Reviewed-by: Paul B Mahol <onemda@gmail.com> Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
		
			
				
	
	
		
			114 lines
		
	
	
		
			3.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			114 lines
		
	
	
		
			3.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Direct Stream Digital (DSD) decoder
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|  * based on BSD licensed dsd2pcm by Sebastian Gesemann
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|  * Copyright (c) 2009, 2011 Sebastian Gesemann. All rights reserved.
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|  * Copyright (c) 2014 Peter Ross
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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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| /**
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|  * @file
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|  * Direct Stream Digital (DSD) decoder
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|  */
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| 
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| #include "libavcodec/internal.h"
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| #include "libavcodec/mathops.h"
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| #include "avcodec.h"
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| #include "dsd.h"
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| 
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| #define DSD_SILENCE 0x69
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| /* 0x69 = 01101001
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|  * This pattern "on repeat" makes a low energy 352.8 kHz tone
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|  * and a high energy 1.0584 MHz tone which should be filtered
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|  * out completely by any playback system --> silence
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|  */
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| 
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| static av_cold int decode_init(AVCodecContext *avctx)
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| {
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|     DSDContext * s;
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|     int i;
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|     uint8_t silence;
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| 
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|     ff_init_dsd_data();
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| 
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|     s = av_malloc_array(sizeof(DSDContext), avctx->channels);
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|     if (!s)
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|         return AVERROR(ENOMEM);
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| 
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|     silence = avctx->codec_id == AV_CODEC_ID_DSD_LSBF || avctx->codec_id == AV_CODEC_ID_DSD_LSBF_PLANAR ? ff_reverse[DSD_SILENCE] : DSD_SILENCE;
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|     for (i = 0; i < avctx->channels; i++) {
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|         s[i].pos = 0;
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|         memset(s[i].buf, silence, sizeof(s[i].buf));
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|     }
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| 
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|     avctx->sample_fmt = AV_SAMPLE_FMT_FLTP;
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|     avctx->priv_data  = s;
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|     return 0;
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| }
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| 
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| static int decode_frame(AVCodecContext *avctx, void *data,
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|                         int *got_frame_ptr, AVPacket *avpkt)
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| {
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|     DSDContext * s = avctx->priv_data;
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|     AVFrame *frame = data;
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|     int ret, i;
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|     int lsbf = avctx->codec_id == AV_CODEC_ID_DSD_LSBF || avctx->codec_id == AV_CODEC_ID_DSD_LSBF_PLANAR;
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|     int src_next;
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|     int src_stride;
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| 
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|     frame->nb_samples = avpkt->size / avctx->channels;
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| 
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|     if (avctx->codec_id == AV_CODEC_ID_DSD_LSBF_PLANAR || avctx->codec_id == AV_CODEC_ID_DSD_MSBF_PLANAR) {
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|         src_next   = frame->nb_samples;
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|         src_stride = 1;
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|     } else {
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|         src_next   = 1;
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|         src_stride = avctx->channels;
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|     }
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| 
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|     if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
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|         return ret;
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| 
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|     for (i = 0; i < avctx->channels; i++) {
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|         float * dst = ((float **)frame->extended_data)[i];
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|         ff_dsd2pcm_translate(&s[i], frame->nb_samples, lsbf,
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|             avpkt->data + i * src_next, src_stride,
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|             dst, 1);
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|     }
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| 
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|     *got_frame_ptr = 1;
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|     return frame->nb_samples * avctx->channels;
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| }
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| 
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| #define DSD_DECODER(id_, name_, long_name_) \
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| AVCodec ff_##name_##_decoder = { \
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|     .name         = #name_, \
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|     .long_name    = NULL_IF_CONFIG_SMALL(long_name_), \
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|     .type         = AVMEDIA_TYPE_AUDIO, \
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|     .id           = AV_CODEC_ID_##id_, \
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|     .init         = decode_init, \
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|     .decode       = decode_frame, \
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|     .sample_fmts  = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_FLTP, \
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|                                                    AV_SAMPLE_FMT_NONE }, \
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| };
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| 
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| DSD_DECODER(DSD_LSBF, dsd_lsbf, "DSD (Direct Stream Digital), least significant bit first")
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| DSD_DECODER(DSD_MSBF, dsd_msbf, "DSD (Direct Stream Digital), most significant bit first")
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| DSD_DECODER(DSD_MSBF_PLANAR, dsd_msbf_planar, "DSD (Direct Stream Digital), most significant bit first, planar")
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| DSD_DECODER(DSD_LSBF_PLANAR, dsd_lsbf_planar, "DSD (Direct Stream Digital), least significant bit first, planar")
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