To express a frame rate, such as 7.5, we have to use 'numerator / denominator'. The high 2 bytes will be used as denominator and the low 2 bytes will be used as numerator.
To keep backward compatible, the low 2 bytes is the real frame rate when the high 2 bytes is 0. Signed-off-by: Xiang, Haihao <[email protected]> --- va/va.h | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/va/va.h b/va/va.h index ed5bb73..33cfde2 100644 --- a/va/va.h +++ b/va/va.h @@ -1258,6 +1258,14 @@ typedef struct _VAEncMiscParameterRateControl typedef struct _VAEncMiscParameterFrameRate { + /* + * fps = numerator / denominator + * The high 2 bytes (bits 16 to 31) of framerate specifies the numerator, and + * the low 2 bytes (bits 0 to 15) of framerate specifies the denominator. For + * example, ((100 < 16 ) | 750) is 7.5 fps + * + * If the high 2 btyes is 0, the frame rate is specified by the low 2 bytes. + */ unsigned int framerate; union { -- 1.9.1 _______________________________________________ Libva mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/libva
