mp3dec_filter.c

   1 /*
   2  * Copyright (C) 2005-2013 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 "buffer_tree.h"
  18 #include "filter.h"
  19 #include "error.h"
  20 #include "string.h"
  21
  22 /** Convert a sample value from libmad to a signed short. */
  23 #define MAD_TO_SHORT(f) (f) >= MAD_F_ONE? SHRT_MAX :\
  24         (f) <= -MAD_F_ONE? -SHRT_MAX : (signed short) ((f) >> (MAD_F_FRACBITS - 15))
  25
  26 /** Data specific to the mp3dec filter. */
  27 struct private_mp3dec_data {
  28         /** Information on the current mp3 stream. */
  29         struct mad_stream stream;
  30         /** Information about the frame which is currently decoded. */
  31         struct mad_frame frame;
  32         /** Contains the PCM output. */
  33         struct mad_synth synth;
  34         /** The number of channels of the current stream. */
  35         unsigned int channels;
  36         /** Current sample rate in Hz. */
  37         unsigned int sample_rate;
  38 };
  39
  40 /* Returns negative on serious errors. */
  41 static int handle_decode_error(struct private_mp3dec_data *pmd)
  42 {
  43         if (!MAD_RECOVERABLE(pmd->stream.error)
  44                         && pmd->stream.error != MAD_ERROR_BUFLEN) {
  45                 PARA_ERROR_LOG("%s\n", mad_stream_errorstr(&pmd->stream));
  46                 return -E_MAD_FRAME_DECODE;
  47         }
  48         PARA_DEBUG_LOG("%s\n", mad_stream_errorstr(&pmd->stream));
  49         return 0;
  50 }
  51
  52 static void mp3dec_consume(struct btr_node *btrn, struct mad_stream *s,
  53                 size_t max)
  54 {
  55         size_t used;
  56
  57         if (!s->next_frame)
  58                 used = max;
  59         else { /* we still have some data */
  60                 used = s->next_frame - s->buffer;
  61                 assert(used <= max);
  62         }
  63         btr_consume(btrn, used);
  64 }
  65
  66 static void mp3dec_close(struct filter_node *fn)
  67 {
  68         struct private_mp3dec_data *pmd = fn->private_data;
  69
  70         mad_synth_finish(&pmd->synth);
  71         mad_frame_finish(&pmd->frame);
  72         mad_stream_finish(&pmd->stream);
  73
  74         free(pmd);
  75         fn->private_data = NULL;
  76 }
  77
  78 #define MP3DEC_MAX_FRAME 8192
  79
  80 static int mp3dec_post_select(__a_unused struct sched *s, struct task *t)
  81 {
  82         struct filter_node *fn = container_of(t, struct filter_node, task);
  83         int i, ret;
  84         struct private_mp3dec_data *pmd = fn->private_data;
  85         struct btr_node *btrn = fn->btrn;
  86         size_t loaded = 0, len, iqs;
  87         char *inbuffer, *outbuffer;
  88
  89 next_buffer:
  90         pmd->stream.error = 0;
  91         iqs = btr_get_input_queue_size(btrn);
  92         ret = btr_node_status(btrn, fn->min_iqs, BTR_NT_INTERNAL);
  93         if (ret < 0)
  94                 goto err;
  95         if (ret == 0)
  96                 return 0;
  97         btr_merge(btrn, fn->min_iqs);
  98         len = btr_next_buffer(btrn, &inbuffer);
  99         /*
 100          * Decode at most 8K in one go to give the post_select() functions of
 101          * other buffer tree nodes a chance to run. This is necessary to avoid
 102          * buffer underruns on slow machines.
