[FFmpeg-devel] [PATCH v2] avcodec/libvpxenc: Apply codec options to alpha codec context

[James Zern]

On Fri, Sep 3, 2021 at 1:33 AM Adam Chelminski
<chelminski.adam at gmail.com> wrote:
>
> When encoding yuva420 (alpha) frames, the vpx encoder uses a second
> vpx_codec_ctx to encode the alpha stream. However, codec options were
> only being applied to the primary encoder. This patch updates
> codecctl_int and codecctl_intp to also apply codec options to the alpha
> codec context when encoding frames with alpha.
>
> This is necessary to take advantage of libvpx speed optimizations
> such as 'row-mt' and 'cpu-used' when encoding videos with alpha.
> Without this patch, the speed optimizations are only applied to the
> primary stream encoding, and the overall encoding is just as slow
> as it would be without the options specified.
>
> Signed-off-by: Adam Chelminski <chelminski.adam at gmail.com>
> ---
>  doc/APIchanges         |  4 ++++
>  libavcodec/libvpxenc.c | 26 ++++++++++++++++++++++++--
>  libavcodec/version.h   |  2 +-
>  3 files changed, 29 insertions(+), 3 deletions(-)
>

lgtm. One could argue that the alpha encoder should have its own set
of options to allow for a higher quality alpha plane, but I think
aligning the configurations makes sense given the current state of the
code. I'll submit this next week if there aren't any comments.

> diff --git a/doc/APIchanges b/doc/APIchanges
> index d58272ebd4..67603162a2 100644
> --- a/doc/APIchanges
> +++ b/doc/APIchanges
> @@ -14,6 +14,10 @@ libavutil:     2021-04-27
>
>  API changes, most recent first:
>
> +2021-09-03 - xxxxxxxxxx - lavc 59.7.101 - avcodec.h
> +  The libvpx encoder now passes command-line encoder options to the
> +  alpha stream encoder in addition to the primary stream encoder.
> +

This isn't an API change and is a little minor for the Changelog;
bumping the micro version should be enough for history tracking. I've
removed this locally.

>  2021-09-02 - xxxxxxxxxx - lavc 59.7.100 - avcodec.h
>    Incremented the number of elements of AVCodecParser.codec_ids to seven.
>
> diff --git a/libavcodec/libvpxenc.c b/libavcodec/libvpxenc.c
> index 0e50fbfd7c..f66345e998 100644
> --- a/libavcodec/libvpxenc.c
> +++ b/libavcodec/libvpxenc.c
> @@ -385,9 +385,20 @@ static av_cold int codecctl_int(AVCodecContext *avctx,
>          snprintf(buf, sizeof(buf), "Failed to set %s codec control",
>                   ctlidstr[id]);
>          log_encoder_error(avctx, buf);
> +        return AVERROR(EINVAL);
>      }
>
> -    return res == VPX_CODEC_OK ? 0 : AVERROR(EINVAL);
> +    if (ctx->is_alpha) {
> +        int res_alpha = vpx_codec_control(&ctx->encoder_alpha, id, val);
> +        if (res_alpha != VPX_CODEC_OK) {
> +            snprintf(buf, sizeof(buf), "Failed to set %s alpha codec control",
> +                     ctlidstr[id]);
> +            log_encoder_error(avctx, buf);
> +            return AVERROR(EINVAL);
> +        }
> +    }
> +
> +    return 0;
>  }
>
>  #if VPX_ENCODER_ABI_VERSION >= 12
> @@ -407,9 +418,20 @@ static av_cold int codecctl_intp(AVCodecContext *avctx,
>          snprintf(buf, sizeof(buf), "Failed to set %s codec control",
>                   ctlidstr[id]);
>          log_encoder_error(avctx, buf);
> +        return AVERROR(EINVAL);
>      }
>
> -    return res == VPX_CODEC_OK ? 0 : AVERROR(EINVAL);
> +    if (ctx->is_alpha) {
> +        int res_alpha = vpx_codec_control(&ctx->encoder_alpha, id, val);
> +        if (res_alpha != VPX_CODEC_OK) {
> +            snprintf(buf, sizeof(buf), "Failed to set %s alpha codec control",
> +                     ctlidstr[id]);
> +            log_encoder_error(avctx, buf);
> +            return AVERROR(EINVAL);
> +        }
> +    }
> +
> +    return 0;
>  }
>  #endif
>
> diff --git a/libavcodec/version.h b/libavcodec/version.h
> index 7faf18a497..7839bf945d 100644
> --- a/libavcodec/version.h
> +++ b/libavcodec/version.h
> @@ -29,7 +29,7 @@
>
>  #define LIBAVCODEC_VERSION_MAJOR  59
>  #define LIBAVCODEC_VERSION_MINOR   7
> -#define LIBAVCODEC_VERSION_MICRO 100
> +#define LIBAVCODEC_VERSION_MICRO 101
>
>  #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
>                                                 LIBAVCODEC_VERSION_MINOR, \
> --
> 2.25.1
>
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