The 16x16 transform unit test suggested that the peak coefficient
value can reach 32639. This could cause potential overflow issue
in the SSSE3 implmentation of 16x16 block quantization. This commit
fixes this issue by replacing addition with saturated addition.
Change-Id: I6d5bb7c5faad4a927be53292324bd2728690717e
The 32x32 forward transform can potentially reach peak coefficient
value close to 32700, while the rounding factor can go upto 610.
This could cause overflow issue in the SSSE3 implementation of 32x32
quantization process.
This commit resolves this issue by replacing the addition operations
with saturated addition operations in 32x32 block quantization.
Change-Id: Id6b98996458e16c5b6241338ca113c332bef6e70
The 32x32 quantization process can potentially have the intermediate
stacks over 16-bit range, thereby causing enc/dec mismatch. This commit
fixes this overflow issue in the SSSE3 implementation, as well as the
prototype, of 32x32 quantization.
This fixes issue 607 from webm@googlecode.
Change-Id: I85635e6ca236b90c3dcfc40d449215c7b9caa806
If none of the 16 coefficients that we quantize per loop iteration
are larger than the zbin, directly skip to the next round of coeffs,
rather than doing a full quantize loop that will eventually result
in 16 zeroes. This incurs a jump cost, but saves a lot of other work.
32x32 quant goes from 1349 -> 1184 cycles. The same approach yielded
no significantly positive results for smaller transforms, so is not
used there (8x8: 103 -> 101 cycles; 16x16: 302 -> 306 cycles).
Change-Id: I8fca17dc2543fc8eed1dbcd5100145e3c3a9b647
Encode time of bus (speed 0) 50 frames @ 1500kbps goes from 2min14.4 to
2min10.1, i.e. a 2.3% overall speed increase.
Change-Id: I3699580e74ec26c7d24e03681bc47ba25ee1ee87
Total encoding time for first 50 frames of bus (speed 0) @ 1500kbps
goes 2min34.8 to 2min14.4, i.e. a 10.4% overall speedup. The code is
x86-64 only, it needs some minor modifications to be 32bit compatible,
because it uses 15 xmm registers, whereas 32bit only has 8.
Change-Id: I2df53770c2e850813ffa713e1a91b45b0082b904
Support for gyp which doesn't support multiple objects in the same
static library having the same basename.
Change-Id: Ib947eefbaf68f8b177a796d23f875ccdfa6bc9dc
