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 "dsd.h"
32
33 #define DSD_SILENCE 0x69
34 #define DSD_SILENCE_REVERSED 0x96
35 /* 0x69 = 01101001
36 * This pattern "on repeat" makes a low energy 352.8 kHz tone
37 * and a high energy 1.0584 MHz tone which should be filtered
38 * out completely by any playback system --> silence
39 */
40
decode_init(AVCodecContext * avctx)41 static av_cold int decode_init(AVCodecContext *avctx)
42 {
43 DSDContext * s;
44 int i;
45 uint8_t silence;
46
47 if (!avctx->channels)
48 return AVERROR_INVALIDDATA;
49
50 ff_init_dsd_data();
51
52 s = av_malloc_array(sizeof(DSDContext), avctx->channels);
53 if (!s)
54 return AVERROR(ENOMEM);
55
56 silence = avctx->codec_id == AV_CODEC_ID_DSD_LSBF || avctx->codec_id == AV_CODEC_ID_DSD_LSBF_PLANAR ? DSD_SILENCE_REVERSED : DSD_SILENCE;
57 for (i = 0; i < avctx->channels; i++) {
58 s[i].pos = 0;
59 memset(s[i].buf, silence, sizeof(s[i].buf));
60 }
61
62 avctx->sample_fmt = AV_SAMPLE_FMT_FLTP;
63 avctx->priv_data = s;
64 return 0;
65 }
66
67 typedef struct ThreadData {
68 AVFrame *frame;
69 const AVPacket *avpkt;
70 } ThreadData;
71
dsd_channel(AVCodecContext * avctx,void * tdata,int j,int threadnr)72 static int dsd_channel(AVCodecContext *avctx, void *tdata, int j, int threadnr)
73 {
74 int lsbf = avctx->codec_id == AV_CODEC_ID_DSD_LSBF || avctx->codec_id == AV_CODEC_ID_DSD_LSBF_PLANAR;
75 DSDContext *s = avctx->priv_data;
76 ThreadData *td = tdata;
77 AVFrame *frame = td->frame;
78 const AVPacket *avpkt = td->avpkt;
79 int src_next, src_stride;
80 float *dst = ((float **)frame->extended_data)[j];
81
82 if (avctx->codec_id == AV_CODEC_ID_DSD_LSBF_PLANAR || avctx->codec_id == AV_CODEC_ID_DSD_MSBF_PLANAR) {
83 src_next = frame->nb_samples;
84 src_stride = 1;
85 } else {
86 src_next = 1;
87 src_stride = avctx->channels;
88 }
89
90 ff_dsd2pcm_translate(&s[j], frame->nb_samples, lsbf,
91 avpkt->data + j * src_next, src_stride,
92 dst, 1);
93
94 return 0;
95 }
96
decode_frame(AVCodecContext * avctx,void * data,int * got_frame_ptr,AVPacket * avpkt)97 static int decode_frame(AVCodecContext *avctx, void *data,
98 int *got_frame_ptr, AVPacket *avpkt)
99 {
100 ThreadData td;
101 AVFrame *frame = data;
102 int ret;
103
104 frame->nb_samples = avpkt->size / avctx->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->channels);
112
113 *got_frame_ptr = 1;
114 return frame->nb_samples * avctx->channels;
115 }
116
117 #define DSD_DECODER(id_, name_, long_name_) \
118 AVCodec ff_##name_##_decoder = { \
119 .name = #name_, \
120 .long_name = NULL_IF_CONFIG_SMALL(long_name_), \
121 .type = AVMEDIA_TYPE_AUDIO, \
122 .id = AV_CODEC_ID_##id_, \
123 .init = decode_init, \
124 .decode = decode_frame, \
125 .capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_SLICE_THREADS, \
126 .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")
135