2 * This file is part of DisOrder
3 * Copyright (C) 2007 Richard Kettlewell
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
20 /** @file server/decode.c
21 * @brief General-purpose decoder for use by speaker process
36 #include <vorbis/vorbisfile.h>
41 #include "speaker-protocol.h"
43 /** @brief Encoding lookup table type */
45 /** @brief Glob pattern matching file */
47 /** @brief Decoder function */
51 /** @brief Input file */
54 /** @brief Output file */
55 static FILE *outputfp;
57 /** @brief Filename */
58 static const char *path;
60 /** @brief Input buffer */
61 static char buffer[1048576];
63 /** @brief Open the input file */
64 static void open_input(void) {
65 if((inputfd = open(path, O_RDONLY)) < 0)
66 fatal(errno, "opening %s", path);
69 /** @brief Fill the buffer
70 * @return Number of bytes read
72 static size_t fill(void) {
73 int n = read(inputfd, buffer, sizeof buffer);
76 fatal(errno, "reading from %s", path);
80 /** @brief Write a 16-bit word in bigendian format */
81 static inline void output_16(uint16_t n) {
82 if(putc(n >> 8, outputfp) < 0
83 || putc(n & 0xFF, outputfp) < 0)
84 fatal(errno, "decoding %s: output error", path);
87 /** @brief Write the header
88 * If called more than once, either does nothing (if you kept the same
89 * output encoding) or fails (if you changed it).
91 static void output_header(int rate,
95 struct stream_header header;
99 header.channels = channels;
100 header.endian = ENDIAN_BIG;
101 header.nbytes = nbytes;
102 if(fwrite(&header, sizeof header, 1, outputfp) < 1)
103 fatal(errno, "decoding %s: writing format header", path);
106 /** @brief Dithering state
107 * Filched from mpg321, which credits it to Robert Leslie */
108 struct audio_dither {
109 mad_fixed_t error[3];
113 /** @brief 32-bit PRNG
114 * Filched from mpg321, which credits it to Robert Leslie */
115 static inline unsigned long prng(unsigned long state)
117 return (state * 0x0019660dL + 0x3c6ef35fL) & 0xffffffffL;
120 /** @brief Generic linear sample quantize and dither routine
121 * Filched from mpg321, which credits it to Robert Leslie */
123 static long audio_linear_dither(mad_fixed_t sample,
124 struct audio_dither *dither) {
125 unsigned int scalebits;
126 mad_fixed_t output, mask, rnd;
134 sample += dither->error[0] - dither->error[1] + dither->error[2];
136 dither->error[2] = dither->error[1];
137 dither->error[1] = dither->error[0] / 2;
140 output = sample + (1L << (MAD_F_FRACBITS + 1 - bits - 1));
142 scalebits = MAD_F_FRACBITS + 1 - bits;
143 mask = (1L << scalebits) - 1;
146 rnd = prng(dither->random);
147 output += (rnd & mask) - (dither->random & mask);
149 dither->random = rnd;
158 else if (output < MIN) {
169 dither->error[0] = sample - output;
172 return output >> scalebits;
176 /** @brief MP3 output callback */
177 static enum mad_flow mp3_output(void attribute((unused)) *data,
178 struct mad_header const *header,
179 struct mad_pcm *pcm) {
180 size_t n = pcm->length;
181 const mad_fixed_t *l = pcm->samples[0], *r = pcm->samples[1];
182 static struct audio_dither ld[1], rd[1];
184 output_header(header->samplerate,
187 2 * pcm->channels * pcm->length);
188 switch(pcm->channels) {
191 output_16(audio_linear_dither(*l++, ld));
195 output_16(audio_linear_dither(*l++, ld));
