUS_SET_VBR_CONSTRAINT(opts->vbr == 2));
yading@10:     if (ret != OPUS_OK)
yading@10:         av_log(avctx, AV_LOG_WARNING,
yading@10:                "Unable to set constrained VBR: %s\n", opus_strerror(ret));
yading@10: 
yading@10:     ret = opus_multistream_encoder_ctl(enc,
yading@10:                                        OPUS_SET_PACKET_LOSS_PERC(opts->packet_loss));
yading@10:     if (ret != OPUS_OK)
yading@10:         av_log(avctx, AV_LOG_WARNING,
yading@10:                "Unable to set expected packet loss percentage: %s\n",
yading@10:                opus_strerror(ret));
yading@10: 
yading@10:     if (avctx->cutoff) {
yading@10:         ret = opus_multistream_encoder_ctl(enc,
yading@10:                                            OPUS_SET_MAX_BANDWIDTH(opts->max_bandwidth));
yading@10:         if (ret != OPUS_OK)
yading@10:             av_log(avctx, AV_LOG_WARNING,
yading@10:                    "Unable to set maximum bandwidth: %s\n", opus_strerror(ret));
yading@10:     }
yading@10: 
yading@10:     return OPUS_OK;
yading@10: }
yading@10: 
yading@10: static int av_cold libopus_encode_init(AVCodecContext *avctx)
yading@10: {
yading@10:     LibopusEncContext *opus = avctx->priv_data;
yading@10:     const uint8_t *channel_mapping;
yading@10:     OpusMSEncoder *enc;
yading@10:     int ret = OPUS_OK;
yading@10:     int coupled_stream_count, header_size, frame_size;
yading@10: 
yading@10:     coupled_stream_count = opus_coupled_streams[avctx->channels - 1];
yading@10:     opus->stream_count   = avctx->channels - coupled_stream_count;
yading@10:     channel_mapping      = libavcodec_libopus_channel_map[avctx->channels - 1];
yading@10: 
yading@10:     /* FIXME: Opus can handle up to 255 channels. However, the mapping for
yading@10:      * anything greater than 8 is undefined. */
yading@10:     if (avctx->channels > 8)
yading@10:         av_log(avctx, AV_LOG_WARNING,
yading@10:                "Channel layout undefined for %d channels.\n", avctx->channels);
yading@10: 
yading@10:     if (!avctx->bit_rate) {
yading@10:         /* Sane default copied from opusenc */
yading@10:         avctx->bit_rate = 64000 * opus->stream_count +
yading@10:                           32000 * coupled_stream_count;
yading@10:         av_log(avctx, AV_LOG_WARNING,
yading@10:                "No bit rate set. Defaulting to %d bps.\n", avctx->bit_rate);
yading@10:     }
yading@10: 
yading@10:     if (avctx->bit_rate < 500 || avctx->bit_rate > 256000 * avctx->channels) {
yading@10:         av_log(avctx, AV_LOG_ERROR, "The bit rate %d bps is unsupported. "
yading@10:                "Please choose a value between 500 and %d.\n", avctx->bit_rate,
yading@10:                256000 * avctx->channels);
yading@10:         return AVERROR(EINVAL);
yading@10:     }
yading@10: 
yading@10:     frame_size = opus->opts.frame_duration * 48000 / 1000;
yading@10:     switch (frame_size) {
yading@10:     case 120:
yading@10:     case 240:
yading@10:         if (opus->opts.application != OPUS_APPLICATION_RESTRICTED_LOWDELAY)
yading@10:             av_log(avctx, AV_LOG_WARNING,
yading@10:                    "LPC mode cannot be used with a frame duration of less "
yading@10:                    "than 10ms. Enabling restricted low-delay mode.\n"
yading@10:                    "Use a longer frame duration if this is not what you want.\n");
yading@10:         /* Frame sizes less than 10 ms can only use MDCT mode, so switching to
yading@10:          * RESTRICTED_LOWDELAY avoids an unnecessary extra 2.5ms lookahead. */
yading@10:         opus->opts.application = OPUS_APPLICATION_RESTRICTED_LOWDELAY;
yading@10:     case 480:
yading@10:     case 960:
yading@10:     case 1920:
yading@10:     case 2880:
