/*
* L3_compress:
* ------------
*/
void L3_compress(void)
{
int frames_processed;
int ch;
int i;
int gr;
static short buffer[2][1152];
short *buffer_window[2];
int remainder;
int bytes_per_frame;
int lag;
int mean_bits;
int sideinfo_len;
static int l3_enc[2][2][samp_per_frame2];
static int l3_sb_sample[2][3][18][SBLIMIT];
static int mdct_freq[2][2][samp_per_frame2];
static L3_side_info_t side_info;
if(config.mpeg.type == MPEG1)
{
config.mpeg.granules = 2;
config.mpeg.samples_per_frame = samp_per_frame;
config.mpeg.resv_limit = ((1<<9)-1)<<3;
sideinfo_len = (config.mpeg.channels == 1) ? 168 : 288;
}
else /* mpeg 2/2.5 */
{
config.mpeg.granules = 1;
config.mpeg.samples_per_frame = samp_per_frame2;
config.mpeg.resv_limit = ((1<<8)-1)<<3;
sideinfo_len = (config.mpeg.channels == 1) ? 104 : 168;
}
scalefac_band_long = sfBandIndex[config.mpeg.type][config.mpeg.samplerate_index];
#ifdef NO_RESERVOIR
config.mpeg.resv_limit = 0;
#endif
{ /* find number of whole bytes per frame and the remainder */
int x = config.mpeg.samples_per_frame * config.mpeg.bitr * (1000/8);
bytes_per_frame = x / config.wave.samplerate;
remainder = x % config.wave.samplerate;
}
config.mpeg.total_frames = /* round up */
(config.wave.total_samples + config.mpeg.samples_per_frame - 1) /
config.mpeg.samples_per_frame;
printf("%d frames\n",config.mpeg.total_frames);
frames_processed = lag = 0;
open_bit_stream(config.outfile);
while(wave_get(buffer))
{
frames_processed++;
if(((frames_processed & 7)==0) || (frames_processed >= config.mpeg.total_frames))
printf("\015[%d] %d%%", frames_processed,(frames_processed*100)/config.mpeg.total_frames);
buffer_window[0] = buffer[0];
buffer_window[1] = buffer[1];
/* sort out padding */
config.mpeg.padding = (lag += remainder) >= config.wave.samplerate;
if (config.mpeg.padding)
lag -= config.wave.samplerate;
config.mpeg.bits_per_frame = 8*(bytes_per_frame + config.mpeg.padding);
/* bits per channel per granule */
mean_bits = (config.mpeg.bits_per_frame - sideinfo_len) >>
(config.mpeg.granules + config.mpeg.channels - 2);
/* polyphase filtering */
for(gr=0; gr<config.mpeg.granules; gr++)
for(ch=0; ch<config.mpeg.channels; ch++)
for(i=0;i<18;i++)
L3_window_filter_subband(&buffer_window[ch], &l3_sb_sample[ch][gr+1][i][0] ,ch);
/* apply mdct to the polyphase output */
L3_mdct_sub(l3_sb_sample, mdct_freq);
/* bit and noise allocation */
L3_iteration_loop(mdct_freq, &side_info, l3_enc, mean_bits);
/* write the frame to the bitstream */
L3_format_bitstream(l3_enc, &side_info);
}
close_bit_stream();
}
/*! Compress a given smplFrame at a given bitRate
*
* \param smplFrame a buffer containing samples to be compressed to layer3
* \param cfg pointer to an initialized config_t structure
* \param bitRate bitRate to encode sample at
* \return status :
* - 0 => Success
* < 0 => any error code
*/
int kb_mp3_Compress( unsigned short *smplFrame, unsigned long smplNmbr, struct config_t *cfg, int bitRate,
char *filePath )
{
int frames_processed;
int channel;
int i;
int gr;
double pe[2][2];
short *buffer_window[2];
double avg_slots_per_frame;
double frac_slots_per_frame;
long whole_slots_per_frame;
double slot_lag;
int mean_bits;
int sideinfo_len;
static short buffer[2][samp_per_frame];
static int l3_enc[2][2][samp_per_frame2];
static long l3_sb_sample[2][3][18][SBLIMIT];
static long mdct_freq[2][2][samp_per_frame2];
static L3_psy_ratio_t ratio;
static L3_side_info_t side_info;
static L3_scalefac_t scalefactor;
static bitstream_t bs;
if(cfg)
cfg->mpeg.bitr = bitRate; /* Override the default bitRate */
if(filePath && cfg)
cfg->outfile = filePath;
else
return -1; /* outfile related error */
open_bit_stream_w(&bs, cfg->outfile, BUFFER_SIZE);
memset((char *)&side_info,0,sizeof(L3_side_info_t));
/* some mpeg layer 3 initialisations */
L3_subband_initialise();
L3_mdct_initialise();
L3_loop_initialise();
cfg->mpeg.samples_per_frame = samp_per_frame;
cfg->mpeg.total_frames = smplNmbr /cfg->mpeg.samples_per_frame;
cfg->mpeg.bits_per_slot = 8;
frames_processed = 0;
sideinfo_len = 288; /* Stereo assumed */ /* (config.wave.channels==1) ? 168 : 288; */
