[FFmpeg-devel] [PATCH 2/3] libfdk-aacdec: Use the decoder's default level limiter settings

[James Almer]

On 2/5/2020 8:07 AM, Martin Storsjö wrote:
> It was disabled by default in 2dbd35b00c6433e587d5f44d5dbc8972ebbaa88e
> as it added delay, but now we compensate for the delay properly
> by offsetting timestamps.
> ---
>  libavcodec/libfdk-aacdec.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/libavcodec/libfdk-aacdec.c b/libavcodec/libfdk-aacdec.c
> index d9b080cf3e..32a97958c4 100644
> --- a/libavcodec/libfdk-aacdec.c
> +++ b/libavcodec/libfdk-aacdec.c
> @@ -81,7 +81,7 @@ static const AVOption fdk_aac_dec_options[] = {
>      { "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
> -    { "level_limit", "Signal level limiting", OFFSET(level_limit), AV_OPT_TYPE_INT, { .i64 = 0 }, -1, 1, AD },
> +    { "level_limit", "Signal level limiting (-1 auto, 0 off, 1 enabled)", OFFSET(level_limit), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, 1, AD },

You need to check that level_limit != -1, same as all the drc_* options
next to it in fdk_aac_decode_init(). Otherwise you'll call
aacDecoder_SetParam() with that value that's only meant to be
interpreted by this wrapper as "Let the decoder use its default".

>  #endif
>  #if FDKDEC_VER_AT_LEAST(3, 0) // 3.0.0
>      { "drc_effect","Dynamic Range Control: effect type, where e.g. [0] is none and [6] is general",
>