Use a combination of table lookups and pshufb to convert coefficients
to zero run/level format. Two 16-entry lookup tables are used for a
total of 192 bytes worth of tables. (The existing SSE2 version uses a
table of size 2048 bytes.)
Speedup is ~1.5x-3x as compared with the SSE2 version on Haswell (the
speedup is greater for input with many trailing zeros).
The use of popcnt makes it require SSE4.2. This can be replaced with
a small LUT and accumulation which would reduce the requirement to
SSSE3.
At lower bitrates, it is overall faster to conditionally do one block
at a time with SSE2 on Haswell and likely other common architectures.
At higher bitrates, it is faster to use the wider routine that IDCTs
four blocks at a time. To avoid potential performance regressions
as compared to MMX, stick with single-block IDCTs with SSE2. There
is still a performance advantage as compared to MMX because the
single-block SSE2 routine is faster than the corresponding MMX
routine.
Stick with four blocks at a time with AVX2 for which that appears
to be consistently faster on Haswell.
Move asm routines to common. Delete obsolete decoder routines.
Use wider routines where applicable.
~1.07x overall faster decode on a quick 720p30 4Mbps test on Haswell.
WelsSampleSatd16x16_avx2 (~2.31x speedup over SSE4.1 on Haswell).
WelsSampleSatd16x8_avx2 (~2.19x speedup over SSE4.1 on Haswell).
WelsSampleSatd8x16_avx2 (~1.68x speedup over SSE4.1 on Haswell).
WelsSampleSatd8x8_avx2 (~1.53x speedup over SSE4.1 on Haswell).
The "Video signal type present" information is written to the output
video file when it is created, and later is used by the decoder to
properly decode the compressed video data. The saved attributes
are:
- format type (PAL, NTSC, etc.)
- color primaries (BT709, SMPTE170M, etc.)
- transfer characteristics (BT709, SMPTE170M, etc.)
- color matrix ((BT709, SMPTE170M, etc.)
These modifications allow the client to specify these attributes
and, if specified, makes sure they are written to the output file.
The "Video signal type present" information is written to the output
video file when it is created, and later is used by the decoder to
properly decode the compressed video data. The saved attributes
are:
- format type (PAL, NTSC, etc.)
- color primaries (BT709, SMPTE170M, etc.)
- transfer characteristics (BT709, SMPTE170M, etc.)
- color matrix ((BT709, SMPTE170M, etc.)
These modifications allow the client to specify these attributes
and, if specified, makes sure they are written to the output file.
We do four blocks at a time when possible, but need to handle
single blocks at a time for intra prediction.
~3.15x speedup over MMX for the DCT on Haswell.
~2.94x speedup over MMX for the IDCT on Haswell.
Returns diminish with increasing vector length because a larger
proportion of the time is spent on load/store/shuffling.
We do four blocks at a time when possible, but need to handle
single blocks at a time for intra prediction.
~2.31x speedup over MMX for the DCT on Haswell.
~1.92x speedup over MMX for the IDCT on Haswell.
IDCT input is defined in such a way that the intermediate values
cannot legally overflow an int16_t. The use of random values
as input causes such overflows. This results in implementation-
dependent output depending on which type is used to hold
intermediate results. Use a template for the test reference
implementation to test implementations with different
intermediate representation.
Initialize input arrays with different random values.
Otherwise, the input to the DCT routines is effectively
all zero values after taking the difference.
Reduce duplication.
