lame.c

MP3编码程序和资料

	n_out=Min(gfp->framesize,nsamples);
	n_in = n_out;
	memcpy( (char *) &mfbuf[ch][gfc->mf_size],(char *)in_buffer[ch],sizeof(short int)*n_out);
      }
      in_buffer[ch] += n_in;
    }

    nsamples -= n_in;
    gfc->mf_size += n_out;
    assert(gfc->mf_size<=MFSIZE);
    gfc->mf_samples_to_encode += n_out;


    if (gfc->mf_size >= mf_needed) {
      /* encode the frame.  */
      ret = lame_encode_frame(gfp,mfbuf[0],mfbuf[1],mp3buf,mp3buf_size);

      if (ret < 0) return ret;
      mp3buf += ret;
      mp3size += ret;

      /* shift out old samples */
      gfc->mf_size -= gfp->framesize;
      gfc->mf_samples_to_encode -= gfp->framesize;
      for (ch=0; ch<gfc->stereo; ch++)
	for (i=0; i<gfc->mf_size; i++)
	  mfbuf[ch][i]=mfbuf[ch][i+gfp->framesize];
    }
  }
  assert(nsamples==0);

  return mp3size;
}




int lame_encode_buffer_interleaved(lame_global_flags *gfp,
   short int buffer[], int nsamples, char *mp3buf, int mp3buf_size)
{
  int mp3size=0,ret=0,i,ch,mf_needed;
  lame_internal_flags *gfc=gfp->internal_flags;
  short int *mfbuf[2];

  if (!gfc->lame_init_params_init) return -3;

  mfbuf[0]=gfc->mfbuf[0];
  mfbuf[1]=gfc->mfbuf[1];

  /* some sanity checks */
  assert(ENCDELAY>=MDCTDELAY);
  assert(BLKSIZE-FFTOFFSET >= 0);
  mf_needed = BLKSIZE+gfp->framesize-FFTOFFSET;
  assert(MFSIZE>=mf_needed);

  if (gfp->num_channels == 1) {
    return lame_encode_buffer(gfp,buffer, NULL ,nsamples,mp3buf,mp3buf_size);
  }

  if (gfc->resample_ratio!=1)  {
    short int *buffer_l;
    short int *buffer_r;
    buffer_l=malloc(sizeof(short int)*nsamples);
    buffer_r=malloc(sizeof(short int)*nsamples);
    if (buffer_l == NULL || buffer_r == NULL) {
      return -2;
    }
    for (i=0; i<nsamples; i++) {
      buffer_l[i]=buffer[2*i];
      buffer_r[i]=buffer[2*i+1];
    }
    ret = lame_encode_buffer(gfp,buffer_l,buffer_r,nsamples,mp3buf,mp3buf_size);
    free(buffer_l);
    free(buffer_r);
    return ret;
  }


  if (gfp->num_channels==2  && gfc->stereo==1) {
    /* downsample to mono */
    for (i=0; i<nsamples; ++i) {
      buffer[2*i]=((int)buffer[2*i]+(int)buffer[2*i+1])/2;
      buffer[2*i+1]=0;
    }
  }


  while (nsamples > 0) {
    int n_out;
    /* copy in new samples */
    n_out = Min(gfp->framesize,nsamples);
    for (i=0; i<n_out; ++i) {
      mfbuf[0][gfc->mf_size+i]=buffer[2*i];
      mfbuf[1][gfc->mf_size+i]=buffer[2*i+1];
    }
    buffer += 2*n_out;

    nsamples -= n_out;
    gfc->mf_size += n_out;
    assert(gfc->mf_size<=MFSIZE);
    gfc->mf_samples_to_encode += n_out;

    if (gfc->mf_size >= mf_needed) {
      /* encode the frame */
      ret = lame_encode_frame(gfp,mfbuf[0],mfbuf[1],mp3buf,mp3buf_size);
      if (ret < 0) {
	/* fatel error: mp3buffer was too small */
	return ret;
      }
      mp3buf += ret;
      mp3size += ret;

      /* shift out old samples */
      gfc->mf_size -= gfp->framesize;
      gfc->mf_samples_to_encode -= gfp->framesize;
      for (ch=0; ch<gfc->stereo; ch++)
	for (i=0; i<gfc->mf_size; i++)
	  mfbuf[ch][i]=mfbuf[ch][i+gfp->framesize];
    }
  }
  assert(nsamples==0);
  return mp3size;
}




