2 * Opus decoder using libopus
3 * Copyright (c) 2012 Nicolas George
5 * This file is part of Libav.
7 * Libav 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.
12 * Libav 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.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with Libav; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 #include <opus_multistream.h>
25 #include "libavutil/intreadwrite.h"
33 struct libopus_context {
37 #define OPUS_HEAD_SIZE 19
39 static av_cold int libopus_decode_init(AVCodecContext *avc)
41 struct libopus_context *opus = avc->priv_data;
42 int ret, channel_map = 0, gain_db = 0, nb_streams, nb_coupled;
43 uint8_t mapping_arr[8] = { 0, 1 }, *mapping;
45 if (avc->channels <= 0) {
46 av_log(avc, AV_LOG_WARNING,
47 "Invalid number of channels %d, defaulting to stereo\n", avc->channels);
51 avc->channels = avc->extradata_size >= 10 ? avc->extradata[9] : (avc->channels == 1) ? 1 : 2;
52 if (avc->channels <= 0) {
53 av_log(avc, AV_LOG_WARNING,
54 "Invalid number of channels %d, defaulting to stereo\n", avc->channels);
58 avc->sample_rate = 48000;
59 avc->sample_fmt = avc->request_sample_fmt == AV_SAMPLE_FMT_FLT ?
60 AV_SAMPLE_FMT_FLT : AV_SAMPLE_FMT_S16;
61 avc->channel_layout = avc->channels > 8 ? 0 :
62 ff_vorbis_channel_layouts[avc->channels - 1];
64 if (avc->extradata_size >= OPUS_HEAD_SIZE) {
65 gain_db = sign_extend(AV_RL16(avc->extradata + 16), 16);
66 channel_map = AV_RL8 (avc->extradata + 18);
68 if (avc->extradata_size >= OPUS_HEAD_SIZE + 2 + avc->channels) {
69 nb_streams = avc->extradata[OPUS_HEAD_SIZE + 0];
70 nb_coupled = avc->extradata[OPUS_HEAD_SIZE + 1];
71 if (nb_streams + nb_coupled != avc->channels)
72 av_log(avc, AV_LOG_WARNING, "Inconsistent channel mapping.\n");
73 mapping = avc->extradata + OPUS_HEAD_SIZE + 2;
75 if (avc->channels > 2 || channel_map) {
76 av_log(avc, AV_LOG_ERROR,
77 "No channel mapping for %d channels.\n", avc->channels);
78 return AVERROR(EINVAL);
81 nb_coupled = avc->channels > 1;
82 mapping = mapping_arr;
85 if (avc->channels > 2 && avc->channels <= 8) {
86 const uint8_t *vorbis_offset = ff_vorbis_channel_layout_offsets[avc->channels - 1];
89 /* Remap channels from Vorbis order to libav order */
90 for (ch = 0; ch < avc->channels; ch++)
91 mapping_arr[ch] = mapping[vorbis_offset[ch]];
92 mapping = mapping_arr;
95 opus->dec = opus_multistream_decoder_create(avc->sample_rate, avc->channels,
96 nb_streams, nb_coupled,
99 av_log(avc, AV_LOG_ERROR, "Unable to create decoder: %s\n",
101 return ff_opus_error_to_averror(ret);
104 ret = opus_multistream_decoder_ctl(opus->dec, OPUS_SET_GAIN(gain_db));
106 av_log(avc, AV_LOG_WARNING, "Failed to set gain: %s\n",
109 avc->delay = 3840; /* Decoder delay (in samples) at 48kHz */
114 static av_cold int libopus_decode_close(AVCodecContext *avc)
116 struct libopus_context *opus = avc->priv_data;
118 opus_multistream_decoder_destroy(opus->dec);
122 #define MAX_FRAME_SIZE (960 * 6)
124 static int libopus_decode(AVCodecContext *avc, void *data,
125 int *got_frame_ptr, AVPacket *pkt)
127 struct libopus_context *opus = avc->priv_data;
128 AVFrame *frame = data;
131 frame->nb_samples = MAX_FRAME_SIZE;
132 ret = ff_get_buffer(avc, frame, 0);
134 av_log(avc, AV_LOG_ERROR, "get_buffer() failed\n");
138 if (avc->sample_fmt == AV_SAMPLE_FMT_S16)
139 nb_samples = opus_multistream_decode(opus->dec, pkt->data, pkt->size,
140 (opus_int16 *)frame->data[0],
141 frame->nb_samples, 0);
143 nb_samples = opus_multistream_decode_float(opus->dec, pkt->data, pkt->size,
144 (float *)frame->data[0],
145 frame->nb_samples, 0);
147 if (nb_samples < 0) {
148 av_log(avc, AV_LOG_ERROR, "Decoding error: %s\n",
149 opus_strerror(nb_samples));
150 return ff_opus_error_to_averror(nb_samples);
153 frame->nb_samples = nb_samples;
159 static void libopus_flush(AVCodecContext *avc)
161 struct libopus_context *opus = avc->priv_data;
163 opus_multistream_decoder_ctl(opus->dec, OPUS_RESET_STATE);
166 AVCodec ff_libopus_decoder = {
168 .long_name = NULL_IF_CONFIG_SMALL("libopus Opus"),
169 .type = AVMEDIA_TYPE_AUDIO,
170 .id = AV_CODEC_ID_OPUS,
171 .priv_data_size = sizeof(struct libopus_context),
172 .init = libopus_decode_init,
173 .close = libopus_decode_close,
174 .decode = libopus_decode,
175 .flush = libopus_flush,
176 .capabilities = AV_CODEC_CAP_DR1,
177 .sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_FLT,
179 AV_SAMPLE_FMT_NONE },