apps/codecs/vorbis.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2002 Björn Stenberg
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version 2
  15  * of the License, or (at your option) any later version.
  16  *
  17  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  18  * KIND, either express or implied.
  19  *
  20  ****************************************************************************/
  21
  22 #include "codeclib.h"
  23 #include "libtremor/ivorbisfile.h"
  24 #include "libtremor/ogg.h"
  25
  26 CODEC_HEADER
  27
  28 /* Some standard functions and variables needed by Tremor */
  29
  30 static size_t read_handler(void *ptr, size_t size, size_t nmemb, void *datasource)
  31 {
  32     (void)datasource;
  33     return ci->read_filebuf(ptr, nmemb*size);
  34 }
  35
  36 static int initial_seek_handler(void *datasource, ogg_int64_t offset, int whence)
  37 {
  38     (void)datasource;
  39     (void)offset;
  40     (void)whence;
  41     return -1;
  42 }
  43
  44 static int seek_handler(void *datasource, ogg_int64_t offset, int whence)
  45 {
  46     (void)datasource;
  47
  48     if (whence == SEEK_CUR) {
  49         offset += ci->curpos;
  50     } else if (whence == SEEK_END) {
  51         offset += ci->filesize;
  52     }
  53
  54     if (ci->seek_buffer(offset)) {
  55         return 0;
  56     }
  57
  58     return -1;
  59 }
  60
  61 static int close_handler(void *datasource)
  62 {
  63     (void)datasource;
  64     return 0;
  65 }
  66
  67 static long tell_handler(void *datasource)
  68 {
  69     (void)datasource;
  70     return ci->curpos;
  71 }
  72
  73 /* This sets the DSP parameters based on the current logical bitstream
  74  * (sampling rate, number of channels, etc).  It also tries to guess
  75  * reasonable buffer parameters based on the current quality setting.
  76  */
  77 static bool vorbis_set_codec_parameters(OggVorbis_File *vf)
  78 {
  79     vorbis_info *vi;
  80
  81     vi = ov_info(vf, -1);
  82
  83     if (vi == NULL) {
  84         //ci->splash(HZ*2, "Vorbis Error");
  85         return false;
  86     }
  87
  88     ci->configure(DSP_SWITCH_FREQUENCY, ci->id3->frequency);
  89     codec_set_replaygain(ci->id3);
  90
  91     if (vi->channels == 2) {
  92           ci->configure(DSP_SET_STEREO_MODE, STEREO_NONINTERLEAVED);
  93     } else if (vi->channels == 1) {
  94           ci->configure(DSP_SET_STEREO_MODE, STEREO_MONO);
  95     }
  96
  97     return true;
  98 }
  99
 100 /* this is the codec entry point */
 101 enum codec_status codec_main(void)
 102 {
 103     ov_callbacks callbacks;
 104     OggVorbis_File vf;
 105     ogg_int32_t **pcm;
 106
 107     int error;
 108     long n;
 109     int current_section;
 110     int previous_section = -1;
 111     int eof;
 112     ogg_int64_t vf_offsets[2];
 113     ogg_int64_t vf_dataoffsets;
 114     ogg_uint32_t vf_serialnos;
 115     ogg_int64_t vf_pcmlengths[2];
 116
 117     ci->configure(DSP_SET_SAMPLE_DEPTH, 24);
 118     /* Note: These are sane defaults for these values.  Perhaps
 119      * they should be set differently based on quality setting
 120      */
 121
 122 /* We need to flush reserver memory every track load. */
 123 next_track:
 124     if (codec_init()) {
 125         error = CODEC_ERROR;
 126         goto exit;
 127     }
 128     ogg_malloc_init();
 129
 130     while (!*ci->taginfo_ready && !ci->stop_codec)
 131         ci->sleep(1);
 132
 133     /* Create a decoder instance */
 134     callbacks.read_func = read_handler;
 135     callbacks.seek_func = initial_seek_handler;
 136     callbacks.tell_func = tell_handler;
 137     callbacks.close_func = close_handler;
 138
 139     /* Open a non-seekable stream */
 140     error = ov_open_callbacks(ci, &vf, NULL, 0, callbacks);
 141
 142     /* If the non-seekable open was successful, we need to supply the missing
 143      * data to make it seekable.  This is a hack, but it's reasonable since we
 144      * don't want to run the whole file through the buffer before we start
 145      * playing.  Using Tremor's seekable open routine would cause us to do
 146      * this, so we pretend not to be seekable at first.  Then we fill in the
 147      * missing fields of vf with 1) information in ci->id3, and 2) info
 148      * obtained by Tremor in the above ov_open call.
