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mpegaudioenc: Move some static tables to MpegAudioContext 

This reduces global state and the amount of globally visible tables.
This commit is contained in:
Diego Biurrun 2013-11-04 21:14:03 +01:00
parent 5d6a990c11
commit 45ef963908
2 changed files with 23 additions and 26 deletions
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40
libavcodec/mpegaudioenc.c
View File

@ -61,6 +61,11 @@ typedef struct MpegAudioContext {
unsigned char scale_code[MPA_MAX_CHANNELS][SBLIMIT]; unsigned char scale_code[MPA_MAX_CHANNELS][SBLIMIT];
int sblimit; /* number of used subbands */ int sblimit; /* number of used subbands */
const unsigned char *alloc_table; const unsigned char *alloc_table;
int16_t filter_bank[512];
int scale_factor_table[64];
unsigned char scale_diff_table[128];
float scale_factor_inv_table[64];
unsigned short total_quant_bits[17]; /* total number of bits per allocation group */
} MpegAudioContext; } MpegAudioContext;
static av_cold int MPA_encode_init(AVCodecContext *avctx) static av_cold int MPA_encode_init(AVCodecContext *avctx)
@ -136,19 +141,19 @@ static av_cold int MPA_encode_init(AVCodecContext *avctx)
#if WFRAC_BITS != 16 #if WFRAC_BITS != 16
v = (v + (1 << (16 - WFRAC_BITS - 1))) >> (16 - WFRAC_BITS); v = (v + (1 << (16 - WFRAC_BITS - 1))) >> (16 - WFRAC_BITS);
#endif #endif
filter_bank[i] = v; s->filter_bank[i] = v;
if ((i & 63) != 0) if ((i & 63) != 0)
v = -v; v = -v;
if (i != 0) if (i != 0)
filter_bank[512 - i] = v; s->filter_bank[512 - i] = v;
} }
for(i=0;i<64;i++) { for(i=0;i<64;i++) {
v = (int)(pow(2.0, (3 - i) / 3.0) * (1 << 20)); v = (int)(pow(2.0, (3 - i) / 3.0) * (1 << 20));
if (v <= 0) if (v <= 0)
v = 1; v = 1;
scale_factor_table[i] = v; s->scale_factor_table[i] = v;
scale_factor_inv_table[i] = pow(2.0, -(3 - i) / 3.0) / (float)(1 << 20); s->scale_factor_inv_table[i] = pow(2.0, -(3 - i) / 3.0) / (float)(1 << 20);
} }
for(i=0;i<128;i++) { for(i=0;i<128;i++) {
v = i - 64; v = i - 64;
@ -162,7 +167,7 @@ static av_cold int MPA_encode_init(AVCodecContext *avctx)
v = 3; v = 3;
else else
v = 4; v = 4;
scale_diff_table[i] = v; s->scale_diff_table[i] = v;
} }
for(i=0;i<17;i++) { for(i=0;i<17;i++) {
@ -171,7 +176,7 @@ static av_cold int MPA_encode_init(AVCodecContext *avctx)
v = -v; v = -v;
else else
v = v * 3; v = v * 3;
total_quant_bits[i] = 12 * v; s->total_quant_bits[i] = 12 * v;
} }
return 0; return 0;
@ -318,7 +323,7 @@ static void filter(MpegAudioContext *s, int ch, const short *samples, int incr)
/* filter */ /* filter */
p = s->samples_buf[ch] + offset; p = s->samples_buf[ch] + offset;
q = filter_bank; q = s->filter_bank;
/* maxsum = 23169 */ /* maxsum = 23169 */
for(i=0;i<64;i++) { for(i=0;i<64;i++) {
sum = p[0*64] * q[0*64]; sum = p[0*64] * q[0*64];
@ -352,7 +357,8 @@ static void filter(MpegAudioContext *s, int ch, const short *samples, int incr)
s->samples_offset[ch] = offset; s->samples_offset[ch] = offset;
} }
static void compute_scale_factors(unsigned char scale_code[SBLIMIT], static void compute_scale_factors(MpegAudioContext *s,
unsigned char scale_code[SBLIMIT],
unsigned char scale_factors[SBLIMIT][3], unsigned char scale_factors[SBLIMIT][3],
int sb_samples[3][12][SBLIMIT], int sb_samples[3][12][SBLIMIT],
int sblimit) int sblimit)
@ -379,7 +385,7 @@ static void compute_scale_factors(unsigned char scale_code[SBLIMIT],
use at most 2 compares to find the index */ use at most 2 compares to find the index */
index = (21 - n) * 3 - 3; index = (21 - n) * 3 - 3;
if (index >= 0) { if (index >= 0) {
while (vmax <= scale_factor_table[index+1]) while (vmax <= s->scale_factor_table[index+1])
