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author | Michael Niedermayer <michaelni@gmx.at> | 2006-03-29 01:59:24 +0000 |
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committer | Michael Niedermayer <michaelni@gmx.at> | 2006-03-29 01:59:24 +0000 |
commit | 22dde0e9550f5a114ce26c65ef4751efeb1d8d02 (patch) | |
tree | 24c288445d84c63c09a982a0669a8282d91bf609 | |
parent | 6a1a892f23d085780c697e78092753fb8f85510d (diff) | |
download | ffmpeg-22dde0e9550f5a114ce26c65ef4751efeb1d8d02.tar.gz |
optimizations by arpi
Originally committed as revision 5235 to svn://svn.ffmpeg.org/ffmpeg/trunk
-rw-r--r-- | libavcodec/mjpeg.c | 25 |
1 files changed, 19 insertions, 6 deletions
diff --git a/libavcodec/mjpeg.c b/libavcodec/mjpeg.c index 951a622ee1..e6cb52a4f5 100644 --- a/libavcodec/mjpeg.c +++ b/libavcodec/mjpeg.c @@ -1246,11 +1246,10 @@ static inline int mjpeg_decode_dc(MJpegDecodeContext *s, int dc_index) /* decode block and dequantize */ static int decode_block(MJpegDecodeContext *s, DCTELEM *block, - int component, int dc_index, int ac_index, int quant_index) + int component, int dc_index, int ac_index, int16_t *quant_matrix) { int code, i, j, level, val; VLC *ac_vlc; - int16_t *quant_matrix; /* DC coef */ val = mjpeg_decode_dc(s, dc_index); @@ -1258,15 +1257,16 @@ static int decode_block(MJpegDecodeContext *s, DCTELEM *block, dprintf("error dc\n"); return -1; } - quant_matrix = s->quant_matrixes[quant_index]; val = val * quant_matrix[0] + s->last_dc[component]; s->last_dc[component] = val; block[0] = val; /* AC coefs */ ac_vlc = &s->vlcs[1][ac_index]; i = 1; + OPEN_READER(re, &s->gb) for(;;) { - code = get_vlc2(&s->gb, s->vlcs[1][ac_index].table, 9, 2); + UPDATE_CACHE(re, &s->gb); + GET_VLC(code, re, &s->gb, s->vlcs[1][ac_index].table, 9, 2) if (code < 0) { dprintf("error ac\n"); @@ -1278,8 +1278,19 @@ static int decode_block(MJpegDecodeContext *s, DCTELEM *block, if (code == 0xf0) { i += 16; } else { - level = get_xbits(&s->gb, code & 0xf); i += code >> 4; + code &= 0xf; + + UPDATE_CACHE(re, &s->gb) + + if ((int32_t)GET_CACHE(re,&s->gb)<0) { //MSB=1 + level = NEG_USR32( GET_CACHE(re,&s->gb),code); + } else { + level = - NEG_USR32(~GET_CACHE(re,&s->gb),code); + } + + SKIP_BITS(re, &s->gb, code) + if (i >= 64) { dprintf("error count: %d\n", i); return -1; @@ -1291,6 +1302,8 @@ static int decode_block(MJpegDecodeContext *s, DCTELEM *block, break; } } + CLOSE_READER(re, &s->gb) + return 0; } @@ -1467,7 +1480,7 @@ static int mjpeg_decode_scan(MJpegDecodeContext *s){ memset(s->block, 0, sizeof(s->block)); if (decode_block(s, s->block, i, s->dc_index[i], s->ac_index[i], - s->quant_index[c]) < 0) { + s->quant_matrixes[ s->quant_index[c] ]) < 0) { dprintf("error y=%d x=%d\n", mb_y, mb_x); return -1; } |