From 3b7117b73a2b88e8c36ed9bd23324370b027f2ee Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Tue, 11 May 2010 21:31:54 +0000 Subject: Do the same sign flip optimization to the low freq decoder. as with the high freq 10-20 cycles faster Originally committed as revision 23099 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavcodec/mpegaudiodec.c | 27 +++++++++++++-------------- 1 file changed, 13 insertions(+), 14 deletions(-) (limited to 'libavcodec/mpegaudiodec.c') diff --git a/libavcodec/mpegaudiodec.c b/libavcodec/mpegaudiodec.c index 2279b8daaa..b12939f566 100644 --- a/libavcodec/mpegaudiodec.c +++ b/libavcodec/mpegaudiodec.c @@ -1454,7 +1454,7 @@ static int huffman_decode(MPADecodeContext *s, GranuleDef *g, /* read huffcode and compute each couple */ for(;j>0;j--) { int exponent, x, y; - INTFLOAT v; + int v; int pos= get_bits_count(&s->gb); if (pos >= end_pos){ @@ -1481,37 +1481,36 @@ static int huffman_decode(MPADecodeContext *s, GranuleDef *g, x = y >> 5; y = y & 0x0f; if (x < 15){ - v = RENAME(expval_table)[ exponent ][ x ]; -// v = RENAME(expval_table)[ (exponent&3) ][ x ] >> FFMIN(0 - (exponent>>2), 31); + READ_FLIP_SIGN(g->sb_hybrid+s_index, RENAME(expval_table)[ exponent ]+x) }else{ x += get_bitsz(&s->gb, linbits); v = l3_unscale(x, exponent); + if (get_bits1(&s->gb)) + v = -v; + g->sb_hybrid[s_index] = v; } - if (get_bits1(&s->gb)) - v = -v; - g->sb_hybrid[s_index] = v; if (y < 15){ - v = RENAME(expval_table)[ exponent ][ y ]; + READ_FLIP_SIGN(g->sb_hybrid+s_index+1, RENAME(expval_table)[ exponent ]+y) }else{ y += get_bitsz(&s->gb, linbits); v = l3_unscale(y, exponent); + if (get_bits1(&s->gb)) + v = -v; + g->sb_hybrid[s_index+1] = v; } - if (get_bits1(&s->gb)) - v = -v; - g->sb_hybrid[s_index+1] = v; }else{ x = y >> 5; y = y & 0x0f; x += y; if (x < 15){ - v = RENAME(expval_table)[ exponent ][ x ]; + READ_FLIP_SIGN(g->sb_hybrid+s_index+!!y, RENAME(expval_table)[ exponent ]+x) }else{ x += get_bitsz(&s->gb, linbits); v = l3_unscale(x, exponent); + if (get_bits1(&s->gb)) + v = -v; + g->sb_hybrid[s_index+!!y] = v; } - if (get_bits1(&s->gb)) - v = -v; - g->sb_hybrid[s_index+!!y] = v; g->sb_hybrid[s_index+ !y] = 0; } s_index+=2; -- cgit v1.2.3