[FFmpeg-devel] [PATCH 15/26] vaapi_encode: Clean up rate control configuration

Xiang, Haihao haihao.xiang at intel.com
Fri Apr 27 07:10:49 EEST 2018


On Sun, 2018-04-22 at 16:29 +0100, Mark Thompson wrote:
> Query which modes are supported and select between VBR and CBR based
> on that.  Removes all of the codec-specific rate control mode selection
> code.  Also ensures that target percentage and window size match the
> target bitrate and RC buffer size in all cases where they are not
> explicitly specified.
> ---
>  doc/encoders.texi               |   2 -
>  libavcodec/vaapi_encode.c       | 166 ++++++++++++++++++++++++++++-----------
> -
>  libavcodec/vaapi_encode.h       |   4 +-
>  libavcodec/vaapi_encode_h264.c  |  12 ---
>  libavcodec/vaapi_encode_h265.c  |  12 ---
>  libavcodec/vaapi_encode_mjpeg.c |   3 +-
>  libavcodec/vaapi_encode_mpeg2.c |   3 +-
>  libavcodec/vaapi_encode_vp8.c   |  11 ---
>  libavcodec/vaapi_encode_vp9.c   |  11 ---
>  9 files changed, 119 insertions(+), 105 deletions(-)
> 
> diff --git a/doc/encoders.texi b/doc/encoders.texi
> index 62a1509a96..0c0a307987 100644
> --- a/doc/encoders.texi
> +++ b/doc/encoders.texi
> @@ -2643,8 +2643,6 @@ Always encodes using the standard quantisation and
> huffman tables -
>  @item mpeg2_vaapi
>  @option{profile} and @option{level} set the value of
> @emph{profile_and_level_indication}.
>  
> -No rate control is supported.
> -
>  @item vp8_vaapi
>  B-frames are not supported.
>  
> diff --git a/libavcodec/vaapi_encode.c b/libavcodec/vaapi_encode.c
> index fc83d3db11..6188423935 100644
> --- a/libavcodec/vaapi_encode.c
> +++ b/libavcodec/vaapi_encode.c
> @@ -1207,7 +1207,6 @@ static av_cold int
> vaapi_encode_config_attributes(AVCodecContext *avctx)
>      int i;
>  
>      VAConfigAttrib attr[] = {
> -        { VAConfigAttribRateControl      },
>          { VAConfigAttribEncMaxRefFrames  },
>          { VAConfigAttribEncPackedHeaders },
>      };
> @@ -1231,32 +1230,6 @@ static av_cold int
> vaapi_encode_config_attributes(AVCodecContext *avctx)
>              continue;
>          }
>          switch (attr[i].type) {
> -        case VAConfigAttribRateControl:
> -            // Hack for backward compatibility: CBR was the only
> -            // usable RC mode for a long time, so old drivers will
> -            // only have it.  Normal default options may now choose
> -            // VBR and then fail, however, so override it here with
> -            // CBR if that is the only supported mode.
> -            if (ctx->va_rc_mode == VA_RC_VBR &&
> -                !(attr[i].value & VA_RC_VBR) &&
> -                (attr[i].value & VA_RC_CBR)) {
> -                av_log(avctx, AV_LOG_WARNING, "VBR rate control is "
> -                       "not supported with this driver version; "
> -                       "using CBR instead.\n");
> -                ctx->va_rc_mode = VA_RC_CBR;
> -            }
> -            if (!(ctx->va_rc_mode & attr[i].value)) {
> -                av_log(avctx, AV_LOG_ERROR, "Rate control mode %#x "
> -                       "is not supported (mask: %#x).\n",
> -                       ctx->va_rc_mode, attr[i].value);
> -                return AVERROR(EINVAL);
> -            }
> -            ctx->config_attributes[ctx->nb_config_attributes++] =
> -                (VAConfigAttrib) {
> -                .type  = VAConfigAttribRateControl,
> -                .value = ctx->va_rc_mode,
> -            };
> -            break;
>          case VAConfigAttribEncMaxRefFrames:
>          {
>              unsigned int ref_l0 = attr[i].value & 0xffff;
> @@ -1303,16 +1276,46 @@ static av_cold int
> vaapi_encode_config_attributes(AVCodecContext *avctx)
>  static av_cold int vaapi_encode_init_rate_control(AVCodecContext *avctx)
>  {
>      VAAPIEncodeContext *ctx = avctx->priv_data;
> -    int rc_bits_per_second;
> -    int rc_target_percentage;
> -    int rc_window_size;
> -    int hrd_buffer_size;
> -    int hrd_initial_buffer_fullness;
> +    int64_t rc_bits_per_second;
> +    int     rc_target_percentage;
> +    int     rc_window_size;
> +    int64_t hrd_buffer_size;
> +    int64_t hrd_initial_buffer_fullness;
