2 * Copyright (C) 2005-2009 Andre Noll <maan@systemlinux.org>
4 * Licensed under the GPL v2. For licencing details see COPYING.
7 /** \file mp3dec_filter.c Paraslash's mp3 decoder. */
13 #include "mp3dec_filter.cmdline.h"
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))
25 /** State of the decoding process. */
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,
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. */
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;
49 static int need_bad_data_delay(struct private_mp3dec_data *pmd,
50 size_t bytes_available)
52 if (!(pmd->flags & MP3DEC_FLAG_BAD_DATA))
54 if (pmd->flags & MP3DEC_FLAG_DECODE_STARTED)
56 if (bytes_available >= pmd->input_len_barrier)
58 if (tv_diff(now, &pmd->stream_start_barrier, NULL) > 0)
64 * Returns negative on serious errors, zero if the error should be ignored and
65 * positive on bad data pointer errors at stream start.
67 static int handle_decode_error(struct private_mp3dec_data *pmd, size_t len)
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;
74 PARA_DEBUG_LOG("%s\n", mad_stream_errorstr(&pmd->stream));
75 if (pmd->stream.error != MAD_ERROR_BADDATAPTR)
77 if (pmd->flags & MP3DEC_FLAG_DECODE_STARTED)
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.
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);
90 static ssize_t mp3dec(char *inbuffer, size_t len, struct filter_node *fn)
93 struct private_mp3dec_data *pmd = fn->private_data;
94 size_t copy = PARA_MIN(len, (size_t)4096);
96 if (fn->loaded + 16384 > fn->bufsize)
98 if (need_bad_data_delay(pmd, len))
100 mad_stream_buffer(&pmd->stream, (unsigned char *) inbuffer, copy);
101 pmd->stream.error = 0;
103 ret = mad_header_decode(&pmd->frame.header, &pmd->stream);
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));
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);
115 ret = handle_decode_error(pmd, len);
120 ret = copy - (pmd->stream.bufend - pmd->stream.next_frame);
121 PARA_NOTICE_LOG("skipping %d input bytes\n", ret);
124 mad_synth_frame(&pmd->synth, &pmd->frame);
125 pmd->flags |= MP3DEC_FLAG_DECODE_STARTED;
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);
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);
136 if (fn->loaded != fn->bufsize) /* output buffer not full */
138 PARA_ERROR_LOG("output buffer full: %zd\n", fn->loaded);
139 return -E_MP3DEC_OVERRUN;
141 if (fn->loaded + 16384 <= fn->bufsize)
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)
153 static void mp3dec_close(struct filter_node *fn)
155 struct private_mp3dec_data *pmd = fn->private_data;
157 mad_synth_finish(&pmd->synth);
158 mad_frame_finish(&pmd->frame);
159 mad_stream_finish(&pmd->stream);
164 fn->private_data = NULL;
167 static void mp3dec_open(struct filter_node *fn)
169 struct private_mp3dec_data *pmd = para_calloc(sizeof(*pmd));
170 struct mp3dec_filter_args_info *mp3_conf = fn->conf;
172 fn->private_data = pmd;
173 mad_stream_init(&pmd->stream);
174 mad_frame_init(&pmd->frame);
175 mad_synth_init(&pmd->synth);
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);
183 static int mp3dec_parse_config(int argc, char **argv, void **config)
186 struct mp3dec_filter_args_info *mp3_conf;
188 mp3_conf = para_calloc(sizeof(*mp3_conf));
189 ret = -E_MP3DEC_SYNTAX;
190 if (mp3dec_cmdline_parser(argc, argv, mp3_conf))
192 ret = -ERRNO_TO_PARA_ERROR(EINVAL);
193 if (mp3_conf->bufsize_arg < 32)
195 if (mp3_conf->bufsize_arg >= INT_MAX / 1024)
205 * The init function of the mp3dec filter.
207 * \param f Pointer to the filter struct to initialize.
211 void mp3dec_filter_init(struct filter *f)
213 struct mp3dec_filter_args_info dummy;
215 mp3dec_cmdline_parser_init(&dummy);
216 f->open = mp3dec_open;
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