speex_a.c

MIDI解码程序(用VC编写)

  ctx->header.nb_channels = ctx->channels;

  ctx->header.frames_per_packet = ctx->nframes = speex_options.nframes;

  ctx->state = speex_encoder_init(ctx->mode);

  /*Set the quality to 8 (15 kbps)*/
  speex_encoder_ctl(ctx->state, SPEEX_SET_QUALITY, &speex_options.quality);

  if(strcmp(fname, "-") == 0) {
    fd = 1; /* data to stdout */
    if(comment == NULL)
      comment = "(stdout)";
  } else {
    /* Open the audio file */
    fd = open(fname, FILE_OUTPUT_MODE);
    if(fd < 0) {
      ctl->cmsg(CMSG_ERROR, VERB_NORMAL, "%s: %s",
                fname, strerror(errno));
      return -1;
    }
    if(comment == NULL)
      comment = fname;
  }

  write_ogg_header(ctx, fd, (char *)comment);

  speex_encoder_ctl(ctx->state, SPEEX_GET_FRAME_SIZE, &ctx->frame_size);
  speex_encoder_ctl(ctx->state, SPEEX_SET_COMPLEXITY, &speex_options.complexity);
  speex_encoder_ctl(ctx->state, SPEEX_SET_SAMPLING_RATE, &dpm.rate);

  if (speex_options.vbr) {
    speex_encoder_ctl(ctx->state, SPEEX_SET_VBR, &speex_options.vbr);
  }
  else if (speex_options.vad) {
    speex_encoder_ctl(ctx->state, SPEEX_SET_VAD, &speex_options.vad);
  }
  if (speex_options.dtx)
    speex_encoder_ctl(ctx->state, SPEEX_SET_DTX, &speex_options.dtx);
  if (speex_options.dtx && !(speex_options.vbr ||
			     speex_options.abr ||
			     speex_options.vad)) {
    ctl->cmsg(CMSG_ERROR, VERB_NORMAL,
	      "--speex-dtx is useless without --speex-vad, --speex-vbr or --speex-abr");
  }
  else if ((speex_options.vbr || speex_options.abr) && (speex_options.vad)) {
    ctl->cmsg(CMSG_ERROR, VERB_NORMAL,
	      "--speex-vad is already implied by --speex-vbr or --speex-abr");
  }
  if (speex_options.abr) {
    speex_encoder_ctl(ctx->state, SPEEX_SET_ABR, &speex_options.abr);
  }

  speex_bits_init(&ctx->bits);

  ctx->input = (float *)safe_malloc(sizeof(float) * MAX_FRAME_SIZE * ctx->channels);
  ctx->input_idx = 0;

  return fd;
}

/*
  code from vorbis_a.c
 */
extern char *create_auto_output_name(const char *input_filename, char *ext_str, char *output_dir, int mode);

static int auto_speex_output_open(const char *input_filename, const char *title)
{
  char *output_filename;

#if !defined ( IA_W32GUI ) && !defined ( IA_W32G_SYN )
  output_filename = create_auto_output_name(input_filename, "ogg", NULL, 0);
#else
  output_filename = create_auto_output_name(input_filename, "ogg", w32g_output_dir, w32g_auto_output_mode);
#endif
  if (output_filename == NULL){
    ctl->cmsg(CMSG_ERROR, VERB_NORMAL, "unknown output file name");
    return -1;
  }
  if ((dpm.fd = speex_output_open(output_filename, input_filename)) == -1) {
    ctl->cmsg(CMSG_ERROR, VERB_NORMAL, "files open failed %s->%s",
	      output_filename, input_filename);
    free(output_filename);
    return -1;
  }
  if (dpm.name != NULL)
    free(dpm.name);
  dpm.name = output_filename;

  ctl->cmsg(CMSG_INFO, VERB_NORMAL, "Output: %s", dpm.name);
  {
    char *st_string="mono";
    if (speex_ctx->channels == 2)
      st_string = "stereo";
    ctl->cmsg(CMSG_INFO, VERB_NORMAL, "Encoding %d Hz audio using %s mode (%s)",
	      speex_ctx->header.rate, speex_ctx->mode->modeName, st_string);
   }

  return 0;
}

static int open_output(void)
{
  int include_enc, exclude_enc;

  include_enc = exclude_enc = 0;