>      int fr_num, fr_den;
> +    VAConfigAttrib rc_attr = { VAConfigAttribRateControl };
> +    VAStatus vas;
> +
> +    vas = vaGetConfigAttributes(ctx->hwctx->display,
> +                                ctx->va_profile, ctx->va_entrypoint,
> +                                &rc_attr, 1);
> +    if (vas != VA_STATUS_SUCCESS) {
> +        av_log(avctx, AV_LOG_ERROR, "Failed to query rate control "
> +               "config attribute: %d (%s).\n", vas, vaErrorStr(vas));
> +        return AVERROR_EXTERNAL;
> +    }
>  
> -    if (avctx->bit_rate > INT32_MAX) {
> -        av_log(avctx, AV_LOG_ERROR, "Target bitrate of 2^31 bps or "
> -               "higher is not supported.\n");
> +    if (rc_attr.value == VA_ATTRIB_NOT_SUPPORTED) {
> +        av_log(avctx, AV_LOG_VERBOSE, "Driver does not report any "
> +               "supported rate control modes: assuming constant-quality.\n");
> +        ctx->va_rc_mode = VA_RC_CQP;
> +        return 0;
> +    }
> +    if (avctx->flags & AV_CODEC_FLAG_QSCALE ||
> +        avctx->bit_rate <= 0) {
> +        if (rc_attr.value & VA_RC_CQP) {
> +            av_log(avctx, AV_LOG_VERBOSE, "Using constant-quality mode.\n");
> +            ctx->va_rc_mode = VA_RC_CQP;
> +            return 0;
> +        } else {
> +            av_log(avctx, AV_LOG_ERROR, "Driver does not support "
> +                   "constant-quality mode (%#x).\n", rc_attr.value);
> +            return AVERROR(EINVAL);
> +        }
> +    }
> +
> +    if (!(rc_attr.value & (VA_RC_CBR | VA_RC_VBR))) {
> +        av_log(avctx, AV_LOG_ERROR, "Driver does not support any "
> +               "bitrate-targetted rate control modes.\n");
>          return AVERROR(EINVAL);
>      }
>  
> @@ -1320,27 +1323,90 @@ static av_cold int
> vaapi_encode_init_rate_control(AVCodecContext *avctx)
>          hrd_buffer_size = avctx->rc_buffer_size;
>      else
>          hrd_buffer_size = avctx->bit_rate;
> -    if (avctx->rc_initial_buffer_occupancy)
> +    if (avctx->rc_initial_buffer_occupancy) {
> +        if (avctx->rc_initial_buffer_occupancy > hrd_buffer_size) {
> +            av_log(avctx, AV_LOG_ERROR, "Invalid RC buffer settings: "
> +                   "must have initial buffer size (%d) < "
> +                   "buffer size (%"PRId64").\n",
> +                   avctx->rc_initial_buffer_occupancy, hrd_buffer_size);
> +            return AVERROR(EINVAL);
> +        }
>          hrd_initial_buffer_fullness = avctx->rc_initial_buffer_occupancy;
> -    else
> +    } else {
>          hrd_initial_buffer_fullness = hrd_buffer_size * 3 / 4;
> +    }
> +
> +    if (avctx->rc_max_rate && avctx->rc_max_rate < avctx->bit_rate) {
> +        av_log(avctx, AV_LOG_ERROR, "Invalid bitrate settings: must have "
> +               "bitrate (%"PRId64") <= maxrate (%"PRId64").\n",
> +               avctx->bit_rate, avctx->rc_max_rate);
> +        return AVERROR(EINVAL);
> +    }
> +
> +    if (avctx->rc_max_rate > avctx->bit_rate) {
> +        if (!(rc_attr.value & VA_RC_VBR)) {
> +            av_log(avctx, AV_LOG_WARNING, "Driver does not support "
> +                   "VBR mode (%#x), using CBR mode instead.\n",
> +                   rc_attr.value);
> +            ctx->va_rc_mode = VA_RC_CBR;
> +        } else {
> +            ctx->va_rc_mode = VA_RC_VBR;
> +        }
> +
> +        rc_bits_per_second   = avctx->rc_max_rate;
> +        rc_target_percentage = (avctx->bit_rate * 100) / avctx->rc_max_rate;
> +
> +    } else if (avctx->rc_max_rate == avctx->bit_rate) {
> +        if (!(rc_attr.value & VA_RC_CBR)) {
> +            av_log(avctx, AV_LOG_WARNING, "Driver does not support "
> +                   "CBR mode (%#x), using VBR mode instead.\n",
> +                   rc_attr.value);
> +            ctx->va_rc_mode = VA_RC_VBR;
> +        } else {
> +            ctx->va_rc_mode = VA_RC_CBR;
> +        }
>  
> -    if (ctx->va_rc_mode == VA_RC_CBR) {
>          rc_bits_per_second   = avctx->bit_rate;
>          rc_target_percentage = 100;
> -        rc_window_size       = 1000;
> +
>      } else {
> -        if (avctx->rc_max_rate < avctx->bit_rate) {
> -            // Max rate is unset or invalid, just use the normal bitrate.
