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  * 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 "libasf/asf.h"
  24 #include "libwma/wmadec.h"
  25
  26 CODEC_HEADER
  27
  28 /* The output buffer containing the decoded samples (channels 0 and 1)
  29    BLOCK_MAX_SIZE is 2048 (samples) and MAX_CHANNELS is 2.
  30  */
  31
  32 static uint32_t decoded[BLOCK_MAX_SIZE * MAX_CHANNELS] IBSS_ATTR;
  33
  34 /* NOTE: WMADecodeContext is 120152 bytes (on x86) */
  35 static WMADecodeContext wmadec;
  36
  37 /*entry point for seeks*/
  38 static int seek(int ms, asf_waveformatex_t* wfx)
  39 {
  40     int time, duration, delta, temp, count=0;
  41
  42     /*estimate packet number from bitrate*/
  43     int initial_packet = ci->curpos/wfx->packet_size;
  44     int packet_num = (((int64_t)ms)*(wfx->bitrate>>3))/wfx->packet_size/1000;
  45     int last_packet = ci->id3->filesize / wfx->packet_size;
  46
  47     if (packet_num > last_packet) {
  48         packet_num = last_packet;
  49     }
  50
  51     /*calculate byte address of the start of that packet*/
  52     int packet_offset = packet_num*wfx->packet_size;
  53
  54     /*seek to estimated packet*/
  55     ci->seek_buffer(ci->id3->first_frame_offset+packet_offset);
  56     temp = ms;
  57     while (1)
  58     {
  59         /*for very large files it can be difficult and unimportant to find the exact packet*/
  60         count++;
  61
  62         /*check the time stamp of our packet*/
  63         time = asf_get_timestamp(&duration);
  64         DEBUGF("seeked to %d ms with duration %d\n", time, duration);
  65
  66         if (time < 0) {
  67             /*unknown error, try to recover*/
  68             DEBUGF("UKNOWN SEEK ERROR\n");
  69             ci->seek_buffer(ci->id3->first_frame_offset+initial_packet*wfx->packet_size);
  70             /*seek failed so return time stamp of the initial packet*/
  71             return asf_get_timestamp(&duration);
  72         }
  73
  74         if ((time+duration>=ms && time<=ms) || count > 10) {
  75             DEBUGF("Found our packet! Now at %d packet\n", packet_num);
  76             return time;
  77         } else {
  78             /*seek again*/
  79             delta = ms-time;
  80             /*estimate new packet number from bitrate and our current position*/
  81             temp += delta;
  82             packet_num = ((temp/1000)*(wfx->bitrate>>3) - (wfx->packet_size>>1))/wfx->packet_size;  //round down!
  83             packet_offset = packet_num*wfx->packet_size;
  84             ci->seek_buffer(ci->id3->first_frame_offset+packet_offset);
  85         }
  86     }
  87 }
  88
  89
  90
  91 /* this is the codec entry point */
  92 enum codec_status codec_main(void)
  93 {
  94     uint32_t elapsedtime;
  95     int retval;
  96     asf_waveformatex_t wfx;
  97     size_t resume_offset;
  98     int i;
  99     int wmares, res;
 100     uint8_t* audiobuf;
 101     int audiobufsize;
 102     int packetlength = 0;
 103     int errcount = 0;
 104
 105     /* Generic codec initialisation */
 106     ci->configure(DSP_SET_SAMPLE_DEPTH, 29);
 107
 108 next_track:
 109
 110     /* Wait for the metadata to be read */
 111     while (!*ci->taginfo_ready && !ci->stop_codec)
 112         ci->sleep(1);
 113
 114     retval = CODEC_OK;
 115
 116     /* Remember the resume position - when the codec is opened, the
 117        playback engine will reset it. */
 118     resume_offset = ci->id3->offset;
 119 restart_track:
 120     if (codec_init()) {
 121         LOGF("WMA: Error initialising codec\n");
 122         retval = CODEC_ERROR;
 123         goto exit;
 124     }
 125
 126     /* Copy the format metadata we've stored in the id3 TOC field.  This
 127        saves us from parsing it again here. */
 128     memcpy(&wfx, ci->id3->toc, sizeof(wfx));
 129
 130     if (wma_decode_init(&wmadec,&wfx) < 0) {
 131         LOGF("WMA: Unsupported or corrupt file\n");
 132         retval = CODEC_ERROR;
 133         goto exit;
 134     }
 135
 136     DEBUGF("**************** IN WMA.C ******************\n");
 137
 138     if (resume_offset > ci->id3->first_frame_offset)
 139     {
 140         /* Get start of current packet */
 141         int packet_offset = (resume_offset - ci->id3->first_frame_offset)
 142             % wfx.packet_size;
 143         ci->seek_buffer(resume_offset - packet_offset);
 144         elapsedtime = asf_get_timestamp(&i);
 145         ci->set_elapsed(elapsedtime);
 146     }
 147     else
 148     {
 149         /* Now advance the file position to the first frame */
 150         ci->seek_buffer(ci->id3->first_frame_offset);
 151         elapsedtime = 0;
 152     }
 153
 154     resume_offset = 0;
 155     ci->configure(DSP_SWITCH_FREQUENCY, wfx.rate);
 156     ci->configure(DSP_SET_STEREO_MODE, wfx.channels == 1 ?