/* old LAME interface.  use lame_encode_buffer instead */
int lame_encode(lame_global_flags *gfp, short int in_buffer[2][1152],char *mp3buf,int size){
  int imp3;
  lame_internal_flags *gfc=gfp->internal_flags;
  if (!gfc->lame_init_params_init) return -3;
  imp3= lame_encode_buffer(gfp,in_buffer[0],in_buffer[1],gfp->framesize,mp3buf,size);
  return imp3;
}


/*****************************************************************/
/* flush internal mp3 buffers,                                   */
/*****************************************************************/
int lame_encode_finish(lame_global_flags *gfp,char *mp3buffer, int mp3buffer_size)
{
  int imp3=0,mp3count,mp3buffer_size_remaining;
  short int buffer[2][1152];
  lame_internal_flags *gfc=gfp->internal_flags;

  memset((char *)buffer,0,sizeof(buffer));
  mp3count = 0;

  while (gfc->mf_samples_to_encode > 0) {

    mp3buffer_size_remaining = mp3buffer_size - mp3count;

    /* if user specifed buffer size = 0, dont check size */
    if (mp3buffer_size == 0) mp3buffer_size_remaining=0;  

    /* send in a frame of 0 padding until all internal sample buffers flushed */
    imp3=lame_encode_buffer(gfp,buffer[0],buffer[1],gfp->framesize,mp3buffer,mp3buffer_size_remaining);
    /* dont count the above padding: */
    gfc->mf_samples_to_encode -= gfp->framesize;

    if (imp3 < 0) {
      /* some type of fatel error */
      freegfc(gfc);    
      return imp3;
    }
    mp3buffer += imp3;
    mp3count += imp3;
  }


  gfp->frameNum--;
  if (!gfp->gtkflag && !gfp->silent) {
      timestatus(gfp->out_samplerate,gfp->frameNum,gfp->totalframes,gfp->framesize);

      if (gfp->brhist_disp)
	{
	  brhist_disp(gfp->totalframes);
	  brhist_disp_total(gfp);
	}

      timestatus_finish();
  }

  mp3buffer_size_remaining = mp3buffer_size - mp3count;
  /* if user specifed buffer size = 0, dont check size */
  if (mp3buffer_size == 0) mp3buffer_size_remaining=0;  

  if (gfp->ogg) {
#ifdef HAVEVORBIS    
    /* ogg related stuff */
    imp3 = lame_encode_ogg_finish(gfp,mp3buffer,mp3buffer_size_remaining);
#endif
  }else{
    /* mp3 related stuff.  bit buffer might still contain some data */
    flush_bitstream(gfp);
    imp3= copy_buffer(mp3buffer,mp3buffer_size_remaining,&gfc->bs);
  }
  if (imp3 < 0) {
    freegfc(gfc);    
    return imp3;
  }
  mp3count += imp3;

  freegfc(gfc);    
  return mp3count;
}


/*****************************************************************/
/* write VBR Xing header, and ID3 tag, if asked for               */
/*****************************************************************/
void lame_mp3_tags(lame_global_flags *gfp)
{
  if (gfp->bWriteVbrTag)
    {
      /* Calculate relative quality of VBR stream
       * 0=best, 100=worst */
      int nQuality=gfp->VBR_q*100/9;
      /* Write Xing header again */
      PutVbrTag(gfp,gfp->outPath,nQuality);
    }


  /* write an ID3 tag  */
  if(gfp->id3tag_used) {
    id3_buildtag(&gfp->id3tag);
    id3_writetag(gfp->outPath, &gfp->id3tag);
  }
}


void lame_version(lame_global_flags *gfp,char *ostring) {
  strncpy(ostring,get_lame_version(),20);
}







/* initialize mp3 encoder */
int lame_init(lame_global_flags *gfp)
{
  lame_internal_flags *gfc;

  /*
   *  Disable floating point exepctions
   */
#ifdef __FreeBSD__
# include <floatingpoint.h>
  {
  /* seet floating point mask to the Linux default */
  fp_except_t mask;
  mask=fpgetmask();
  /* if bit is set, we get SIGFPE on that error! */
  fpsetmask(mask & ~(FP_X_INV|FP_X_DZ));
  /*  DEBUGF("FreeBSD mask is 0x%x\n",mask); */
  }
#endif
#if defined(__riscos__) && !defined(ABORTFP)
  /* Disable FPE's under RISC OS */
  /* if bit is set, we disable trapping that error! */
  /*   _FPE_IVO : invalid operation */
  /*   _FPE_DVZ : divide by zero */
  /*   _FPE_OFL : overflow */
  /*   _FPE_UFL : underflow */
  /*   _FPE_INX : inexact */
  DisableFPETraps( _FPE_IVO | _FPE_DVZ | _FPE_OFL );
#endif


  /*
   *  Debugging stuff
   *  The default is to ignore FPE's, unless compiled with -DABORTFP
   *  so add code below to ENABLE FPE's.
   */