> +        if (rc_attr.value & VA_RC_VBR) {
> +            ctx->va_rc_mode = VA_RC_VBR;
> +
> +            rc_bits_per_second   = avctx->bit_rate + hrd_buffer_size;

Why hrd_buffer_size is added? User may set a large hrd buffer size. 

> +            rc_target_percentage = (avctx->bit_rate * 100) /
> rc_bits_per_second;
> +        } else {
> +            ctx->va_rc_mode = VA_RC_CBR;
> +
>              rc_bits_per_second   = avctx->bit_rate;
>              rc_target_percentage = 100;
> -        } else {
> -            rc_bits_per_second   = avctx->rc_max_rate;
> -            rc_target_percentage = (avctx->bit_rate * 100) /
> rc_bits_per_second;
>          }
> -        rc_window_size = (hrd_buffer_size * 1000) / avctx->bit_rate;
>      }
>  
> +    rc_window_size = ((int64_t)hrd_buffer_size * 100 * 1000) /
> +                   (rc_target_percentage * rc_bits_per_second);

I think it should be (hrd_buffer_size * 1000) / rc_bits_per_second. Could you
explain why is it multiplied by (100 / rc_target_percentage) here?

> +
> +    av_log(avctx, AV_LOG_VERBOSE, "RC mode: %s, %d%% of %"PRId64" bps "
> +           "over %d ms.\n", ctx->va_rc_mode == VA_RC_VBR ? "VBR" : "CBR",
> +           rc_target_percentage, rc_bits_per_second, rc_window_size);
> +    av_log(avctx, AV_LOG_VERBOSE, "RC buffer: %"PRId64" bits, "
> +           "initial fullness %"PRId64" bits.\n",
> +           hrd_buffer_size, hrd_initial_buffer_fullness);
> +
> +    if (rc_bits_per_second          > UINT32_MAX ||
> +        hrd_buffer_size             > UINT32_MAX ||
> +        hrd_initial_buffer_fullness > UINT32_MAX) {
> +        av_log(avctx, AV_LOG_ERROR, "RC parameters of 2^32 or "
> +               "greater are not supported by VAAPI.\n");
> +        return AVERROR(EINVAL);
> +    }
> +
> +    ctx->config_attributes[ctx->nb_config_attributes++] =
> +        (VAConfigAttrib) {
> +        .type  = VAConfigAttribRateControl,
> +        .value = ctx->va_rc_mode,
> +    };
> +
>      ctx->rc_params.misc.type = VAEncMiscParameterTypeRateControl;
>      ctx->rc_params.rc = (VAEncMiscParameterRateControl) {
>          .bits_per_second   = rc_bits_per_second,
> @@ -1602,6 +1668,10 @@ av_cold int ff_vaapi_encode_init(AVCodecContext *avctx)
>      if (err < 0)
>          goto fail;
>  
> +    err = vaapi_encode_init_rate_control(avctx);
> +    if (err < 0)
> +        goto fail;
> +
>      err = vaapi_encode_config_attributes(avctx);
>      if (err < 0)
>          goto fail;
> @@ -1651,12 +1721,6 @@ av_cold int ff_vaapi_encode_init(AVCodecContext *avctx)
>          goto fail;
>      }
>  
> -    if (ctx->va_rc_mode & ~VA_RC_CQP) {
> -        err = vaapi_encode_init_rate_control(avctx);
> -        if (err < 0)
> -            goto fail;
> -    }
> -
>      if (ctx->codec->configure) {
>          err = ctx->codec->configure(avctx);
>          if (err < 0)
> diff --git a/libavcodec/vaapi_encode.h b/libavcodec/vaapi_encode.h
> index 35d48eff2f..3fb39113a4 100644
> --- a/libavcodec/vaapi_encode.h
> +++ b/libavcodec/vaapi_encode.h
> @@ -118,8 +118,6 @@ typedef struct VAAPIEncodeContext {
>      // Use low power encoding mode.
