mp3dec_filter.c

   1 /*
   2  * Copyright (C) 2005-2011 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 #include <stdbool.h>
  12
  13 #include "para.h"
  14 #include "mp3dec_filter.cmdline.h"
  15 #include "list.h"
  16 #include "sched.h"
  17 #include "ggo.h"
  18 #include "buffer_tree.h"
  19 #include "filter.h"
  20 #include "error.h"
  21 #include "string.h"
  22
  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))
  26
  27 /** Data specific to the mp3dec filter. */
  28 struct private_mp3dec_data {
  29         /** Information on the current mp3 stream. */
  30         struct mad_stream stream;
  31         /** Information about the frame which is currently decoded. */
  32         struct mad_frame frame;
  33         /** Contains the PCM output. */
  34         struct mad_synth synth;
  35         /** The number of channels of the current stream. */
  36         unsigned int channels;
  37         /** Current sample rate in Hz. */
  38         unsigned int sample_rate;
  39 };
  40
  41 /* Returns negative on serious errors. */
  42 static int handle_decode_error(struct private_mp3dec_data *pmd)
  43 {
  44         if (!MAD_RECOVERABLE(pmd->stream.error)
  45                         && pmd->stream.error != MAD_ERROR_BUFLEN) {
  46                 PARA_ERROR_LOG("%s\n", mad_stream_errorstr(&pmd->stream));
  47                 return -E_MAD_FRAME_DECODE;
  48         }
  49         PARA_DEBUG_LOG("%s\n", mad_stream_errorstr(&pmd->stream));
  50         return 0;
  51 }
  52
  53 static void mp3dec_consume(struct btr_node *btrn, struct mad_stream *s,
  54                 size_t max)
  55 {
  56         size_t used;
  57
  58         if (!s->next_frame)
  59                 used = max;
  60         else { /* we still have some data */
  61                 used = s->next_frame - s->buffer;
  62                 assert(used <= max);
  63         }
  64         btr_consume(btrn, used);
  65 }
  66
  67 static void mp3dec_close(struct filter_node *fn)
  68 {
  69         struct private_mp3dec_data *pmd = fn->private_data;
  70
  71         mad_synth_finish(&pmd->synth);
  72         mad_frame_finish(&pmd->frame);
  73         mad_stream_finish(&pmd->stream);
  74
  75         free(pmd);
  76         fn->private_data = NULL;
  77 }
  78
  79 #define MP3DEC_MAX_FRAME 8192
  80
  81 static void mp3dec_post_select(__a_unused struct sched *s, struct task *t)
  82 {
  83         struct filter_node *fn = container_of(t, struct filter_node, task);
  84         int i, ret;
  85         struct private_mp3dec_data *pmd = fn->private_data;
  86         struct btr_node *btrn = fn->btrn;
  87         size_t loaded = 0, len, iqs;
  88         char *inbuffer, *outbuffer;
  89
  90 next_buffer:
  91         pmd->stream.error = 0;
  92         t->error = 0;
  93         iqs = btr_get_input_queue_size(btrn);
  94         ret = btr_node_status(btrn, fn->min_iqs, BTR_NT_INTERNAL);
  95         if (ret < 0)
  96                 goto err;
  97         if (ret == 0)
  98                 return;
  99         btr_merge(btrn, fn->min_iqs);
 100         len = btr_next_buffer(btrn, &inbuffer);
 101         /*
 102          * Decode at most 8K in one go to give the post_select() functions of
 103          * other buffer tree nodes a chance to run. This is necessary to avoid
 104          * buffer underruns on slow machines.
