[FFmpeg-devel] [PATCH] avcodec/atrac3: use AVCodec.init_static_data() to initialize static data

[Paul B Mahol]

On 1/6/17, James Almer <jamrial at gmail.com> wrote:
> On 1/6/2017 6:26 AM, Paul B Mahol wrote:
>> On 1/6/17, James Almer <jamrial at gmail.com> wrote:
>>> Signed-off-by: James Almer <jamrial at gmail.com>
>>> ---
>>>  libavcodec/atrac3.c | 8 ++------
>>>  1 file changed, 2 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/libavcodec/atrac3.c b/libavcodec/atrac3.c
>>> index 256990b..208762d 100644
>>> --- a/libavcodec/atrac3.c
>>> +++ b/libavcodec/atrac3.c
>>> @@ -771,7 +771,7 @@ static int atrac3_decode_frame(AVCodecContext *avctx,
>>> void *data,
>>>      return avctx->block_align;
>>>  }
>>>
>>> -static av_cold void atrac3_init_static_data(void)
>>> +static av_cold void atrac3_decode_init_static_data(AVCodec *codec)
>>>  {
>>>      int i;
>>>
>>> @@ -791,7 +791,6 @@ static av_cold void atrac3_init_static_data(void)
>>>
>>>  static av_cold int atrac3_decode_init(AVCodecContext *avctx)
>>>  {
>>> -    static int static_init_done;
>>>      int i, ret;
>>>      int version, delay, samples_per_frame, frame_factor;
>>>      const uint8_t *edata_ptr = avctx->extradata;
>>> @@ -802,10 +801,6 @@ static av_cold int atrac3_decode_init(AVCodecContext
>>> *avctx)
>>>          return AVERROR(EINVAL);
>>>      }
>>>
>>> -    if (!static_init_done)
>>> -        atrac3_init_static_data();
>>> -    static_init_done = 1;
>>> -
>>>      /* Take care of the codec-specific extradata. */
>>>      if (avctx->extradata_size == 14) {
>>>          /* Parse the extradata, WAV format */
>>> @@ -932,6 +927,7 @@ AVCodec ff_atrac3_decoder = {
>>>      .id               = AV_CODEC_ID_ATRAC3,
>>>      .priv_data_size   = sizeof(ATRAC3Context),
>>>      .init             = atrac3_decode_init,
>>> +    .init_static_data = atrac3_decode_init_static_data,
>>>      .close            = atrac3_decode_close,
>>>      .decode           = atrac3_decode_frame,
>>>      .capabilities     = AV_CODEC_CAP_SUBFRAMES | AV_CODEC_CAP_DR1,
>>> --
>>> 2.10.2
>>
>> The issue is that init_static_data is called even when codec is never
>> gonna be used.
>> And it is called for both encoder and decoder.
>>
>> Do we really want such startup speed and memory overhead?
>
> Supposedly hardcoded tables builds were added to counter that, at least
> partially.
>
> In any case it's not important for me, so this can be dropped if it has
> no real advantages. I remember more than one email from people loathing
> global state, so I assumed it would be proper to do it this way.

I have no real opinion on this, but maybe others do have?

We could add smarter init_static_data...