From 33dbc1b7ca4bf8679079e1fede69dde92abf4d19 Mon Sep 17 00:00:00 2001 From: David Conrad Date: Sun, 21 Feb 2010 00:10:47 +0000 Subject: Use memset to set the runs partially coded superblocks Much faster for long runs (e.g. nearly uncoded frames), slightly faster for the general case. Originally committed as revision 21927 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavcodec/vp3.c | 22 +++++++++++++--------- 1 file changed, 13 insertions(+), 9 deletions(-) (limited to 'libavcodec/vp3.c') diff --git a/libavcodec/vp3.c b/libavcodec/vp3.c index 59698d2..9268d5e 100644 --- a/libavcodec/vp3.c +++ b/libavcodec/vp3.c @@ -461,17 +461,21 @@ static int unpack_superblocks(Vp3DecodeContext *s, GetBitContext *gb) /* unpack the list of partially-coded superblocks */ bit = get_bits1(gb); - /* toggle the bit because as soon as the first run length is - * fetched the bit will be toggled again */ - bit ^= 1; while (current_superblock < s->superblock_count) { - if (current_run-- == 0) { - bit ^= 1; current_run = get_vlc2(gb, - s->superblock_run_length_vlc.table, 6, 2); - if (current_run == 33) + s->superblock_run_length_vlc.table, 6, 2) + 1; + if (current_run == 34) current_run += get_bits(gb, 12); + if (current_superblock + current_run > s->superblock_count) { + av_log(s->avctx, AV_LOG_ERROR, "Invalid partially coded superblock run length\n"); + return -1; + } + + memset(s->superblock_coding + current_superblock, bit, current_run); + + current_superblock += current_run; + /* if any of the superblocks are not partially coded, flag * a boolean to decode the list of fully-coded superblocks */ if (bit == 0) { @@ -482,8 +486,8 @@ static int unpack_superblocks(Vp3DecodeContext *s, GetBitContext *gb) * superblocks */ decode_partial_blocks = 1; } - } - s->superblock_coding[current_superblock++] = bit; + + bit ^= 1; } /* unpack the list of fully coded superblocks if any of the blocks were -- cgit v1.1