/* Figure average number of 'slots' per frame. */
avg_slots_per_frame = ((double)cfg->mpeg.samples_per_frame /
((double)smplNmbr/1000)) *
((double)cfg->mpeg.bitr /
(double)cfg->mpeg.bits_per_slot);
whole_slots_per_frame = (int)avg_slots_per_frame;
frac_slots_per_frame = avg_slots_per_frame - (double)whole_slots_per_frame;
slot_lag = -frac_slots_per_frame;
if(frac_slots_per_frame==0)
cfg->mpeg.padding = 0;
//while(wave_get(buffer))
for( i = 0; i < smplNmbr; i++)
{
kb_mp3_updStatus(cfg, ++frames_processed);
buffer_window[0] = buffer[0];
buffer_window[1] = buffer[1];
if(frac_slots_per_frame)
if(slot_lag>(frac_slots_per_frame-1.0))
{ /* No padding for this frame */
slot_lag -= frac_slots_per_frame;
cfg->mpeg.padding = 0;
}
else
{ /* Padding for this frame */
slot_lag += (1-frac_slots_per_frame);
cfg->mpeg.padding = 1;
}
cfg->mpeg.bits_per_frame = 8*(whole_slots_per_frame + cfg->mpeg.padding);
mean_bits = (cfg->mpeg.bits_per_frame - sideinfo_len)>>1;
/* polyphase filtering */
for(gr=0;gr<2;gr++)
for(channel=2; channel-- ; ) /* assumed stereo */ /* for(channel=cfg->wave.channels; channel--; ) */
for(i=0;i<18;i++)
L3_window_filter_subband(&buffer_window[channel], &l3_sb_sample[channel][gr+1][i][0] ,channel);
/* apply mdct to the polyphase output */
L3_mdct_sub(cfg, l3_sb_sample, mdct_freq);
/* bit and noise allocation */
L3_iteration_loop(cfg, pe,mdct_freq,&ratio,&side_info, l3_enc, mean_bits,&scalefactor);
/* write the frame to the bitstream */
L3_format_bitstream(cfg, l3_enc,&side_info,&scalefactor, &bs,mdct_freq,NULL,0);
}
close_bit_stream(&bs);
}
/*
* L3_compress:
* ------------
*/
void L3_compress(config_t *config)
{
int frames_processed;
int channel;
int i;
int gr;
double pe[2][2];
short *buffer_window[2];
double avg_slots_per_frame;
double frac_slots_per_frame;
long whole_slots_per_frame;
double slot_lag;
int mean_bits;
int sideinfo_len;
static short buffer[2][samp_per_frame];
static int l3_enc[2][2][samp_per_frame2];
static long l3_sb_sample[2][3][18][SBLIMIT];
static long mdct_freq[2][2][samp_per_frame2];
static L3_psy_ratio_t ratio;
static L3_side_info_t side_info;
static L3_scalefac_t scalefactor;
static bitstream_t bs;
open_bit_stream_w(&bs, config->outfile, BUFFER_SIZE);
memset((char *)&side_info,0,sizeof(L3_side_info_t));
L3_subband_initialise();
L3_mdct_initialise();
L3_loop_initialise();
config->mpeg.samples_per_frame = samp_per_frame;
config->mpeg.total_frames = config->wave.total_samples/config->mpeg.samples_per_frame;
config->mpeg.bits_per_slot = 8;
frames_processed = 0;
sideinfo_len = (config->wave.channels==1) ? 168 : 288;
/* Figure average number of 'slots' per frame. */
avg_slots_per_frame = ((double)config->mpeg.samples_per_frame /
((double)config->wave.samplerate/1000)) *
((double)config->mpeg.bitr /
(double)config->mpeg.bits_per_slot);
whole_slots_per_frame = (int)avg_slots_per_frame;
frac_slots_per_frame = avg_slots_per_frame - (double)whole_slots_per_frame;
slot_lag = -frac_slots_per_frame;
if(frac_slots_per_frame==0)
config->mpeg.padding = 0;
while(config->get_pcm(buffer, config))
{
update_status(++frames_processed, config);
buffer_window[0] = buffer[0];
buffer_window[1] = buffer[1];
if(frac_slots_per_frame)
{
if(slot_lag>(frac_slots_per_frame-1.0))
{ /* No padding for this frame */
slot_lag -= frac_slots_per_frame;
config->mpeg.padding = 0;
}
else
{ /* Padding for this frame */
slot_lag += (1-frac_slots_per_frame);
config->mpeg.padding = 1;
}
}
config->mpeg.bits_per_frame = 8*(whole_slots_per_frame + config->mpeg.padding);
mean_bits = (config->mpeg.bits_per_frame - sideinfo_len)>>1;
/* polyphase filtering */
for(gr=0;gr<2;gr++)
for(channel=config->wave.channels; channel--; )
for(i=0;i<18;i++)
L3_window_filter_subband(&buffer_window[channel], &l3_sb_sample[channel][gr+1][i][0] ,channel);
/* apply mdct to the polyphase output */
L3_mdct_sub(l3_sb_sample, mdct_freq, config);
/* bit and noise allocation */
L3_iteration_loop(pe,mdct_freq,&ratio,&side_info, l3_enc, mean_bits,&scalefactor, config);
/* write the frame to the bitstream */
L3_format_bitstream(l3_enc,&side_info,&scalefactor, &bs,mdct_freq,NULL,0, config);
}
close_bit_stream(&bs);
}