summaryrefslogtreecommitdiff
path: root/modules/mpa/decode.c
blob: 7dfaccb5afc9ffade75cb93d4b9d013a404c28ab (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
/**
 * @file mpa/decode.c mpa Decode
 *
 * Copyright (C) 2016 Symonics GmbH
 */

#include <re.h>
#include <baresip.h>
#include <mpg123.h>
#include <speex/speex_resampler.h>
#include <string.h>
#include "mpa.h"

struct audec_state {
	mpg123_handle *dec;
	SpeexResamplerState *resampler;
	int channels;
	int16_t intermediate_buffer[MPA_FRAMESIZE*2];
	int start;
};


static void destructor(void *arg)
{
	struct audec_state *ads = arg;

	if (ads->resampler)
		speex_resampler_destroy(ads->resampler);

	mpg123_close(ads->dec);
	mpg123_delete(ads->dec);
#ifdef DEBUG
	debug("MPA dec destroyed\n");
#endif
}


int mpa_decode_update(struct audec_state **adsp, const struct aucodec *ac,
		       const char *fmtp)
{
	struct audec_state *ads;
	int result, err=0;
	(void)fmtp;

	if (!adsp || !ac || !ac->ch)
		return EINVAL;

	ads = *adsp;

#ifdef DEBUG
	debug("MPA dec created %s\n",fmtp);
#endif

	if (ads)
		mem_deref(ads);

	ads = mem_zalloc(sizeof(*ads), destructor);
	if (!ads)
		return ENOMEM;
	ads->channels = 0;
	ads->resampler = NULL;
	ads->start = 0;

	ads->dec = mpg123_new(NULL,&result);
	if (!ads->dec) {
		error("MPA dec create: %s\n",
			mpg123_plain_strerror(result));
		err = ENOMEM;
		goto out;
	}

#ifdef DEBUG
	result = mpg123_param(ads->dec, MPG123_VERBOSE, 4, 4.);
#else
	result = mpg123_param(ads->dec, MPG123_VERBOSE, 0, 0.);
#endif
	if (result != MPG123_OK) {
		error("MPA dec param error %s\n",
			mpg123_plain_strerror(result));
		err = EINVAL;
		goto out;
	}


	result = mpg123_format_all(ads->dec);
	if (result != MPG123_OK) {
		error("MPA dec format error %s\n",
			mpg123_plain_strerror(result));
		err = EINVAL;
		goto out;
	}

	result = mpg123_open_feed(ads->dec);
	if (result != MPG123_OK) {
		error("MPA dec open feed error %s\n",
			mpg123_plain_strerror(result));
		err = EINVAL;
		goto out;
	}


 out:
	if (err)
		mem_deref(ads);
	else
		*adsp = ads;

	return err;
}


int mpa_decode_frm(struct audec_state *ads, int16_t *sampv, size_t *sampc,
		    const uint8_t *buf, size_t len)
{
	int result, channels, encoding, i;
	long samplerate;
	size_t n;
	spx_uint32_t intermediate_len;
	spx_uint32_t out_len;

#ifdef DEBUG
	debug("MPA dec start %d %ld\n",len, *sampc);
#endif

	if (!ads || !sampv || !sampc || !buf || len<=4)
		return EINVAL;

	if (*(uint32_t*)(void *)buf != 0) {
		error("MPA dec header is not zero %08X, not supported yet\n",
			*(uint32_t*)(void *)buf);
		return EPROTO;
	}

	n = 0;
	result = mpg123_decode(ads->dec, buf+4, len-4,
				(unsigned char*)ads->intermediate_buffer,
				sizeof(ads->intermediate_buffer), &n);
				/* n counts bytes */
#ifdef DEBUG
	debug("MPA dec %d %d %d %d\n",result, len-4, n, ads->channels);
#endif

	if (result == MPG123_NEW_FORMAT) {
		mpg123_getformat(ads->dec, &samplerate, &channels, &encoding);
		info("MPA dec format change %d %d %04X\n",samplerate
			,channels,encoding);

		ads->channels = channels;
		ads->start = 0;
		if (ads->resampler)
			speex_resampler_destroy(ads->resampler);
		if (samplerate != MPA_IORATE) {
			ads->resampler = speex_resampler_init(channels,
				      (uint32_t)samplerate, MPA_IORATE,
				      3, &result);
			if (result!=RESAMPLER_ERR_SUCCESS
				|| ads->resampler==NULL) {
				error("MPA dec upsampler failed %d\n",result);
				return EINVAL;
			}
		}
		else
			ads->resampler = NULL;
	}
	else if (result == MPG123_NEED_MORE)
		;			/* workaround: do nothing */
	else if (result != MPG123_OK) {
		error("MPA dec feed error %d %s\n", result,
			mpg123_plain_strerror(result));
		return EPROTO;
	}

	if (ads->resampler)  {
		intermediate_len = (uint32_t)(n / 2 / ads->channels);
			/* intermediate_len counts samples per channel */
		out_len = (uint32_t)(*sampc / 2);

		result=speex_resampler_process_interleaved_int(
			ads->resampler, ads->intermediate_buffer,
			&intermediate_len, sampv, &out_len);
		if (result!=RESAMPLER_ERR_SUCCESS) {
			error("MPA dec upsample error: %s %d %d\n",
				strerror(result), out_len, *sampc/2);
			return EPROTO;
		}
		if (ads->channels==1) {
			for (i=out_len-1;i>=0;i--)
				sampv[i+i+1]=sampv[i+i]=sampv[i];
			*sampc = out_len * 2;
		}
		else
			*sampc = out_len * ads->channels;
	}
	else {
		n /= 2;
		if (ads->channels!=1) {
			for (i=0;(unsigned)i<n;i++)
				sampv[i]=ads->intermediate_buffer[i];
			*sampc = n;
		}
		else {
			for (i=0;(unsigned)i<n;i++)
				sampv[i*2]=sampv[i*2+1]=
					ads->intermediate_buffer[i];
			*sampc = n * 2;
	}

#ifdef DEBUG
	debug("MPA dec done %d\n",*sampc);
#endif
	}

	return 0;
}