 157                   STEREO_MONO : STEREO_INTERLEAVED);
 158     codec_set_replaygain(ci->id3);
 159
 160     /* The main decoding loop */
 161
 162     res = 1;
 163     while (res >= 0)
 164     {
 165         ci->yield();
 166         if (ci->stop_codec || ci->new_track) {
 167             goto done;
 168         }
 169
 170         /* Deal with any pending seek requests */
 171         if (ci->seek_time){
 172
 173             if (ci->seek_time == 1) {
 174                 ci->seek_complete();
 175                 goto restart_track; /* Pretend you never saw this... */
 176             }
 177
 178             elapsedtime = seek(ci->seek_time, &wfx);
 179             if (elapsedtime < 1){
 180                 ci->seek_complete();
 181                 goto next_track;
 182             }
 183             /*DEBUGF("Seek returned %d\n", (int)elapsedtime);*/
 184             ci->set_elapsed(elapsedtime);
 185
 186             /*flush the wma decoder state*/
 187             wmadec.last_superframe_len = 0;
 188             wmadec.last_bitoffset = 0;
 189             ci->seek_complete();
 190         }
 191         errcount = 0;
 192 new_packet:
 193         res = asf_read_packet(&audiobuf, &audiobufsize, &packetlength, &wfx);
 194
 195         if (res < 0) {
 196             /* We'll try to recover from a parse error a certain number of
 197              * times. If we succeed, the error counter will be reset.
 198              */
 199
 200             errcount++;
 201             DEBUGF("read_packet error %d, errcount %d\n",wmares, errcount);
 202             if (errcount > 5) {
 203                 goto done;
 204             } else {
 205                 ci->advance_buffer(packetlength);
 206                 goto new_packet;
 207             }
 208         } else if (res > 0) {
 209             wma_decode_superframe_init(&wmadec, audiobuf, audiobufsize);
 210
 211             for (i=0; i < wmadec.nb_frames; i++)
 212             {
 213                 wmares = wma_decode_superframe_frame(&wmadec,
 214                                                      decoded,
 215                                                      audiobuf, audiobufsize);
 216
 217                 ci->yield ();
 218
 219                 if (wmares < 0) {
 220                     /* Do the above, but for errors in decode. */
 221                     errcount++;
 222                     DEBUGF("WMA decode error %d, errcount %d\n",wmares, errcount);
 223                     if (errcount > 5) {
 224                         goto done;
 225                     } else {
 226                         ci->advance_buffer(packetlength);
 227                         goto new_packet;
 228                     }
 229                 } else if (wmares > 0) {
 230                     ci->pcmbuf_insert(decoded, NULL, wmares);
 231                     elapsedtime += (wmares*10)/(wfx.rate/100);
 232                     ci->set_elapsed(elapsedtime);
 233                 }
 234                 ci->yield();
 235             }
 236         }
 237
 238         ci->advance_buffer(packetlength);
 239     }
 240     retval = CODEC_OK;
 241
 242 done:
 243     /*LOGF("WMA: Decoded %ld samples\n",elapsedtime*wfx.rate/1000);*/
 244
 245     if (ci->request_next_track())
 246         goto next_track;
 247 exit:
 248     return retval;
 249 }