[FFmpeg-devel] [PATCH] nvenc set slice number to 1 to improve encoding quality and clamp initial qp value to [1, 51]

[Agatha Hu]

On 2015/12/11 11:10, Agatha Hu wrote:
>
> ---
>   libavcodec/nvenc.c | 19 +++++++++++++++----
>   1 file changed, 15 insertions(+), 4 deletions(-)
>
> diff --git a/libavcodec/nvenc.c b/libavcodec/nvenc.c
> index 43b8e78..6365434 100644
> --- a/libavcodec/nvenc.c
> +++ b/libavcodec/nvenc.c
> @@ -762,6 +762,17 @@ static av_cold int nvenc_encode_init(AVCodecContext
> *avctx)
>           }
>       }
>
> +    switch (avctx->codec->id) {
> +    case AV_CODEC_ID_H264:
> +        ctx->encode_config.encodeCodecConfig.h264Config.sliceMode = 3;
> +        ctx->encode_config.encodeCodecConfig.h264Config.sliceModeData = 1;
> +        break;
> +    case AV_CODEC_ID_H265:
> +        ctx->encode_config.encodeCodecConfig.hevcConfig.sliceMode = 3;
> +        ctx->encode_config.encodeCodecConfig.hevcConfig.sliceModeData = 1;
> +        break;
> +    }
> +
>       /* when there're b frames, set dts offset */
>       if (ctx->encode_config.frameIntervalP >= 2)
>           ctx->last_dts = -2;
> @@ -843,10 +854,10 @@ static av_cold int
> nvenc_encode_init(AVCodecContext *avctx)
>           ctx->encode_config.rcParams.initialRCQP.qpInterP  = qp_inter_p;
>
>           if(avctx->i_quant_factor != 0.0 && avctx->b_quant_factor !=
> 0.0) {
> -            ctx->encode_config.rcParams.initialRCQP.qpIntra =
> qp_inter_p * fabs(avctx->i_quant_factor);
> -            ctx->encode_config.rcParams.initialRCQP.qpIntra +=
> avctx->i_quant_offset;
> -            ctx->encode_config.rcParams.initialRCQP.qpInterB =
> qp_inter_p * fabs(avctx->b_quant_factor);
> -            ctx->encode_config.rcParams.initialRCQP.qpInterB +=
> avctx->b_quant_offset;
> +            ctx->encode_config.rcParams.initialRCQP.qpIntra = av_clip(
> +                qp_inter_p * fabs(avctx->i_quant_factor) +
> avctx->i_quant_offset, 0, 51);
> +            ctx->encode_config.rcParams.initialRCQP.qpInterB = av_clip(
> +                qp_inter_p * fabs(avctx->b_quant_factor) +
> avctx->b_quant_offset, 0, 51);
>           } else {
>               ctx->encode_config.rcParams.initialRCQP.qpIntra = qp_inter_p;
>               ctx->encode_config.rcParams.initialRCQP.qpInterB =
> qp_inter_p;

Hi all, before switching to the new released nvenc6.0 header, can you 
take a look at this fix?

Agatha Hu