>      int             low_power;
>  
> -    // Rate control mode.
> -    unsigned int    va_rc_mode;
>      // Supported packed headers (initially the desired set, modified
>      // later to what is actually supported).
>      unsigned int    va_packed_headers;
> @@ -140,6 +138,8 @@ typedef struct VAAPIEncodeContext {
>      VAProfile       va_profile;
>      // Encoding entrypoint (VAEntryoint*).
>      VAEntrypoint    va_entrypoint;
> +    // Rate control mode.
> +    unsigned int    va_rc_mode;
>  
>      // Configuration attributes to use when creating va_config.
>      VAConfigAttrib  config_attributes[MAX_CONFIG_ATTRIBUTES];
> diff --git a/libavcodec/vaapi_encode_h264.c b/libavcodec/vaapi_encode_h264.c
> index a20cf15c1e..e75b91eb55 100644
> --- a/libavcodec/vaapi_encode_h264.c
> +++ b/libavcodec/vaapi_encode_h264.c
> @@ -819,10 +819,6 @@ static av_cold int
> vaapi_encode_h264_configure(AVCodecContext *avctx)
>          priv->fixed_qp_p   = 26;
>          priv->fixed_qp_b   = 26;
>  
> -        av_log(avctx, AV_LOG_DEBUG, "Using %s-bitrate = %"PRId64" bps.\n",
> -               ctx->va_rc_mode == VA_RC_CBR ? "constant" : "variable",
> -               avctx->bit_rate);
> -
>      } else {
>          av_assert0(0 && "Invalid RC mode.");
>      }
> @@ -928,14 +924,6 @@ static av_cold int vaapi_encode_h264_init(AVCodecContext
> *avctx)
>          return AVERROR_PATCHWELCOME;
>      }
>  
> -    if (avctx->bit_rate > 0) {
> -        if (avctx->rc_max_rate == avctx->bit_rate)
> -            ctx->va_rc_mode = VA_RC_CBR;
> -        else
> -            ctx->va_rc_mode = VA_RC_VBR;
> -    } else
> -        ctx->va_rc_mode = VA_RC_CQP;
> -
>      ctx->va_packed_headers =
>          VA_ENC_PACKED_HEADER_SEQUENCE | // SPS and PPS.
>          VA_ENC_PACKED_HEADER_SLICE    | // Slice headers.
> diff --git a/libavcodec/vaapi_encode_h265.c b/libavcodec/vaapi_encode_h265.c
> index a818650811..fa9d838bdc 100644
> --- a/libavcodec/vaapi_encode_h265.c
> +++ b/libavcodec/vaapi_encode_h265.c
> @@ -864,10 +864,6 @@ static av_cold int
> vaapi_encode_h265_configure(AVCodecContext *avctx)
>          priv->fixed_qp_p   = 30;
>          priv->fixed_qp_b   = 30;
>  
> -        av_log(avctx, AV_LOG_DEBUG, "Using %s-bitrate = %"PRId64" bps.\n",
> -               ctx->va_rc_mode == VA_RC_CBR ? "constant" : "variable",
> -               avctx->bit_rate);
> -
>      } else {
>          av_assert0(0 && "Invalid RC mode.");
>      }
> @@ -924,14 +920,6 @@ static av_cold int vaapi_encode_h265_init(AVCodecContext
> *avctx)
>      if (avctx->level == FF_LEVEL_UNKNOWN)
>          avctx->level = priv->level;
>  
> -    if (avctx->bit_rate > 0) {
> -        if (avctx->rc_max_rate == avctx->bit_rate)
> -            ctx->va_rc_mode = VA_RC_CBR;
> -        else
> -            ctx->va_rc_mode = VA_RC_VBR;
> -    } else
> -        ctx->va_rc_mode = VA_RC_CQP;
> -
>      ctx->va_packed_headers =
>          VA_ENC_PACKED_HEADER_SEQUENCE | // VPS, SPS and PPS.
>          VA_ENC_PACKED_HEADER_SLICE;     // Slice headers.
