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 size_t used_mad_buffer_bytes(struct mad_stream *s, size_t max)
  54 {
  55         size_t rv;
  56
  57         if (!s->next_frame)
  58                 return max;
  59         /* we still have some data */
  60         rv = s->next_frame - s->buffer;
  61         assert(rv <= max);
  62         return rv;
  63 }
  64
  65 static void mp3dec_close(struct filter_node *fn)
  66 {
  67         struct private_mp3dec_data *pmd = fn->private_data;
  68
  69         mad_synth_finish(&pmd->synth);
  70         mad_frame_finish(&pmd->frame);
  71         mad_stream_finish(&pmd->stream);
  72
  73         free(pmd);
  74         fn->private_data = NULL;
  75 }
  76
  77 static void mp3dec_post_select(__a_unused struct sched *s, struct task *t)
  78 {
  79         struct filter_node *fn = container_of(t, struct filter_node, task);
  80         int i, ret;
  81         struct private_mp3dec_data *pmd = fn->private_data;
  82         struct btr_node *btrn = fn->btrn;
  83         size_t loaded, used, len, iqs;
  84         char *inbuffer, *outbuffer;
  85
  86 next_buffer:
  87         pmd->stream.error = 0;
  88         t->error = 0;
  89         iqs = btr_get_input_queue_size(btrn);
  90         ret = btr_node_status(btrn, fn->min_iqs, BTR_NT_INTERNAL);
  91         if (ret < 0)
  92                 goto err;
  93         if (ret == 0)
  94                 return;
  95         btr_merge(btrn, fn->min_iqs);
  96         len = btr_next_buffer(btrn, &inbuffer);
  97         /*
  98          * Decode at most 8K in one go to give the post_select() functions of
  99          * other buffer tree nodes a chance to run. This is necessary to avoid
 100          * buffer underruns on slow machines.
 101          */
 102         len = PARA_MIN(len, (size_t)8192);
 103         mad_stream_buffer(&pmd->stream, (unsigned char *)inbuffer, len);
 104 next_frame:
 105         ret = mad_header_decode(&pmd->frame.header, &pmd->stream);
 106         if (ret < 0) {
 107                 used = used_mad_buffer_bytes(&pmd->stream, len);
 108                 btr_consume(btrn, used);
 109                 if (pmd->stream.error == MAD_ERROR_BUFLEN) {
 110                         if (len == iqs && btr_no_parent(btrn)) {
 111                                 ret = -E_MP3DEC_EOF;
 112                                 goto err;
 113                         }
 114                         fn->min_iqs += 100;
 115                         goto next_buffer;
 116                 } else if (pmd->stream.error != MAD_ERROR_LOSTSYNC)
 117                         PARA_DEBUG_LOG("header decode: %s\n",
 118                                 mad_stream_errorstr(&pmd->stream));
 119                 goto next_buffer;
 120         }
 121         fn->min_iqs = 0;
 122         pmd->sample_rate = pmd->frame.header.samplerate;
 123         pmd->channels = MAD_NCHANNELS(&pmd->frame.header);
 124         ret = mad_frame_decode(&pmd->frame, &pmd->stream);
 125         if (ret != 0) {
 126                 PARA_INFO_LOG("frame decode: %s\n", mad_stream_errorstr(&pmd->stream));
 127                 used = used_mad_buffer_bytes(&pmd->stream, len);
 128                 ret = handle_decode_error(pmd);
 129                 btr_consume(btrn, used);
 130                 if (ret < 0)
 131                         goto err;
 132                 if (ret == 0)
 133                         goto next_buffer;
 134                 return;
 135         }
 136         mad_synth_frame(&pmd->synth, &pmd->frame);
 137         outbuffer = para_malloc(pmd->synth.pcm.length * 2 * pmd->channels);
 138         loaded = 0;
 139         for (i = 0; i < pmd->synth.pcm.length; i++) {
 140                 int sample = MAD_TO_SHORT(pmd->synth.pcm.samples[0][i]);
 141                 write_int16_host_endian(outbuffer + loaded, sample);
 142                 loaded += 2;
 143                 if (pmd->channels == 2) { /* stereo */
 144                         sample = MAD_TO_SHORT(pmd->synth.pcm.samples[1][i]);
 145                         write_int16_host_endian(outbuffer + loaded, sample);
 146                         loaded += 2;
 147                 }
 148         }
 149         btr_add_output(outbuffer, loaded, btrn);
 150         goto next_frame;
 151 err:
 152         assert(ret < 0);
 153         t->error = ret;
 154         btr_remove_node(btrn);
 155 }
 156
 157 static void mp3dec_open(struct filter_node *fn)
 158 {
 159         struct private_mp3dec_data *pmd = para_calloc(sizeof(*pmd));
 160         struct mp3dec_filter_args_info *mp3_conf = fn->conf;
 161
 162         fn->private_data = pmd;
 163         mad_stream_init(&pmd->stream);
 164         mad_frame_init(&pmd->frame);
 165         mad_synth_init(&pmd->synth);
 166         if (mp3_conf->ignore_crc_given)
 167                 mad_stream_options(&pmd->stream, MAD_OPTION_IGNORECRC);
 168 }
 169
 170 static int mp3dec_parse_config(int argc, char **argv, void **config)
 171 {
 172         int ret;
 173         struct mp3dec_filter_args_info *mp3_conf;
 174
 175         mp3_conf = para_calloc(sizeof(*mp3_conf));
 176         ret = -E_MP3DEC_SYNTAX;
 177         if (mp3dec_cmdline_parser(argc, argv, mp3_conf))
 178                 goto err;
 179         *config = mp3_conf;
 180         return 1;
 181 err:
 182         free(mp3_conf);
 183         return ret;
 184 }
 185
 186 static int mp3dec_execute(struct btr_node *btrn, const char *cmd, char **result)
 187 {
 188         struct filter_node *fn = btr_context(btrn);
 189         struct private_mp3dec_data *pmd = fn->private_data;
 190
 191         return decoder_execute(cmd, pmd->sample_rate, pmd->channels, result);
 192 }
 193
 194 static void mp3dec_free_config(void *conf)
 195 {
 196         mp3dec_cmdline_parser_free(conf);
 197 }
 198 /**
 199  * The init function of the mp3dec filter.
 200  *
 201  * \param f Pointer to the filter struct to initialize.
 202  *
 203  * \sa filter::init.
 204  */
 205 void mp3dec_filter_init(struct filter *f)
 206 {
 207         struct mp3dec_filter_args_info dummy;
 208
 209         mp3dec_cmdline_parser_init(&dummy);
 210         f->open = mp3dec_open;
 211         f->close = mp3dec_close;
 212         f->parse_config = mp3dec_parse_config;
 213         f->free_config = mp3dec_free_config;
 214         f->pre_select = generic_filter_pre_select;
 215         f->post_select = mp3dec_post_select;
 216         f->execute = mp3dec_execute;
 217         f->help = (struct ggo_help) {
 218                 .short_help = mp3dec_filter_args_info_help,
 219                 .detailed_help = mp3dec_filter_args_info_detailed_help
 220         };
 221 }