196 output_16(audio_linear_dither(*r++, rd));
200 fatal(0, "decoding %s: unsupported channel count %d", path, pcm->channels);
202 return MAD_FLOW_CONTINUE;
205 /** @brief MP3 input callback */
206 static enum mad_flow mp3_input(void attribute((unused)) *data,
207 struct mad_stream *stream) {
208 const size_t n = fill();
211 return MAD_FLOW_STOP;
212 mad_stream_buffer(stream, (unsigned char *)buffer, n);
213 return MAD_FLOW_CONTINUE;
217 /** @brief MP3 error callback */
218 static enum mad_flow mp3_error(void attribute((unused)) *data,
219 struct mad_stream *stream,
220 struct mad_frame attribute((unused)) *frame) {
222 /* Just generates pointless verbosity l-( */
223 error(0, "decoding %s: %s (%#04x)",
224 path, mad_stream_errorstr(stream), stream->error);
225 return MAD_FLOW_CONTINUE;
228 /** @brief MP3 decoder */
229 static void decode_mp3(void) {
230 struct mad_decoder mad[1];
233 mad_decoder_init(mad, 0/*data*/, mp3_input, 0/*header*/, 0/*filter*/,
234 mp3_output, mp3_error, 0/*message*/);
235 if(mad_decoder_run(mad, MAD_DECODER_MODE_SYNC))
237 mad_decoder_finish(mad);
240 /** @brief OGG decoder */
241 static void decode_ogg(void) {
243 OggVorbis_File vf[1];
249 if(!(fp = fopen(path, "rb")))
250 fatal(errno, "cannot open %s", path);
251 /* There doesn't seem to be any standard function for mapping the error codes
253 if((err = ov_open(fp, vf, 0/*initial*/, 0/*ibytes*/)))
254 fatal(0, "ov_fopen %s: %d", path, err);
255 if(!(vi = ov_info(vf, 0/*link*/)))
256 fatal(0, "ov_info %s: failed", path);
257 while((n = ov_read(vf, buffer, sizeof buffer, 1/*bigendianp*/,
258 2/*bytes/word*/, 1/*signed*/, &bitstream))) {
260 fatal(0, "ov_read %s: %ld", path, n);
262 fatal(0, "only single-bitstream ogg files are supported");
263 output_header(vi->rate, vi->channels, 16/*bits*/, n);
264 if(fwrite(buffer, 1, n, outputfp) < (size_t)n)
265 fatal(errno, "decoding %s: writing sample data", path);
269 /** @brief Lookup table of decoders */
270 static const struct decoder decoders[] = {
271 { "*.mp3", decode_mp3 },
272 { "*.MP3", decode_mp3 },
273 { "*.ogg", decode_ogg },
274 { "*.OGG", decode_ogg },
278 static const struct option options[] = {
279 { "help", no_argument, 0, 'h' },
280 { "version", no_argument, 0, 'V' },
284 /* Display usage message and terminate. */
285 static void help(void) {
287 " disorder-decode [OPTIONS] PATH\n"
289 " --help, -h Display usage message\n"
290 " --version, -V Display version number\n"
292 "Audio decoder for DisOrder. Only intended to be used by speaker\n"
293 "process, not for normal users.\n");
298 /* Display version number and terminate. */
299 static void version(void) {
300 xprintf("disorder-decode version %s\n", disorder_version_string);
305 int main(int argc, char **argv) {
310 if(!setlocale(LC_CTYPE, "")) fatal(errno, "calling setlocale");
311 while((n = getopt_long(argc, argv, "hV", options, 0)) >= 0) {
315 default: fatal(0, "invalid option");
319 fatal(0, "missing filename");
320 if(optind + 1 < argc)
321 fatal(0, "excess arguments");
322 if((e = getenv("DISORDER_RAW_FD"))) {
323 if(!(outputfp = fdopen(atoi(e), "wb")))
324 fatal(errno, "fdopen");
330 && fnmatch(decoders[n].pattern, path, 0) != 0;
333 if(!decoders[n].pattern)
334 fatal(0, "cannot determine file type for %s", path);
335 decoders[n].decode();