[FFmpeg-devel] [PATCH v2 1/2] lavc: add new unsafe_output hwaccel_flag

[Philip Langdale]

On Fri,  9 Dec 2022 15:16:16 +0100
Timo Rothenpieler <timo at rothenpieler.org> wrote:

> ---
>  doc/APIchanges             |  3 +++
>  libavcodec/avcodec.h       | 16 ++++++++++++++++
>  libavcodec/options_table.h |  1 +
>  libavcodec/version.h       |  4 ++--
>  4 files changed, 22 insertions(+), 2 deletions(-)
> 
> diff --git a/doc/APIchanges b/doc/APIchanges
> index ab7ce15fae..328028f293 100644
> --- a/doc/APIchanges
> +++ b/doc/APIchanges
> @@ -14,6 +14,9 @@ libavutil:     2021-04-27
>  
>  API changes, most recent first:
>  
> +2022-12-xx - xxxxxxxxxx - lavc 59.55.100 - avcodec.h
> +  Add AV_HWACCEL_FLAG_UNSAFE_OUTPUT.
> +
>  2022-11-xx - xxxxxxxxxx - lavu 57.43.100 - tx.h
>    Add AV_TX_FLOAT_DCT, AV_TX_DOUBLE_DCT and AV_TX_INT32_DCT.
>  
> diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
> index 3edd8e2636..0ac581d660 100644
> --- a/libavcodec/avcodec.h
> +++ b/libavcodec/avcodec.h
> @@ -2253,6 +2253,22 @@ typedef struct AVHWAccel {
>   */
>  #define AV_HWACCEL_FLAG_ALLOW_PROFILE_MISMATCH (1 << 2)
>  
> +/**
> + * Some hardware decoders (namely nvdec) can either output direct
> decoder
> + * surfaces, or make an on-device copy and return said copy.
> + * There is a hard limit on how many decoder surfaces there can be,
> and it
> + * cannot be accurately guessed ahead of time.
> + * For some processing chains, this can be okay, but others will run
> into the
> + * limit and in turn produce very confusing errors that require fine
> tuning of
> + * more or less obscure options by the user, or in extreme cases
> cannot be
> + * resolved at all without inserting an avfilter that forces a copy.
> + *
> + * Thus, the hwaccel will by default make a copy for safety and
> resilience.
> + * If a users really wants to minimize the amount of copies, they
> can set this
> + * flag and ensure their processing chain does not exhaust the
> surface pool.
> + */
> +#define AV_HWACCEL_FLAG_UNSAFE_OUTPUT (1 << 3)
> +
>  /**
>   * @}
>   */
> diff --git a/libavcodec/options_table.h b/libavcodec/options_table.h
> index cd02f5096f..7924ca6144 100644
> --- a/libavcodec/options_table.h
> +++ b/libavcodec/options_table.h
> @@ -399,6 +399,7 @@ static const AVOption avcodec_options[] = {
>  {"ignore_level", "ignore level even if the codec level used is
> unknown or higher than the maximum supported level reported by the
> hardware driver", 0, AV_OPT_TYPE_CONST, { .i64 =
> AV_HWACCEL_FLAG_IGNORE_LEVEL }, INT_MIN, INT_MAX, V | D,
> "hwaccel_flags" }, {"allow_high_depth", "allow to output YUV pixel
> formats with a different chroma sampling than 4:2:0 and/or other than
> 8 bits per component", 0, AV_OPT_TYPE_CONST, {.i64 =
> AV_HWACCEL_FLAG_ALLOW_HIGH_DEPTH }, INT_MIN, INT_MAX, V | D,
> "hwaccel_flags"}, {"allow_profile_mismatch", "attempt to decode
> anyway if HW accelerated decoder's supported profiles do not exactly
> match the stream", 0, AV_OPT_TYPE_CONST, {.i64 =
> AV_HWACCEL_FLAG_ALLOW_PROFILE_MISMATCH }, INT_MIN, INT_MAX, V | D,
> "hwaccel_flags"}, +{"unsafe_output", "allow potentially unsafe
> hwaccel frame output that might require special care to process
> successfully", 0, AV_OPT_TYPE_CONST, {.i64 =
> AV_HWACCEL_FLAG_UNSAFE_OUTPUT }, INT_MIN, INT_MAX, V | D,
> "hwaccel_flags"}, {"extra_hw_frames", "Number of extra hardware
> frames to allocate for the user", OFFSET(extra_hw_frames),
> AV_OPT_TYPE_INT, { .i64 = -1 }, -1, INT_MAX, V|D },
> {"discard_damaged_percentage", "Percentage of damaged samples to
> discard a frame", OFFSET(discard_damaged_percentage),
> AV_OPT_TYPE_INT, {.i64 = 95 }, 0, 100, V|D }, {NULL}, diff --git
> a/libavcodec/version.h b/libavcodec/version.h index
> 9e66920593..9f42f09f4e 100644 --- a/libavcodec/version.h +++
> b/libavcodec/version.h @@ -29,8 +29,8 @@ #include "version_major.h"
> -#define LIBAVCODEC_VERSION_MINOR  54 -#define
> LIBAVCODEC_VERSION_MICRO 101 +#define LIBAVCODEC_VERSION_MINOR  55
> +#define LIBAVCODEC_VERSION_MICRO 100 #define LIBAVCODEC_VERSION_INT
> AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \ LIBAVCODEC_VERSION_MINOR, \

LGTM


--phil