mp3dec_filter.c

   1 /*
   2  * Copyright (C) 2005-2009 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 "filter.h"
  18 #include "error.h"
  19 #include "string.h"
  20
  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))
  24
  25 /** Data specific to the mp3dec filter. */
  26 struct private_mp3dec_data {
  27         /** Information on the current mp3 stream. */
  28         struct mad_stream stream;
  29         /** Information about the frame which is currently decoded. */
  30         struct mad_frame frame;
  31         /** Contains the PCM output. */
  32         struct mad_synth synth;
  33 };
  34
  35 static ssize_t mp3dec(char *inbuffer, size_t len, struct filter_node *fn)
  36 {
  37         int i, ret;
  38         struct private_mp3dec_data *pmd = fn->private_data;
  39         size_t copy = PARA_MIN(len, (size_t)4096);
  40
  41         if (fn->loaded + 16384 > fn->bufsize)
  42                 return 0;
  43         mad_stream_buffer(&pmd->stream, (unsigned char *) inbuffer, copy);
  44         pmd->stream.error = 0;
  45 next_frame:
  46         ret = mad_header_decode(&pmd->frame.header, &pmd->stream);
  47         if (ret < 0) {
  48                 if (pmd->stream.error != MAD_ERROR_BUFLEN &&
  49                         pmd->stream.error != MAD_ERROR_LOSTSYNC)
  50                         PARA_DEBUG_LOG("header decode: %s\n",
  51                                 mad_stream_errorstr(&pmd->stream));
  52                 goto out;
  53         }
  54         fn->fc->samplerate = pmd->frame.header.samplerate;
  55         fn->fc->channels = MAD_NCHANNELS(&pmd->frame.header);
  56         ret = mad_frame_decode(&pmd->frame, &pmd->stream);
  57         if (ret) {
  58                 if (MAD_RECOVERABLE(pmd->stream.error) ||
  59                         pmd->stream.error == MAD_ERROR_BUFLEN) {
  60                         PARA_DEBUG_LOG("frame decode: %s\n",
  61                                 mad_stream_errorstr(&pmd->stream));
  62                         goto out;
  63                 }
  64                 PARA_ERROR_LOG("frame decode: %s\n",
  65                         mad_stream_errorstr(&pmd->stream));
  66                 return -E_MAD_FRAME_DECODE;
  67         }
  68         mad_synth_frame(&pmd->synth, &pmd->frame);
  69
  70         for (i = 0; i < pmd->synth.pcm.length; i++) {
  71                 int s = MAD_TO_SHORT(pmd->synth.pcm.samples[0][i]);
  72                 write_int16_host_endian(fn->buf + fn->loaded, s);
  73                 fn->loaded += 2;
  74                 if (MAD_NCHANNELS(&pmd->frame.header) == 2) { /* stereo */
  75                         s = MAD_TO_SHORT(pmd->synth.pcm.samples[1][i]);
  76                         write_int16_host_endian(fn->buf + fn->loaded, s);
  77                         fn->loaded += 2;
  78                 }
  79                 if (fn->loaded != fn->bufsize) /* output buffer not full */
  80                         continue;
  81                 PARA_ERROR_LOG("output buffer full: %zd\n", fn->loaded);
  82                         return -E_MP3DEC_OVERRUN;
  83         }
  84         if (fn->loaded + 16384 <= fn->bufsize)
  85                 goto next_frame;
  86 out:
  87         if (pmd->stream.next_frame) { /* we still have some data */
  88                 size_t off = pmd->stream.bufend - pmd->stream.next_frame;
  89                 if (fn->loaded + 16384 <= fn->bufsize && off > 2048)
  90                         goto next_frame;
  91                 return copy - off;
  92         }
  93         return copy;
  94 }
  95
  96 static void mp3dec_close(struct filter_node *fn)
  97 {
  98         struct private_mp3dec_data *pmd = fn->private_data;
  99
 100         mad_synth_finish(&pmd->synth);
 101         mad_frame_finish(&pmd->frame);
 102         mad_stream_finish(&pmd->stream);
 103
 104         free(fn->buf);
 105         fn->buf = NULL;
 106         free(pmd);
 107         fn->private_data = NULL;
 108 }
 109
 110 static void mp3dec_open(struct filter_node *fn)
 111 {
 112         struct private_mp3dec_data *pmd = para_calloc(sizeof(*pmd));
 113         struct mp3dec_filter_args_info *mp3_conf = fn->conf;
 114
 115         fn->private_data = pmd;
 116         mad_stream_init(&pmd->stream);
 117         mad_frame_init(&pmd->frame);
 118         mad_synth_init(&pmd->synth);
 119         fn->loaded = 0;
 120         fn->bufsize = mp3_conf->bufsize_arg * 1024;
 121         fn->buf = para_calloc(fn->bufsize);
 122         if (mp3_conf->ignore_crc_given)
 123                 mad_stream_options(&pmd->stream, MAD_OPTION_IGNORECRC);
 124 }
 125
 126 static int mp3dec_parse_config(int argc, char **argv, void **config)
 127 {
 128         int ret;
 129         struct mp3dec_filter_args_info *mp3_conf;
 130
 131         mp3_conf = para_calloc(sizeof(*mp3_conf));
 132         ret = -E_MP3DEC_SYNTAX;
 133         if (mp3dec_cmdline_parser(argc, argv, mp3_conf))
 134                 goto err;
 135         ret = -ERRNO_TO_PARA_ERROR(EINVAL);
 136         if (mp3_conf->bufsize_arg < 32)
 137                 goto err;
 138         if (mp3_conf->bufsize_arg >= INT_MAX / 1024)
 139                 goto err;
 140         *config = mp3_conf;
 141         return 1;
 142 err:
 143         free(mp3_conf);
 144         return ret;
 145 }
 146
 147 /**
 148  * The init function of the mp3dec filter.
 149  *
 150  * \param f Pointer to the filter struct to initialize.
 151  *
 152  * \sa filter::init.
 153  */
 154 void mp3dec_filter_init(struct filter *f)
 155 {
 156         struct mp3dec_filter_args_info dummy;
 157
 158         mp3dec_cmdline_parser_init(&dummy);
 159         f->open = mp3dec_open;
 160         f->convert = mp3dec;
 161         f->close = mp3dec_close;
 162         f->parse_config = mp3dec_parse_config;
 163         f->help = (struct ggo_help) {
 164                 .short_help = mp3dec_filter_args_info_help,
 165                 .detailed_help = mp3dec_filter_args_info_detailed_help
 166         };
 167 }