Make rc4 encryption/decryption more explicit.
[paraslash.git] / mp3dec_filter.c
1 /*
2 * Copyright (C) 2005-2009 Andre Noll <maan@systemlinux.org>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6
7 /** \file mp3dec_filter.c Paraslash's mp3 decoder. */
8
9 #include "para.h"
10 #include "mp3dec_filter.cmdline.h"
11 #include "list.h"
12 #include "sched.h"
13 #include "ggo.h"
14 #include "filter.h"
15 #include "error.h"
16 #include <mad.h>
17 #include "string.h"
18
19 /** Convert a sample value from libmad to a signed short. */
20 #define MAD_TO_SHORT(f) (f) >= MAD_F_ONE? SHRT_MAX :\
21 (f) <= -MAD_F_ONE? -SHRT_MAX : (signed short) ((f) >> (MAD_F_FRACBITS - 15))
22
23 /** Data specific to the mp3dec filter. */
24 struct private_mp3dec_data {
25 /** Information on the current mp3 stream. */
26 struct mad_stream stream;
27 /** Information about the frame which is currently decoded. */
28 struct mad_frame frame;
29 /** Contains the PCM output. */
30 struct mad_synth synth;
31 };
32
33 static ssize_t mp3dec(char *inbuffer, size_t len, struct filter_node *fn)
34 {
35 int i, ret;
36 struct private_mp3dec_data *pmd = fn->private_data;
37 size_t copy = PARA_MIN(len, (size_t)4096);
38
39 if (fn->loaded + 16384 > fn->bufsize)
40 return 0;
41 mad_stream_buffer(&pmd->stream, (unsigned char *) inbuffer, copy);
42 pmd->stream.error = 0;
43 next_frame:
44 ret = mad_header_decode(&pmd->frame.header, &pmd->stream);
45 if (ret < 0) {
46 if (pmd->stream.error != MAD_ERROR_BUFLEN &&
47 pmd->stream.error != MAD_ERROR_LOSTSYNC)
48 PARA_DEBUG_LOG("header decode: %s\n",
49 mad_stream_errorstr(&pmd->stream));
50 goto out;
51 }
52 fn->fc->samplerate = pmd->frame.header.samplerate;
53 fn->fc->channels = MAD_NCHANNELS(&pmd->frame.header);
54 ret = mad_frame_decode(&pmd->frame, &pmd->stream);
55 if (ret) {
56 if (MAD_RECOVERABLE(pmd->stream.error) ||
57 pmd->stream.error == MAD_ERROR_BUFLEN) {
58 PARA_DEBUG_LOG("frame decode: %s\n",
59 mad_stream_errorstr(&pmd->stream));
60 goto out;
61 }
62 PARA_ERROR_LOG("frame decode: %s\n",
63 mad_stream_errorstr(&pmd->stream));
64 return -E_MAD_FRAME_DECODE;
65 }
66 mad_synth_frame(&pmd->synth, &pmd->frame);
67
68 for (i = 0; i < pmd->synth.pcm.length; i++) {
69 int s = MAD_TO_SHORT(pmd->synth.pcm.samples[0][i]);
70 write_int16_host_endian(fn->buf + fn->loaded, s);
71 fn->loaded += 2;
72 if (MAD_NCHANNELS(&pmd->frame.header) == 2) { /* stereo */
73 s = MAD_TO_SHORT(pmd->synth.pcm.samples[1][i]);
74 write_int16_host_endian(fn->buf + fn->loaded, s);
75 fn->loaded += 2;
76 }
77 if (fn->loaded != fn->bufsize) /* output buffer not full */
78 continue;
79 PARA_ERROR_LOG("output buffer full: %zd\n", fn->loaded);
80 return -E_MP3DEC_OVERRUN;
81 }
82 if (fn->loaded + 16384 <= fn->bufsize)
83 goto next_frame;
84 out:
85 if (pmd->stream.next_frame) { /* we still have some data */
86 size_t off = pmd->stream.bufend - pmd->stream.next_frame;
87 if (fn->loaded + 16384 <= fn->bufsize && off > 2048)
88 goto next_frame;
89 return copy - off;
90 }
91 return copy;
92 }
93
94 static void mp3dec_close(struct filter_node *fn)
95 {
96 struct private_mp3dec_data *pmd = fn->private_data;
97
98 mad_synth_finish(&pmd->synth);
99 mad_frame_finish(&pmd->frame);
100 mad_stream_finish(&pmd->stream);
101
102 free(fn->buf);
103 fn->buf = NULL;
104 free(pmd);
105 fn->private_data = NULL;
106 }
107
108 static void mp3dec_open(struct filter_node *fn)
109 {
110 struct private_mp3dec_data *pmd = para_calloc(sizeof(*pmd));
111 struct mp3dec_filter_args_info *mp3_conf = fn->conf;
112
113 fn->private_data = pmd;
114 mad_stream_init(&pmd->stream);
115 mad_frame_init(&pmd->frame);
116 mad_synth_init(&pmd->synth);
117 fn->loaded = 0;
118 fn->bufsize = mp3_conf->bufsize_arg * 1024;
119 fn->buf = para_calloc(fn->bufsize);
120 if (mp3_conf->ignore_crc_given)
121 mad_stream_options(&pmd->stream, MAD_OPTION_IGNORECRC);
122 }
123
124 static int mp3dec_parse_config(int argc, char **argv, void **config)
125 {
126 int ret;
127 struct mp3dec_filter_args_info *mp3_conf;
128
129 mp3_conf = para_calloc(sizeof(*mp3_conf));
130 ret = -E_MP3DEC_SYNTAX;
131 if (mp3dec_cmdline_parser(argc, argv, mp3_conf))
132 goto err;
133 ret = -ERRNO_TO_PARA_ERROR(EINVAL);
134 if (mp3_conf->bufsize_arg < 32)
135 goto err;
136 if (mp3_conf->bufsize_arg >= INT_MAX / 1024)
137 goto err;
138 *config = mp3_conf;
139 return 1;
140 err:
141 free(mp3_conf);
142 return ret;
143 }
144
145 /**
146 * The init function of the mp3dec filter.
147 *
148 * \param f Pointer to the filter struct to initialize.
149 *
150 * \sa filter::init.
151 */
152 void mp3dec_filter_init(struct filter *f)
153 {
154 struct mp3dec_filter_args_info dummy;
155
156 mp3dec_cmdline_parser_init(&dummy);
157 f->open = mp3dec_open;
158 f->convert = mp3dec;
159 f->close = mp3dec_close;
160 f->parse_config = mp3dec_parse_config;
161 f->help = (struct ggo_help) {
162 .short_help = mp3dec_filter_args_info_help,
163 .detailed_help = mp3dec_filter_args_info_detailed_help
164 };
165 }