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			245 lines
		
	
	
	
		
			8.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			245 lines
		
	
	
	
		
			8.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Opus decoder using libopus
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|  * Copyright (c) 2012 Nicolas George
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|  *
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|  * This file is part of FFmpeg.
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|  *
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|  * FFmpeg is free software; you can redistribute it and/or
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|  * modify it under the terms of the GNU Lesser General Public
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|  * License as published by the Free Software Foundation; either
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|  * version 2.1 of the License, or (at your option) any later version.
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|  *
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|  * FFmpeg is distributed in the hope that it will be useful,
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|  * but WITHOUT ANY WARRANTY; without even the implied warranty of
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|  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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|  * Lesser General Public License for more details.
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|  *
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|  * You should have received a copy of the GNU Lesser General Public
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|  * License along with FFmpeg; if not, write to the Free Software
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|  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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|  */
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| 
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| #include <opus.h>
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| #include <opus_multistream.h>
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| 
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| #include "libavutil/internal.h"
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| #include "libavutil/intreadwrite.h"
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| #include "libavutil/ffmath.h"
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| #include "libavutil/opt.h"
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| 
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| #include "avcodec.h"
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| #include "internal.h"
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| #include "vorbis.h"
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| #include "mathops.h"
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| #include "libopus.h"
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| 
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| struct libopus_context {
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|     AVClass *class;
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|     OpusMSDecoder *dec;
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|     int pre_skip;
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| #ifndef OPUS_SET_GAIN
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|     union { int i; double d; } gain;
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| #endif
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| #ifdef OPUS_SET_PHASE_INVERSION_DISABLED_REQUEST
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|     int apply_phase_inv;
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| #endif
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| };
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| 
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| #define OPUS_HEAD_SIZE 19
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| 
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| static av_cold int libopus_decode_init(AVCodecContext *avc)
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| {
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|     struct libopus_context *opus = avc->priv_data;
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|     int ret, channel_map = 0, gain_db = 0, nb_streams, nb_coupled;
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|     uint8_t mapping_arr[8] = { 0, 1 }, *mapping;
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| 
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|     avc->channels = avc->extradata_size >= 10 ? avc->extradata[9] : (avc->channels == 1) ? 1 : 2;
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|     if (avc->channels <= 0) {
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|         av_log(avc, AV_LOG_WARNING,
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|                "Invalid number of channels %d, defaulting to stereo\n", avc->channels);
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|         avc->channels = 2;
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|     }
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| 
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|     avc->sample_rate    = 48000;
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|     avc->sample_fmt     = avc->request_sample_fmt == AV_SAMPLE_FMT_FLT ?
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|                           AV_SAMPLE_FMT_FLT : AV_SAMPLE_FMT_S16;
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|     avc->channel_layout = avc->channels > 8 ? 0 :
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|                           ff_vorbis_channel_layouts[avc->channels - 1];
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| 
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|     if (avc->extradata_size >= OPUS_HEAD_SIZE) {
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|         opus->pre_skip = AV_RL16(avc->extradata + 10);
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|         gain_db     = sign_extend(AV_RL16(avc->extradata + 16), 16);
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|         channel_map = AV_RL8 (avc->extradata + 18);
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|     }
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|     if (avc->extradata_size >= OPUS_HEAD_SIZE + 2 + avc->channels) {
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|         nb_streams = avc->extradata[OPUS_HEAD_SIZE + 0];
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|         nb_coupled = avc->extradata[OPUS_HEAD_SIZE + 1];
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|         if (nb_streams + nb_coupled != avc->channels)
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|             av_log(avc, AV_LOG_WARNING, "Inconsistent channel mapping.\n");
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|         mapping = avc->extradata + OPUS_HEAD_SIZE + 2;
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|     } else {
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|         if (avc->channels > 2 || channel_map) {
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|             av_log(avc, AV_LOG_ERROR,
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|                    "No channel mapping for %d channels.\n", avc->channels);
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|             return AVERROR(EINVAL);
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|         }
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|         nb_streams = 1;
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|         nb_coupled = avc->channels > 1;
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|         mapping    = mapping_arr;
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|     }
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| 
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|     if (avc->channels > 2 && avc->channels <= 8) {
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|         const uint8_t *vorbis_offset = ff_vorbis_channel_layout_offsets[avc->channels - 1];
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|         int ch;
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| 
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|         /* Remap channels from Vorbis order to ffmpeg order */
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|         for (ch = 0; ch < avc->channels; ch++)
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|             mapping_arr[ch] = mapping[vorbis_offset[ch]];
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|         mapping = mapping_arr;
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|     }
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| 
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|     opus->dec = opus_multistream_decoder_create(avc->sample_rate, avc->channels,
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|                                                 nb_streams, nb_coupled,
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|                                                 mapping, &ret);
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|     if (!opus->dec) {
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|         av_log(avc, AV_LOG_ERROR, "Unable to create decoder: %s\n",
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|                opus_strerror(ret));
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|         return ff_opus_error_to_averror(ret);
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|     }
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| 
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| #ifdef OPUS_SET_GAIN
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|     ret = opus_multistream_decoder_ctl(opus->dec, OPUS_SET_GAIN(gain_db));
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|     if (ret != OPUS_OK)
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|         av_log(avc, AV_LOG_WARNING, "Failed to set gain: %s\n",
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|                opus_strerror(ret));
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| #else
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|     {
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|         double gain_lin = ff_exp10(gain_db / (20.0 * 256));
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|         if (avc->sample_fmt == AV_SAMPLE_FMT_FLT)
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|             opus->gain.d = gain_lin;
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|         else
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|             opus->gain.i = FFMIN(gain_lin * 65536, INT_MAX);
