1/*
2 * Opus encoder using libopus
3 * Copyright (c) 2012 Nathan Caldwell
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22#include <opus.h>
23#include <opus_multistream.h>
24
25#include "libavutil/channel_layout.h"
26#include "libavutil/opt.h"
27#include "avcodec.h"
28#include "bytestream.h"
29#include "codec_internal.h"
30#include "encode.h"
31#include "libopus.h"
32#include "vorbis.h"
33#include "audio_frame_queue.h"
34
35typedef struct LibopusEncOpts {
36    int vbr;
37    int application;
38    int packet_loss;
39    int fec;
40    int complexity;
41    float frame_duration;
42    int packet_size;
43    int max_bandwidth;
44    int mapping_family;
45#ifdef OPUS_SET_PHASE_INVERSION_DISABLED_REQUEST
46    int apply_phase_inv;
47#endif
48} LibopusEncOpts;
49
50typedef struct LibopusEncContext {
51    AVClass *class;
52    OpusMSEncoder *enc;
53    int stream_count;
54    uint8_t *samples;
55    LibopusEncOpts opts;
56    AudioFrameQueue afq;
57    const uint8_t *encoder_channel_map;
58} LibopusEncContext;
59
60static const uint8_t opus_coupled_streams[8] = {
61    0, 1, 1, 2, 2, 2, 2, 3
62};
63
64/* Opus internal to Vorbis channel order mapping written in the header */
65static const uint8_t opus_vorbis_channel_map[8][8] = {
66    { 0 },
67    { 0, 1 },
68    { 0, 2, 1 },
69    { 0, 1, 2, 3 },
70    { 0, 4, 1, 2, 3 },
71    { 0, 4, 1, 2, 3, 5 },
72    { 0, 4, 1, 2, 3, 5, 6 },
73    { 0, 6, 1, 2, 3, 4, 5, 7 },
74};
75
76/* libavcodec to libopus channel order mapping, passed to libopus */
77static const uint8_t libavcodec_libopus_channel_map[8][8] = {
78    { 0 },
79    { 0, 1 },
80    { 0, 1, 2 },
81    { 0, 1, 2, 3 },
82    { 0, 1, 3, 4, 2 },
83    { 0, 1, 4, 5, 2, 3 },
84    { 0, 1, 5, 6, 2, 4, 3 },
85    { 0, 1, 6, 7, 4, 5, 2, 3 },
86};
87
88static void libopus_write_header(AVCodecContext *avctx, int stream_count,
89                                 int coupled_stream_count,
90                                 int mapping_family,
91                                 const uint8_t *channel_mapping)
92{
93    uint8_t *p   = avctx->extradata;
94    int channels = avctx->ch_layout.nb_channels;
95
96    bytestream_put_buffer(&p, "OpusHead", 8);
97    bytestream_put_byte(&p, 1); /* Version */
98    bytestream_put_byte(&p, channels);
99    bytestream_put_le16(&p, avctx->initial_padding * 48000 / avctx->sample_rate); /* Lookahead samples at 48kHz */
100    bytestream_put_le32(&p, avctx->sample_rate); /* Original sample rate */
101    bytestream_put_le16(&p, 0); /* Gain of 0dB is recommended. */
102
103    /* Channel mapping */
104    bytestream_put_byte(&p, mapping_family);
105    if (mapping_family != 0) {
106        bytestream_put_byte(&p, stream_count);
107        bytestream_put_byte(&p, coupled_stream_count);
108        bytestream_put_buffer(&p, channel_mapping, channels);
109    }
110}
111
112static int libopus_configure_encoder(AVCodecContext *avctx, OpusMSEncoder *enc,
113                                     LibopusEncOpts *opts)
114{
115    int ret;
116
117    if (avctx->global_quality) {
118        av_log(avctx, AV_LOG_ERROR,
119               "Quality-based encoding not supported, "
120               "please specify a bitrate and VBR setting.\n");
121        return AVERROR(EINVAL);
122    }
123
124    ret = opus_multistream_encoder_ctl(enc, OPUS_SET_BITRATE(avctx->bit_rate));
125    if (ret != OPUS_OK) {
126        av_log(avctx, AV_LOG_ERROR,
127               "Failed to set bitrate: %s\n", opus_strerror(ret));
128        return ret;
129    }
130
131    ret = opus_multistream_encoder_ctl(enc,
132                                       OPUS_SET_COMPLEXITY(opts->complexity));
133    if (ret != OPUS_OK)
134        av_log(avctx, AV_LOG_WARNING,
135               "Unable to set complexity: %s\n", opus_strerror(ret));
136
137    ret = opus_multistream_encoder_ctl(enc, OPUS_SET_VBR(!!opts->vbr));
138    if (ret != OPUS_OK)
139        av_log(avctx, AV_LOG_WARNING,
