| Message ID | 20190910102239.23545-1-p.zabel@pengutronix.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] media: uapi: h264: clarify num_ref_idx_l[01]_(default_)active fields | expand |
diff --git a/Documentation/media/uapi/v4l/ext-ctrls-codec.rst b/Documentation/media/uapi/v4l/ext-ctrls-codec.rst index bc5dd8e76567..6b3bb71655a3 100644 --- a/Documentation/media/uapi/v4l/ext-ctrls-codec.rst +++ b/Documentation/media/uapi/v4l/ext-ctrls-codec.rst @@ -1820,10 +1820,12 @@ enum v4l2_mpeg_video_h264_hierarchical_coding_type - - * - __u8 - ``num_ref_idx_l0_active_minus1`` - - + - If num_ref_idx_active_override_flag is not set, this field must be + set to the value of num_ref_idx_l0_default_active_minus1. * - __u8 - ``num_ref_idx_l1_active_minus1`` - - + - If num_ref_idx_active_override_flag is not set, this field must be + set to the value of num_ref_idx_l1_default_active_minus1. * - __u32 - ``slice_group_change_cycle`` -
Since the uapi does not contain the num_ref_idx_active_override_flag, drivers for decoders that do not parse slices themselves don't know how to choose between the num_ref_idx_l[01]_default_active and the num_ref_idx_l[01]_active override fields. Instead, userspace must set the override fields to the default values if the slice does not have the num_ref_idx_active_override flag set. The drivers will then always enable the override internally and ignore the default fields completely. Clarify this requirement in the API documentation. Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> --- Changes since v1: - Drop sentences about num_ref_idx_l[011](_default)_active_minus1 fields only being used by decoders that do/do not parse slice headers. --- Documentation/media/uapi/v4l/ext-ctrls-codec.rst | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)