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simplify

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Originally committed as revision 6058 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Michael Niedermayer 2006-08-23 23:40:03 +00:00
parent acba32385b
commit c7aa36964e
1 changed files with 17 additions and 24 deletions
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41
libavcodec/mpegaudiodec.c
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@ -166,7 +166,6 @@ static void compute_antialias_float(MPADecodeContext *s, GranuleDef *g);
/* vlc structure for decoding layer 3 huffman tables */
static VLC huff_vlc[16];
static uint8_t *huff_code_table[16];
static VLC huff_quad_vlc[2];
/* computed from band_size_long */
static uint16_t band_index_long[9][23];
@ -368,26 +367,30 @@ static int decode_init(AVCodecContext * avctx)
ff_mpa_synth_init(window);
/* huffman decode tables */
huff_code_table[0] = NULL;
for(i=1;i<16;i++) {
const HuffTable *h = &mpa_huff_tables[i];
int xsize, x, y;
unsigned int n;
uint8_t *code_table;
uint8_t tmp_bits [256];
uint16_t tmp_codes[256];
memset(tmp_bits , 0, sizeof(tmp_bits ));
memset(tmp_codes, 0, sizeof(tmp_codes));
xsize = h->xsize;
n = xsize * xsize;
/* XXX: fail test */
init_vlc(&huff_vlc[i], 8, n,
h->bits, 1, 1, h->codes, 2, 2, 1);
code_table = av_mallocz(n);
j = 0;
for(x=0;x<xsize;x++) {
for(y=0;y<xsize;y++)
code_table[j++] = (x << 4) | y;
for(y=0;y<xsize;y++){
tmp_bits [(x << 4) | y]= h->bits [j ];
tmp_codes[(x << 4) | y]= h->codes[j++];
}
}
huff_code_table[i] = code_table;
/* XXX: fail test */
init_vlc(&huff_vlc[i], 8, 256,
tmp_bits, 1, 1, tmp_codes, 2, 2, 1);
}
for(i=0;i<2;i++) {
init_vlc(&huff_quad_vlc[i], i == 0 ? 7 : 4, 16,
@ -1670,7 +1673,6 @@ static int huffman_decode(MPADecodeContext *s, GranuleDef *g,
int linbits, code, x, y, l, v, i, j, k, pos;
GetBitContext last_gb;
VLC *vlc;
uint8_t *code_table;
/* low frequencies (called big values) */
s_index = 0;
@ -1683,17 +1685,13 @@ static int huffman_decode(MPADecodeContext *s, GranuleDef *g,
l = mpa_huff_data[k][0];
linbits = mpa_huff_data[k][1];
vlc = &huff_vlc[l];
code_table = huff_code_table[l];
/* read huffcode and compute each couple */
for(;j>0;j--) {
if (get_bits_count(&s->gb) >= end_pos)
break;
if (code_table) {
code = get_vlc2(&s->gb, vlc->table, 8, 3);
if (code < 0)
return -1;
y = code_table[code];
if (l) {
y = get_vlc2(&s->gb, vlc->table, 8, 3);
x = y >> 4;
y = y & 0x0f;
} else {
@ -2232,9 +2230,7 @@ static int mp_decode_layer3(MPADecodeContext *s)
g->region_size[2] = (576 / 2);
j = 0;
for(i=0;i<3;i++) {
k = g->region_size[i];
if (k > g->big_values)
k = g->big_values;
k = FFMIN(g->region_size[i], g->big_values);
g->region_size[i] = k - j;
j = k;
}
@ -2252,10 +2248,7 @@ static int mp_decode_layer3(MPADecodeContext *s)
else
g->long_end = 4; /* 8000 Hz */
if (s->sample_rate_index != 8)
g->short_start = 3;
else
g->short_start = 2;
g->short_start = 2 + (s->sample_rate_index != 8);
} else {
g->long_end = 0;
g->short_start = 0;