libavcodec/libopusdec.c

   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 "decode.h"
  33 #include "internal.h"
  34 #include "mathops.h"
  35 #include "libopus.h"
  36 #include "vorbis_data.h"
  37
  38 struct libopus_context {
  39     AVClass *class;
  40     OpusMSDecoder *dec;
  41     int pre_skip;
  42 #ifndef OPUS_SET_GAIN
  43     union { int i; double d; } gain;
  44 #endif
  45 #ifdef OPUS_SET_PHASE_INVERSION_DISABLED_REQUEST
  46     int apply_phase_inv;
  47 #endif
  48 };
  49
  50 #define OPUS_HEAD_SIZE 19
  51
  52 static av_cold int libopus_decode_init(AVCodecContext *avc)
  53 {
  54     struct libopus_context *opus = avc->priv_data;
  55     int ret, channel_map = 0, gain_db = 0, nb_streams, nb_coupled, channels;
  56     uint8_t mapping_arr[8] = { 0, 1 }, *mapping;
  57
  58     channels = avc->extradata_size >= 10 ? avc->extradata[9] : (avc->ch_layout.nb_channels == 1) ? 1 : 2;
  59     if (channels <= 0) {
  60         av_log(avc, AV_LOG_WARNING,
  61                "Invalid number of channels %d, defaulting to stereo\n", channels);
  62         channels = 2;
  63     }
  64
  65     avc->sample_rate    = 48000;
  66     avc->sample_fmt     = avc->request_sample_fmt == AV_SAMPLE_FMT_FLT ?
  67                           AV_SAMPLE_FMT_FLT : AV_SAMPLE_FMT_S16;
  68     av_channel_layout_uninit(&avc->ch_layout);
  69     if (channels > 8) {
  70         avc->ch_layout.order       = AV_CHANNEL_ORDER_UNSPEC;
  71         avc->ch_layout.nb_channels = channels;
  72     } else {
  73         av_channel_layout_copy(&avc->ch_layout, &ff_vorbis_ch_layouts[channels - 1]);
  74     }
  75
  76     if (avc->extradata_size >= OPUS_HEAD_SIZE) {
  77         opus->pre_skip = AV_RL16(avc->extradata + 10);
  78         gain_db     = sign_extend(AV_RL16(avc->extradata + 16), 16);
  79         channel_map = AV_RL8 (avc->extradata + 18);
  80     }
  81     if (avc->extradata_size >= OPUS_HEAD_SIZE + 2 + channels) {
  82         nb_streams = avc->extradata[OPUS_HEAD_SIZE + 0];
  83         nb_coupled = avc->extradata[OPUS_HEAD_SIZE + 1];
  84         if (nb_streams + nb_coupled != channels)
  85             av_log(avc, AV_LOG_WARNING, "Inconsistent channel mapping.\n");
  86         mapping = avc->extradata + OPUS_HEAD_SIZE + 2;
  87     } else {
  88         if (channels > 2 || channel_map) {
  89             av_log(avc, AV_LOG_ERROR,
  90                    "No channel mapping for %d channels.\n", channels);
  91             return AVERROR(EINVAL);
  92         }
  93         nb_streams = 1;
  94         nb_coupled = channels > 1;
  95         mapping    = mapping_arr;
  96     }
  97
  98     if (channels > 2 && channels <= 8) {
  99         const uint8_t *vorbis_offset = ff_vorbis_channel_layout_offsets[channels - 1];
 100         int ch;
 101
 102         /* Remap channels from Vorbis order to ffmpeg order */
 103         for (ch = 0; ch < channels; ch++)
 104             mapping_arr[ch] = mapping[vorbis_offset[ch]];
 105         mapping = mapping_arr;
 106     }
 107
 108     opus->dec = opus_multistream_decoder_create(avc->sample_rate, channels,
 109                                                 nb_streams, nb_coupled,
 110                                                 mapping, &ret);
 111     if (!opus->dec) {
 112         av_log(avc, AV_LOG_ERROR, "Unable to create decoder: %s\n",
 113                opus_strerror(ret));
 114         return ff_opus_error_to_averror(ret);
 115     }
 116
 117 #ifdef OPUS_SET_GAIN
 118     ret = opus_multistream_decoder_ctl(opus->dec, OPUS_SET_GAIN(gain_db));
 119     if (ret != OPUS_OK)
 120         av_log(avc, AV_LOG_WARNING, "Failed to set gain: %s\n",
 121                opus_strerror(ret));
 122 #else
 123     {
 124         double gain_lin = ff_exp10(gain_db / (20.0 * 256));
 125         if (avc->sample_fmt == AV_SAMPLE_FMT_FLT)
 126             opus->gain.d = gain_lin;
 127         else
 128             opus->gain.i = FFMIN(gain_lin * 65536, INT_MAX);
 129     }
 130 #endif
 131
 132 #ifdef OPUS_SET_PHASE_INVERSION_DISABLED_REQUEST
 133     ret = opus_multistream_decoder_ctl(opus->dec,
 134                                        OPUS_SET_PHASE_INVERSION_DISABLED(!opus->apply_phase_inv));
 135     if (ret != OPUS_OK)
 136         av_log(avc, AV_LOG_WARNING,
 137                "Unable to set phase inversion: %s\n",
 138                opus_strerror(ret));