 105          */
 106         len = PARA_MIN(len, (size_t)MP3DEC_MAX_FRAME);
 107         mad_stream_buffer(&pmd->stream, (unsigned char *)inbuffer, len);
 108 next_frame:
 109         ret = mad_header_decode(&pmd->frame.header, &pmd->stream);
 110         if (ret < 0) {
 111                 mp3dec_consume(btrn, &pmd->stream, len);
 112                 if (pmd->stream.error == MAD_ERROR_BUFLEN) {
 113                         if (len == iqs && btr_no_parent(btrn)) {
 114                                 ret = -E_MP3DEC_EOF;
 115                                 goto err;
 116                         }
 117                         fn->min_iqs += 100;
 118                         ret = -E_MP3DEC_CORRUPT;
 119                         if (fn->min_iqs > MP3DEC_MAX_FRAME)
 120                                 goto err;
 121                 }
 122                 if (loaded == 0)
 123                         goto next_buffer;
 124                 return;
 125         }
 126         pmd->sample_rate = pmd->frame.header.samplerate;
 127         pmd->channels = MAD_NCHANNELS(&pmd->frame.header);
 128 decode:
 129         ret = mad_frame_decode(&pmd->frame, &pmd->stream);
 130         if (ret != 0) {
 131                 ret = handle_decode_error(pmd);
 132                 if (ret < 0)
 133                         goto err;
 134                 ret = mad_stream_sync(&pmd->stream);
 135                 if (pmd->stream.error == MAD_ERROR_BUFLEN) {
 136                         ret = -E_MP3DEC_EOF;
 137                         if (len == iqs && btr_no_parent(btrn))
 138                                 goto err;
 139                         fn->min_iqs += 100;
 140                         ret = -E_MP3DEC_CORRUPT;
 141                         if (fn->min_iqs > MP3DEC_MAX_FRAME)
 142                                 goto err;
 143                         mp3dec_consume(btrn, &pmd->stream, len);
 144                         return;
 145                 }
 146                 if (pmd->stream.error != MAD_ERROR_BADDATAPTR)
 147                         goto decode;
 148                 mp3dec_consume(btrn, &pmd->stream, len);
 149                 return;
 150         }
 151         fn->min_iqs = 0;
 152         mad_synth_frame(&pmd->synth, &pmd->frame);
 153         outbuffer = para_malloc(pmd->synth.pcm.length * 2 * pmd->channels);
 154         loaded = 0;
 155         for (i = 0; i < pmd->synth.pcm.length; i++) {
 156                 int sample = MAD_TO_SHORT(pmd->synth.pcm.samples[0][i]);
 157                 write_int16_host_endian(outbuffer + loaded, sample);
 158                 loaded += 2;
 159                 if (pmd->channels == 2) { /* stereo */
 160                         sample = MAD_TO_SHORT(pmd->synth.pcm.samples[1][i]);
 161                         write_int16_host_endian(outbuffer + loaded, sample);
 162                         loaded += 2;
 163                 }
 164         }
 165         btr_add_output(outbuffer, loaded, btrn);
 166         goto next_frame;
 167 err:
 168         assert(ret < 0);
 169         t->error = ret;
 170         btr_remove_node(btrn);
 171 }
 172
 173 static void mp3dec_open(struct filter_node *fn)
 174 {
 175         struct private_mp3dec_data *pmd = para_calloc(sizeof(*pmd));
 176         struct mp3dec_filter_args_info *mp3_conf = fn->conf;
 177
 178         fn->private_data = pmd;
 179         mad_stream_init(&pmd->stream);
 180         mad_frame_init(&pmd->frame);
 181         mad_synth_init(&pmd->synth);
 182         if (mp3_conf->ignore_crc_given)
 183                 mad_stream_options(&pmd->stream, MAD_OPTION_IGNORECRC);
 184 }
 185
 186 static int mp3dec_parse_config(int argc, char **argv, void **config)
 187 {
 188         int ret;
 189         struct mp3dec_filter_args_info *mp3_conf;
 190
 191         mp3_conf = para_calloc(sizeof(*mp3_conf));
 192         ret = -E_MP3DEC_SYNTAX;
 193         if (mp3dec_cmdline_parser(argc, argv, mp3_conf))
 194                 goto err;
 195         *config = mp3_conf;
 196         return 1;
 197 err:
 198         free(mp3_conf);
 199         return ret;
 200 }
 201
 202 static int mp3dec_execute(struct btr_node *btrn, const char *cmd, char **result)
 203 {
 204         struct filter_node *fn = btr_context(btrn);
 205         struct private_mp3dec_data *pmd = fn->private_data;
 206
 207         return decoder_execute(cmd, pmd->sample_rate, pmd->channels, result);
 208 }
 209
 210 static void mp3dec_free_config(void *conf)
 211 {
 212         mp3dec_cmdline_parser_free(conf);
 213 }
 214 /**
 215  * The init function of the mp3dec filter.
 216  *
 217  * \param f Pointer to the filter struct to initialize.
 218  *
 219  * \sa filter::init.
 220  */
 221 void mp3dec_filter_init(struct filter *f)
 222 {
 223         struct mp3dec_filter_args_info dummy;
 224
 225         mp3dec_cmdline_parser_init(&dummy);
 226         f->open = mp3dec_open;
 227         f->close = mp3dec_close;
 228         f->parse_config = mp3dec_parse_config;
 229         f->free_config = mp3dec_free_config;
 230         f->pre_select = generic_filter_pre_select;
 231         f->post_select = mp3dec_post_select;
 232         f->execute = mp3dec_execute;
 233         f->help = (struct ggo_help) {
 234                 .short_help = mp3dec_filter_args_info_help,
 235                 .detailed_help = mp3dec_filter_args_info_detailed_help
 236         };
 237 }