 149      *
 150      * Note that this assumes there is only ONE logical Vorbis bitstream in our
 151      * physical Ogg bitstream.  This is verified in metadata.c, well before we
 152      * get here.
 153      */
 154     if (!error) {
 155          vf.offsets = vf_offsets;
 156          vf.dataoffsets = &vf_dataoffsets;
 157          vf.serialnos = &vf_serialnos;
 158          vf.pcmlengths = vf_pcmlengths;
 159
 160          vf.offsets[0] = 0;
 161          vf.offsets[1] = ci->id3->filesize;
 162          vf.dataoffsets[0] = vf.offset;
 163          vf.pcmlengths[0] = 0;
 164          vf.pcmlengths[1] = ci->id3->samples;
 165          vf.serialnos[0] = vf.current_serialno;
 166          vf.callbacks.seek_func = seek_handler;
 167          vf.seekable = 1;
 168          vf.end = ci->id3->filesize;
 169          vf.ready_state = OPENED;
 170          vf.links = 1;
 171     } else {
 172          //ci->logf("ov_open: %d", error);
 173          error = CODEC_ERROR;
 174          goto done;
 175     }
 176
 177     if (ci->id3->offset) {
 178         ci->advance_buffer(ci->id3->offset);
 179         ov_raw_seek(&vf, ci->id3->offset);
 180         ci->set_elapsed(ov_time_tell(&vf));
 181         ci->set_offset(ov_raw_tell(&vf));
 182     }
 183
 184     eof = 0;
 185     while (!eof) {
 186         ci->yield();
 187         if (ci->stop_codec || ci->new_track)
 188             break;
 189
 190         if (ci->seek_time) {
 191             if (ov_time_seek(&vf, ci->seek_time - 1)) {
 192                 //ci->logf("ov_time_seek failed");
 193             }
 194             ci->seek_complete();
 195         }
 196
 197         /* Read host-endian signed 24-bit PCM samples */
 198         n = ov_read_fixed(&vf, &pcm, 1024, &current_section);
 199
 200         /* Change DSP and buffer settings for this bitstream */
 201         if (current_section != previous_section) {
 202             if (!vorbis_set_codec_parameters(&vf)) {
 203                 error = CODEC_ERROR;
 204                 goto done;
 205             } else {
 206                 previous_section = current_section;
 207             }
 208         }
 209
 210         if (n == 0) {
 211             eof = 1;
 212         } else if (n < 0) {
 213             DEBUGF("Error decoding frame\n");
 214         } else {
 215             ci->pcmbuf_insert(pcm[0], pcm[1], n);
 216             ci->set_offset(ov_raw_tell(&vf));
 217             ci->set_elapsed(ov_time_tell(&vf));
 218         }
 219     }
 220     error = CODEC_OK;
 221
 222 done:
 223     if (ci->request_next_track()) {
 224         /* Clean things up for the next track */
 225         vf.dataoffsets = NULL;
 226         vf.offsets = NULL;
 227         vf.serialnos = NULL;
 228         vf.pcmlengths = NULL;
 229         ov_clear(&vf);
 230         previous_section = -1;
 231         goto next_track;
 232     }
 233
 234 exit:
 235     return error;
 236 }
 237