summaryrefslogtreecommitdiff
path: root/libavcodec/libopusdec.c (plain)
blob: e6ca61a78f3fc250f1e371f310241f2b6dc1095d
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
28#include "avcodec.h"
29#include "internal.h"
30#include "vorbis.h"
31#include "mathops.h"
32#include "libopus.h"
33
34struct libopus_context {
35 OpusMSDecoder *dec;
36 int pre_skip;
37#ifndef OPUS_SET_GAIN
38 union { int i; double d; } gain;
39#endif
40};
41
42#define OPUS_HEAD_SIZE 19
43
44static av_cold int libopus_decode_init(AVCodecContext *avc)
45{
46 struct libopus_context *opus = avc->priv_data;
47 int ret, channel_map = 0, gain_db = 0, nb_streams, nb_coupled;
48 uint8_t mapping_arr[8] = { 0, 1 }, *mapping;
49
50 avc->channels = avc->extradata_size >= 10 ? avc->extradata[9] : (avc->channels == 1) ? 1 : 2;
51 if (avc->channels <= 0) {
52 av_log(avc, AV_LOG_WARNING,
53 "Invalid number of channels %d, defaulting to stereo\n", avc->channels);
54 avc->channels = 2;
55 }
56
57 avc->sample_rate = 48000;
58 avc->sample_fmt = avc->request_sample_fmt == AV_SAMPLE_FMT_FLT ?
59 AV_SAMPLE_FMT_FLT : AV_SAMPLE_FMT_S16;
60 avc->channel_layout = avc->channels > 8 ? 0 :
61 ff_vorbis_channel_layouts[avc->channels - 1];
62
63 if (avc->extradata_size >= OPUS_HEAD_SIZE) {
64 opus->pre_skip = AV_RL16(avc->extradata + 10);
65 gain_db = sign_extend(AV_RL16(avc->extradata + 16), 16);
66 channel_map = AV_RL8 (avc->extradata + 18);
67 }
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;
74 } else {
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);
79 }
80 nb_streams = 1;
81 nb_coupled = avc->channels > 1;
82 mapping = mapping_arr;
83 }
84
85 if (avc->channels > 2 && avc->channels <= 8) {
86 const uint8_t *vorbis_offset = ff_vorbis_channel_layout_offsets[avc->channels - 1];
87 int ch;
88
89 /* Remap channels from Vorbis order to ffmpeg order */
90 for (ch = 0; ch < avc->channels; ch++)
91 mapping_arr[ch] = mapping[vorbis_offset[ch]];
92 mapping = mapping_arr;
93 }
94
95 opus->dec = opus_multistream_decoder_create(avc->sample_rate, avc->channels,
96 nb_streams, nb_coupled,
97 mapping, &ret);
98 if (!opus->dec) {
99 av_log(avc, AV_LOG_ERROR, "Unable to create decoder: %s\n",
100 opus_strerror(ret));
101 return ff_opus_error_to_averror(ret);
102 }
103
104#ifdef OPUS_SET_GAIN
105 ret = opus_multistream_decoder_ctl(opus->dec, OPUS_SET_GAIN(gain_db));
106 if (ret != OPUS_OK)
107 av_log(avc, AV_LOG_WARNING, "Failed to set gain: %s\n",
108 opus_strerror(ret));
109#else
110 {
111 double gain_lin = ff_exp10(gain_db / (20.0 * 256));
112 if (avc->sample_fmt == AV_SAMPLE_FMT_FLT)
113 opus->gain.d = gain_lin;
114 else
115 opus->gain.i = FFMIN(gain_lin * 65536, INT_MAX);
116 }
117#endif
118
119 /* Decoder delay (in samples) at 48kHz */
120 avc->delay = avc->internal->skip_samples = opus->pre_skip;
121
122 return 0;
123}
124
125static av_cold int libopus_decode_close(AVCodecContext *avc)
126{
127 struct libopus_context *opus = avc->priv_data;
128
129 opus_multistream_decoder_destroy(opus->dec);
130 return 0;
131}
132
133#define MAX_FRAME_SIZE (960 * 6)
134
135static int libopus_decode(AVCodecContext *avc, void *data,
136 int *got_frame_ptr, AVPacket *pkt)
137{
138 struct libopus_context *opus = avc->priv_data;
139 AVFrame *frame = data;
140 int ret, nb_samples;
141
142 frame->nb_samples = MAX_FRAME_SIZE;
143 if ((ret = ff_get_buffer(avc, frame, 0)) < 0)
144 return ret;
145
146 if (avc->sample_fmt == AV_SAMPLE_FMT_S16)
147 nb_samples = opus_multistream_decode(opus->dec, pkt->data, pkt->size,
148 (opus_int16 *)frame->data[0],
149 frame->nb_samples, 0);
150 else
151 nb_samples = opus_multistream_decode_float(opus->dec, pkt->data, pkt->size,
152 (float *)frame->data[0],
153 frame->nb_samples, 0);
154
155 if (nb_samples < 0) {
156 av_log(avc, AV_LOG_ERROR, "Decoding error: %s\n",
157 opus_strerror(nb_samples));
158 return ff_opus_error_to_averror(nb_samples);
159 }
160
161#ifndef OPUS_SET_GAIN
162 {
163 int i = avc->channels * nb_samples;
164 if (avc->sample_fmt == AV_SAMPLE_FMT_FLT) {
165 float *pcm = (float *)frame->data[0];
166 for (; i > 0; i--, pcm++)
167 *pcm = av_clipf(*pcm * opus->gain.d, -1, 1);
168 } else {
169 int16_t *pcm = (int16_t *)frame->data[0];
170 for (; i > 0; i--, pcm++)
171 *pcm = av_clip_int16(((int64_t)opus->gain.i * *pcm) >> 16);
172 }
173 }
174#endif
175
176 frame->nb_samples = nb_samples;
177 *got_frame_ptr = 1;
178
179 return pkt->size;
180}
181
182static void libopus_flush(AVCodecContext *avc)
183{
184 struct libopus_context *opus = avc->priv_data;
185
186 opus_multistream_decoder_ctl(opus->dec, OPUS_RESET_STATE);
187 /* The stream can have been extracted by a tool that is not Opus-aware.
188 Therefore, any packet can become the first of the stream. */
189 avc->internal->skip_samples = opus->pre_skip;
190}
191
192AVCodec ff_libopus_decoder = {
193 .name = "libopus",
194 .long_name = NULL_IF_CONFIG_SMALL("libopus Opus"),
195 .type = AVMEDIA_TYPE_AUDIO,
196 .id = AV_CODEC_ID_OPUS,
197 .priv_data_size = sizeof(struct libopus_context),
198 .init = libopus_decode_init,
199 .close = libopus_decode_close,
200 .decode = libopus_decode,
201 .flush = libopus_flush,
202 .capabilities = AV_CODEC_CAP_DR1,
203 .sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_FLT,
204 AV_SAMPLE_FMT_S16,
205 AV_SAMPLE_FMT_NONE },
206};
207
generated by cgit at 2024-05-17 04:18:30 (GMT)