140               "Unable to set VBR: %s\n", opus_strerror(ret));
141
142    ret = opus_multistream_encoder_ctl(enc,
143                                       OPUS_SET_VBR_CONSTRAINT(opts->vbr == 2));
144    if (ret != OPUS_OK)
145        av_log(avctx, AV_LOG_WARNING,
146               "Unable to set constrained VBR: %s\n", opus_strerror(ret));
147
148    ret = opus_multistream_encoder_ctl(enc,
149                                       OPUS_SET_PACKET_LOSS_PERC(opts->packet_loss));
150    if (ret != OPUS_OK)
151        av_log(avctx, AV_LOG_WARNING,
152               "Unable to set expected packet loss percentage: %s\n",
153               opus_strerror(ret));
154
155    ret = opus_multistream_encoder_ctl(enc,
156                                       OPUS_SET_INBAND_FEC(opts->fec));
157    if (ret != OPUS_OK)
158        av_log(avctx, AV_LOG_WARNING,
159               "Unable to set inband FEC: %s\n",
160               opus_strerror(ret));
161
162    if (avctx->cutoff) {
163        ret = opus_multistream_encoder_ctl(enc,
164                                           OPUS_SET_MAX_BANDWIDTH(opts->max_bandwidth));
165        if (ret != OPUS_OK)
166            av_log(avctx, AV_LOG_WARNING,
167                   "Unable to set maximum bandwidth: %s\n", opus_strerror(ret));
168    }
169
170#ifdef OPUS_SET_PHASE_INVERSION_DISABLED_REQUEST
171    ret = opus_multistream_encoder_ctl(enc,
172                                       OPUS_SET_PHASE_INVERSION_DISABLED(!opts->apply_phase_inv));
173    if (ret != OPUS_OK)
174        av_log(avctx, AV_LOG_WARNING,
175               "Unable to set phase inversion: %s\n",
176               opus_strerror(ret));
177#endif
178    return OPUS_OK;
179}
180
181static int libopus_check_max_channels(AVCodecContext *avctx,
182                                      int max_channels) {
183    if (avctx->ch_layout.nb_channels > max_channels) {
184        av_log(avctx, AV_LOG_ERROR, "Opus mapping family undefined for %d channels.\n",
185               avctx->ch_layout.nb_channels);
186        return AVERROR(EINVAL);
187    }
188
189    return 0;
190}
191
192static int libopus_check_vorbis_layout(AVCodecContext *avctx, int mapping_family) {
193    av_assert2(avctx->ch_layout.nb_channels < FF_ARRAY_ELEMS(ff_vorbis_ch_layouts));
194
195    if (avctx->ch_layout.order == AV_CHANNEL_ORDER_UNSPEC) {
196        av_log(avctx, AV_LOG_WARNING,
197               "No channel layout specified. Opus encoder will use Vorbis "
198               "channel layout for %d channels.\n", avctx->ch_layout.nb_channels);
199    } else if (av_channel_layout_compare(&avctx->ch_layout, &ff_vorbis_ch_layouts[avctx->ch_layout.nb_channels - 1])) {
200        char name[32];
201
202        av_channel_layout_describe(&avctx->ch_layout, name, sizeof(name));
203        av_log(avctx, AV_LOG_ERROR,
204               "Invalid channel layout %s for specified mapping family %d.\n",
205               name, mapping_family);
206
207        return AVERROR(EINVAL);
208    }
209
210    return 0;
211}
212
213static int libopus_validate_layout_and_get_channel_map(
214        AVCodecContext *avctx,
215        int mapping_family,
216        const uint8_t ** channel_map_result)
217{
218    const uint8_t * channel_map = NULL;
219    int ret;
220
221    switch (mapping_family) {
222    case -1:
223        ret = libopus_check_max_channels(avctx, 8);
224        if (ret == 0) {
225            ret = libopus_check_vorbis_layout(avctx, mapping_family);
226            /* Channels do not need to be reordered. */
227        }
228
229        break;
230    case 0:
231        ret = libopus_check_max_channels(avctx, 2);
232        if (ret == 0) {
233            ret = libopus_check_vorbis_layout(avctx, mapping_family);
234        }
235        break;
236    case 1:
237        /* Opus expects channels to be in Vorbis order. */
238        ret = libopus_check_max_channels(avctx, 8);
239        if (ret == 0) {
240            ret = libopus_check_vorbis_layout(avctx, mapping_family);
