[FFmpeg-cvslog] avcodec/hq_hqa: Don't zero in small chunks, don't zero twice

[Andreas Rheinhardt]

ffmpeg | branch: master | Andreas Rheinhardt <andreas.rheinhardt at outlook.com> | Wed Apr  9 16:44:12 2025 +0200| [c12108cdaa7033645963ba61af8a0edfc0c1792c] | committer: Andreas Rheinhardt

avcodec/hq_hqa: Don't zero in small chunks, don't zero twice

Up until now, hq_decode_block() zeroed every block (of 128 bytes)
before decoding a block; yet this is suboptimal for all modes,
because all modes need to reset all the blocks they use anyway
and so it should be done in one go for all blocks.

For the alpha mode (where blocks need not be coded) all blocks
are zeroed initially anyway, because decode_block() might not
be doing it, so zeroing there again for the coded blocks is
a waste.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=c12108cdaa7033645963ba61af8a0edfc0c1792c
---

 libavcodec/hq_hqa.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/libavcodec/hq_hqa.c b/libavcodec/hq_hqa.c
index 48fc4896ee..5a7d8f12b6 100644
--- a/libavcodec/hq_hqa.c
+++ b/libavcodec/hq_hqa.c
@@ -78,8 +78,6 @@ static int hq_decode_block(HQContext *c, GetBitContext *gb, int16_t block[64],
     const int32_t *q;
     int val, pos = 1;
 
-    memset(block, 0, 64 * sizeof(*block));
-
     if (!is_hqa) {
         block[0] = get_sbits(gb, 9) * 64;
         q = hq_quants[qsel][is_chroma][get_bits(gb, 2)];
@@ -109,6 +107,8 @@ static int hq_decode_mb(HQContext *c, AVFrame *pic,
     int qgroup, flag;
     int i, ret;
 
+    memset(c->block, 0, 8 * sizeof(c->block[0]));
+
     qgroup = get_bits(gb, 4);
     flag = get_bits1(gb);
 
@@ -197,8 +197,7 @@ static int hqa_decode_mb(HQContext *c, AVFrame *pic, int qgroup,
     if (get_bits_left(gb) < 1)
         return AVERROR_INVALIDDATA;
 
-    for (i = 0; i < 12; i++)
-        memset(c->block[i], 0, sizeof(*c->block));
+    memset(c->block, 0, 12 * sizeof(c->block[0]));
     for (i = 0; i < 12; i++)
         c->block[i][0] = -128 * (1 << 6);