[FFmpeg-devel] [PATCH v2 28/36] vaapi_encode_h264: Set level based on stream if not set by user

[Xiang, Haihao]

On Fri, 2018-06-08 at 00:43 +0100, Mark Thompson wrote:
> ---
>  libavcodec/vaapi_encode_h264.c | 34 ++++++++++++++++++++++++++++++----
>  1 file changed, 30 insertions(+), 4 deletions(-)
> 
> diff --git a/libavcodec/vaapi_encode_h264.c b/libavcodec/vaapi_encode_h264.c
> index 82166d4457..4034053dc0 100644
> --- a/libavcodec/vaapi_encode_h264.c
> +++ b/libavcodec/vaapi_encode_h264.c
> @@ -30,6 +30,7 @@
>  #include "cbs.h"
>  #include "cbs_h264.h"
>  #include "h264.h"
> +#include "h264_levels.h"
>  #include "h264_sei.h"
>  #include "internal.h"
>  #include "vaapi_encode.h"
> @@ -294,6 +295,7 @@ static int
> vaapi_encode_h264_init_sequence_params(AVCodecContext *avctx)
>      H264RawPPS                        *pps = &priv->raw_pps;
>      VAEncSequenceParameterBufferH264 *vseq = ctx->codec_sequence_params;
>      VAEncPictureParameterBufferH264  *vpic = ctx->codec_picture_params;
> +    int dpb_frames;
>  
>      memset(&priv->current_access_unit, 0,
>             sizeof(priv->current_access_unit));
> @@ -319,7 +321,32 @@ static int
> vaapi_encode_h264_init_sequence_params(AVCodecContext *avctx)
>          sps->constraint_set5_flag = ctx->b_per_p == 0;
>      }
>  
> -    sps->level_idc = avctx->level;
> +    if (ctx->gop_size == 1)
> +        dpb_frames = 0;
> +    else
> +        dpb_frames = 1 + (ctx->b_per_p > 0);
> +
> +    if (avctx->level != FF_LEVEL_UNKNOWN) {
> +        sps->level_idc = avctx->level;

Is avctx->level always legal? if not, I think some checks on avctx->level should
be added.

> +    } else {
> +        const H264LevelDescriptor *level;
> +
> +        level = ff_h264_guess_level(sps->profile_idc,
> +                                    avctx->bit_rate,
> +                                    priv->mb_width  * 16,
> +                                    priv->mb_height * 16,
> +                                    dpb_frames);
> +        if (level) {
> +            av_log(avctx, AV_LOG_VERBOSE, "Using level %s.\n", level->name);
> +            if (level->constraint_set3_flag)
> +                sps->constraint_set3_flag = 1;
> +            sps->level_idc = level->level_idc;
> +        } else {
> +            av_log(avctx, AV_LOG_WARNING, "Stream will not conform "
> +                   "to any level: using level 6.2.\n");
> +            sps->level_idc = 62;
> +        }
> +    }
>  
>      sps->seq_parameter_set_id = 0;
>      sps->chroma_format_idc    = 1;
> @@ -329,8 +356,7 @@ static int
> vaapi_encode_h264_init_sequence_params(AVCodecContext *avctx)
>      sps->log2_max_pic_order_cnt_lsb_minus4 =
>          av_clip(av_log2(ctx->b_per_p + 1) - 2, 0, 12);
>  
> -    sps->max_num_ref_frames =
> -        ctx->gop_size == 1 ? 0 : 1 + (ctx->b_per_p > 0);
> +    sps->max_num_ref_frames = dpb_frames;
>  
>      sps->pic_width_in_mbs_minus1        = priv->mb_width  - 1;
>      sps->pic_height_in_map_units_minus1 = priv->mb_height - 1;
> @@ -1005,7 +1031,7 @@ static const AVOption vaapi_encode_h264_options[] = {
>  
>      { "level", "Set level (level_idc)",
>        OFFSET(level), AV_OPT_TYPE_INT,
> -      { .i64 = 51 }, 0x00, 0xff, FLAGS, "level" },
> +      { .i64 = FF_LEVEL_UNKNOWN }, FF_LEVEL_UNKNOWN, 0xff, FLAGS, "level" },
>  
>  #define LEVEL(name, value) name, NULL, 0, AV_OPT_TYPE_CONST, \
>        { .i64 = value }, 0, 0, FLAGS, "level"