241            channel_map = ff_vorbis_channel_layout_offsets[avctx->ch_layout.nb_channels - 1];
242        }
243        break;
244    case 255:
245        ret = libopus_check_max_channels(avctx, 254);
246        break;
247    default:
248        av_log(avctx, AV_LOG_WARNING,
249               "Unknown channel mapping family %d. Output channel layout may be invalid.\n",
250               mapping_family);
251        ret = 0;
252    }
253
254    *channel_map_result = channel_map;
255    return ret;
256}
257
258static av_cold int libopus_encode_init(AVCodecContext *avctx)
259{
260    LibopusEncContext *opus = avctx->priv_data;
261    OpusMSEncoder *enc;
262    uint8_t libopus_channel_mapping[255];
263    int ret = OPUS_OK;
264    int channels = avctx->ch_layout.nb_channels;
265    int av_ret;
266    int coupled_stream_count, header_size, frame_size;
267    int mapping_family;
268
269    frame_size = opus->opts.frame_duration * 48000 / 1000;
270    switch (frame_size) {
271    case 120:
272    case 240:
273        if (opus->opts.application != OPUS_APPLICATION_RESTRICTED_LOWDELAY)
274            av_log(avctx, AV_LOG_WARNING,
275                   "LPC mode cannot be used with a frame duration of less "
276                   "than 10ms. Enabling restricted low-delay mode.\n"
277                   "Use a longer frame duration if this is not what you want.\n");
278        /* Frame sizes less than 10 ms can only use MDCT mode, so switching to
279         * RESTRICTED_LOWDELAY avoids an unnecessary extra 2.5ms lookahead. */
280        opus->opts.application = OPUS_APPLICATION_RESTRICTED_LOWDELAY;
281    case 480:
282    case 960:
283    case 1920:
284    case 2880:
285#ifdef OPUS_FRAMESIZE_120_MS
286    case 3840:
287    case 4800:
288    case 5760:
289#endif
290        opus->opts.packet_size =
291        avctx->frame_size      = frame_size * avctx->sample_rate / 48000;
292        break;
293    default:
294        av_log(avctx, AV_LOG_ERROR, "Invalid frame duration: %g.\n"
295               "Frame duration must be exactly one of: 2.5, 5, 10, 20, 40"
296#ifdef OPUS_FRAMESIZE_120_MS
297               ", 60, 80, 100 or 120.\n",
298#else
299               " or 60.\n",
300#endif
301               opus->opts.frame_duration);
302        return AVERROR(EINVAL);
303    }
304
305    if (avctx->compression_level < 0 || avctx->compression_level > 10) {
306        av_log(avctx, AV_LOG_WARNING,
307               "Compression level must be in the range 0 to 10. "
308               "Defaulting to 10.\n");
309        opus->opts.complexity = 10;
310    } else {
311        opus->opts.complexity = avctx->compression_level;
312    }
313
314    if (avctx->cutoff) {
315        switch (avctx->cutoff) {
316        case  4000:
317            opus->opts.max_bandwidth = OPUS_BANDWIDTH_NARROWBAND;
318            break;
319        case  6000:
320            opus->opts.max_bandwidth = OPUS_BANDWIDTH_MEDIUMBAND;
321            break;
322        case  8000:
323            opus->opts.max_bandwidth = OPUS_BANDWIDTH_WIDEBAND;
324            break;
325        case 12000:
326            opus->opts.max_bandwidth = OPUS_BANDWIDTH_SUPERWIDEBAND;
327            break;
328        case 20000:
329            opus->opts.max_bandwidth = OPUS_BANDWIDTH_FULLBAND;
330            break;
331        default:
332            av_log(avctx, AV_LOG_WARNING,
333                   "Invalid frequency cutoff: %d. Using default maximum bandwidth.\n"
334                   "Cutoff frequency must be exactly one of: 4000, 6000, 8000, 12000 or 20000.\n",
335                   avctx->cutoff);
336            avctx->cutoff = 0;
337        }
338    }
339
340    /* Channels may need to be reordered to match opus mapping. */
341    av_ret = libopus_validate_layout_and_get_channel_map(avctx, opus->opts.mapping_family,
342                                                         &opus->encoder_channel_map);
343    if (av_ret) {
344        return av_ret;