> diff --git a/libavcodec/vaapi_encode_mjpeg.c b/libavcodec/vaapi_encode_mjpeg.c
> index 3baf5c8915..77104583bf 100644
> --- a/libavcodec/vaapi_encode_mjpeg.c
> +++ b/libavcodec/vaapi_encode_mjpeg.c
> @@ -388,8 +388,6 @@ static av_cold int vaapi_encode_mjpeg_init(AVCodecContext
> *avctx)
>  
>      ctx->codec = &vaapi_encode_type_mjpeg;
>  
> -    ctx->va_rc_mode = VA_RC_CQP;
> -
>      // The JPEG image header - see note above.
>      ctx->va_packed_headers =
>          VA_ENC_PACKED_HEADER_RAW_DATA;
> @@ -402,6 +400,7 @@ static av_cold int vaapi_encode_mjpeg_init(AVCodecContext
> *avctx)
>  
>  static const AVCodecDefault vaapi_encode_mjpeg_defaults[] = {
>      { "global_quality", "80" },
> +    { "b",              "0"  },
>      { NULL },
>  };
>  
> diff --git a/libavcodec/vaapi_encode_mpeg2.c b/libavcodec/vaapi_encode_mpeg2.c
> index 09c3663220..b7189b2d67 100644
> --- a/libavcodec/vaapi_encode_mpeg2.c
> +++ b/libavcodec/vaapi_encode_mpeg2.c
> @@ -615,8 +615,6 @@ static av_cold int vaapi_encode_mpeg2_init(AVCodecContext
> *avctx)
>          return AVERROR(EINVAL);
>      }
>  
> -    ctx->va_rc_mode    = VA_RC_CQP;
> -
>      ctx->va_packed_headers = VA_ENC_PACKED_HEADER_SEQUENCE |
>                               VA_ENC_PACKED_HEADER_PICTURE;
>  
> @@ -667,6 +665,7 @@ static const AVOption vaapi_encode_mpeg2_options[] = {
>  };
>  
>  static const AVCodecDefault vaapi_encode_mpeg2_defaults[] = {
> +    { "b",              "0"   },
>      { "bf",             "1"   },
>      { "g",              "120" },
>      { "i_qfactor",      "1"   },
> diff --git a/libavcodec/vaapi_encode_vp8.c b/libavcodec/vaapi_encode_vp8.c
> index d9c359a4e1..dd7943133e 100644
> --- a/libavcodec/vaapi_encode_vp8.c
> +++ b/libavcodec/vaapi_encode_vp8.c
> @@ -203,17 +203,6 @@ static av_cold int vaapi_encode_vp8_init(AVCodecContext
> *avctx)
>  
>      ctx->codec = &vaapi_encode_type_vp8;
>  
> -    if (avctx->flags & AV_CODEC_FLAG_QSCALE) {
> -        ctx->va_rc_mode = VA_RC_CQP;
> -    } else if (avctx->bit_rate > 0) {
> -        if (avctx->rc_max_rate == avctx->bit_rate)
> -            ctx->va_rc_mode = VA_RC_CBR;
> -        else
> -            ctx->va_rc_mode = VA_RC_VBR;
> -    } else {
> -        ctx->va_rc_mode = VA_RC_CQP;
> -    }
> -
>      // Packed headers are not currently supported.
>      ctx->va_packed_headers = 0;
>  
> diff --git a/libavcodec/vaapi_encode_vp9.c b/libavcodec/vaapi_encode_vp9.c
> index eabacbd0fd..794b308fa5 100644
> --- a/libavcodec/vaapi_encode_vp9.c
> +++ b/libavcodec/vaapi_encode_vp9.c
> @@ -227,17 +227,6 @@ static av_cold int vaapi_encode_vp9_init(AVCodecContext
> *avctx)
>  
>      ctx->codec = &vaapi_encode_type_vp9;
>  
> -    if (avctx->flags & AV_CODEC_FLAG_QSCALE) {
> -        ctx->va_rc_mode = VA_RC_CQP;
> -    } else if (avctx->bit_rate > 0) {
> -        if (avctx->bit_rate == avctx->rc_max_rate)
> -            ctx->va_rc_mode = VA_RC_CBR;
> -        else
> -            ctx->va_rc_mode = VA_RC_VBR;
> -    } else {
> -        ctx->va_rc_mode = VA_RC_CQP;
> -    }
> -
>      // Packed headers are not currently supported.
>      ctx->va_packed_headers = 0;
>  


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