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| author | Andreas Rheinhardt <andreas.rheinhardt@gmail.com> | 2020-10-10 06:13:21 +0200 |
|---|---|---|
| committer | Andreas Rheinhardt <andreas.rheinhardt@gmail.com> | 2020-10-10 15:37:25 +0200 |
| commit | 1bff2f3d929b7e1229b9a125e3cf938ece1665cc (patch) | |
| tree | 49b797c6991c12ec968732f18854fc800615f56c | |
| parent | 11a6347f9e544a1b9fba059ae02c30c0e512c195 (diff) | |
| download | ffmpeg-1bff2f3d929b7e1229b9a125e3cf938ece1665cc.tar.gz | |
avcodec/sheervideo: Improve creating VLC tables
Don't needlessly copy an array around; don't create a table with
default symbols; and use smaller types to save stack space: The longest
code here is 16 bits, so one can store the codes in this type.
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
| -rw-r--r-- | libavcodec/sheervideo.c | 19 |
1 files changed, 7 insertions, 12 deletions
diff --git a/libavcodec/sheervideo.c b/libavcodec/sheervideo.c index ba9aecbb11..3f9b299a1e 100644 --- a/libavcodec/sheervideo.c +++ b/libavcodec/sheervideo.c @@ -1782,25 +1782,20 @@ static void decode_rgb(AVCodecContext *avctx, AVFrame *p, GetBitContext *gb) static int build_vlc(VLC *vlc, const uint8_t *len, int count) { - uint32_t codes[1024]; - uint8_t bits[1024]; - uint16_t syms[1024]; - uint64_t index; + uint16_t codes[1024]; + unsigned index; int i; index = 0; for (i = 0; i < count; i++) { - codes[i] = index >> (32 - len[i]); - bits[i] = len[i]; - syms[i] = i; - index += 1ULL << (32 - len[i]); + codes[i] = index >> (32 - len[i]); + index += 1U << (32 - len[i]); } ff_free_vlc(vlc); - return ff_init_vlc_sparse(vlc, 12, count, - bits, sizeof(*bits), sizeof(*bits), - codes, sizeof(*codes), sizeof(*codes), - syms, sizeof(*syms), sizeof(*syms), 0); + return init_vlc(vlc, 12, count, + len, sizeof(*len), sizeof(*len), + codes, sizeof(*codes), sizeof(*codes), 0); } static int decode_frame(AVCodecContext *avctx, |