345    }
346
347    if (opus->opts.mapping_family == -1) {
348        /* By default, use mapping family 1 for the header but use the older
349         * libopus multistream API to avoid surround masking. */
350
351        /* Set the mapping family so that the value is correct in the header */
352        mapping_family = channels > 2 ? 1 : 0;
353        coupled_stream_count = opus_coupled_streams[channels - 1];
354        opus->stream_count   = channels - coupled_stream_count;
355        memcpy(libopus_channel_mapping,
356               opus_vorbis_channel_map[channels - 1],
357               channels * sizeof(*libopus_channel_mapping));
358
359        enc = opus_multistream_encoder_create(
360            avctx->sample_rate, channels, opus->stream_count,
361            coupled_stream_count,
362            libavcodec_libopus_channel_map[channels - 1],
363            opus->opts.application, &ret);
364    } else {
365        /* Use the newer multistream API. The encoder will set the channel
366         * mapping and coupled stream counts to its internal defaults and will
367         * use surround masking analysis to save bits. */
368        mapping_family = opus->opts.mapping_family;
369        enc = opus_multistream_surround_encoder_create(
370            avctx->sample_rate, channels, mapping_family,
371            &opus->stream_count, &coupled_stream_count, libopus_channel_mapping,
372            opus->opts.application, &ret);
373    }
374
375    if (ret != OPUS_OK) {
376        av_log(avctx, AV_LOG_ERROR,
377               "Failed to create encoder: %s\n", opus_strerror(ret));
378        return ff_opus_error_to_averror(ret);
379    }
380
381    if (!avctx->bit_rate) {
382        /* Sane default copied from opusenc */
383        avctx->bit_rate = 64000 * opus->stream_count +
384                          32000 * coupled_stream_count;
385        av_log(avctx, AV_LOG_WARNING,
386               "No bit rate set. Defaulting to %"PRId64" bps.\n", avctx->bit_rate);
387    }
388
389    if (avctx->bit_rate < 500 || avctx->bit_rate > 256000 * channels) {
390        av_log(avctx, AV_LOG_ERROR, "The bit rate %"PRId64" bps is unsupported. "
391               "Please choose a value between 500 and %d.\n", avctx->bit_rate,
392               256000 * channels);
393        ret = AVERROR(EINVAL);
394        goto fail;
395    }
396
397    ret = libopus_configure_encoder(avctx, enc, &opus->opts);
398    if (ret != OPUS_OK) {
399        ret = ff_opus_error_to_averror(ret);
400        goto fail;
401    }
402
403    /* Header includes channel mapping table if and only if mapping family is NOT 0 */
404    header_size = 19 + (mapping_family == 0 ? 0 : 2 + channels);
405    avctx->extradata = av_malloc(header_size + AV_INPUT_BUFFER_PADDING_SIZE);
406    if (!avctx->extradata) {
407        av_log(avctx, AV_LOG_ERROR, "Failed to allocate extradata.\n");
408        ret = AVERROR(ENOMEM);
409        goto fail;
410    }
411    avctx->extradata_size = header_size;
412
413    opus->samples = av_calloc(frame_size, channels *
414                               av_get_bytes_per_sample(avctx->sample_fmt));
415    if (!opus->samples) {
416        av_log(avctx, AV_LOG_ERROR, "Failed to allocate samples buffer.\n");
417        ret = AVERROR(ENOMEM);
418        goto fail;
419    }
420
421    ret = opus_multistream_encoder_ctl(enc, OPUS_GET_LOOKAHEAD(&avctx->initial_padding));
422    if (ret != OPUS_OK)
423        av_log(avctx, AV_LOG_WARNING,
424               "Unable to get number of lookahead samples: %s\n",
425               opus_strerror(ret));
426
427    libopus_write_header(avctx, opus->stream_count, coupled_stream_count,
428                         mapping_family, libopus_channel_mapping);
429
430    ff_af_queue_init(avctx, &opus->afq);
431
432    opus->enc = enc;
433
434    return 0;
435
436fail:
437    opus_multistream_encoder_destroy(enc);
438    return ret;
439}
440
441static void libopus_copy_samples_with_channel_map(