  /* only 16 bit is supported */
  include_enc |= PE_16BIT|PE_SIGNED;
  exclude_enc |= PE_BYTESWAP|PE_24BIT;
  dpm.encoding = validate_encoding(dpm.encoding, include_enc, exclude_enc);

#if !defined (IA_W32GUI) && !defined (IA_W32G_SYN)
  if (dpm.name == NULL) {
    dpm.flag |= PF_AUTO_SPLIT_FILE;
    dpm.name = NULL;
  }
  else {
    dpm.flag &= ~PF_AUTO_SPLIT_FILE;
    if ((dpm.fd = speex_output_open(dpm.name, NULL)) == -1)
      return -1;
  }
#else
  if (w32g_auto_output_mode > 0){
    dpm.flag |= PF_AUTO_SPLIT_FILE;
    dpm.name = NULL;
  }
  else {
    dpm.flag &= ~PF_AUTO_SPLIT_FILE;
    if ((dpm.fd = speex_output_open(dpm.name, NULL)) == -1)
      return -1;
  }
#endif
  return 0;
}

static int output_data(char *buf, int32 nbytes)
{
  char cbits[MAX_FRAME_BYTES];
  Speex_ctx *ctx = speex_ctx;
  int nbBytes;
  int16 *s;
  int i, j;
  int ret;
  int nbytes_left;

  if (dpm.fd < 0)
    return 0;

  ctx->in_bytes += nbytes;

  /*
    Main encoding loop (one frame per iteration)
  */
  nbytes_left = nbytes;
  s = (int16 *)buf;
  while (1) {
    ctx->ogg_packetid++;
    /*
      packing 16 bit -> float sample
    */
    for (i = ctx->input_idx; i < ctx->frame_size * ctx->channels; i++) {
      /* stream is ended, and buffer is not full. wait next spooling */
      if (nbytes_left < 0) {
	/* canceling ogg packet */
	ctx->ogg_packetid--;
	return 0;
      }
      ctx->input[i] = *s++;
      nbytes_left -= 2; /* -16 bit*/
      ctx->input_idx++;
    }
    /*
      buffer is full. encode now.
    */
    ctx->input_idx = 0;

    if (ctx->channels == 2)
      speex_encode_stereo(ctx->input, ctx->frame_size, &ctx->bits);
    /* Encode the frame */
    speex_encode(ctx->state, ctx->input, &ctx->bits);

    if ((ctx->ogg_packetid + 1) % ctx->nframes != 0)
      continue;

    speex_bits_insert_terminator(&ctx->bits);
    /* Copy the bits to an array of char that can be written */
    nbBytes = speex_bits_write(&ctx->bits, cbits, MAX_FRAME_BYTES);
    
    /* Flush all the bits in the struct so we can encode a new frame */
    speex_bits_reset(&ctx->bits);

    /* ogg packet setup */
    ctx->op.packet = (unsigned char *)cbits;
    ctx->op.bytes = nbBytes;
    ctx->op.b_o_s = 0;
    ctx->op.e_o_s = 0;

    ctx->op.granulepos = (ctx->ogg_packetid + ctx->nframes) * ctx->frame_size;
    ctx->op.packetno = 2 + ctx->ogg_packetid / ctx->nframes;
    ogg_stream_packetin(&ctx->os, &ctx->op);

    /* Write all new pages (most likely 0 or 1) */
    while (ogg_stream_pageout(&ctx->os, &ctx->og)) {
      ret = oe_write_page(&ctx->og, dpm.fd);
      if (ret != ctx->og.header_len + ctx->og.body_len) {
	ctl->cmsg(CMSG_ERROR, VERB_NORMAL, "failed writing header to output stream");
	return -1;
      }
      else
	ctx->out_bytes += ret;
    }
  }
  
  return 0;
}

static void close_output(void)
{
  int i;
  char cbits[MAX_FRAME_BYTES];
  Speex_ctx *ctx = speex_ctx;
  int nbBytes;
  int ret;

  if (ctx == NULL)
    return;

  if (dpm.fd < 0)
    return;