 139 #endif
 140
 141     /* Decoder delay (in samples) at 48kHz */
 142     avc->delay = avc->internal->skip_samples = opus->pre_skip;
 143
 144     return 0;
 145 }
 146
 147 static av_cold int libopus_decode_close(AVCodecContext *avc)
 148 {
 149     struct libopus_context *opus = avc->priv_data;
 150
 151     if (opus->dec) {
 152         opus_multistream_decoder_destroy(opus->dec);
 153         opus->dec = NULL;
 154     }
 155     return 0;
 156 }
 157
 158 #define MAX_FRAME_SIZE (960 * 6)
 159
 160 static int libopus_decode(AVCodecContext *avc, AVFrame *frame,
 161                           int *got_frame_ptr, AVPacket *pkt)
 162 {
 163     struct libopus_context *opus = avc->priv_data;
 164     int ret, nb_samples;
 165
 166     frame->nb_samples = MAX_FRAME_SIZE;
 167     if ((ret = ff_get_buffer(avc, frame, 0)) < 0)
 168         return ret;
 169
 170     if (avc->sample_fmt == AV_SAMPLE_FMT_S16)
 171         nb_samples = opus_multistream_decode(opus->dec, pkt->data, pkt->size,
 172                                              (opus_int16 *)frame->data[0],
 173                                              frame->nb_samples, 0);
 174     else
 175         nb_samples = opus_multistream_decode_float(opus->dec, pkt->data, pkt->size,
 176                                                    (float *)frame->data[0],
 177                                                    frame->nb_samples, 0);
 178
 179     if (nb_samples < 0) {
 180         av_log(avc, AV_LOG_ERROR, "Decoding error: %s\n",
 181                opus_strerror(nb_samples));
 182         return ff_opus_error_to_averror(nb_samples);
 183     }
 184
 185 #ifndef OPUS_SET_GAIN
 186     {
 187         int i = avc->ch_layout.nb_channels * nb_samples;
 188         if (avc->sample_fmt == AV_SAMPLE_FMT_FLT) {
 189             float *pcm = (float *)frame->data[0];
 190             for (; i > 0; i--, pcm++)
 191                 *pcm = av_clipf(*pcm * opus->gain.d, -1, 1);
 192         } else {
 193             int16_t *pcm = (int16_t *)frame->data[0];
 194             for (; i > 0; i--, pcm++)
 195                 *pcm = av_clip_int16(((int64_t)opus->gain.i * *pcm) >> 16);
 196         }
 197     }
 198 #endif
 199
 200     frame->nb_samples = nb_samples;
 201     *got_frame_ptr    = 1;
 202
 203     return pkt->size;
 204 }
 205
 206 static void libopus_flush(AVCodecContext *avc)
 207 {
 208     struct libopus_context *opus = avc->priv_data;
 209
 210     opus_multistream_decoder_ctl(opus->dec, OPUS_RESET_STATE);
 211     /* The stream can have been extracted by a tool that is not Opus-aware.
 212        Therefore, any packet can become the first of the stream. */
 213     avc->internal->skip_samples = opus->pre_skip;
 214 }
 215
 216
 217 #define OFFSET(x) offsetof(struct libopus_context, x)
 218 #define FLAGS AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_DECODING_PARAM
 219 static const AVOption libopusdec_options[] = {
 220 #ifdef OPUS_SET_PHASE_INVERSION_DISABLED_REQUEST
 221     { "apply_phase_inv", "Apply intensity stereo phase inversion", OFFSET(apply_phase_inv), AV_OPT_TYPE_BOOL, { .i64 = 1 }, 0, 1, FLAGS },
 222 #endif
 223     { NULL },
 224 };
 225
 226 static const AVClass libopusdec_class = {
 227     .class_name = "libopusdec",
 228     .item_name  = av_default_item_name,
 229     .option     = libopusdec_options,
 230     .version    = LIBAVUTIL_VERSION_INT,
 231 };
 232
 233
 234 const FFCodec ff_libopus_decoder = {
 235     .p.name         = "libopus",
 236     CODEC_LONG_NAME("libopus Opus"),
 237     .p.type         = AVMEDIA_TYPE_AUDIO,
 238     .p.id           = AV_CODEC_ID_OPUS,
 239     .priv_data_size = sizeof(struct libopus_context),
 240     .init           = libopus_decode_init,
 241     .close          = libopus_decode_close,
 242     FF_CODEC_DECODE_CB(libopus_decode),
 243     .flush          = libopus_flush,
 244     .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_CHANNEL_CONF,
 245     .caps_internal  = FF_CODEC_CAP_NOT_INIT_THREADSAFE |
 246                       FF_CODEC_CAP_INIT_CLEANUP,
 247     .p.sample_fmts  = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_FLT,
 248                                                      AV_SAMPLE_FMT_S16,
 249                                                      AV_SAMPLE_FMT_NONE },
 250     .p.priv_class   = &libopusdec_class,
 251     .p.wrapper_name = "libopus",
 252 };