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
decode_init(AVCodecContext *avctx)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
dsd_channel(AVCodecContext *avctx, void *tdata, int j, int threadnr)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
decode_frame(AVCodecContext *avctx, AVFrame *frame, int *got_frame_ptr, AVPacket *avpkt)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")
135