2 * Copyright (C) 2005-2010 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. */
14 #include "mp3dec_filter.cmdline.h"
18 #include "buffer_tree.h"
23 /** Convert a sample value from libmad to a signed short. */
24 #define MAD_TO_SHORT(f) (f) >= MAD_F_ONE? SHRT_MAX :\
25 (f) <= -MAD_F_ONE? -SHRT_MAX : (signed short) ((f) >> (MAD_F_FRACBITS - 15))
27 /** State of the decoding process. */
29 /** Bad main_data_begin pointer encounterd. */
30 MP3DEC_FLAG_BAD_DATA = 1,
31 /** Some output has already been produced. */
32 MP3DEC_FLAG_DECODE_STARTED = 2,
33 MP3DEC_FLAG_NEED_MORE = 4,
36 /** Data specific to the mp3dec filter. */
37 struct private_mp3dec_data {
38 /** Information on the current mp3 stream. */
39 struct mad_stream stream;
40 /** Information about the frame which is currently decoded. */
41 struct mad_frame frame;
42 /** Contains the PCM output. */
43 struct mad_synth synth;
44 /** See \ref mp3dec_flags. */
46 /** Defer decoding until this time. */
47 struct timeval stream_start_barrier;
48 /** Wait until this many input bytes are available. */
49 size_t input_len_barrier;
50 /** The number of channels of the current stream. */
51 unsigned int channels;
52 /** Current sample rate in Hz. */
53 unsigned int sample_rate;
56 static int need_bad_data_delay(struct private_mp3dec_data *pmd,
57 size_t bytes_available)
59 if (!(pmd->flags & MP3DEC_FLAG_BAD_DATA))
61 if (pmd->flags & MP3DEC_FLAG_DECODE_STARTED)
63 if (bytes_available >= pmd->input_len_barrier)
65 if (tv_diff(now, &pmd->stream_start_barrier, NULL) > 0)
71 * Returns negative on serious errors, zero if the error should be ignored and
72 * positive on bad data pointer errors at stream start.
74 static int handle_decode_error(struct private_mp3dec_data *pmd, size_t len)
76 const struct timeval delay = {0, 60 * 1000};
77 if (!MAD_RECOVERABLE(pmd->stream.error)
78 && pmd->stream.error != MAD_ERROR_BUFLEN) {
79 PARA_ERROR_LOG("%s\n", mad_stream_errorstr(&pmd->stream));
80 return -E_MAD_FRAME_DECODE;
82 PARA_DEBUG_LOG("%s\n", mad_stream_errorstr(&pmd->stream));
83 if (pmd->stream.error != MAD_ERROR_BADDATAPTR)
85 if (pmd->flags & MP3DEC_FLAG_DECODE_STARTED)
88 * Bad data pointer at stream start. Defer decoding until the amount of
89 * data we are about to skip is available again, but wait at most 60ms.
91 pmd->flags |= MP3DEC_FLAG_BAD_DATA;
92 pmd->input_len_barrier = len;
93 tv_add(now, &delay, &pmd->stream_start_barrier);
97 static size_t used_mad_buffer_bytes(struct mad_stream *s, size_t max)
103 /* we still have some data */
104 rv = s->next_frame - s->buffer;
109 static void mp3dec_close(struct filter_node *fn)
111 struct private_mp3dec_data *pmd = fn->private_data;
113 mad_synth_finish(&pmd->synth);
114 mad_frame_finish(&pmd->frame);
115 mad_stream_finish(&pmd->stream);
118 fn->private_data = NULL;
121 static void mp3dec_post_select(__a_unused struct sched *s, struct task *t)
123 struct filter_node *fn = container_of(t, struct filter_node, task);
125 struct private_mp3dec_data *pmd = fn->private_data;
126 struct btr_node *btrn = fn->btrn;
127 size_t loaded, used, len, iqs;
128 char *inbuffer, *outbuffer;
131 pmd->stream.error = 0;
133 iqs = btr_get_input_queue_size(btrn);
134 ret = btr_node_status(btrn, fn->min_iqs, BTR_NT_INTERNAL);
137 if (need_bad_data_delay(pmd, iqs))
141 btr_merge(btrn, fn->min_iqs);
142 len = btr_next_buffer(btrn, &inbuffer);
144 * Decode at most 8K in one go to give the post_select() functions of
145 * other buffer tree nodes a chance to run. This is necessary to avoid
146 * buffer underruns on slow machines.