index++; index++;
} else { } else {
index = 0; /* very unlikely case of overflow */ index = 0; /* very unlikely case of overflow */
@ -389,7 +395,7 @@ static void compute_scale_factors(unsigned char scale_code[SBLIMIT],
} }
av_dlog(NULL, "%2d:%d in=%x %x %d\n", av_dlog(NULL, "%2d:%d in=%x %x %d\n",
j, i, vmax, scale_factor_table[index], index); j, i, vmax, s->scale_factor_table[index], index);
/* store the scale factor */ /* store the scale factor */
assert(index >=0 && index <= 63); assert(index >=0 && index <= 63);
sf[i] = index; sf[i] = index;
@ -397,8 +403,8 @@ static void compute_scale_factors(unsigned char scale_code[SBLIMIT],
/* compute the transmission factor : look if the scale factors /* compute the transmission factor : look if the scale factors
are close enough to each other */ are close enough to each other */
d1 = scale_diff_table[sf[0] - sf[1] + 64]; d1 = s->scale_diff_table[sf[0] - sf[1] + 64];
d2 = scale_diff_table[sf[1] - sf[2] + 64]; d2 = s->scale_diff_table[sf[1] - sf[2] + 64];
/* handle the 25 cases */ /* handle the 25 cases */
switch(d1 * 5 + d2) { switch(d1 * 5 + d2) {
@ -548,12 +554,12 @@ static void compute_bit_allocation(MpegAudioContext *s,
if (subband_status[max_ch][max_sb] == SB_NOTALLOCATED) { if (subband_status[max_ch][max_sb] == SB_NOTALLOCATED) {
/* nothing was coded for this band: add the necessary bits */ /* nothing was coded for this band: add the necessary bits */
incr = 2 + nb_scale_factors[s->scale_code[max_ch][max_sb]] * 6; incr = 2 + nb_scale_factors[s->scale_code[max_ch][max_sb]] * 6;
incr += total_quant_bits[alloc[1]]; incr += s->total_quant_bits[alloc[1]];
} else { } else {
/* increments bit allocation */ /* increments bit allocation */
b = bit_alloc[max_ch][max_sb]; b = bit_alloc[max_ch][max_sb];
incr = total_quant_bits[alloc[b + 1]] - incr = s->total_quant_bits[alloc[b + 1]] -
total_quant_bits[alloc[b]]; s->total_quant_bits[alloc[b]];
} }
if (current_frame_size + incr <= max_frame_size) { if (current_frame_size + incr <= max_frame_size) {
@ -665,7 +671,7 @@ static void encode_frame(MpegAudioContext *s,
float a; float a;
sample = s->sb_samples[ch][k][l + m][i]; sample = s->sb_samples[ch][k][l + m][i];
/* divide by scale factor */ /* divide by scale factor */
a = (float)sample * scale_factor_inv_table[s->scale_factors[ch][i][k]]; a = (float)sample * s->scale_factor_inv_table[s->scale_factors[ch][i][k]];
q[m] = (int)((a + 1.0) * steps * 0.5); q[m] = (int)((a + 1.0) * steps * 0.5);
if (q[m] >= steps) if (q[m] >= steps)
q[m] = steps - 1; q[m] = steps - 1;
@ -711,7 +717,7 @@ static int MPA_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
} }
for(i=0;i<s->nb_channels;i++) { for(i=0;i<s->nb_channels;i++) {
compute_scale_factors(s->scale_code[i], s->scale_factors[i], compute_scale_factors(s, s->scale_code[i], s->scale_factors[i],
s->sb_samples[i], s->sblimit); s->sb_samples[i], s->sblimit);
} }
for(i=0;i<s->nb_channels;i++) { for(i=0;i<s->nb_channels;i++) {

9
libavcodec/mpegaudiotab.h
View File

@ -79,15 +79,6 @@ static const int bitinv32[32] = {
}; };
static int16_t filter_bank[512];
static int scale_factor_table[64];
static float scale_factor_inv_table[64];
static unsigned char scale_diff_table[128];
/* total number of bits per allocation group */
static unsigned short total_quant_bits[17];
/* signal to noise ratio of each quantification step (could be /* signal to noise ratio of each quantification step (could be
computed from quant_steps[]). The values are dB multiplied by 10 computed from quant_steps[]). The values are dB multiplied by 10
*/ */