1 /*
2 * Opus decoder using libopus
3 * Copyright (c) 2012 Nicolas George
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/internal.h"
26 #include "libavutil/intreadwrite.h"
27 #include "libavutil/ffmath.h"
28 #include "libavutil/opt.h"
29
30 #include "avcodec.h"
31 #include "internal.h"
32 #include "vorbis.h"
33 #include "mathops.h"
34 #include "libopus.h"
35
36 struct libopus_context {
37 AVClass *class;
38 OpusMSDecoder *dec;
39 int pre_skip;
40 #ifndef OPUS_SET_GAIN
41 union { int i; double d; } gain;
42 #endif
43 #ifdef OPUS_SET_PHASE_INVERSION_DISABLED_REQUEST
44 int apply_phase_inv;
45 #endif
46 };
47
48 #define OPUS_HEAD_SIZE 19
49
libopus_decode_init(AVCodecContext * avc)50 static av_cold int libopus_decode_init(AVCodecContext *avc)
51 {
52 struct libopus_context *opus = avc->priv_data;
53 int ret, channel_map = 0, gain_db = 0, nb_streams, nb_coupled;
54 uint8_t mapping_arr[8] = { 0, 1 }, *mapping;
55
56 avc->channels = avc->extradata_size >= 10 ? avc->extradata[9] : (avc->channels == 1) ? 1 : 2;
57 if (avc->channels <= 0) {
58 av_log(avc, AV_LOG_WARNING,
59 "Invalid number of channels %d, defaulting to stereo\n", avc->channels);
60 avc->channels = 2;
61 }
62
63 avc->sample_rate = 48000;
64 avc->sample_fmt = avc->request_sample_fmt == AV_SAMPLE_FMT_FLT ?
65 AV_SAMPLE_FMT_FLT : AV_SAMPLE_FMT_S16;
66 avc->channel_layout = avc->channels > 8 ? 0 :
67 ff_vorbis_channel_layouts[avc->channels - 1];
68
69 if (avc->extradata_size >= OPUS_HEAD_SIZE) {
70 opus->pre_skip = AV_RL16(avc->extradata + 10);
71 gain_db = sign_extend(AV_RL16(avc->extradata + 16), 16);
72 channel_map = AV_RL8 (avc->extradata + 18);
73 }
74 if (avc->extradata_size >= OPUS_HEAD_SIZE + 2 + avc->channels) {
75 nb_streams = avc->extradata[OPUS_HEAD_SIZE + 0];
76 nb_coupled = avc->extradata[OPUS_HEAD_SIZE + 1];
77 if (nb_streams + nb_coupled != avc->channels)
78 av_log(avc, AV_LOG_WARNING, "Inconsistent channel mapping.\n");
79 mapping = avc->extradata + OPUS_HEAD_SIZE + 2;
80 } else {
81 if (avc->channels > 2 || channel_map) {
82 av_log(avc, AV_LOG_ERROR,
83 "No channel mapping for %d channels.\n", avc->channels);
84 return AVERROR(EINVAL);
85 }
86 nb_streams = 1;
87 nb_coupled = avc->channels > 1;
88 mapping = mapping_arr;
89 }
90
91 if (avc->channels > 2 && avc->channels <= 8) {
92 const uint8_t *vorbis_offset = ff_vorbis_channel_layout_offsets[avc->channels - 1];
93 int ch;
94
95 /* Remap channels from Vorbis order to ffmpeg order */
96 for (ch = 0; ch < avc->channels; ch++)
97 mapping_arr[ch] = mapping[vorbis_offset[ch]];
98 mapping = mapping_arr;
99 }
100
101 opus->dec = opus_multistream_decoder_create(avc->sample_rate, avc->channels,
102 nb_streams, nb_coupled,
103 mapping, &ret);
104 if (!opus->dec) {
105 av_log(avc, AV_LOG_ERROR, "Unable to create decoder: %s\n",
106 opus_strerror(ret));
107 return ff_opus_error_to_averror(ret);
108 }
109
110 #ifdef OPUS_SET_GAIN
111 ret = opus_multistream_decoder_ctl(opus->dec, OPUS_SET_GAIN(gain_db));
112 if (ret != OPUS_OK)
113 av_log(avc, AV_LOG_WARNING, "Failed to set gain: %s\n",
114 opus_strerror(ret));
115 #else
116 {
117 double gain_lin = ff_exp10(gain_db / (20.0 * 256));
118 if (avc->sample_fmt == AV_SAMPLE_FMT_FLT)
119 opus->gain.d = gain_lin;
120 else
121 opus->gain.i = FFMIN(gain_lin * 65536, INT_MAX);
122 }
123 #endif
124
125 #ifdef OPUS_SET_PHASE_INVERSION_DISABLED_REQUEST
126 ret = opus_multistream_decoder_ctl(opus->dec,
127 OPUS_SET_PHASE_INVERSION_DISABLED(!opus->apply_phase_inv));
128 if (ret != OPUS_OK)
129 av_log(avc, AV_LOG_WARNING,
130 "Unable to set phase inversion: %s\n",
131 opus_strerror(ret));
132 #endif
133
