apps/codecs/wma.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2007 Dave Chapman
  11  *
  12  * ASF parsing code based on libasf by Juho Vähä-Herttua
  13  * http://code.google.com/p/libasf/  libasf itself was based on the ASF
  14  * parser in VLC - http://www.videolan.org/
  15  *
  16  * This program is free software; you can redistribute it and/or
  17  * modify it under the terms of the GNU General Public License
  18  * as published by the Free Software Foundation; either version 2
  19  * of the License, or (at your option) any later version.
  20  *
  21  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  22  * KIND, either express or implied.
  23  *
  24  ****************************************************************************/
  25
  26 #include "codeclib.h"
  27 #include "libasf/asf.h"
  28 #include "libwma/wmadec.h"
  29
  30 CODEC_HEADER
  31
  32 /* The output buffer containing the decoded samples (channels 0 and 1)
  33    BLOCK_MAX_SIZE is 2048 (samples) and MAX_CHANNELS is 2.
  34  */
  35
  36 static uint32_t decoded[BLOCK_MAX_SIZE * MAX_CHANNELS] IBSS_ATTR;
  37
  38 /* NOTE: WMADecodeContext is 120152 bytes (on x86) */
  39 static WMADecodeContext wmadec;
  40
  41 /*entry point for seeks*/
  42 static int seek(int ms, asf_waveformatex_t* wfx)
  43 {
  44     int time, duration, delta, temp, count=0;
  45
  46     /*estimate packet number from bitrate*/
  47     int initial_packet = ci->curpos/wfx->packet_size;
  48     int packet_num = (((int64_t)ms)*(wfx->bitrate>>3))/wfx->packet_size/1000;
  49     int last_packet = ci->id3->filesize / wfx->packet_size;
  50
  51     if (packet_num > last_packet) {
  52         packet_num = last_packet;
  53     }
  54
  55     /*calculate byte address of the start of that packet*/
  56     int packet_offset = packet_num*wfx->packet_size;
  57
  58     /*seek to estimated packet*/
  59     ci->seek_buffer(ci->id3->first_frame_offset+packet_offset);
  60     temp = ms;
  61     while (1)
  62     {
  63         /*for very large files it can be difficult and unimportant to find the exact packet*/
  64         count++;
  65
  66         /*check the time stamp of our packet*/
  67         time = asf_get_timestamp(&duration, ci);
  68         DEBUGF("seeked to %d ms with duration %d\n", time, duration);
  69
  70         if (time < 0) {
  71             /*unknown error, try to recover*/
  72             DEBUGF("UKNOWN SEEK ERROR\n");
  73             ci->seek_buffer(ci->id3->first_frame_offset+initial_packet*wfx->packet_size);
  74             /*seek failed so return time stamp of the initial packet*/
  75             return asf_get_timestamp(&duration, ci);
  76         }
  77
  78         if ((time+duration>=ms && time<=ms) || count > 10) {
  79             DEBUGF("Found our packet! Now at %d packet\n", packet_num);
  80             return time;
  81         } else {
  82             /*seek again*/
  83             delta = ms-time;
  84             /*estimate new packet number from bitrate and our current position*/
  85             temp += delta;
  86             packet_num = ((temp/1000)*(wfx->bitrate>>3) - (wfx->packet_size>>1))/wfx->packet_size;  //round down!
