1// SPDX-License-Identifier: GPL-2.0
2//
3// container-au.c - a parser/builder for a container of Sun Audio File.
4//
5// Copyright (c) 2018 Takashi Sakamoto <o-takashi@sakamocchi.jp>
6//
7// Licensed under the terms of the GNU General Public License, version 2.
8
9#include "container.h"
10#include "misc.h"
11
12// Not portable to all of UNIX platforms.
13#include <endian.h>
14
15// Reference:
16//  * http://pubs.opengroup.org/external/auformat.html
17
18#define AU_MAGIC	".snd"
19#define UNKNOWN_SIZE	UINT32_MAX
20
21enum code_id {
22	CODE_ID_CCIT_MU_LAW_BE		= 0x01,
23	CODE_ID_GENERIC_MBLA_S8		= 0x02,
24	CODE_ID_GENERIC_MBLA_S16_BE	= 0x03,
25	CODE_ID_GENERIC_MBLA_S32_BE	= 0x05,
26	CODE_ID_IEEE754_FLOAT_S32_BE	= 0x06,
27	CODE_ID_IEEE754_DOUBLE_S64_BE	= 0x07,
28	CODE_ID_CCIT_ADPCM_G721_4BIT_BE	= 0x17,
29	CODE_ID_CCIT_ADPCM_G723_3BIT_BE	= 0x19,
30	CODE_ID_CCIT_A_LAW_BE		= 0x1b,
31};
32
33struct format_map {
34	enum code_id code_id;
35	snd_pcm_format_t format;
36};
37
38static const struct format_map format_maps[] = {
39	{CODE_ID_GENERIC_MBLA_S8,		SND_PCM_FORMAT_S8},
40	{CODE_ID_GENERIC_MBLA_S16_BE,		SND_PCM_FORMAT_S16_BE},
41	{CODE_ID_GENERIC_MBLA_S32_BE,		SND_PCM_FORMAT_S32_BE},
42	{CODE_ID_IEEE754_FLOAT_S32_BE,		SND_PCM_FORMAT_FLOAT_BE},
43	{CODE_ID_IEEE754_DOUBLE_S64_BE,		SND_PCM_FORMAT_FLOAT64_BE},
44	// CODE_ID_CCIT_ADPCM_G721_4BIT_BE is not supported by ALSA.
45	// CODE_ID_CCIT_ADPCM_G723_3BIT_BE is not supported due to width of
46	// its sample.
47	{CODE_ID_CCIT_A_LAW_BE,			SND_PCM_FORMAT_A_LAW},
48	{CODE_ID_CCIT_MU_LAW_BE,		SND_PCM_FORMAT_MU_LAW},
49};
50
51struct container_header {
52	uint8_t magic[4];
53	uint32_t hdr_size;
54	uint32_t data_size;
55	uint32_t code_id;
56	uint32_t frames_per_second;
57	uint32_t samples_per_frame;
58};
59
60struct container_annotation {
61	uint32_t chunks[0];
62};
63
64struct parser_state {
65	enum code_id code_id;
66	unsigned int samples_per_frame;
67	unsigned int bytes_per_sample;
68};
69
70static int au_parser_pre_process(struct container_context *cntr,
71				 snd_pcm_format_t *format,
72				 unsigned int *samples_per_frame,
73				 unsigned int *frames_per_second,
74				 uint64_t *byte_count)
75{
76	struct parser_state *state = cntr->private_data;
77	struct container_header header;
78	enum code_id code_id;
79	unsigned int i;
80	int err;
81
82	// Parse header. 4 bytes are enough to detect supported containers.
