Merge branch 'in_mem_user_list'
[paraslash.git] / mp3dec.c
1 /*
2 * Copyright (C) 2005-2006 Andre Noll <maan@systemlinux.org>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
17 */
18
19 /** \file mp3dec.c paraslash's mp3 decoder */
20
21 #include "para.h"
22 #include "list.h"
23 #include "sched.h"
24 #include "filter.h"
25 #include "error.h"
26 #include <mad.h>
27 #include "string.h"
28
29 /** the output buffer size */
30 #define MP3_OUTBUF_SIZE 128 * 1024
31
32 /** \cond a helper macro */
33 #define MAD_TO_SHORT(f) (f) >= MAD_F_ONE? SHRT_MAX :\
34 (f) <= -MAD_F_ONE? -SHRT_MAX : (signed short) ((f) >> (MAD_F_FRACBITS - 15))
35 /** \endcond */
36
37 /**
38 * data specific to the mp3dec filter
39 *
40 * \sa filter, filter_node
41 */
42 struct private_mp3dec_data {
43 /** information on the current mp3 stream */
44 struct mad_stream stream;
45 /** information about the frame which is currently decoded */
46 struct mad_frame frame;
47 /** contains the PCM output */
48 struct mad_synth synth;
49 };
50
51 /* TODO: Convert all input if possible */
52 static ssize_t mp3dec(char *inbuffer, size_t len, struct filter_node *fn)
53 {
54 int i, ret;
55 struct private_mp3dec_data *pmd = fn->private_data;
56 size_t copy = PARA_MIN(len, 4096);
57
58 if (fn->loaded > fn->bufsize * 4 / 5)
59 return 0;
60 mad_stream_buffer(&pmd->stream, (unsigned char *) inbuffer, copy);
61 pmd->stream.error = 0;
62 next_frame:
63 ret = mad_header_decode(&pmd->frame.header, &pmd->stream);
64 if (ret < 0)
65 goto out;
66 fn->fc->samplerate = pmd->frame.header.samplerate;
67 fn->fc->channels = MAD_NCHANNELS(&pmd->frame.header);
68 ret = mad_frame_decode(&pmd->frame, &pmd->stream);
69 if (ret) {
70 if (MAD_RECOVERABLE(pmd->stream.error) || pmd->stream.error == MAD_ERROR_BUFLEN)
71 goto out;
72 PARA_ERROR_LOG("fatal: ret = %d, loaded = %zd\n", ret, fn->loaded);
73 return -E_MAD_FRAME_DECODE;
74 }
75 mad_synth_frame(&pmd->synth, &pmd->frame);
76
77 for (i = 0; i < pmd->synth.pcm.length; i++) {
78 /* output format: unsigned 16 bit little endian */
79 signed short s = MAD_TO_SHORT(pmd->synth.pcm.samples[0][i]);
80 fn->buf[fn->loaded++] = s & 0xff;
81 fn->buf[fn->loaded++] = s >> 8;
82 if (MAD_NCHANNELS(&pmd->frame.header) == 2) { /* stereo */
83 s = MAD_TO_SHORT(pmd->synth.pcm.samples[1][i]);
84 fn->buf[fn->loaded++] = s & 0xff;
85 fn->buf[fn->loaded++] = s >> 8;
86 }
87 if (fn->loaded != fn->bufsize) /* output buffer not full */
88 continue;
89 PARA_ERROR_LOG("output buffer full: %zd\n", fn->loaded);
90 return -E_MP3DEC_OVERRUN;
91 }
92 if (fn->loaded <= fn->bufsize * 4 / 5)
93 goto next_frame;
94 out:
95 if (pmd->stream.next_frame) { /* we still have some data */
96 size_t off = pmd->stream.bufend - pmd->stream.next_frame;
97 // PARA_INFO_LOG("off: %zd, rate: %u, returning %zd\n", off,
98 // fn->fc->samplerate, copy - off);
99 return copy - off;
100 }
101 return copy;
102 }
103
104 static void mp3dec_close(struct filter_node *fn)
105 {
106 struct private_mp3dec_data *pmd = fn->private_data;
107
108 mad_synth_finish(&pmd->synth);
109 mad_frame_finish(&pmd->frame);
110 mad_stream_finish(&pmd->stream);
111
112 free(fn->buf);
113 fn->buf = NULL;
114 free(pmd);
115 fn->private_data = NULL;
116 }
117
118 static void mp3dec_open(struct filter_node *fn)
119 {
120 fn->private_data = para_calloc(sizeof(struct private_mp3dec_data));
121 struct private_mp3dec_data *pmd = fn->private_data;
122
123 mad_stream_init(&pmd->stream);
124 mad_frame_init(&pmd->frame);
125 mad_synth_init(&pmd->synth);
126 fn->loaded = 0;
127 fn->bufsize = MP3_OUTBUF_SIZE;
128 fn->buf = para_calloc(fn->bufsize);
129 }
130 /**
131 * the init function of the mp3dec filter
132 *
133 * \sa filter::init
134 */
135 void mp3dec_init(struct filter *f)
136 {
137 f->open = mp3dec_open;
138 f->convert = mp3dec;
139 f->close = mp3dec_close;
140 }