apps/codecs/wmapro.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2010 Mohamed Tarek
  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 "libwmapro/wmaprodec.h"
  25
  26 CODEC_HEADER
  27
  28 #define MAXSAMPLES  (1L << 12)  /* Max number of samples in a wma pro subframe */
  29 #define MAXCHANNELS 8
  30 #define BUFSIZE     MAXCHANNELS * MAXSAMPLES
  31 static int32_t decoded[BUFSIZE] IBSS_ATTR;
  32
  33 AVCodecContext avctx;
  34 AVPacket avpkt;
  35
  36 /* This function initialises AVCodecContext with the data needed for the wmapro
  37  * decoder to work. The required data is taken from asf_waveformatex_t because that's
  38  * what the rockbox asf metadata parser fill/work with. In the future, when the
  39  * codec is being optimised for on-target playback this function should not be needed,
  40  * as we will be working directly with WMAProDecodeCtx (declared in wmaprodec.c) */
  41 static void init_codec_ctx(AVCodecContext *avctx, asf_waveformatex_t *wfx)
  42 {
  43     /* Copy the extra-data */
  44     avctx->extradata_size = wfx->datalen;
  45     avctx->extradata = (uint8_t *)malloc(wfx->datalen*sizeof(uint8_t));
  46     memcpy(avctx->extradata, wfx->data, wfx->datalen*sizeof(uint8_t));
  47
  48     avctx->block_align = wfx->blockalign;
  49     avctx->sample_rate = wfx->rate;
  50     avctx->channels    = wfx->channels;
  51
  52 }
  53
  54 /* this is the codec entry point */
  55 enum codec_status codec_main(void)
  56 {
  57     uint32_t elapsedtime;
  58     int retval;
  59     asf_waveformatex_t wfx;     /* Holds the stream properties */
  60     size_t resume_offset;
  61     int res;                    /* Return values from asf_read_packet() and decode_packet() */
  62     uint8_t* audiobuf;          /* Pointer to the payload of one wma pro packet */
  63     int audiobufsize;           /* Payload size */
  64     int packetlength = 0;       /* Logical packet size (minus the header size) */
  65     int outlen = 0;             /* Number of bytes written to the output buffer */
  66     int pktcnt = 0;             /* Count of the packets played */
  67
  68     /* Generic codec initialisation */
  69     ci->configure(DSP_SET_SAMPLE_DEPTH, 32);
  70
  71
  72 next_track:
  73
  74     /* Wait for the metadata to be read */
  75     while (!*ci->taginfo_ready && !ci->stop_codec)
  76         ci->sleep(1);
  77
  78     retval = CODEC_OK;
  79
  80     /* Remember the resume position */
  81     resume_offset = ci->id3->offset;
  82  restart_track:
  83     if (codec_init()) {
  84         LOGF("(WMA PRO) Error: Error initialising codec\n");
  85         retval = CODEC_ERROR;
  86         goto done;
  87     }
  88
  89     /* Copy the format metadata we've stored in the id3 TOC field.  This
  90        saves us from parsing it again here. */
  91     memcpy(&wfx, ci->id3->toc, sizeof(wfx));
  92
  93     ci->configure(DSP_SWITCH_FREQUENCY, wfx.rate);
  94     ci->configure(DSP_SET_STEREO_MODE, wfx.channels == 1 ?
  95                   STEREO_MONO : STEREO_INTERLEAVED);
  96     codec_set_replaygain(ci->id3);
  97
  98     /* Initialise the AVCodecContext */
  99     init_codec_ctx(&avctx, &wfx);
 100
 101     if (decode_init(&avctx) < 0) {
 102         LOGF("(WMA PRO) Error: Unsupported or corrupt file\n");
 103         retval = CODEC_ERROR;
 104         goto done;
 105     }
 106
 107     /* Now advance the file position to the first frame */
 108     ci->seek_buffer(ci->id3->first_frame_offset);
 109
 110     elapsedtime = 0;
 111     resume_offset = 0;
 112
 113     /* The main decoding loop */
 114
 115     while (pktcnt < wfx.numpackets)
 116     {
 117         ci->yield();
 118         if (ci->stop_codec || ci->new_track) {
 119             goto done;
 120         }
 121
 122         /* Deal with any pending seek requests */
 123         if (ci->seek_time){
 124
 125             if (ci->seek_time == 1) {
 126                 ci->seek_complete();
 127                 goto restart_track; /* Pretend you never saw this... */
 128             }
 129
 130             elapsedtime = asf_seek(ci->seek_time, &wfx);
 131             if (elapsedtime < 1){
 132                 ci->seek_complete();
 133                 goto next_track;
 134             }
 135
 136             ci->set_elapsed(elapsedtime);
 137             ci->seek_complete();
 138         }
 139
 140         res = asf_read_packet(&audiobuf, &audiobufsize, &packetlength, &wfx);
 141
 142         if (res < 0) {
 143            LOGF("(WMA PRO) Warning: asf_read_packet returned %d", res);
 144            goto done;
 145         } else {
 146             avpkt.data = audiobuf;
 147             avpkt.size = audiobufsize;
 148             pktcnt++;
 149
 150             /* We now loop on the packet, decoding and outputting the subframes
 151              * one-by-one. For more information about how wma pro structures its
 152              * audio frames, see libwmapro/wmaprodec.c */
 153             while(avpkt.size > 0)
 154             {
 155                 outlen = BUFSIZE;   /* decode_packet needs to know the size of the output buffer */
 156                 res = decode_packet(&avctx, decoded, &outlen, &avpkt);
 157                 avpkt.data += res;
 158                 avpkt.size -= res;
 159                 avctx.frame_number++;
 160                 if(outlen) {
 161                     ci->yield ();
 162                     /* outlen now holds the size of the data in bytes - we want the
 163                      * number of samples. */
 164                     outlen /= (sizeof(int32_t) * wfx.channels);
 165                     ci->pcmbuf_insert(decoded, NULL, outlen);
 166                     elapsedtime += outlen*10/(wfx.rate/100);
 167                     ci->set_elapsed(elapsedtime);
 168                     ci->yield ();
 169                 }
 170             }
 171
 172         }
 173
 174         /* Advance to the next logical packet */
 175         ci->advance_buffer(packetlength);
 176     }
 177     retval = CODEC_OK;
 178
 179 done:
 180     if (ci->request_next_track())
 181         goto next_track;
 182
 183     return retval;
 184 }
 185