trivial mdct cleanups
[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 <mad.h>
10 #include <regex.h>
11
12 #include "para.h"
13 #include "mp3dec_filter.cmdline.h"
14 #include "list.h"
15 #include "sched.h"
16 #include "ggo.h"
17 #include "filter.h"
18 #include "error.h"
19 #include "string.h"
20
21 /** Convert a sample value from libmad to a signed short. */
22 #define MAD_TO_SHORT(f) (f) >= MAD_F_ONE? SHRT_MAX :\
23 (f) <= -MAD_F_ONE? -SHRT_MAX : (signed short) ((f) >> (MAD_F_FRACBITS - 15))
24
25 /** State of the decoding process. */
26 enum mp3dec_flags {
27 /** Bad main_data_begin pointer encounterd. */
28 MP3DEC_FLAG_BAD_DATA = 1,
29 /** Some output has already been produced. */
30 MP3DEC_FLAG_DECODE_STARTED = 2,
31 };
32
33 /** Data specific to the mp3dec filter. */
34 struct private_mp3dec_data {
35 /** Information on the current mp3 stream. */
36 struct mad_stream stream;
37 /** Information about the frame which is currently decoded. */
38 struct mad_frame frame;
39 /** Contains the PCM output. */
40 struct mad_synth synth;
41 /** See \ref mp3dec_flags. */
42 unsigned flags;
43 /** Defer decoding until this time. */
44 struct timeval stream_start_barrier;
45 /** Wait until this many input bytes are available. */
46 size_t input_len_barrier;
47 };
48
49 static int need_bad_data_delay(struct private_mp3dec_data *pmd,
50 size_t bytes_available)
51 {
52 if (!(pmd->flags & MP3DEC_FLAG_BAD_DATA))
53 return 0;
54 if (pmd->flags & MP3DEC_FLAG_DECODE_STARTED)
55 return 0;
56 if (bytes_available >= pmd->input_len_barrier)
57 return 0;
58 if (tv_diff(now, &pmd->stream_start_barrier, NULL) > 0)
59 return 0;
60 return 1;
61 }
62
63 /*
64 * Returns negative on serious errors, zero if the error should be ignored and
65 * positive on bad data pointer errors at stream start.
66 */
67 static int handle_decode_error(struct private_mp3dec_data *pmd, size_t len)
68 {
69 if (!MAD_RECOVERABLE(pmd->stream.error)
70 && pmd->stream.error != MAD_ERROR_BUFLEN) {
71 PARA_ERROR_LOG("%s\n", mad_stream_errorstr(&pmd->stream));
72 return -E_MAD_FRAME_DECODE;
73 }
74 PARA_DEBUG_LOG("%s\n", mad_stream_errorstr(&pmd->stream));
75 if (pmd->stream.error != MAD_ERROR_BADDATAPTR)
76 return 0;
77 if (pmd->flags & MP3DEC_FLAG_DECODE_STARTED)
78 return 0;
79 /*
80 * Bad data pointer at stream start. Defer decoding until the amount of
81 * data we are about to skip is available again, but wait at most 60ms.
82 */
83 pmd->flags |= MP3DEC_FLAG_BAD_DATA;
84 pmd->input_len_barrier = len;
85 tv_add(now, &(struct timeval){0, 60 * 1000},
86 &pmd->stream_start_barrier);
87 return 1;
88 }
89
90 static ssize_t mp3dec(char *inbuffer, size_t len, struct filter_node *fn)
91 {
92 int i, ret;
93 struct private_mp3dec_data *pmd = fn->private_data;
94 size_t copy = PARA_MIN(len, (size_t)4096);
95
96 if (fn->loaded + 16384 > fn->bufsize)
97 return 0;
98 if (need_bad_data_delay(pmd, len))
99 return 0;
100 mad_stream_buffer(&pmd->stream, (unsigned char *) inbuffer, copy);
101 pmd->stream.error = 0;
102 next_frame:
103 ret = mad_header_decode(&pmd->frame.header, &pmd->stream);
104 if (ret < 0) {
105 if (pmd->stream.error != MAD_ERROR_BUFLEN &&
106 pmd->stream.error != MAD_ERROR_LOSTSYNC)
107 PARA_DEBUG_LOG("header decode: %s\n",
108 mad_stream_errorstr(&pmd->stream));
109 goto out;
110 }
111 fn->fc->samplerate = pmd->frame.header.samplerate;