yading@10:         opus->opts.packet_size =
yading@10:         avctx->frame_size      = frame_size * avctx->sample_rate / 48000;
yading@10:         break;
yading@10:     default:
yading@10:         av_log(avctx, AV_LOG_ERROR, "Invalid frame duration: %g.\n"
yading@10:                "Frame duration must be exactly one of: 2.5, 5, 10, 20, 40 or 60.\n",
yading@10:                opus->opts.frame_duration);
yading@10:         return AVERROR(EINVAL);
yading@10:     }
yading@10: 
yading@10:     if (avctx->compression_level < 0 || avctx->compression_level > 10) {
yading@10:         av_log(avctx, AV_LOG_WARNING,
yading@10:                "Compression level must be in the range 0 to 10. "
yading@10:                "Defaulting to 10.\n");
yading@10:         opus->opts.complexity = 10;
yading@10:     } else {
yading@10:         opus->opts.complexity = avctx->compression_level;
yading@10:     }
yading@10: 
yading@10:     if (avctx->cutoff) {
yading@10:         switch (avctx->cutoff) {
yading@10:         case  4000:
yading@10:             opus->opts.max_bandwidth = OPUS_BANDWIDTH_NARROWBAND;
yading@10:             break;
yading@10:         case  6000:
yading@10:             opus->opts.max_bandwidth = OPUS_BANDWIDTH_MEDIUMBAND;
yading@10:             break;
yading@10:         case  8000:
yading@10:             opus->opts.max_bandwidth = OPUS_BANDWIDTH_WIDEBAND;
yading@10:             break;
yading@10:         case 12000:
yading@10:             opus->opts.max_bandwidth = OPUS_BANDWIDTH_SUPERWIDEBAND;
yading@10:             break;
yading@10:         case 20000:
yading@10:             opus->opts.max_bandwidth = OPUS_BANDWIDTH_FULLBAND;
yading@10:             break;
yading@10:         default:
yading@10:             av_log(avctx, AV_LOG_WARNING,
yading@10:                    "Invalid frequency cutoff: %d. Using default maximum bandwidth.\n"
yading@10:                    "Cutoff frequency must be exactly one of: 4000, 6000, 8000, 12000 or 20000.\n",
yading@10:                    avctx->cutoff);
yading@10:             avctx->cutoff = 0;
yading@10:         }
yading@10:     }
yading@10: 
yading@10:     enc = opus_multistream_encoder_create(avctx->sample_rate, avctx->channels,
yading@10:                                           opus->stream_count,
yading@10:                                           coupled_stream_count,
yading@10:                                           channel_mapping,
yading@10:                                           opus->opts.application, &ret);
yading@10:     if (ret != OPUS_OK) {
yading@10:         av_log(avctx, AV_LOG_ERROR,
yading@10:                "Failed to create encoder: %s\n", opus_strerror(ret));
yading@10:         return ff_opus_error_to_averror(ret);
yading@10:     }
yading@10: 
yading@10:     ret = libopus_configure_encoder(avctx, enc, &opus->opts);
yading@10:     if (ret != OPUS_OK) {
yading@10:         ret = ff_opus_error_to_averror(ret);
yading@10:         goto fail;
yading@10:     }
yading@10: 
yading@10:     header_size = 19 + (avctx->channels > 2 ? 2 + avctx->channels : 0);
yading@10:     avctx->extradata = av_malloc(header_size + FF_INPUT_BUFFER_PADDING_SIZE);
yading@10:     if (!avctx->extradata) {
yading@10:         av_log(avctx, AV_LOG_ERROR, "Failed to allocate extradata.\n");
yading@10:         ret = AVERROR(ENOMEM);
yading@10:         goto fail;
yading@10:     }
yading@10:     avctx->extradata_size = header_size;
yading@10: 
yading@10:     opus->samples = av_mallocz(frame_size * avctx->channels *
yading@10:                                av_get_bytes_per_sample(avctx->sample_fmt));
yading@10:     if (!opus->samples) {
yading@10:         av_log(avctx, AV_LOG_ERROR, "Failed to allocate samples buffer.\n");
