sr1.c

来自「君正早期ucos系统(只有早期的才不没有打包成库),MPLAYER,文件系统,图」· C语言 代码 · 共 619 行 · 第 1/2 页

  return 1;
}


/*****************************************************************
 * read next frame     return number of frames read.
 */
LOCAL int read_frame(struct frame *fr){
  uint32_t newhead;
  union {
    unsigned char buf[8];
    unsigned long dummy; // for alignment
  } hbuf;
  int skipped,resyncpos;
  int frames=0;

resync:
  skipped=MP3_fpos;
  resyncpos=MP3_fpos;

  set_pointer(512);
  fsizeold=fr->framesize;       /* for Layer3 */
  if(!stream_head_read(hbuf.buf,&newhead)) return 0;
  if(!decode_header(fr,newhead)){
    // invalid header! try to resync stream!
#ifdef DEBUG_RESYNC
    printf("ReSync: searching for a valid header...  (pos=%X)\n",MP3_fpos);
#endif
retry1:
    while(!decode_header(fr,newhead)){
      if(!stream_head_shift(hbuf.buf,&newhead)) return 0;
    }
    resyncpos=MP3_fpos-4;
    // found valid header
#ifdef DEBUG_RESYNC
    printf("ReSync: found valid hdr at %X  fsize=%ld  ",resyncpos,fr->framesize);
#endif
    if(!stream_read_frame_body(fr->framesize)) return 0; // read body
    set_pointer(512);
    fsizeold=fr->framesize;       /* for Layer3 */
    if(!stream_head_read(hbuf.buf,&newhead)) return 0;
    if(!decode_header(fr,newhead)){
      // invalid hdr! go back...
#ifdef DEBUG_RESYNC
      printf("INVALID\n");
#endif
//      mp3_seek(resyncpos+1);
      if(!stream_head_read(hbuf.buf,&newhead)) return 0;
      goto retry1;
    }
#ifdef DEBUG_RESYNC
    printf("OK!\n");
    ++frames;
#endif
  }

  skipped=resyncpos-skipped;
//  if(skipped && !MP3_resync) printf("\r%d bad bytes skipped  (resync at 0x%X)                          \n",skipped,resyncpos);

//  printf("%8X [%08X] %d %d (%d)%s%s\n",MP3_fpos-4,newhead,fr->framesize,fr->mode,fr->mode_ext,fr->error_protection?" CRC":"",fr->padding?" PAD":"");

  /* read main data into memory */
  if(!stream_read_frame_body(fr->framesize)){
    printf("\nBroken frame at 0x%X                                                  \n",resyncpos);
    return 0;
  }
  ++frames;

  if(MP3_resync){
    MP3_resync=0;
    if(frames==1) goto resync;
  }

  return frames;
}

static int _has_mmx = 0;  // used by layer2.c, layer3.c to pre-scale coeffs

#include "layer2.c"
#include "layer3.c"
#include "layer1.c"

/******************************************************************************/
/*           PUBLIC FUNCTIONS                  */
/******************************************************************************/

/* It's hidden from gcc in assembler */
extern void dct64_MMX(short *, short *, real *);
extern void dct64_MMX_3dnow(short *, short *, real *);
extern void dct64_MMX_3dnowex(short *, short *, real *);
extern void dct64_sse(short *, short *, real *);
void (*dct64_MMX_func)(short *, short *, real *);

#include "cpudetect.h"

// Init decoder tables.  Call first, once!
#ifdef USE_FAKE_MONO
void MP3_Init(int fakemono){
#else
void MP3_Init(){
#endif

//gCpuCaps.hasMMX=gCpuCaps.hasMMX2=gCpuCaps.hasSSE=0; // for testing!

    _has_mmx = 0;
    dct36_func = dct36;

    make_decode_tables(outscale);

#ifdef HAVE_MMX
    if (gCpuCaps.hasMMX)
    {
	_has_mmx = 1;
	synth_func = synth_1to1_MMX;
    }
#endif

#ifdef HAVE_3DNOWEX
    if (gCpuCaps.has3DNowExt)
    {
	dct36_func=dct36_3dnowex;
	dct64_MMX_func= dct64_MMX_3dnowex;
	mp_msg(MSGT_DECAUDIO,MSGL_V,"mp3lib: using 3DNow!Ex optimized decore!\n");
    }
    else
#endif
#ifdef HAVE_3DNOW
    if (gCpuCaps.has3DNow)
    {
	dct36_func = dct36_3dnow;
	dct64_MMX_func = dct64_MMX_3dnow;
	mp_msg(MSGT_DECAUDIO,MSGL_V,"mp3lib: using 3DNow! optimized decore!\n");
    }
    else
#endif
#ifdef HAVE_SSE
    if (gCpuCaps.hasSSE)
    {
	dct64_MMX_func = dct64_sse;
	mp_msg(MSGT_DECAUDIO,MSGL_V,"mp3lib: using SSE optimized decore!\n");
    }
    else
#endif
#ifdef ARCH_X86_32
#ifdef HAVE_MMX
    if (gCpuCaps.hasMMX)
    {
	dct64_MMX_func = dct64_MMX;
	mp_msg(MSGT_DECAUDIO,MSGL_V,"mp3lib: using MMX optimized decore!\n");
    }
    else
#endif
    if (gCpuCaps.cpuType >= CPUTYPE_I586)
    {
	synth_func = synth_1to1_pent;
	mp_msg(MSGT_DECAUDIO,MSGL_V,"mp3lib: using Pentium optimized decore!\n");
    }
    else
#endif /* ARCH_X86_32 */
#ifdef HAVE_ALTIVEC
    if (gCpuCaps.hasAltiVec)
    {
	mp_msg(MSGT_DECAUDIO,MSGL_V,"mp3lib: using AltiVec optimized decore!\n");
    }
    else
#endif
    {
	synth_func = NULL; /* use default c version */
	mp_msg(MSGT_DECAUDIO,MSGL_V,"mp3lib: using generic C decore!\n");
    }