442    uint8_t *dst, const uint8_t *src, const uint8_t *channel_map,
443    int nb_channels, int nb_samples, int bytes_per_sample) {
444    int sample, channel;
445    for (sample = 0; sample < nb_samples; ++sample) {
446        for (channel = 0; channel < nb_channels; ++channel) {
447            const size_t src_pos = bytes_per_sample * (nb_channels * sample + channel);
448            const size_t dst_pos = bytes_per_sample * (nb_channels * sample + channel_map[channel]);
449
450            memcpy(&dst[dst_pos], &src[src_pos], bytes_per_sample);
451        }
452    }
453}
454
455static int libopus_encode(AVCodecContext *avctx, AVPacket *avpkt,
456                          const AVFrame *frame, int *got_packet_ptr)
457{
458    LibopusEncContext *opus = avctx->priv_data;
459    const int bytes_per_sample = av_get_bytes_per_sample(avctx->sample_fmt);
460    const int channels         = avctx->ch_layout.nb_channels;
461    const int sample_size      = channels * bytes_per_sample;
462    uint8_t *audio;
463    int ret;
464    int discard_padding;
465
466    if (frame) {
467        ret = ff_af_queue_add(&opus->afq, frame);
468        if (ret < 0)
469            return ret;
470        if (opus->encoder_channel_map != NULL) {
471            audio = opus->samples;
472            libopus_copy_samples_with_channel_map(
473                audio, frame->data[0], opus->encoder_channel_map,
474                channels, frame->nb_samples, bytes_per_sample);
475        } else if (frame->nb_samples < opus->opts.packet_size) {
476            audio = opus->samples;
477            memcpy(audio, frame->data[0], frame->nb_samples * sample_size);
478        } else
479            audio = frame->data[0];
480    } else {
481        if (!opus->afq.remaining_samples || (!opus->afq.frame_alloc && !opus->afq.frame_count))
482            return 0;
483        audio = opus->samples;
484        memset(audio, 0, opus->opts.packet_size * sample_size);
485    }
486
487    /* Maximum packet size taken from opusenc in opus-tools. 120ms packets
488     * consist of 6 frames in one packet. The maximum frame size is 1275
489     * bytes along with the largest possible packet header of 7 bytes. */
490    if ((ret = ff_alloc_packet(avctx, avpkt, (1275 * 6 + 7) * opus->stream_count)) < 0)
491        return ret;
492
493    if (avctx->sample_fmt == AV_SAMPLE_FMT_FLT)
494        ret = opus_multistream_encode_float(opus->enc, (float *)audio,
495                                            opus->opts.packet_size,
496                                            avpkt->data, avpkt->size);
497    else
498        ret = opus_multistream_encode(opus->enc, (opus_int16 *)audio,
499                                      opus->opts.packet_size,
500                                      avpkt->data, avpkt->size);
501
502    if (ret < 0) {
503        av_log(avctx, AV_LOG_ERROR,
504               "Error encoding frame: %s\n", opus_strerror(ret));
505        return ff_opus_error_to_averror(ret);
506    }
507
508    av_shrink_packet(avpkt, ret);
509
510    ff_af_queue_remove(&opus->afq, opus->opts.packet_size,
511                       &avpkt->pts, &avpkt->duration);
512
513    discard_padding = opus->opts.packet_size - avpkt->duration;
514    // Check if subtraction resulted in an overflow
515    if ((discard_padding < opus->opts.packet_size) != (avpkt->duration > 0)) {
516        av_packet_unref(avpkt);
517        return AVERROR(EINVAL);
518    }
519    if (discard_padding > 0) {
520        uint8_t* side_data = av_packet_new_side_data(avpkt,
521                                                     AV_PKT_DATA_SKIP_SAMPLES,
522                                                     10);
523        if(!side_data) {
524            av_packet_unref(avpkt);
525            return AVERROR(ENOMEM);
526        }
527        AV_WL32(side_data + 4, discard_padding);
528    }
529
530    *got_packet_ptr = 1;
531
532    return 0;
533}
534