#if defined(ABORTFP) 
#if defined(_MSC_VER)
  {
	#include <float.h>
	unsigned int mask;
	mask=_controlfp( 0, 0 );
	mask&=~(_EM_OVERFLOW|_EM_UNDERFLOW|_EM_ZERODIVIDE|_EM_INVALID);
	mask=_controlfp( mask, _MCW_EM );
	}
#elif defined(__CYGWIN__)
#  define _FPU_GETCW(cw) __asm__ ("fnstcw %0" : "=m" (*&cw))
#  define _FPU_SETCW(cw) __asm__ ("fldcw %0" : : "m" (*&cw))

#  define _EM_INEXACT     0x00000001 /* inexact (precision) */
#  define _EM_UNDERFLOW   0x00000002 /* underflow */
#  define _EM_OVERFLOW    0x00000004 /* overflow */
#  define _EM_ZERODIVIDE  0x00000008 /* zero divide */
#  define _EM_INVALID     0x00000010 /* invalid */
  {
    unsigned int mask;
    _FPU_GETCW(mask);
    /* Set the FPU control word to abort on most FPEs */
    mask &= ~(_EM_UNDERFLOW | _EM_OVERFLOW | _EM_ZERODIVIDE | _EM_INVALID);
    _FPU_SETCW(mask);
  }
# elif (defined(__linux__) || defined(__FreeBSD__))
  {
#  include <fpu_control.h>
#  ifndef _FPU_GETCW
#  define _FPU_GETCW(cw) __asm__ ("fnstcw %0" : "=m" (*&cw))
#  endif
#  ifndef _FPU_SETCW
#  define _FPU_SETCW(cw) __asm__ ("fldcw %0" : : "m" (*&cw))
#  endif
    unsigned int mask;
    _FPU_GETCW(mask);
    /* Set the Linux mask to abort on most FPE's */
    /* if bit is set, we _mask_ SIGFPE on that error! */
    /*  mask &= ~( _FPU_MASK_IM | _FPU_MASK_ZM | _FPU_MASK_OM | _FPU_MASK_UM );*/
    mask &= ~( _FPU_MASK_IM | _FPU_MASK_ZM | _FPU_MASK_OM );
    _FPU_SETCW(mask);
  }
#endif
#endif /* ABORTFP */



  memset(gfp,0,sizeof(lame_global_flags));
  if (NULL==(gfp->internal_flags = malloc(sizeof(lame_internal_flags))))
    return -1;
  gfc=(lame_internal_flags *) gfp->internal_flags;
  memset(gfc,0,sizeof(lame_internal_flags));

  /* Global flags.  set defaults here */
  gfp->mode = MPG_MD_JOINT_STEREO;
  gfp->mode_fixed=0;
  gfp->force_ms=0;
  gfp->brate=0;
  gfp->copyright=0;
  gfp->original=1;
  gfp->extension=0;
  gfp->error_protection=0;
  gfp->emphasis=0;
  gfp->in_samplerate=1000*44.1;
  gfp->out_samplerate=0;
  gfp->num_channels=2;
  gfp->num_samples=MAX_U_32_NUM;

  gfp->allow_diff_short=0;
  gfp->ATHonly=0;
  gfp->noATH=0;
  gfp->bWriteVbrTag=1;
  gfp->cwlimit=0;
  gfp->disable_reservoir=0;
  gfp->experimentalX = 0;
  gfp->experimentalY = 0;
  gfp->experimentalZ = 0;
  gfp->gtkflag=0;
  gfp->quality=5;
  gfp->input_format=sf_unknown;

  gfp->lowpassfreq=0;
  gfp->highpassfreq=0;
  gfp->lowpasswidth=-1;
  gfp->highpasswidth=-1;

  gfp->no_short_blocks=0;
  gfp->padding_type=2;
  gfp->swapbytes=0;
  gfp->silent=1;
  gfp->VBR=vbr_off;
  gfp->VBR_q=4;
  gfp->VBR_mean_bitrate_kbps=128;
  gfp->VBR_min_bitrate_kbps=0;
  gfp->VBR_max_bitrate_kbps=0;
  gfp->VBR_hard_min=0;

  gfc->pcmbitwidth = 16;
  gfc->resample_ratio=1;
  gfc->lowpass_band=32;
  gfc->highpass_band=-1;
  gfc->VBR_min_bitrate=1;
  gfc->VBR_max_bitrate=13;

  gfc->OldValue[0]=180;
  gfc->OldValue[1]=180;
  gfc->CurrentStep=4;
  gfc->masking_lower=1;



  return 0;
}