[FFmpeg-devel] [PATCHv2 2/3] libfdk-aacdec: Use the decoder's default level limiter settings

[Martin Storsjö]

On Fri, 7 Feb 2020, Martin Storsjö wrote:

> On Fri, 7 Feb 2020, James Almer wrote:
>
>> On 2/5/2020 10:06 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 | 3 ++-
>>>  1 file changed, 2 insertions(+), 1 deletion(-)
>>> 
>>> diff --git a/libavcodec/libfdk-aacdec.c 
> b/libavcodec/libfdk-aacdec.c
>>> index d9b080cf3e..b43226f515 100644
>>> --- a/libavcodec/libfdk-aacdec.c
>>> +++ b/libavcodec/libfdk-aacdec.c
>>> @@ -81,7 +81,8 @@ 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",
>>> +                     OFFSET(level_limit), 
> AV_OPT_TYPE_BOOL,  { .i64 = -1 }, -1, 1, AD },
>>>  #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",
>>
>> Meant to reply to this patch, sorry. Quoting here:
>>
>>> 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".
>
> The code already has this treatment of -1, see line 296 in 
> current master.

Sorry, I misread, that was a different option.

But -1 is actually treated by the decoder lib as explicit auto mode, which 
probably also is the default setting if the setting isn't set.

// Martin