535static av_cold int libopus_encode_close(AVCodecContext *avctx)
536{
537    LibopusEncContext *opus = avctx->priv_data;
538
539    opus_multistream_encoder_destroy(opus->enc);
540
541    ff_af_queue_close(&opus->afq);
542
543    av_freep(&opus->samples);
544
545    return 0;
546}
547
548#define OFFSET(x) offsetof(LibopusEncContext, opts.x)
549#define FLAGS AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_ENCODING_PARAM
550static const AVOption libopus_options[] = {
551    { "application",    "Intended application type",           OFFSET(application),    AV_OPT_TYPE_INT,   { .i64 = OPUS_APPLICATION_AUDIO }, OPUS_APPLICATION_VOIP, OPUS_APPLICATION_RESTRICTED_LOWDELAY, FLAGS, "application" },
552        { "voip",           "Favor improved speech intelligibility",   0, AV_OPT_TYPE_CONST, { .i64 = OPUS_APPLICATION_VOIP },                0, 0, FLAGS, "application" },
553        { "audio",          "Favor faithfulness to the input",         0, AV_OPT_TYPE_CONST, { .i64 = OPUS_APPLICATION_AUDIO },               0, 0, FLAGS, "application" },
554        { "lowdelay",       "Restrict to only the lowest delay modes", 0, AV_OPT_TYPE_CONST, { .i64 = OPUS_APPLICATION_RESTRICTED_LOWDELAY }, 0, 0, FLAGS, "application" },
555    { "frame_duration", "Duration of a frame in milliseconds", OFFSET(frame_duration), AV_OPT_TYPE_FLOAT, { .dbl = 20.0 }, 2.5, 120.0, FLAGS },
556    { "packet_loss",    "Expected packet loss percentage",     OFFSET(packet_loss),    AV_OPT_TYPE_INT,   { .i64 = 0 },    0,   100,  FLAGS },
557    { "fec",             "Enable inband FEC. Expected packet loss must be non-zero",     OFFSET(fec),    AV_OPT_TYPE_BOOL,   { .i64 = 0 }, 0, 1, FLAGS },
558    { "vbr",            "Variable bit rate mode",              OFFSET(vbr),            AV_OPT_TYPE_INT,   { .i64 = 1 },    0,   2,    FLAGS, "vbr" },
559        { "off",            "Use constant bit rate", 0, AV_OPT_TYPE_CONST, { .i64 = 0 }, 0, 0, FLAGS, "vbr" },
560        { "on",             "Use variable bit rate", 0, AV_OPT_TYPE_CONST, { .i64 = 1 }, 0, 0, FLAGS, "vbr" },
561        { "constrained",    "Use constrained VBR",   0, AV_OPT_TYPE_CONST, { .i64 = 2 }, 0, 0, FLAGS, "vbr" },
562    { "mapping_family", "Channel Mapping Family",              OFFSET(mapping_family), AV_OPT_TYPE_INT,   { .i64 = -1 },   -1,  255,  FLAGS, "mapping_family" },
563#ifdef OPUS_SET_PHASE_INVERSION_DISABLED_REQUEST
564    { "apply_phase_inv", "Apply intensity stereo phase inversion", OFFSET(apply_phase_inv), AV_OPT_TYPE_BOOL, { .i64 = 1 }, 0, 1, FLAGS },
565#endif
566    { NULL },
567};
568
569static const AVClass libopus_class = {
570    .class_name = "libopus",
571    .item_name  = av_default_item_name,
572    .option     = libopus_options,
573    .version    = LIBAVUTIL_VERSION_INT,
574};
575
576static const FFCodecDefault libopus_defaults[] = {
577    { "b",                 "0" },
578    { "compression_level", "10" },
579    { NULL },
580};
581
582static const int libopus_sample_rates[] = {
583    48000, 24000, 16000, 12000, 8000, 0,
584};
585
586const FFCodec ff_libopus_encoder = {
587    .p.name          = "libopus",
588    .p.long_name     = NULL_IF_CONFIG_SMALL("libopus Opus"),
589    .p.type          = AVMEDIA_TYPE_AUDIO,
590    .p.id            = AV_CODEC_ID_OPUS,
591    .priv_data_size  = sizeof(LibopusEncContext),
592    .init            = libopus_encode_init,
593    FF_CODEC_ENCODE_CB(libopus_encode),
594    .close           = libopus_encode_close,
595    .p.capabilities  = AV_CODEC_CAP_DELAY | AV_CODEC_CAP_SMALL_LAST_FRAME,
596    .p.sample_fmts   = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16,
597                                                      AV_SAMPLE_FMT_FLT,
598                                                      AV_SAMPLE_FMT_NONE },
599    .p.supported_samplerates = libopus_sample_rates,
600    .p.priv_class    = &libopus_class,
601    .defaults        = libopus_defaults,
602    .p.wrapper_name  = "libopus",
603};
604