  /*
    Write last frame
  */
  if (speex_ctx != NULL) {
    if ((ctx->ogg_packetid + 1) % ctx->nframes != 0) {
      while ((ctx->ogg_packetid + 1) % ctx->nframes != 0) {
	ctx->ogg_packetid++;
	speex_bits_pack(&ctx->bits, 15, 5);
      }
      nbBytes = speex_bits_write(&ctx->bits, cbits, MAX_FRAME_BYTES);
      ctx->op.packet = (unsigned char *)cbits;
      ctx->op.bytes = nbBytes;
      ctx->op.b_o_s = 0;
      ctx->op.e_o_s = 1;
      ctx->op.granulepos = (ctx->ogg_packetid + ctx->nframes) * ctx->frame_size;
      ctx->op.packetno = 2 + ctx->ogg_packetid / ctx->nframes;
      ogg_stream_packetin(&ctx->os, &ctx->op);
    }
    for (i = ctx->input_idx; i < ctx->frame_size * ctx->channels; i++) {
      /* left is zero-cleaned */
      ctx->input[i] = 0;
    }
    if (ctx->channels == 2)
      speex_encode_stereo(ctx->input, ctx->frame_size, &ctx->bits);
    /* Encode the frame */
    speex_encode(ctx->state, ctx->input, &ctx->bits);
    speex_bits_insert_terminator(&ctx->bits);
    /* Copy the bits to an array of char that can be written */
    nbBytes = speex_bits_write(&ctx->bits, cbits, MAX_FRAME_BYTES);
    
    /* Flush all the bits in the struct so we can encode a new frame */
    speex_bits_reset(&ctx->bits);

    /* ogg packet setup */
    ctx->op.packet = (unsigned char *)cbits;
    ctx->op.bytes = nbBytes;
    ctx->op.b_o_s = 0;
    ctx->op.e_o_s = 1;

    ctx->op.granulepos = (ctx->ogg_packetid + ctx->nframes) * ctx->frame_size;
    ctx->op.packetno = 2 + ctx->ogg_packetid / ctx->nframes;
    ogg_stream_packetin(&ctx->os, &ctx->op);

    /* Write all new pages (most likely 0 or 1) */
    while (ogg_stream_pageout(&ctx->os, &ctx->og)) {
      ret = oe_write_page(&ctx->og, dpm.fd);
      if (ret != ctx->og.header_len + ctx->og.body_len) {
	ctl->cmsg(CMSG_ERROR, VERB_NORMAL, "failed writing header to output stream");
	return;
      }
      else
	ctx->out_bytes += ret;
    }

    ogg_stream_clear(&speex_ctx->os);
    speex_bits_destroy(&speex_ctx->bits);
    speex_encoder_destroy(speex_ctx->state);
    close(dpm.fd);
    dpm.fd = -1;
    free(speex_ctx->input);

    ctl->cmsg(CMSG_INFO, VERB_NORMAL, "Wrote %lu/%lu bytes(%g%% compressed)",
	      ctx->out_bytes, ctx->in_bytes, ((double)ctx->out_bytes / (double)ctx->in_bytes)) * 100.;


    speex_ctx->input = NULL;
    free(speex_ctx);
    speex_ctx = NULL;
  }
  return;
}

static int acntl(int request, void *arg)
{
  switch(request) {
  case PM_REQ_PLAY_START:
    if(dpm.flag & PF_AUTO_SPLIT_FILE)
      return auto_speex_output_open(current_file_info->filename,current_file_info->seq_name);
      break;
  case PM_REQ_PLAY_END:
    if(dpm.flag & PF_AUTO_SPLIT_FILE) {
      close_output();
      return 0;
    }
    break;
  case PM_REQ_DISCARD:
    return 0;
  }
  return -1;
}