[FFmpeg-devel] [PATCH 1/2] avcodec/jpeg2000dec: Set sample aspect ratio before getting buffer

[Andreas Rheinhardt]

Tomas Härdin:
> fre 2022-09-23 klockan 20:48 +0200 skrev Andreas Rheinhardt:
>> Tomas Härdin:
>>> fre 2022-09-23 klockan 17:40 +0200 skrev Andreas Rheinhardt:
>>>> That way the SAR will be automatically set on the AVFrame.
>>>>
>>>> Signed-off-by: Andreas Rheinhardt
>>>> <andreas.rheinhardt at outlook.com>
>>>> ---
>>>> If I am not mistaken, then the earlier code would set the sar
>>>> with a delay of one frame on the returned frames in case
>>>> there is a sar change mid-stream. But I don't have a sample
>>>> for this.
>>>>
>>>>  libavcodec/jpeg2000dec.c | 7 ++++---
>>>>  1 file changed, 4 insertions(+), 3 deletions(-)
>>>>
>>>> diff --git a/libavcodec/jpeg2000dec.c b/libavcodec/jpeg2000dec.c
>>>> index 7d9661f29f..c3f2a7aa03 100644
>>>> --- a/libavcodec/jpeg2000dec.c
>>>> +++ b/libavcodec/jpeg2000dec.c
>>>> @@ -2519,6 +2519,10 @@ static int
>>>> jpeg2000_decode_frame(AVCodecContext *avctx, AVFrame *picture,
>>>>      if (ret = jpeg2000_read_main_headers(s))
>>>>          goto end;
>>>>  
>>>> +    if (s->sar.num && s->sar.den)
>>>> +        avctx->sample_aspect_ratio = s->sar;
>>>> +    s->sar.num = s->sar.den = 0;
>>>> +
>>>>      /* get picture buffer */
>>>>      if ((ret = ff_thread_get_buffer(avctx, picture, 0)) < 0)
>>>>          goto end;
>>>> @@ -2547,9 +2551,6 @@ static int
>>>> jpeg2000_decode_frame(AVCodecContext
>>>> *avctx, AVFrame *picture,
>>>>  
>>>>      if (s->avctx->pix_fmt == AV_PIX_FMT_PAL8)
>>>>          memcpy(picture->data[1], s->palette, 256 *
>>>> sizeof(uint32_t));
>>>> -    if (s->sar.num && s->sar.den)
>>>> -        avctx->sample_aspect_ratio = s->sar;
>>>> -    s->sar.num = s->sar.den = 0;
>>>
>>> I suspect not doing this is what caused my simple hack to not work
>>> when
>>> ff_thread_get_buffer() was skipped. Looks OK, passes FATE.
>>>
>>
>> FYI: Patch two passes FATE even without patch one. In what way did
>> your
>> simple hack not work when ff_thread_get_buffer() is skipped?
> 
> I had it like patch attached. I suspect the reason it didn't work is
> because it sets *got_frame. If I run it then I get
> 
>   Assertion frame->buf[0] failed at libavcodec/decode.c:502
>   Avbruten (SIGABRT)
> 
> /Tomas
> 

Yeah, that's not how it's supposed to work. Will apply my patches.
Thanks for the review.

- Andreas