134 /* Decoder delay (in samples) at 48kHz */
135 avc->delay = avc->internal->skip_samples = opus->pre_skip;
136
137 return 0;
138 }
139
libopus_decode_close(AVCodecContext * avc)140 static av_cold int libopus_decode_close(AVCodecContext *avc)
141 {
142 struct libopus_context *opus = avc->priv_data;
143
144 if (opus->dec) {
145 opus_multistream_decoder_destroy(opus->dec);
146 opus->dec = NULL;
147 }
148 return 0;
149 }
150
151 #define MAX_FRAME_SIZE (960 * 6)
152
libopus_decode(AVCodecContext * avc,void * data,int * got_frame_ptr,AVPacket * pkt)153 static int libopus_decode(AVCodecContext *avc, void *data,
154 int *got_frame_ptr, AVPacket *pkt)
155 {
156 struct libopus_context *opus = avc->priv_data;
157 AVFrame *frame = data;
158 int ret, nb_samples;
159
160 frame->nb_samples = MAX_FRAME_SIZE;
161 if ((ret = ff_get_buffer(avc, frame, 0)) < 0)
162 return ret;
163
164 if (avc->sample_fmt == AV_SAMPLE_FMT_S16)
165 nb_samples = opus_multistream_decode(opus->dec, pkt->data, pkt->size,
166 (opus_int16 *)frame->data[0],
167 frame->nb_samples, 0);
168 else
169 nb_samples = opus_multistream_decode_float(opus->dec, pkt->data, pkt->size,
170 (float *)frame->data[0],
171 frame->nb_samples, 0);
172
173 if (nb_samples < 0) {
174 av_log(avc, AV_LOG_ERROR, "Decoding error: %s\n",
175 opus_strerror(nb_samples));
176 return ff_opus_error_to_averror(nb_samples);
177 }
178
179 #ifndef OPUS_SET_GAIN
180 {
181 int i = avc->channels * nb_samples;
182 if (avc->sample_fmt == AV_SAMPLE_FMT_FLT) {
183 float *pcm = (float *)frame->data[0];
184 for (; i > 0; i--, pcm++)
185 *pcm = av_clipf(*pcm * opus->gain.d, -1, 1);
186 } else {
187 int16_t *pcm = (int16_t *)frame->data[0];
188 for (; i > 0; i--, pcm++)
189 *pcm = av_clip_int16(((int64_t)opus->gain.i * *pcm) >> 16);
190 }
191 }
192 #endif
193
194 frame->nb_samples = nb_samples;
195 *got_frame_ptr = 1;
196
197 return pkt->size;
198 }
199
libopus_flush(AVCodecContext * avc)200 static void libopus_flush(AVCodecContext *avc)
201 {
202 struct libopus_context *opus = avc->priv_data;
203
204 opus_multistream_decoder_ctl(opus->dec, OPUS_RESET_STATE);
205 /* The stream can have been extracted by a tool that is not Opus-aware.
206 Therefore, any packet can become the first of the stream. */
207 avc->internal->skip_samples = opus->pre_skip;
208 }
209
210
211 #define OFFSET(x) offsetof(struct libopus_context, x)
212 #define FLAGS AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_DECODING_PARAM
213 static const AVOption libopusdec_options[] = {
214 #ifdef OPUS_SET_PHASE_INVERSION_DISABLED_REQUEST
215 { "apply_phase_inv", "Apply intensity stereo phase inversion", OFFSET(apply_phase_inv), AV_OPT_TYPE_BOOL, { .i64 = 1 }, 0, 1, FLAGS },
216 #endif
217 { NULL },
218 };
219
220 static const AVClass libopusdec_class = {
221 .class_name = "libopusdec",
222 .item_name = av_default_item_name,
223 .option = libopusdec_options,
224 .version = LIBAVUTIL_VERSION_INT,
225 };
226
227
228 AVCodec ff_libopus_decoder = {
229 .name = "libopus",
230 .long_name = NULL_IF_CONFIG_SMALL("libopus Opus"),
231 .type = AVMEDIA_TYPE_AUDIO,
232 .id = AV_CODEC_ID_OPUS,
233 .priv_data_size = sizeof(struct libopus_context),
234 .init = libopus_decode_init,
235 .close = libopus_decode_close,
236 .decode = libopus_decode,
237 .flush = libopus_flush,
238 .capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_CHANNEL_CONF,
239 .caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
240 .sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_FLT,
241 AV_SAMPLE_FMT_S16,
242 AV_SAMPLE_FMT_NONE },
243 .priv_class = &libopusdec_class,
244 .wrapper_name = "libopus",
245 };
246