yading@10:         ret = AVERROR(ENOMEM);
yading@10:         goto fail;
yading@10:     }
yading@10: 
yading@10:     ret = opus_multistream_encoder_ctl(enc, OPUS_GET_LOOKAHEAD(&avctx->delay));
yading@10:     if (ret != OPUS_OK)
yading@10:         av_log(avctx, AV_LOG_WARNING,
yading@10:                "Unable to get number of lookahead samples: %s\n",
yading@10:                opus_strerror(ret));
yading@10: 
yading@10:     libopus_write_header(avctx, opus->stream_count, coupled_stream_count,
yading@10:                          opus_vorbis_channel_map[avctx->channels - 1]);
yading@10: 
yading@10:     ff_af_queue_init(avctx, &opus->afq);
yading@10: 
yading@10:     opus->enc = enc;
yading@10: 
yading@10:     return 0;
yading@10: 
yading@10: fail:
yading@10:     opus_multistream_encoder_destroy(enc);
yading@10:     av_freep(&avctx->extradata);
yading@10:     return ret;
yading@10: }
yading@10: 
yading@10: static int libopus_encode(AVCodecContext *avctx, AVPacket *avpkt,
yading@10:                           const AVFrame *frame, int *got_packet_ptr)
yading@10: {
yading@10:     LibopusEncContext *opus = avctx->priv_data;
yading@10:     const int sample_size   = avctx->channels *
yading@10:                               av_get_bytes_per_sample(avctx->sample_fmt);
yading@10:     uint8_t *audio;
yading@10:     int ret;
yading@10: 
yading@10:     if (frame) {
yading@10:         ff_af_queue_add(&opus->afq, frame);
yading@10:         if (frame->nb_samples < opus->opts.packet_size) {
yading@10:             audio = opus->samples;
yading@10:             memcpy(audio, frame->data[0], frame->nb_samples * sample_size);
yading@10:         } else
yading@10:             audio = frame->data[0];
yading@10:     } else {
yading@10:         if (!opus->afq.remaining_samples)
yading@10:             return 0;
yading@10:         audio = opus->samples;
yading@10:         memset(audio, 0, opus->opts.packet_size * sample_size);
yading@10:     }
yading@10: 
yading@10:     /* Maximum packet size taken from opusenc in opus-tools. 60ms packets
yading@10:      * consist of 3 frames in one packet. The maximum frame size is 1275
yading@10:      * bytes along with the largest possible packet header of 7 bytes. */
yading@10:     if ((ret = ff_alloc_packet2(avctx, avpkt, (1275 * 3 + 7) * opus->stream_count)) < 0)
yading@10:         return ret;
yading@10: 
yading@10:     if (avctx->sample_fmt == AV_SAMPLE_FMT_FLT)
yading@10:         ret = opus_multistream_encode_float(opus->enc, (float *)audio,
yading@10:                                             opus->opts.packet_size,
yading@10:                                             avpkt->data, avpkt->size);
yading@10:     else
yading@10:         ret = opus_multistream_encode(opus->enc, (opus_int16 *)audio,
yading@10:                                       opus->opts.packet_size,
yading@10:                                       avpkt->data, avpkt->size);
yading@10: 
yading@10:     if (ret < 0) {
yading@10:         av_log(avctx, AV_LOG_ERROR,
yading@10:                "Error encoding frame: %s\n", opus_strerror(ret));
yading@10:         return ff_opus_error_to_averror(ret);
yading@10:     }
yading@10: 
yading@10:     av_shrink_packet(avpkt, ret);
yading@10: 
yading@10:     ff_af_queue_remove(&opus->afq, opus->opts.packet_size,
yading@10:                        &avpkt->pts, &avpkt->duration);
yading@10: 
yading@10:     *got_packet_ptr = 1;
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static int av_cold libopus_encode_close(AVCodecContext *avctx)
yading@10: {
yading@10:     LibopusEncContext *opus = avctx->priv_data;
yading@10: 
yading@10:     opus_multistream_encoder_destroy(opus->enc);
yading@10: 
yading@10:     ff_af_queue_close(&opus->afq);