83	memcpy(&header.magic, cntr->magic, sizeof(cntr->magic));
84	err = container_recursive_read(cntr,
85				       (char *)&header + sizeof(cntr->magic),
86				       sizeof(header) - sizeof(cntr->magic));
87	if (err < 0)
88		return err;
89	if (cntr->eof)
90		return 0;
91
92	if (memcmp(header.magic, AU_MAGIC, sizeof(header.magic)) != 0)
93		return -EINVAL;
94	if (be32toh(header.hdr_size) != sizeof(struct container_header))
95		return -EINVAL;
96
97	code_id = be32toh(header.code_id);
98	for (i = 0; i < ARRAY_SIZE(format_maps); ++i) {
99		if (format_maps[i].code_id == code_id)
100			break;
101	}
102	if (i == ARRAY_SIZE(format_maps))
103		return -EINVAL;
104	*format = format_maps[i].format;
105	*frames_per_second = be32toh(header.frames_per_second);
106	*samples_per_frame = be32toh(header.samples_per_frame);
107
108	state->code_id = code_id;
109	state->samples_per_frame = *samples_per_frame;
110	state->bytes_per_sample = snd_pcm_format_physical_width(*format) / 8;
111
112	*byte_count = be32toh(header.data_size);
113
114	return 0;
115}
116
117struct builder_state {
118	unsigned int bytes_per_sample;
119	unsigned int samples_per_frame;
120	unsigned int frames_per_second;
121	enum code_id code_id;
122};
123
124static void build_container_header(struct builder_state *state,
125				   struct container_header *header,
126				   unsigned int frames_per_second,
127				   uint64_t byte_count)
128{
129	memcpy(header->magic, AU_MAGIC, sizeof(header->magic));
130	header->hdr_size = htobe32(sizeof(struct container_header));
131	header->data_size = htobe32(byte_count);
132	header->code_id = htobe32(state->code_id);
133	header->frames_per_second = htobe32(frames_per_second);
134	header->samples_per_frame = htobe32(state->samples_per_frame);
135}
136
137static int write_container_header(struct container_context *cntr,
138				  uint64_t byte_count)
139{
140	struct builder_state *state = cntr->private_data;
141	struct container_header header;
142
143	build_container_header(state, &header, state->frames_per_second,
144			       byte_count);
145
146	return container_recursive_write(cntr, &header, sizeof(header));
147}
148
149static int au_builder_pre_process(struct container_context *cntr,
150				  snd_pcm_format_t *format,
151				  unsigned int *samples_per_frame,
152				  unsigned int *frames_per_second,
153				  uint64_t *byte_count)
154{
155	struct builder_state *status = cntr->private_data;
156	unsigned int i;
157
158	for (i = 0; i < ARRAY_SIZE(format_maps); ++i) {
159		if (format_maps[i].format == *format)
160			break;
161	}
162	if (i == ARRAY_SIZE(format_maps))
163		return -EINVAL;
164
165	status->code_id = format_maps[i].code_id;
166	status->bytes_per_sample = snd_pcm_format_physical_width(*format) / 8;
167	status->frames_per_second = *frames_per_second;
168	status->samples_per_frame = *samples_per_frame;
169
170	return write_container_header(cntr, *byte_count);
171}
172
173static int au_builder_post_process(struct container_context *cntr,
174				   uint64_t handled_byte_count)
175{
176	int err;
177
178	err = container_seek_offset(cntr, 0);
179	if (err < 0)
180		return err;
181
182	return write_container_header(cntr, handled_byte_count);
183}
184
185const struct container_parser container_parser_au = {
186	.format = CONTAINER_FORMAT_AU,
187	.magic = AU_MAGIC,
188	.max_size = UINT32_MAX,
189	.ops = {
190		.pre_process = au_parser_pre_process,
191	},
192	.private_size = sizeof(struct parser_state),
193};
194
195const struct container_builder container_builder_au = {
196	.format = CONTAINER_FORMAT_AU,
197	.max_size = UINT32_MAX,
198	.ops = {
199		.pre_process	= au_builder_pre_process,
200		.post_process	= au_builder_post_process,
201	},
202	.private_size = sizeof(struct builder_state),
203};
204