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|     }
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| #endif
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| 
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| #ifdef OPUS_SET_PHASE_INVERSION_DISABLED_REQUEST
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|     ret = opus_multistream_decoder_ctl(opus->dec,
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|                                        OPUS_SET_PHASE_INVERSION_DISABLED(!opus->apply_phase_inv));
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|     if (ret != OPUS_OK)
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|         av_log(avc, AV_LOG_WARNING,
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|                "Unable to set phase inversion: %s\n",
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|                opus_strerror(ret));
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| #endif
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| 
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|     /* Decoder delay (in samples) at 48kHz */
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|     avc->delay = avc->internal->skip_samples = opus->pre_skip;
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| 
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|     return 0;
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| }
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| 
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| static av_cold int libopus_decode_close(AVCodecContext *avc)
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| {
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|     struct libopus_context *opus = avc->priv_data;
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| 
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|     if (opus->dec) {
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|         opus_multistream_decoder_destroy(opus->dec);
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|         opus->dec = NULL;
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|     }
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|     return 0;
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| }
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| 
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| #define MAX_FRAME_SIZE (960 * 6)
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| 
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| static int libopus_decode(AVCodecContext *avc, void *data,
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|                           int *got_frame_ptr, AVPacket *pkt)
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| {
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|     struct libopus_context *opus = avc->priv_data;
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|     AVFrame *frame               = data;
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|     int ret, nb_samples;
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| 
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|     frame->nb_samples = MAX_FRAME_SIZE;
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|     if ((ret = ff_get_buffer(avc, frame, 0)) < 0)
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|         return ret;
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| 
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|     if (avc->sample_fmt == AV_SAMPLE_FMT_S16)
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|         nb_samples = opus_multistream_decode(opus->dec, pkt->data, pkt->size,
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|                                              (opus_int16 *)frame->data[0],
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|                                              frame->nb_samples, 0);
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|     else
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|         nb_samples = opus_multistream_decode_float(opus->dec, pkt->data, pkt->size,
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|                                                    (float *)frame->data[0],
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|                                                    frame->nb_samples, 0);
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| 
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|     if (nb_samples < 0) {
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|         av_log(avc, AV_LOG_ERROR, "Decoding error: %s\n",
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|                opus_strerror(nb_samples));
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|         return ff_opus_error_to_averror(nb_samples);
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|     }
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| 
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| #ifndef OPUS_SET_GAIN
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|     {
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|         int i = avc->channels * nb_samples;
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|         if (avc->sample_fmt == AV_SAMPLE_FMT_FLT) {
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|             float *pcm = (float *)frame->data[0];
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|             for (; i > 0; i--, pcm++)
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|                 *pcm = av_clipf(*pcm * opus->gain.d, -1, 1);
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|         } else {
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|             int16_t *pcm = (int16_t *)frame->data[0];
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|             for (; i > 0; i--, pcm++)
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|                 *pcm = av_clip_int16(((int64_t)opus->gain.i * *pcm) >> 16);
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|         }
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|     }
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| #endif
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| 
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|     frame->nb_samples = nb_samples;
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|     *got_frame_ptr    = 1;
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| 
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|     return pkt->size;
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| }
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| 
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| static void libopus_flush(AVCodecContext *avc)
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| {
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|     struct libopus_context *opus = avc->priv_data;
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| 
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|     opus_multistream_decoder_ctl(opus->dec, OPUS_RESET_STATE);
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|     /* The stream can have been extracted by a tool that is not Opus-aware.
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|        Therefore, any packet can become the first of the stream. */
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|     avc->internal->skip_samples = opus->pre_skip;
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| }
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| 
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| 
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| #define OFFSET(x) offsetof(struct libopus_context, x)
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| #define FLAGS AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_DECODING_PARAM
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| static const AVOption libopusdec_options[] = {
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| #ifdef OPUS_SET_PHASE_INVERSION_DISABLED_REQUEST
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|     { "apply_phase_inv", "Apply intensity stereo phase inversion", OFFSET(apply_phase_inv), AV_OPT_TYPE_BOOL, { .i64 = 1 }, 0, 1, FLAGS },
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| #endif
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|     { NULL },
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| };
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| 
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| static const AVClass libopusdec_class = {
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|     .class_name = "libopusdec",
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|     .item_name  = av_default_item_name,
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|     .option     = libopusdec_options,
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|     .version    = LIBAVUTIL_VERSION_INT,
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| };
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| 
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| 
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| AVCodec ff_libopus_decoder = {
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|     .name           = "libopus",
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|     .long_name      = NULL_IF_CONFIG_SMALL("libopus Opus"),
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|     .type           = AVMEDIA_TYPE_AUDIO,
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|     .id             = AV_CODEC_ID_OPUS,
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|     .priv_data_size = sizeof(struct libopus_context),
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|     .init           = libopus_decode_init,
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|     .close          = libopus_decode_close,
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|     .decode         = libopus_decode,
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|     .flush          = libopus_flush,
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|     .capabilities   = AV_CODEC_CAP_DR1,
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|     .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP,
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|     .sample_fmts    = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_FLT,
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|                                                      AV_SAMPLE_FMT_S16,
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|                                                      AV_SAMPLE_FMT_NONE },
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|     .priv_class     = &libopusdec_class,
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|     .wrapper_name   = "libopus",
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| };
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