[FFmpeg-devel] [PATCH v3 2/3] avcodec/libopenh264enc: make the profile configuablable correctly

[Martin Storsjö]

On Fri, 14 Jan 2022, lance.lmwang at gmail.com wrote:

> From: Limin Wang <lance.lmwang at gmail.com>
>
> due to the limitations set in d3a7bdd4ac54349aea9150a234478635d50ebd87,
> you weren't able to use main profile with OpenH264 1.8, or high profile
> with older versions
>
> Reviewed-by: Martin Storsjö <martin at martin.st>
> Signed-off-by: Limin Wang <lance.lmwang at gmail.com>
> ---
> libavcodec/libopenh264enc.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/libavcodec/libopenh264enc.c b/libavcodec/libopenh264enc.c
> index 5b5914c..1bad233 100644
> --- a/libavcodec/libopenh264enc.c
> +++ b/libavcodec/libopenh264enc.c
> @@ -220,26 +220,25 @@ static av_cold int svc_encode_init(AVCodecContext *avctx)
> #endif
>
>     switch (s->profile) {
> -#if OPENH264_VER_AT_LEAST(1, 8)
>     case FF_PROFILE_H264_HIGH:
>         param.iEntropyCodingModeFlag = 1;
>         av_log(avctx, AV_LOG_VERBOSE, "Using CABAC, "
>                 "select EProfileIdc PRO_HIGH in libopenh264.\n");
>         break;
> -#else
>     case FF_PROFILE_H264_MAIN:
>         param.iEntropyCodingModeFlag = 1;
>         av_log(avctx, AV_LOG_VERBOSE, "Using CABAC, "
>                 "select EProfileIdc PRO_MAIN in libopenh264.\n");
>         break;
> -#endif
> -    case FF_PROFILE_H264_CONSTRAINED_BASELINE:
>     case FF_PROFILE_UNKNOWN:
> +        s->profile = FF_PROFILE_H264_CONSTRAINED_BASELINE;
> +    case FF_PROFILE_H264_CONSTRAINED_BASELINE:

I don't think it's specifically necessary to move the case labels around 
like this; you could just leave both case labels above it, and the 
assignment would be a no-op for one case. (No need to resend the patch for 
that, do whichever form you prefer.)

>         param.iEntropyCodingModeFlag = 0;
>         av_log(avctx, AV_LOG_VERBOSE, "Using CAVLC, "
>                "select EProfileIdc PRO_BASELINE in libopenh264.\n");
>         break;
>     default:
> +        s->profile = FF_PROFILE_H264_CONSTRAINED_BASELINE;
>         param.iEntropyCodingModeFlag = 0;
>         av_log(avctx, AV_LOG_WARNING, "Unsupported profile, "
>                "select EProfileIdc PRO_BASELINE in libopenh264.\n");
> @@ -251,6 +250,7 @@ static av_cold int svc_encode_init(AVCodecContext *avctx)
>     param.sSpatialLayers[0].fFrameRate          = param.fMaxFrameRate;
>     param.sSpatialLayers[0].iSpatialBitrate     = param.iTargetBitrate;
>     param.sSpatialLayers[0].iMaxSpatialBitrate  = param.iMaxBitrate;
> +    param.sSpatialLayers[0].uiProfileIdc        = s->profile;

Thanks, this seems sensible to me. This is ok if you've tested that 
setting profile to FF_PROFILE_H264_CONSTRAINED_BASELINE (as opposed to 
PRO_BASELINE) does work with both some old and some recent version of 
OpenH264.

// Martin