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 "codec_internal.h"
32 #include "internal.h"
33 #include "vorbis.h"
34 #include "mathops.h"
35 #include "libopus.h"
36
37 struct libopus_context {
38 AVClass *class;
39 OpusMSDecoder *dec;
40 int pre_skip;
41 #ifndef OPUS_SET_GAIN
42 union { int i; double d; } gain;
43 #endif
44 #ifdef OPUS_SET_PHASE_INVERSION_DISABLED_REQUEST
45 int apply_phase_inv;
46 #endif
47 };
48
49 #define OPUS_HEAD_SIZE 19
50
libopus_decode_init(AVCodecContext *avc)51 static av_cold int libopus_decode_init(AVCodecContext *avc)
52 {
53 struct libopus_context *opus = avc->priv_data;
54 int ret, channel_map = 0, gain_db = 0, nb_streams, nb_coupled, channels;
55 uint8_t mapping_arr[8] = { 0, 1 }, *mapping;
56
57 channels = avc->extradata_size >= 10 ? avc->extradata[9] : (avc->ch_layout.nb_channels == 1) ? 1 : 2;
58 if (channels <= 0) {
59 av_log(avc, AV_LOG_WARNING,
60 "Invalid number of channels %d, defaulting to stereo\n", channels);
61 channels = 2;
62 }
63
64 avc->sample_rate = 48000;
65 avc->sample_fmt = avc->request_sample_fmt == AV_SAMPLE_FMT_FLT ?
66 AV_SAMPLE_FMT_FLT : AV_SAMPLE_FMT_S16;
67 av_channel_layout_uninit(&avc->ch_layout);
68 if (channels > 8) {
69 avc->ch_layout.order = AV_CHANNEL_ORDER_UNSPEC;
70 avc->ch_layout.nb_channels = channels;
71 } else {
72 av_channel_layout_copy(&avc->ch_layout, &ff_vorbis_ch_layouts[channels - 1]);
73 }
74
75 if (avc->extradata_size >= OPUS_HEAD_SIZE) {
76 opus->pre_skip = AV_RL16(avc->extradata + 10);
77 gain_db = sign_extend(AV_RL16(avc->extradata + 16), 16);
78 channel_map = AV_RL8 (avc->extradata + 18);
79 }
80 if (avc->extradata_size >= OPUS_HEAD_SIZE + 2 + channels) {
81 nb_streams = avc->extradata[OPUS_HEAD_SIZE + 0];
82 nb_coupled = avc->extradata[OPUS_HEAD_SIZE + 1];
83 if (nb_streams + nb_coupled != channels)
84 av_log(avc, AV_LOG_WARNING, "Inconsistent channel mapping.\n");
85 mapping = avc->extradata + OPUS_HEAD_SIZE + 2;
86 } else {
87 if (channels > 2 || channel_map) {
88 av_log(avc, AV_LOG_ERROR,
89 "No channel mapping for %d channels.\n", channels);
90 return AVERROR(EINVAL);
91 }
92 nb_streams = 1;
93 nb_coupled = channels > 1;
94 mapping = mapping_arr;
95 }
96
97 if (channels > 2 && channels <= 8) {
98 const uint8_t *vorbis_offset = ff_vorbis_channel_layout_offsets[channels - 1];
99 int ch;
100
101 /* Remap channels from Vorbis order to ffmpeg order */
102 for (ch = 0; ch < channels; ch++)
103 mapping_arr[ch] = mapping[vorbis_offset[ch]];
104 mapping = mapping_arr;
105 }
106
107 opus->dec = opus_multistream_decoder_create(avc->sample_rate, channels,
108 nb_streams, nb_coupled,
109 mapping, &ret);
110 if (!opus->dec) {
111 av_log(avc, AV_LOG_ERROR, "Unable to create decoder: %s\n",
112 opus_strerror(ret));
113 return ff_opus_error_to_averror(ret);
114 }
115
116 #ifdef OPUS_SET_GAIN
117 ret = opus_multistream_decoder_ctl(opus->dec, OPUS_SET_GAIN(gain_db));
118 if (ret != OPUS_OK)
119 av_log(avc, AV_LOG_WARNING, "Failed to set gain: %s\n",
120 opus_strerror(ret));
121 #else
122 {
123 double gain_lin = ff_exp10(gain_db / (20.0 * 256));
124 if (avc->sample_fmt == AV_SAMPLE_FMT_FLT)
125 opus->gain.d = gain_lin;
126 else
127 opus->gain.i = FFMIN(gain_lin * 65536, INT_MAX);
128 }
129 #endif
130
131 #ifdef OPUS_SET_PHASE_INVERSION_DISABLED_REQUEST
132 ret = opus_multistream_decoder_ctl(opus->dec,
133 OPUS_SET_PHASE_INVERSION_DISABLED(!opus->apply_phase_inv));
134 if (ret != OPUS_OK)
135 av_log(avc, AV_LOG_WARNING,
136 "Unable to set phase inversion: %s\n",
137 opus_strerror(ret));
138 #endif
139
140 /* Decoder delay (in samples) at 48kHz */
