[FFmpeg-devel] [PATCH 3/3] libfdk-aacdec: Allow explicitly disabling the DRC reference level option

James Almer jamrial at gmail.com
Wed Feb 5 15:10:10 EET 2020


On 2/5/2020 8:07 AM, Martin Storsjö wrote:
> Previously, it was always left in the automatic mode, if the option
> was set to the only special (negative) value. Now there's two separate
> special values for this option, -1 for automatic (metadata based)
> and -2 for explicitly disabled.
> ---
>  libavcodec/libfdk-aacdec.c | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/libavcodec/libfdk-aacdec.c b/libavcodec/libfdk-aacdec.c
> index 32a97958c4..cc50fdce2f 100644
> --- a/libavcodec/libfdk-aacdec.c
> +++ b/libavcodec/libfdk-aacdec.c
> @@ -76,8 +76,8 @@ static const AVOption fdk_aac_dec_options[] = {
>                       OFFSET(drc_boost),      AV_OPT_TYPE_INT,   { .i64 = -1 }, -1, 127, AD, NULL    },
>      { "drc_cut",   "Dynamic Range Control: attenuation factor, where [0] is none and [127] is max compression",
>                       OFFSET(drc_cut),        AV_OPT_TYPE_INT,   { .i64 = -1 }, -1, 127, AD, NULL    },
> -    { "drc_level", "Dynamic Range Control: reference level, quantized to 0.25dB steps where [0] is 0dB and [127] is -31.75dB",
> -                     OFFSET(drc_level),      AV_OPT_TYPE_INT,   { .i64 = -1},  -1, 127, AD, NULL    },
> +    { "drc_level", "Dynamic Range Control: reference level, quantized to 0.25dB steps where [0] is 0dB and [127] is -31.75dB, -1 for auto, and -2 for disabled",

Not against adding this extra explanation here since this one is not a
simple boolean option, but i see there's no entry for fdk-aacdec in
decoders.texy, so could you add one with all the options described in it?

Bump micro, and LGTM.

> +                     OFFSET(drc_level),      AV_OPT_TYPE_INT,   { .i64 = -1},  -2, 127, AD, NULL    },
>      { "drc_heavy", "Dynamic Range Control: heavy compression, where [1] is on (RF mode) and [0] is off",
>                       OFFSET(drc_heavy),      AV_OPT_TYPE_INT,   { .i64 = -1},  -1, 1,   AD, NULL    },
>  #if FDKDEC_VER_AT_LEAST(2, 5) // 2.5.10
> @@ -298,6 +298,12 @@ static av_cold int fdk_aac_decode_init(AVCodecContext *avctx)
>      }
>  
>      if (s->drc_level != -1) {
> +        // This option defaults to -1, i.e. not calling
> +        // aacDecoder_SetParam(AAC_DRC_REFERENCE_LEVEL) at all, which defaults
> +        // to the level from DRC metadata, if available. The user can set
> +        // -drc_level -2, which calls aacDecoder_SetParam(
> +        // AAC_DRC_REFERENCE_LEVEL) with a negative value, which then
> +        // explicitly disables the feature.
>          if (aacDecoder_SetParam(s->handle, AAC_DRC_REFERENCE_LEVEL, s->drc_level) != AAC_DEC_OK) {
>              av_log(avctx, AV_LOG_ERROR, "Unable to set DRC reference level in the decoder\n");
>              return AVERROR_UNKNOWN;
> 



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