148 len = PARA_MIN(len, (size_t)8192);
149 mad_stream_buffer(&pmd->stream, (unsigned char *)inbuffer, len);
151 ret = mad_header_decode(&pmd->frame.header, &pmd->stream);
153 used = used_mad_buffer_bytes(&pmd->stream, len);
154 btr_consume(btrn, used);
155 if (pmd->stream.error == MAD_ERROR_BUFLEN) {
156 if (len == iqs && btr_no_parent(btrn)) {
162 } else if (pmd->stream.error != MAD_ERROR_LOSTSYNC)
163 PARA_DEBUG_LOG("header decode: %s\n",
164 mad_stream_errorstr(&pmd->stream));
168 pmd->sample_rate = pmd->frame.header.samplerate;
169 pmd->channels = MAD_NCHANNELS(&pmd->frame.header);
170 ret = mad_frame_decode(&pmd->frame, &pmd->stream);
172 PARA_INFO_LOG("frame decode: %s\n", mad_stream_errorstr(&pmd->stream));
173 used = used_mad_buffer_bytes(&pmd->stream, len);
174 ret = handle_decode_error(pmd, used);
175 btr_consume(btrn, used);
182 mad_synth_frame(&pmd->synth, &pmd->frame);
183 pmd->flags |= MP3DEC_FLAG_DECODE_STARTED;
185 outbuffer = para_malloc(pmd->synth.pcm.length * 4);
187 for (i = 0; i < pmd->synth.pcm.length; i++) {
188 int sample = MAD_TO_SHORT(pmd->synth.pcm.samples[0][i]);
189 write_int16_host_endian(outbuffer + loaded, sample);
191 if (MAD_NCHANNELS(&pmd->frame.header) == 2) { /* stereo */
192 sample = MAD_TO_SHORT(pmd->synth.pcm.samples[1][i]);
193 write_int16_host_endian(outbuffer + loaded, sample);
197 btr_add_output(outbuffer, loaded, btrn);
202 btr_remove_node(btrn);
205 static void mp3dec_open(struct filter_node *fn)
207 struct private_mp3dec_data *pmd = para_calloc(sizeof(*pmd));
208 struct mp3dec_filter_args_info *mp3_conf = fn->conf;
210 fn->private_data = pmd;
211 mad_stream_init(&pmd->stream);
212 mad_frame_init(&pmd->frame);
213 mad_synth_init(&pmd->synth);
214 if (mp3_conf->ignore_crc_given)
215 mad_stream_options(&pmd->stream, MAD_OPTION_IGNORECRC);
218 static int mp3dec_parse_config(int argc, char **argv, void **config)
221 struct mp3dec_filter_args_info *mp3_conf;
223 mp3_conf = para_calloc(sizeof(*mp3_conf));
224 ret = -E_MP3DEC_SYNTAX;
225 if (mp3dec_cmdline_parser(argc, argv, mp3_conf))
234 static int mp3dec_execute(struct btr_node *btrn, const char *cmd, char **result)
236 struct filter_node *fn = btr_context(btrn);
237 struct private_mp3dec_data *pmd = fn->private_data;
239 return decoder_execute(cmd, pmd->sample_rate, pmd->channels, result);
242 static void mp3dec_free_config(void *conf)
244 mp3dec_cmdline_parser_free(conf);
247 * The init function of the mp3dec filter.
249 * \param f Pointer to the filter struct to initialize.
253 void mp3dec_filter_init(struct filter *f)
255 struct mp3dec_filter_args_info dummy;
257 mp3dec_cmdline_parser_init(&dummy);
258 f->open = mp3dec_open;
259 f->close = mp3dec_close;
260 f->parse_config = mp3dec_parse_config;
261 f->free_config = mp3dec_free_config;
262 f->pre_select = generic_filter_pre_select;
263 f->post_select = mp3dec_post_select;
264 f->execute = mp3dec_execute;
265 f->help = (struct ggo_help) {
266 .short_help = mp3dec_filter_args_info_help,
267 .detailed_help = mp3dec_filter_args_info_detailed_help