[FFmpeg-devel] [PATCH 1/5] avutil/frame: add new interlaced and top_field_first flags

[James Almer]

On 4/17/2023 7:49 AM, Anton Khirnov wrote:
> Quoting James Almer (2023-04-12 21:49:32)
>> Signed-off-by: James Almer <jamrial at gmail.com>
>> ---
>> Missing version bump and APIChanges entry.
>>
>>   libavutil/frame.h | 9 +++++++++
>>   1 file changed, 9 insertions(+)
>>
> 
> Changing all those into bitfields of size 1 might be better, because no
> code would need to be changed.

Can you elaborate on this? If i do

> diff --git a/libavutil/frame.h b/libavutil/frame.h
> index f85d630c5c..3f3deab657 100644
> --- a/libavutil/frame.h
> +++ b/libavutil/frame.h
> @@ -494,12 +494,12 @@ typedef struct AVFrame {
>      /**
>       * The content of the picture is interlaced.
>       */
> -    int interlaced_frame;
> +    int interlaced_frame: 1;
> 
>      /**
>       * If the content is interlaced, is top field displayed first.
>       */
> -    int top_field_first;
> +    int top_field_first: 1;
> 
>      /**
>       * Tell user application that palette has changed from previous frame.

It's not only an ABI break, but i assume the compiler will still 
pad/align the struct for the next field, so you're not saving many bytes.