#ifdef USE_FAKE_MONO
    if (fakemono == 1)
        fr.synth=synth_1to1_l;
    else if (fakemono == 2)
        fr.synth=synth_1to1_r;
    else
        fr.synth=synth_1to1;
#else
    fr.synth=synth_1to1;
#endif
    fr.synth_mono=synth_1to1_mono2stereo;
    fr.down_sample=0;
    fr.down_sample_sblimit = SBLIMIT>>(fr.down_sample);

    init_layer2();
    init_layer3(fr.down_sample_sblimit);
    mp_msg(MSGT_DECAUDIO,MSGL_V,"MP3lib: init layer2&3 finished, tables done\n");
}

#if 0

void MP3_Close(){
  MP3_eof=1;
  if(mp3_file) fclose(mp3_file);
  mp3_file=NULL;
}

// Open a file, init buffers. Call once per file!
int MP3_Open(char *filename,int buffsize){
  MP3_eof=1;   // lock decoding
  MP3_pause=1; // lock playing
  if(mp3_file) MP3_Close(); // close prev. file
  MP3_frames=0;

  mp3_file=fopen(filename,"rb");
//  printf("MP3_Open: file='%s'",filename);
//  if(!mp3_file){ printf(" not found!\n"); return 0;} else printf("Ok!\n");
  if(!mp3_file) return 0;

  MP3_filesize=MP3_PrintTAG();
  fseek(mp3_file,0,SEEK_SET);

  MP3_InitBuffers(buffsize);
  if(!tables_done_flag) MP3_Init();
  MP3_eof=0;  // allow decoding
  MP3_pause=0; // allow playing
  return MP3_filesize;
}

#endif

// Read & decode a single frame. Called by sound driver.
int MP3_DecodeFrame(unsigned char *hova,short single){
   pcm_sample = hova;
   pcm_point = 0;
   if(!read_frame(&fr))return(0);
   if(single==-2){ set_pointer(512); return(1); }
   if(fr.error_protection) getbits(16); /* skip crc */
   fr.single=single;
   switch(fr.lay){
     case 2: do_layer2(&fr,single);break;
     case 3: do_layer3(&fr,single);break;
     case 1: do_layer1(&fr,single);break;
     default:
         return 0;	// unsupported
   }
//   ++MP3_frames;
   return(pcm_point?pcm_point:2);
}

// Prints last frame header in ascii.
void MP3_PrintHeader(void){
        static char *modes[4] = { "Stereo", "Joint-Stereo", "Dual-Channel", "Single-Channel" };
        static char *layers[4] = { "???" , "I", "II", "III" };

        mp_msg(MSGT_DECAUDIO,MSGL_V,"\rMPEG %s, Layer %s, %d Hz %d kbit %s, BPF: %d\n",
                fr.mpeg25 ? "2.5" : (fr.lsf ? "2.0" : "1.0"),
                layers[fr.lay],freqs[fr.sampling_frequency],
    tabsel_123[fr.lsf][fr.lay-1][fr.bitrate_index],
                modes[fr.mode],fr.framesize+4);
        mp_msg(MSGT_DECAUDIO,MSGL_V,"Channels: %d, copyright: %s, original: %s, CRC: %s, emphasis: %d\n",
                fr.stereo,fr.copyright?"Yes":"No",
                fr.original?"Yes":"No",fr.error_protection?"Yes":"No",
                fr.emphasis);
}

#if 0
#include "genre.h"

// Read & print ID3 TAG. Do not call when playing!!!  returns filesize.
int MP3_PrintTAG(){
        struct id3tag {
                char tag[3];
                char title[30];
                char artist[30];
                char album[30];
                char year[4];
                char comment[30];
                unsigned char genre;
        };
        struct id3tag tag;
        char title[31]={0,};
        char artist[31]={0,};
        char album[31]={0,};
        char year[5]={0,};
        char comment[31]={0,};
        char genre[31]={0,};
  int fsize;
  int ret;

  fseek(mp3_file,0,SEEK_END);
  fsize=ftell(mp3_file);
  if(fseek(mp3_file,-128,SEEK_END)) return fsize;
  ret=fread(&tag,128,1,mp3_file);
  if(ret!=1 || tag.tag[0]!='T' || tag.tag[1]!='A' || tag.tag[2]!='G') return fsize;

        strncpy(title,tag.title,30);
        strncpy(artist,tag.artist,30);
        strncpy(album,tag.album,30);
        strncpy(year,tag.year,4);
        strncpy(comment,tag.comment,30);

        if ( tag.genre <= sizeof(genre_table)/sizeof(*genre_table) ) {
                strncpy(genre, genre_table[tag.genre], 30);
        } else {
                strncpy(genre,"Unknown",30);
        }

//      printf("\n");
        printf("Title  : %30s  Artist: %s\n",title,artist);
        printf("Album  : %30s  Year  : %4s\n",album,year);
        printf("Comment: %30s  Genre : %s\n",comment,genre);
        printf("\n");
  return fsize-128;
}

#endif