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| author | Jingning Han <jingning@google.com> | 2015-06-12 10:38:45 -0700 |
|---|---|---|
| committer | Jingning Han <jingning@google.com> | 2015-06-12 10:39:49 -0700 |
| commit | 4f52d49f1e21dde76640f22c5932ce6ec08cb534 (patch) | |
| tree | 48799585c0e2c590b4955cccf5fc17a21bad1fac | |
| parent | 254a4c033c7bcec3b6b0fbbb86301d18491ebc26 (diff) | |
| download | libvpx-4f52d49f1e21dde76640f22c5932ce6ec08cb534.tar libvpx-4f52d49f1e21dde76640f22c5932ce6ec08cb534.tar.gz libvpx-4f52d49f1e21dde76640f22c5932ce6ec08cb534.tar.bz2 libvpx-4f52d49f1e21dde76640f22c5932ce6ec08cb534.zip | |
Add dynamic range comment to hadamard_8x8()
Add comment to assist SIMD optimization.
Change-Id: I300d5a848e6e9947e451de2a871a88940703fc9f
| -rw-r--r-- | vp9/encoder/vp9_avg.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/vp9/encoder/vp9_avg.c b/vp9/encoder/vp9_avg.c index b9987c1ce..e5150c905 100644 --- a/vp9/encoder/vp9_avg.c +++ b/vp9/encoder/vp9_avg.c @@ -29,6 +29,8 @@ unsigned int vp9_avg_4x4_c(const uint8_t *s, int p) { return (sum + 8) >> 4; } +// src_diff: first pass, 9 bit, dynamic range [-255, 255] +// second pass, 12 bit, dynamic range [-2040, 2040] static void hadamard_col8(const int16_t *src_diff, int src_stride, int16_t *coeff) { int16_t b0 = src_diff[0 * src_stride] + src_diff[1 * src_stride]; @@ -65,15 +67,18 @@ void vp9_hadamard_8x8_c(int16_t const *src_diff, int src_stride, int16_t buffer[64]; int16_t *tmp_buf = &buffer[0]; for (idx = 0; idx < 8; ++idx) { - hadamard_col8(src_diff, src_stride, tmp_buf); + hadamard_col8(src_diff, src_stride, tmp_buf); // src_diff: 9 bit + // dynamic range [-255, 255] tmp_buf += 8; ++src_diff; } tmp_buf = &buffer[0]; for (idx = 0; idx < 8; ++idx) { - hadamard_col8(tmp_buf, 8, coeff); - coeff += 8; + hadamard_col8(tmp_buf, 8, coeff); // tmp_buf: 12 bit + // dynamic range [-2040, 2040] + coeff += 8; // coeff: 15 bit + // dynamic range [-16320, 16320] ++tmp_buf; } } |