libavcodec/dsddec.c

   1 /*
   2  * Direct Stream Digital (DSD) decoder
   3  * based on BSD licensed dsd2pcm by Sebastian Gesemann
   4  * Copyright (c) 2009, 2011 Sebastian Gesemann. All rights reserved.
   5  * Copyright (c) 2014 Peter Ross
   6  *
   7  * This file is part of FFmpeg.
   8  *
   9  * FFmpeg is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public
  11  * License as published by the Free Software Foundation; either
  12  * version 2.1 of the License, or (at your option) any later version.
  13  *
  14  * FFmpeg is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public
  20  * License along with FFmpeg; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  22  */
  23
  24 /**
  25  * @file
  26  * Direct Stream Digital (DSD) decoder
  27  */
  28
  29 #include "libavcodec/internal.h"
  30 #include "avcodec.h"
  31 #include "codec_internal.h"
  32 #include "dsd.h"
  33
  34 #define DSD_SILENCE 0x69
  35 #define DSD_SILENCE_REVERSED 0x96
  36 /* 0x69 = 01101001
  37  * This pattern "on repeat" makes a low energy 352.8 kHz tone
  38  * and a high energy 1.0584 MHz tone which should be filtered
  39  * out completely by any playback system --> silence
  40  */
  41
  42 static av_cold int decode_init(AVCodecContext *avctx)
  43 {
  44     DSDContext * s;
  45     int i;
  46     uint8_t silence;
  47
  48     if (!avctx->ch_layout.nb_channels)
  49         return AVERROR_INVALIDDATA;
  50
  51     ff_init_dsd_data();
  52
  53     s = av_malloc_array(sizeof(DSDContext), avctx->ch_layout.nb_channels);
  54     if (!s)
  55         return AVERROR(ENOMEM);
  56
  57     silence = avctx->codec_id == AV_CODEC_ID_DSD_LSBF || avctx->codec_id == AV_CODEC_ID_DSD_LSBF_PLANAR ? DSD_SILENCE_REVERSED : DSD_SILENCE;
  58     for (i = 0; i < avctx->ch_layout.nb_channels; i++) {
  59         s[i].pos = 0;
  60         memset(s[i].buf, silence, sizeof(s[i].buf));
  61     }
  62
  63     avctx->sample_fmt = AV_SAMPLE_FMT_FLTP;
  64     avctx->priv_data  = s;
  65     return 0;
  66 }
  67
  68 typedef struct ThreadData {
  69     AVFrame *frame;
  70     const AVPacket *avpkt;
  71 } ThreadData;
  72
  73 static int dsd_channel(AVCodecContext *avctx, void *tdata, int j, int threadnr)
  74 {
  75     int lsbf = avctx->codec_id == AV_CODEC_ID_DSD_LSBF || avctx->codec_id == AV_CODEC_ID_DSD_LSBF_PLANAR;
  76     DSDContext *s = avctx->priv_data;
  77     ThreadData *td = tdata;
  78     AVFrame *frame = td->frame;
  79     const AVPacket *avpkt = td->avpkt;
  80     int src_next, src_stride;
  81     float *dst = ((float **)frame->extended_data)[j];
  82
  83     if (avctx->codec_id == AV_CODEC_ID_DSD_LSBF_PLANAR || avctx->codec_id == AV_CODEC_ID_DSD_MSBF_PLANAR) {
  84         src_next   = frame->nb_samples;
  85         src_stride = 1;
  86     } else {
  87         src_next   = 1;
  88         src_stride = avctx->ch_layout.nb_channels;
  89     }
  90
  91     ff_dsd2pcm_translate(&s[j], frame->nb_samples, lsbf,
  92                          avpkt->data + j * src_next, src_stride,
  93                          dst, 1);
  94
  95     return 0;
  96 }
  97
  98 static int decode_frame(AVCodecContext *avctx, AVFrame *frame,
  99                         int *got_frame_ptr, AVPacket *avpkt)
 100 {
 101     ThreadData td;
 102     int ret;
 103
 104     frame->nb_samples = avpkt->size / avctx->ch_layout.nb_channels;
 105
 106     if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
 107         return ret;
 108
 109     td.frame = frame;
 110     td.avpkt = avpkt;
 111     avctx->execute2(avctx, dsd_channel, &td, NULL, avctx->ch_layout.nb_channels);
 112
 113     *got_frame_ptr = 1;
 114     return frame->nb_samples * avctx->ch_layout.nb_channels;
 115 }
 116
 117 #define DSD_DECODER(id_, name_, long_name_) \
 118 const FFCodec ff_ ## name_ ## _decoder = { \
 119     .p.name       = #name_, \
 120     .p.long_name  = NULL_IF_CONFIG_SMALL(long_name_), \
 121     .p.type       = AVMEDIA_TYPE_AUDIO, \
 122     .p.id         = AV_CODEC_ID_##id_, \
 123     .init         = decode_init, \
 124     FF_CODEC_DECODE_CB(decode_frame), \
 125     .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_SLICE_THREADS, \
 126     .p.sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_FLTP, \
 127                                                    AV_SAMPLE_FMT_NONE }, \
 128     .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE, \
 129 };
 130
 131 DSD_DECODER(DSD_LSBF, dsd_lsbf, "DSD (Direct Stream Digital), least significant bit first")
 132 DSD_DECODER(DSD_MSBF, dsd_msbf, "DSD (Direct Stream Digital), most significant bit first")
 133 DSD_DECODER(DSD_MSBF_PLANAR, dsd_msbf_planar, "DSD (Direct Stream Digital), most significant bit first, planar")
 134 DSD_DECODER(DSD_LSBF_PLANAR, dsd_lsbf_planar, "DSD (Direct Stream Digital), least significant bit first, planar")