[FFmpeg-devel] [PATCH] lavc/qsvenc: allows the SDK runtime to choose LowPower/non-LowPower modes

[Xiang, Haihao]

On Sat, 2020-10-10 at 14:22 +0800, Haihao Xiang wrote:
> The SDK supports LowPower and non-LowPower modes, but some features are
> available only under one of the two modes. Currently non-LowPower mode
> is always chosen in FFmpeg if the mode is not set explicitly, which will
> result in some SDK errors if a feature is unavailable under non-LowPower
> mode. With this patch, the mode is unknown in FFmpeg if the mode is not
> set explicitly, the SDK is responsible for mode selection
> ---
> This is the new version for "lavc/qsvenc: let the SDK to choose the
> encoding mode by default" and the git commit log is updated only

Hi,

Is there any comment for this patch? Without this patch, user has to set the
mode to LowPower mode explicitly for some features. It is really inconvenient
because lots of user do not know these features are available only under
LowPower mode. If not objection, I may rebase this patch against the current
master.

Thanks
Haihao

> 
>  libavcodec/qsvenc.c | 6 ++++--
>  libavcodec/qsvenc.h | 2 +-
>  2 files changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/libavcodec/qsvenc.c b/libavcodec/qsvenc.c
> index 1ed8f5d973..cff96e59c9 100644
> --- a/libavcodec/qsvenc.c
> +++ b/libavcodec/qsvenc.c
> @@ -510,7 +510,7 @@ static int init_video_param(AVCodecContext *avctx,
> QSVEncContext *q)
>          }
>      }
>  
> -    if (q->low_power) {
> +    if (q->low_power == 1) {
>  #if QSV_HAVE_VDENC
>          q->param.mfx.LowPower = MFX_CODINGOPTION_ON;
>  #else
> @@ -519,7 +519,9 @@ static int init_video_param(AVCodecContext *avctx,
> QSVEncContext *q)
>          q->low_power = 0;
>          q->param.mfx.LowPower = MFX_CODINGOPTION_OFF;
>  #endif
> -    } else
> +    } else if (q->low_power == -1)
> +        q->param.mfx.LowPower = MFX_CODINGOPTION_UNKNOWN;
> +    else
>          q->param.mfx.LowPower = MFX_CODINGOPTION_OFF;
>  
>      q->param.mfx.CodecProfile       = q->profile;
> diff --git a/libavcodec/qsvenc.h b/libavcodec/qsvenc.h
> index 4f579d1db1..577775cc1a 100644
> --- a/libavcodec/qsvenc.h
> +++ b/libavcodec/qsvenc.h
> @@ -96,7 +96,7 @@
>  { "adaptive_b",     "Adaptive B-frame
> placement",             OFFSET(qsv.adaptive_b),     AV_OPT_TYPE_INT, { .i64 =
> -1 }, -1,          1, VE },                         \
>  { "b_strategy",     "Strategy to choose between I/P/B-frames",
> OFFSET(qsv.b_strategy),    AV_OPT_TYPE_INT, { .i64 = -1 }, -1,          1, VE
> },                         \
>  { "forced_idr",     "Forcing I frames as IDR
> frames",         OFFSET(qsv.forced_idr),     AV_OPT_TYPE_BOOL,{ .i64 =
> 0  },  0,          1, VE },                         \
> -{ "low_power", "enable low power mode(experimental: many limitations by mfx
> version, BRC modes, etc.)", OFFSET(qsv.low_power), AV_OPT_TYPE_BOOL, { .i64 =
> 0}, 0, 1, VE},\
> +{ "low_power", "enable low power mode(experimental: many limitations by mfx
> version, BRC modes, etc.)", OFFSET(qsv.low_power), AV_OPT_TYPE_BOOL, { .i64 =
> -1}, -1, 1, VE},\
>  
>  extern const AVCodecHWConfigInternal *ff_qsv_enc_hw_configs[];
>