 103          */
 104         len = PARA_MIN(len, (size_t)MP3DEC_MAX_FRAME);
 105         mad_stream_buffer(&pmd->stream, (unsigned char *)inbuffer, len);
 106 next_frame:
 107         ret = mad_header_decode(&pmd->frame.header, &pmd->stream);
 108         if (ret < 0) {
 109                 mp3dec_consume(btrn, &pmd->stream, len);
 110                 if (pmd->stream.error == MAD_ERROR_BUFLEN) {
 111                         if (len == iqs && btr_no_parent(btrn)) {
 112                                 ret = -E_MP3DEC_EOF;
 113                                 goto err;
 114                         }
 115                         fn->min_iqs += 100;
 116                         ret = -E_MP3DEC_CORRUPT;
 117                         if (fn->min_iqs > MP3DEC_MAX_FRAME)
 118                                 goto err;
 119                 }
 120                 if (loaded == 0)
 121                         goto next_buffer;
 122                 return 0;
 123         }
 124         pmd->sample_rate = pmd->frame.header.samplerate;
 125         pmd->channels = MAD_NCHANNELS(&pmd->frame.header);
 126 decode:
 127         ret = mad_frame_decode(&pmd->frame, &pmd->stream);
 128         if (ret != 0) {
 129                 ret = handle_decode_error(pmd);
 130                 if (ret < 0)
 131                         goto err;
 132                 mad_stream_sync(&pmd->stream);
 133                 if (pmd->stream.error == MAD_ERROR_BUFLEN) {
 134                         ret = -E_MP3DEC_EOF;
 135                         if (len == iqs && btr_no_parent(btrn))
 136                                 goto err;
 137                         fn->min_iqs += 100;
 138                         ret = -E_MP3DEC_CORRUPT;
 139                         if (fn->min_iqs > MP3DEC_MAX_FRAME)
 140                                 goto err;
 141                         mp3dec_consume(btrn, &pmd->stream, len);
 142                         return 0;
 143                 }
 144                 if (pmd->stream.error != MAD_ERROR_BADDATAPTR)
 145                         goto decode;
 146                 mp3dec_consume(btrn, &pmd->stream, len);
 147                 return 0;
 148         }
 149         fn->min_iqs = 0;
 150         mad_synth_frame(&pmd->synth, &pmd->frame);
 151         outbuffer = para_malloc(pmd->synth.pcm.length * 2 * pmd->channels);
 152         loaded = 0;
 153         for (i = 0; i < pmd->synth.pcm.length; i++) {
 154                 int sample = MAD_TO_SHORT(pmd->synth.pcm.samples[0][i]);
 155                 write_int16_host_endian(outbuffer + loaded, sample);
 156                 loaded += 2;
 157                 if (pmd->channels == 2) { /* stereo */
 158                         sample = MAD_TO_SHORT(pmd->synth.pcm.samples[1][i]);
 159                         write_int16_host_endian(outbuffer + loaded, sample);
 160                         loaded += 2;
 161                 }
 162         }
 163         btr_add_output(outbuffer, loaded, btrn);
 164         goto next_frame;
 165 err:
 166         assert(ret < 0);
 167         btr_remove_node(&fn->btrn);
 168         return ret;
 169 }
 170
 171 static void mp3dec_open(struct filter_node *fn)
 172 {
 173         struct private_mp3dec_data *pmd = para_calloc(sizeof(*pmd));
 174         struct mp3dec_filter_args_info *mp3_conf = fn->conf;
 175
 176         fn->private_data = pmd;
 177         mad_stream_init(&pmd->stream);
 178         mad_frame_init(&pmd->frame);
 179         mad_synth_init(&pmd->synth);
 180         if (mp3_conf->ignore_crc_given)
 181                 mad_stream_options(&pmd->stream, MAD_OPTION_IGNORECRC);
 182 }
 183
 184 static int mp3dec_parse_config(int argc, char **argv, void **config)
 185 {
 186         struct mp3dec_filter_args_info *conf = para_calloc(sizeof(*conf));
 187
 188         mp3dec_filter_cmdline_parser(argc, argv, conf);
 189         *config = conf;
 190         return 1;
 191 }
 192
 193 static int mp3dec_execute(struct btr_node *btrn, const char *cmd, char **result)
 194 {
 195         struct filter_node *fn = btr_context(btrn);
 196         struct private_mp3dec_data *pmd = fn->private_data;
 197
 198         return decoder_execute(cmd, pmd->sample_rate, pmd->channels, result);
 199 }
 200
 201 static void mp3dec_free_config(void *conf)
 202 {
 203         mp3dec_filter_cmdline_parser_free(conf);
 204 }
 205 /**
 206  * The init function of the mp3dec filter.
 207  *
 208  * \param f Pointer to the filter struct to initialize.
 209  *
 210  * \sa filter::init.
 211  */
 212 void mp3dec_filter_init(struct filter *f)
 213 {
 214         struct mp3dec_filter_args_info dummy;
 215
 216         mp3dec_filter_cmdline_parser_init(&dummy);
 217         f->open = mp3dec_open;
 218         f->close = mp3dec_close;
 219         f->parse_config = mp3dec_parse_config;
 220         f->free_config = mp3dec_free_config;
 221         f->pre_select = generic_filter_pre_select;
 222         f->post_select = mp3dec_post_select;
 223         f->execute = mp3dec_execute;
 224         f->help = (struct ggo_help)DEFINE_GGO_HELP(mp3dec_filter);
 225 }