path: root/libavcodec/dsddec.c (plain)
blob: 2c5c357acc51fa86740e37d142b95d77077d8e85

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 "libavcodec/mathops.h"
31	#include "avcodec.h"
32	#include "dsd.h"
33
34	#define DSD_SILENCE 0x69
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
41	static av_cold int decode_init(AVCodecContext *avctx)
42	{
43	DSDContext * s;
44	int i;
45	uint8_t silence;
46
47	ff_init_dsd_data();
48
49	s = av_malloc_array(sizeof(DSDContext), avctx->channels);
50	if (!s)
51	return AVERROR(ENOMEM);
52
53	silence = avctx->codec_id == AV_CODEC_ID_DSD_LSBF || avctx->codec_id == AV_CODEC_ID_DSD_LSBF_PLANAR ? ff_reverse[DSD_SILENCE] : DSD_SILENCE;
54	for (i = 0; i < avctx->channels; i++) {
55	s[i].pos = 0;
56	memset(s[i].buf, silence, sizeof(s[i].buf));
57	}
58
59	avctx->sample_fmt = AV_SAMPLE_FMT_FLTP;
60	avctx->priv_data = s;
61	return 0;
62	}
63
64	static int decode_frame(AVCodecContext *avctx, void *data,
65	int *got_frame_ptr, AVPacket *avpkt)
66	{
67	DSDContext * s = avctx->priv_data;
68	AVFrame *frame = data;
69	int ret, i;
70	int lsbf = avctx->codec_id == AV_CODEC_ID_DSD_LSBF || avctx->codec_id == AV_CODEC_ID_DSD_LSBF_PLANAR;
71	int src_next;
72	int src_stride;
73
74	frame->nb_samples = avpkt->size / avctx->channels;
75
76	if (avctx->codec_id == AV_CODEC_ID_DSD_LSBF_PLANAR || avctx->codec_id == AV_CODEC_ID_DSD_MSBF_PLANAR) {
77	src_next = frame->nb_samples;
78	src_stride = 1;
79	} else {
80	src_next = 1;
81	src_stride = avctx->channels;
82	}
83
84	if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
85	return ret;
86
87	for (i = 0; i < avctx->channels; i++) {
88	float * dst = ((float **)frame->extended_data)[i];
89	ff_dsd2pcm_translate(&s[i], frame->nb_samples, lsbf,
90	avpkt->data + i * src_next, src_stride,
91	dst, 1);
92	}
93
94	*got_frame_ptr = 1;
95	return frame->nb_samples * avctx->channels;
96	}
97
98	#define DSD_DECODER(id_, name_, long_name_) \
99	AVCodec ff_##name_##_decoder = { \
100	.name = #name_, \
101	.long_name = NULL_IF_CONFIG_SMALL(long_name_), \
102	.type = AVMEDIA_TYPE_AUDIO, \
103	.id = AV_CODEC_ID_##id_, \
104	.init = decode_init, \
105	.decode = decode_frame, \
106	.sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_FLTP, \
107	AV_SAMPLE_FMT_NONE }, \
108	};
109
110	DSD_DECODER(DSD_LSBF, dsd_lsbf, "DSD (Direct Stream Digital), least significant bit first")
111	DSD_DECODER(DSD_MSBF, dsd_msbf, "DSD (Direct Stream Digital), most significant bit first")
112	DSD_DECODER(DSD_MSBF_PLANAR, dsd_msbf_planar, "DSD (Direct Stream Digital), most significant bit first, planar")
113	DSD_DECODER(DSD_LSBF_PLANAR, dsd_lsbf_planar, "DSD (Direct Stream Digital), least significant bit first, planar")
114