  87             packet_offset = packet_num*wfx->packet_size;
  88             ci->seek_buffer(ci->id3->first_frame_offset+packet_offset);
  89         }
  90     }
  91 }
  92
  93
  94
  95 /* this is the codec entry point */
  96 enum codec_status codec_main(void)
  97 {
  98     uint32_t elapsedtime;
  99     int retval;
 100     asf_waveformatex_t wfx;
 101     size_t resume_offset;
 102     int i;
 103     int wmares, res;
 104     uint8_t* audiobuf;
 105     int audiobufsize;
 106     int packetlength = 0;
 107     int errcount = 0;
 108
 109     /* Generic codec initialisation */
 110     ci->configure(DSP_SET_SAMPLE_DEPTH, 29);
 111
 112 next_track:
 113
 114     /* Wait for the metadata to be read */
 115     while (!*ci->taginfo_ready && !ci->stop_codec)
 116         ci->sleep(1);
 117
 118     retval = CODEC_OK;
 119
 120     /* Remember the resume position - when the codec is opened, the
 121        playback engine will reset it. */
 122     resume_offset = ci->id3->offset;
 123 restart_track:
 124     if (codec_init()) {
 125         LOGF("WMA: Error initialising codec\n");
 126         retval = CODEC_ERROR;
 127         goto exit;
 128     }
 129
 130     /* Copy the format metadata we've stored in the id3 TOC field.  This
 131        saves us from parsing it again here. */
 132     memcpy(&wfx, ci->id3->toc, sizeof(wfx));
 133
 134     if (wma_decode_init(&wmadec,&wfx) < 0) {
 135         LOGF("WMA: Unsupported or corrupt file\n");
 136         retval = CODEC_ERROR;
 137         goto exit;
 138     }
 139
 140     DEBUGF("**************** IN WMA.C ******************\n");
 141
 142     if (resume_offset > ci->id3->first_frame_offset)
 143     {
 144         /* Get start of current packet */
 145         int packet_offset = (resume_offset - ci->id3->first_frame_offset)
 146             % wfx.packet_size;
 147         ci->seek_buffer(resume_offset - packet_offset);
 148         elapsedtime = asf_get_timestamp(&i, ci);
 149         ci->set_elapsed(elapsedtime);
 150     }
 151     else
 152     {
 153         /* Now advance the file position to the first frame */
 154         ci->seek_buffer(ci->id3->first_frame_offset);
 155         elapsedtime = 0;
 156     }
 157
 158     resume_offset = 0;
 159     ci->configure(DSP_SWITCH_FREQUENCY, wfx.rate);
 160     ci->configure(DSP_SET_STEREO_MODE, wfx.channels == 1 ?
 161                   STEREO_MONO : STEREO_INTERLEAVED);
 162     codec_set_replaygain(ci->id3);
 163
 164     /* The main decoding loop */
 165
 166     res = 1;
 167     while (res >= 0)
 168     {
 169         ci->yield();
 170         if (ci->stop_codec || ci->new_track) {
 171             goto done;
 172         }
 173
 174         /* Deal with any pending seek requests */
 175         if (ci->seek_time){
 176
 177             if (ci->seek_time == 1) {
 178                 ci->seek_complete();
 179                 goto restart_track; /* Pretend you never saw this... */
 180             }
 181
 182             elapsedtime = seek(ci->seek_time, &wfx);
 183             if (elapsedtime < 1){
 184                 ci->seek_complete();
 185                 goto next_track;
 186             }
 187             /*DEBUGF("Seek returned %d\n", (int)elapsedtime);*/
 188             ci->set_elapsed(elapsedtime);
 189
 190             /*flush the wma decoder state*/
 191             wmadec.last_superframe_len = 0;
 192             wmadec.last_bitoffset = 0;
 193             ci->seek_complete();
 194         }
 195         errcount = 0;
 196 new_packet:
 197         res = asf_read_packet(&audiobuf, &audiobufsize, &packetlength, &wfx, ci);
 198
 199         if (res < 0) {
 200             /* We'll try to recover from a parse error a certain number of
 201              * times. If we succeed, the error counter will be reset.
 202              */
 203
 204             errcount++;
 205             DEBUGF("read_packet error %d, errcount %d\n",wmares, errcount);
 206             if (errcount > 5) {
 207                 goto done;
 208             } else {
 209                 ci->advance_buffer(packetlength);
 210                 goto new_packet;
 211             }
 212         } else if (res > 0) {
 213             wma_decode_superframe_init(&wmadec, audiobuf, audiobufsize);
 214
 215             for (i=0; i < wmadec.nb_frames; i++)
 216             {
 217                 wmares = wma_decode_superframe_frame(&wmadec,
 218                                                      decoded,
 219                                                      audiobuf, audiobufsize);
 220
 221                 ci->yield ();
 222
 223                 if (wmares < 0) {
 224                     /* Do the above, but for errors in decode. */
 225                     errcount++;
 226                     DEBUGF("WMA decode error %d, errcount %d\n",wmares, errcount);
 227                     if (errcount > 5) {
 228                         goto done;
 229                     } else {
 230                         ci->advance_buffer(packetlength);
 231                         goto new_packet;
 232                     }
 233                 } else if (wmares > 0) {
 234                     ci->pcmbuf_insert(decoded, NULL, wmares);
 235                     elapsedtime += (wmares*10)/(wfx.rate/100);
 236                     ci->set_elapsed(elapsedtime);
 237                 }
 238                 ci->yield();
 239             }
 240         }
 241
 242         ci->advance_buffer(packetlength);
 243     }
 244     retval = CODEC_OK;
 245
 246 done:
 247     /*LOGF("WMA: Decoded %ld samples\n",elapsedtime*wfx.rate/1000);*/
 248
 249     if (ci->request_next_track())
 250         goto next_track;
 251 exit:
 252     return retval;
 253 }