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.
Do some shuffling in load/store unpack/pack to save some
work in horizontal DCTs.
Use a few 128-bit broadcasts to compact data vectors a bit.
~1.04x speedup for the DCT case on Haswell.
~1.12x speedup for the IDCT case on Haswell.
Use a combination of instruction types that distributes more
evenly across execution ports on common architectures.
Do the horizontal IDCT without transposing back and forth.
Minor tweaks.
~1.14x faster on Haswell. Should be faster on other architectures
as well.
Use a combination of instruction types that distributes more
evenly across execution ports on common architectures.
Do the horizontal DCT without transposing back and forth.
Minor tweaks.
~1.54x faster on Haswell. Should be faster on other architectures
as well.
