[FFmpeg-devel] [PATCH] avcodec/h264_ps: fix storage size for offset_for_ref_frame

[James Almer]

On 4/10/2019 3:30 PM, James Almer wrote:
> The spec defines the valid range of values to be INT32_MIN + 1 to INT32_MAX, inclusive.
> 
> Signed-off-by: James Almer <jamrial at gmail.com>
> ---
> A good example of why making offsets and sizes of structs like this tied to the
> ABI is not a good idea.
> 
>  libavcodec/h264_ps.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/libavcodec/h264_ps.h b/libavcodec/h264_ps.h
> index e967b9cbcf..9014326dfb 100644
> --- a/libavcodec/h264_ps.h
> +++ b/libavcodec/h264_ps.h
> @@ -81,7 +81,7 @@ typedef struct SPS {
>      uint32_t num_units_in_tick;
>      uint32_t time_scale;
>      int fixed_frame_rate_flag;
> -    short offset_for_ref_frame[256]; // FIXME dyn aloc?
> +    int32_t offset_for_ref_frame[256];

The doxy for get_se_golomb() doesn't mention the range of values it can
handle, but seeing there's also a get_se_golomb_long(), I guess the
relevant line in h264_ps.c should now use the latter instead?

>      int bitstream_restriction_flag;
>      int num_reorder_frames;
>      int scaling_matrix_present;
>