112 fn->fc->channels = MAD_NCHANNELS(&pmd->frame.header);
113 ret = mad_frame_decode(&pmd->frame, &pmd->stream);
114 if (ret != 0) {
115 ret = handle_decode_error(pmd, len);
116 if (ret < 0)
117 return ret;
118 if (ret == 0)
119 goto out;
120 ret = copy - (pmd->stream.bufend - pmd->stream.next_frame);
121 PARA_NOTICE_LOG("skipping %d input bytes\n", ret);
122 return ret;
123 }
124 mad_synth_frame(&pmd->synth, &pmd->frame);
125 pmd->flags |= MP3DEC_FLAG_DECODE_STARTED;
126
127 for (i = 0; i < pmd->synth.pcm.length; i++) {
128 int s = MAD_TO_SHORT(pmd->synth.pcm.samples[0][i]);
129 write_int16_host_endian(fn->buf + fn->loaded, s);
130 fn->loaded += 2;
131 if (MAD_NCHANNELS(&pmd->frame.header) == 2) { /* stereo */
132 s = MAD_TO_SHORT(pmd->synth.pcm.samples[1][i]);
133 write_int16_host_endian(fn->buf + fn->loaded, s);
134 fn->loaded += 2;
135 }
136 if (fn->loaded != fn->bufsize) /* output buffer not full */
137 continue;
138 PARA_ERROR_LOG("output buffer full: %zd\n", fn->loaded);
139 return -E_MP3DEC_OVERRUN;
140 }
141 if (fn->loaded + 16384 <= fn->bufsize)
142 goto next_frame;
143 out:
144 if (pmd->stream.next_frame) { /* we still have some data */
145 size_t off = pmd->stream.bufend - pmd->stream.next_frame;
146 if (fn->loaded + 16384 <= fn->bufsize && off > 2048)
147 goto next_frame;
148 return copy - off;
149 }
150 return copy;
151 }
152
153 static void mp3dec_close(struct filter_node *fn)
154 {
155 struct private_mp3dec_data *pmd = fn->private_data;
156
157 mad_synth_finish(&pmd->synth);
158 mad_frame_finish(&pmd->frame);
159 mad_stream_finish(&pmd->stream);
160
161 free(fn->buf);
162 fn->buf = NULL;
163 free(pmd);
164 fn->private_data = NULL;
165 }
166
167 static void mp3dec_open(struct filter_node *fn)
168 {
169 struct private_mp3dec_data *pmd = para_calloc(sizeof(*pmd));
170 struct mp3dec_filter_args_info *mp3_conf = fn->conf;
171
172 fn->private_data = pmd;
173 mad_stream_init(&pmd->stream);
174 mad_frame_init(&pmd->frame);
175 mad_synth_init(&pmd->synth);
176 fn->loaded = 0;
177 fn->bufsize = mp3_conf->bufsize_arg * 1024;
178 fn->buf = para_calloc(fn->bufsize);
179 if (mp3_conf->ignore_crc_given)
180 mad_stream_options(&pmd->stream, MAD_OPTION_IGNORECRC);
181 }
182
183 static int mp3dec_parse_config(int argc, char **argv, void **config)
184 {
185 int ret;
186 struct mp3dec_filter_args_info *mp3_conf;
187
188 mp3_conf = para_calloc(sizeof(*mp3_conf));
189 ret = -E_MP3DEC_SYNTAX;
190 if (mp3dec_cmdline_parser(argc, argv, mp3_conf))
191 goto err;
192 ret = -ERRNO_TO_PARA_ERROR(EINVAL);
193 if (mp3_conf->bufsize_arg < 32)
194 goto err;
195 if (mp3_conf->bufsize_arg >= INT_MAX / 1024)
196 goto err;
197 *config = mp3_conf;
198 return 1;
199 err:
200 free(mp3_conf);
201 return ret;
202 }
203
204 /**
205 * The init function of the mp3dec filter.
206 *
207 * \param f Pointer to the filter struct to initialize.
208 *
209 * \sa filter::init.
210 */
211 void mp3dec_filter_init(struct filter *f)
212 {
213 struct mp3dec_filter_args_info dummy;
214
215 mp3dec_cmdline_parser_init(&dummy);
216 f->open = mp3dec_open;
217 f->convert = mp3dec;
218 f->close = mp3dec_close;
219 f->parse_config = mp3dec_parse_config;
220 f->help = (struct ggo_help) {
221 .short_help = mp3dec_filter_args_info_help,
222 .detailed_help = mp3dec_filter_args_info_detailed_help
223 };
224 }