141 avc->delay = avc->internal->skip_samples = opus->pre_skip;
142
143 return 0;
144 }
145
libopus_decode_close(AVCodecContext *avc)146 static av_cold int libopus_decode_close(AVCodecContext *avc)
147 {
148 struct libopus_context *opus = avc->priv_data;
149
150 if (opus->dec) {
151 opus_multistream_decoder_destroy(opus->dec);
152 opus->dec = NULL;
153 }
154 return 0;
155 }
156
157 #define MAX_FRAME_SIZE (960 * 6)
158
libopus_decode(AVCodecContext *avc, AVFrame *frame, int *got_frame_ptr, AVPacket *pkt)159 static int libopus_decode(AVCodecContext *avc, AVFrame *frame,
160 int *got_frame_ptr, AVPacket *pkt)
161 {
162 struct libopus_context *opus = avc->priv_data;
163 int ret, nb_samples;
164
165 frame->nb_samples = MAX_FRAME_SIZE;
166 if ((ret = ff_get_buffer(avc, frame, 0)) < 0)
167 return ret;
168
169 if (avc->sample_fmt == AV_SAMPLE_FMT_S16)
170 nb_samples = opus_multistream_decode(opus->dec, pkt->data, pkt->size,
171 (opus_int16 *)frame->data[0],
172 frame->nb_samples, 0);
173 else
174 nb_samples = opus_multistream_decode_float(opus->dec, pkt->data, pkt->size,
175 (float *)frame->data[0],
176 frame->nb_samples, 0);
177
178 if (nb_samples < 0) {
179 av_log(avc, AV_LOG_ERROR, "Decoding error: %s\n",
180 opus_strerror(nb_samples));
181 return ff_opus_error_to_averror(nb_samples);
182 }
183
184 #ifndef OPUS_SET_GAIN
185 {
186 int i = avc->ch_layout.nb_channels * nb_samples;
187 if (avc->sample_fmt == AV_SAMPLE_FMT_FLT) {
188 float *pcm = (float *)frame->data[0];
189 for (; i > 0; i--, pcm++)
190 *pcm = av_clipf(*pcm * opus->gain.d, -1, 1);
191 } else {
192 int16_t *pcm = (int16_t *)frame->data[0];
193 for (; i > 0; i--, pcm++)
194 *pcm = av_clip_int16(((int64_t)opus->gain.i * *pcm) >> 16);
195 }
196 }
197 #endif
198
199 frame->nb_samples = nb_samples;
200 *got_frame_ptr = 1;
201
202 return pkt->size;
203 }
204
libopus_flush(AVCodecContext *avc)205 static void libopus_flush(AVCodecContext *avc)
206 {
207 struct libopus_context *opus = avc->priv_data;
208
209 opus_multistream_decoder_ctl(opus->dec, OPUS_RESET_STATE);
210 /* The stream can have been extracted by a tool that is not Opus-aware.
211 Therefore, any packet can become the first of the stream. */
212 avc->internal->skip_samples = opus->pre_skip;
213 }
214
215
216 #define OFFSET(x) offsetof(struct libopus_context, x)
217 #define FLAGS AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_DECODING_PARAM
218 static const AVOption libopusdec_options[] = {
219 #ifdef OPUS_SET_PHASE_INVERSION_DISABLED_REQUEST
220 { "apply_phase_inv", "Apply intensity stereo phase inversion", OFFSET(apply_phase_inv), AV_OPT_TYPE_BOOL, { .i64 = 1 }, 0, 1, FLAGS },
221 #endif
222 { NULL },
223 };
224
225 static const AVClass libopusdec_class = {
226 .class_name = "libopusdec",
227 .item_name = av_default_item_name,
228 .option = libopusdec_options,
229 .version = LIBAVUTIL_VERSION_INT,
230 };
231
232
233 const FFCodec ff_libopus_decoder = {
234 .p.name = "libopus",
235 .p.long_name = NULL_IF_CONFIG_SMALL("libopus Opus"),
236 .p.type = AVMEDIA_TYPE_AUDIO,
237 .p.id = AV_CODEC_ID_OPUS,
238 .priv_data_size = sizeof(struct libopus_context),
239 .init = libopus_decode_init,
240 .close = libopus_decode_close,
241 FF_CODEC_DECODE_CB(libopus_decode),
242 .flush = libopus_flush,
243 .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_CHANNEL_CONF,
244 .caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
245 .p.sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_FLT,
246 AV_SAMPLE_FMT_S16,
247 AV_SAMPLE_FMT_NONE },
248 .p.priv_class = &libopusdec_class,
249 .p.wrapper_name = "libopus",
250 };
251