yading@10: 
yading@10:     av_freep(&opus->samples);
yading@10:     av_freep(&avctx->extradata);
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: #define OFFSET(x) offsetof(LibopusEncContext, opts.x)
yading@10: #define FLAGS AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_ENCODING_PARAM
yading@10: static const AVOption libopus_options[] = {
yading@10:     { "application",    "Intended application type",           OFFSET(application),    AV_OPT_TYPE_INT,   { .i64 = OPUS_APPLICATION_AUDIO }, OPUS_APPLICATION_VOIP, OPUS_APPLICATION_RESTRICTED_LOWDELAY, FLAGS, "application" },
yading@10:         { "voip",           "Favor improved speech intelligibility",   0, AV_OPT_TYPE_CONST, { .i64 = OPUS_APPLICATION_VOIP },                0, 0, FLAGS, "application" },
yading@10:         { "audio",          "Favor faithfulness to the input",         0, AV_OPT_TYPE_CONST, { .i64 = OPUS_APPLICATION_AUDIO },               0, 0, FLAGS, "application" },
yading@10:         { "lowdelay",       "Restrict to only the lowest delay modes", 0, AV_OPT_TYPE_CONST, { .i64 = OPUS_APPLICATION_RESTRICTED_LOWDELAY }, 0, 0, FLAGS, "application" },
yading@10:     { "frame_duration", "Duration of a frame in milliseconds", OFFSET(frame_duration), AV_OPT_TYPE_FLOAT, { .dbl = 10.0 }, 2.5, 60.0, FLAGS },
yading@10:     { "packet_loss",    "Expected packet loss percentage",     OFFSET(packet_loss),    AV_OPT_TYPE_INT,   { .i64 = 0 },    0,   100,  FLAGS },
yading@10:     { "vbr",            "Variable bit rate mode",              OFFSET(vbr),            AV_OPT_TYPE_INT,   { .i64 = 1 },    0,   2,    FLAGS, "vbr" },
yading@10:         { "off",            "Use constant bit rate", 0, AV_OPT_TYPE_CONST, { .i64 = 0 }, 0, 0, FLAGS, "vbr" },
yading@10:         { "on",             "Use variable bit rate", 0, AV_OPT_TYPE_CONST, { .i64 = 1 }, 0, 0, FLAGS, "vbr" },
yading@10:         { "constrained",    "Use constrained VBR",   0, AV_OPT_TYPE_CONST, { .i64 = 2 }, 0, 0, FLAGS, "vbr" },
yading@10:     { NULL },
yading@10: };
yading@10: 
yading@10: static const AVClass libopus_class = {
yading@10:     .class_name = "libopus",
yading@10:     .item_name  = av_default_item_name,
yading@10:     .option     = libopus_options,
yading@10:     .version    = LIBAVUTIL_VERSION_INT,
yading@10: };
yading@10: 
yading@10: static const AVCodecDefault libopus_defaults[] = {
yading@10:     { "b",                 "0" },
yading@10:     { "compression_level", "10" },
yading@10:     { NULL },
yading@10: };
yading@10: 
yading@10: static const int libopus_sample_rates[] = {
yading@10:     48000, 24000, 16000, 12000, 8000, 0,
yading@10: };
yading@10: 
yading@10: AVCodec ff_libopus_encoder = {
yading@10:     .name            = "libopus",
yading@10:     .type            = AVMEDIA_TYPE_AUDIO,
yading@10:     .id              = AV_CODEC_ID_OPUS,
yading@10:     .priv_data_size  = sizeof(LibopusEncContext),
yading@10:     .init            = libopus_encode_init,
yading@10:     .encode2         = libopus_encode,
yading@10:     .close           = libopus_encode_close,
yading@10:     .capabilities    = CODEC_CAP_DELAY | CODEC_CAP_SMALL_LAST_FRAME,
yading@10:     .sample_fmts     = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16,
yading@10:                                                       AV_SAMPLE_FMT_FLT,
yading@10:                                                       AV_SAMPLE_FMT_NONE },
yading@10:     .channel_layouts = ff_vorbis_channel_layouts,
yading@10:     .supported_samplerates = libopus_sample_rates,
yading@10:     .long_name       = NULL_IF_CONFIG_SMALL("libopus Opus"),
yading@10:     .priv_class      = &libopus_class,
yading@10:     .defaults        = libopus_defaults,
yading@10: };