[FFmpeg-devel] [PATCH 1/2] filter_units, trace_headers: Always use fragment from context

[Mark Thompson]

On 11/02/2019 22:47, Andreas Rheinhardt wrote:
> This is in preparation for another patch that will stop needless
> reallocations of the unit array.
> 
> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at googlemail.com>
> ---
>  libavcodec/filter_units_bsf.c  |  8 ++++----
>  libavcodec/trace_headers_bsf.c | 13 +++++++------
>  2 files changed, 11 insertions(+), 10 deletions(-)

On 11/02/2019 22:47, Andreas Rheinhardt wrote:> Currently, a fragment's unit array is constantly reallocated during
> splitting of a packet. This commit changes this: One can keep the units
> array by distinguishing between the number of allocated and the number
> of valid units in the units array.
> 
> The more units a packet is split into, the bigger the benefit.
> So MPEG-2 benefits the most; for a video coming from an NTSC-DVD
> (usually 32 units per frame) the average cost of cbs_insert_unit (for a
> single unit) went down from 6717 decicycles to 450 decicycles (based
> upon 10 runs with 4194304 runs each); if each packet consists of only
> one unit, it went down from 2425 to 448; for a H.264 video where most
> packets contain nine units, it went from 4431 to 450.
> 
> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at googlemail.com>
> ---
>  This time I have also changed VAAPI to stop reallocating the units
> array. Keep in mind that I couldn't test this at all.
>  libavcodec/av1_metadata_bsf.c       |  6 ++-
>  libavcodec/av1_parser.c             |  5 ++-
>  libavcodec/cbs.c                    | 62 +++++++++++++++++------------
>  libavcodec/cbs.h                    | 33 +++++++++++++--
>  libavcodec/filter_units_bsf.c       |  7 ++--
>  libavcodec/h264_metadata_bsf.c      |  6 ++-
>  libavcodec/h264_redundant_pps_bsf.c |  6 ++-
>  libavcodec/h265_metadata_bsf.c      |  6 ++-
>  libavcodec/mpeg2_metadata_bsf.c     |  6 ++-
>  libavcodec/trace_headers_bsf.c      |  5 ++-
>  libavcodec/vaapi_encode_h264.c      |  9 +++--
>  libavcodec/vaapi_encode_h265.c      |  9 +++--
>  libavcodec/vaapi_encode_mjpeg.c     |  3 +-
>  libavcodec/vaapi_encode_mpeg2.c     |  5 ++-
>  libavcodec/vp9_metadata_bsf.c       |  4 +-
>  15 files changed, 113 insertions(+), 59 deletions(-)

LGTM, applied.

Thank you!

- Mark