Le jeudi 20 août 2020 à 04:32 -0300, Ezequiel Garcia a écrit : > Hi Paul, > > On Wed, 2020-08-19 at 15:54 +0200, Paul Kocialkowski wrote: > > Hi, > > > > On Fri 07 Aug 20, 11:44, Ezequiel Garcia wrote: > > > On Thu, 2020-08-06 at 17:50 +0200, Paul Kocialkowski wrote: > > > > Hi, > > > > > > > > On Thu 06 Aug 20, 12:13, Ezequiel Garcia wrote: > > > > > The SLICE_PARAMS control is intended for slice-based > > > > > devices. In this mode, the OUTPUT buffer contains > > > > > a single slice, and so the buffer's plane payload size > > > > > can be used to query the slice size. > > > > > > > > If we later extend the API for supporting multiple slices with dynamic array > > > > controls, I guess we'll need to know the size of each slice in each control > > > > elements. So I'd rather keep that even if it's indeed redundant with > > > > vb2_get_plane_payload in single-slice mode. > > > > > > > > > > If we later extend the API, another control (possibly > > > another decoding mode?) shall be introduced. > > > > > > This API covers single-slice-per-request as specified > > > and documented in patch 9/14 "Clarify SLICE_BASED mode". > > > > > > This is along the lines of the proposal drafted by Nicolas, > > > see my reply: https://lkml.org/lkml/2020/8/5/791. > > > > > > This applies to num_slices, slice size and slice start offset. > > > > > > There are multiple ways of doing this. > > > > If feels a bit problematic to remove these fields without a clear plan yet > > on how to support multiple slices in the future. These may need to be added > > again later, except that it will be too late and new controls will need to be > > introduced. > > > > As Nicolas and I have repeatedly mentioned we do have a plan :) > > Nothing prevents us from implementing this now, but since it seems > we don't have any need since the 1-slice-per-buffer is working well, > there is no motivation for it. > > As you well mention, it does require new controls. This is > totally expected since new decoding semantics will need new controls. > > Here's my version of the plan: > > enum v4l2_mpeg_video_h264_decode_mode { > V4L2_MPEG_VIDEO_H264_DECODE_MODE_SLICE_BASED, > V4L2_MPEG_VIDEO_H264_DECODE_MODE_SLICE_ARRAY_BASED, > V4L2_MPEG_VIDEO_H264_DECODE_MODE_FRAME_BASED, > }; > > #define V4L2_CID_MPEG_VIDEO_H264_SLICE_ARRAY (V4L2_CID_MPEG_BASE+1008) > > struct v4l2_ctrl_h264_slice_array { > __u16 num_slices; > > struct v4l2_ctrl_h264_slice slices[16]; > } Well, ideally the new dynamic array control format can hold this information for us, avoiding the 16 slice limit again, but that is inded the plan. > > struct v4l2_ctrl_h264_slice { > __u32 size; > __u32 start_byte_offset; > struct v4l2_ctrl_h264_slice_params params; > } > > Now, the _specific_ way this will be done is not under > discussion at the moment. > > > Also, could we consider adding more reserved fields to handle such future needs? > > > > I have considered that (on each control), but I fail > to see the reason for it. The same may be said of all controls, > yet I don't think we bloat each one just in case. > > Thanks, > Ezequiel > > > Cheers, > > > > Paul > > > > > Thanks! > > > Ezequiel > > > > > > > What do you think? > > > > > > > > Paul > > > > > > > > > To reduce the API surface drop the size from the > > > > > SLICE_PARAMS control. > > > > > > > > > > A follow-up change will remove other members in SLICE_PARAMS > > > > > so we don't need to add padding fields here. > > > > > > > > > > Signed-off-by: Ezequiel Garcia <ezequiel@xxxxxxxxxxxxx> > > > > > --- > > > > > Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst | 3 --- > > > > > drivers/staging/media/sunxi/cedrus/cedrus_h264.c | 7 +++---- > > > > > include/media/h264-ctrls.h | 3 --- > > > > > 3 files changed, 3 insertions(+), 10 deletions(-) > > > > > > > > > > diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst > > > > > index 427fc5727ec0..fff74b7bf32a 100644 > > > > > --- a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst > > > > > +++ b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst > > > > > @@ -1760,9 +1760,6 @@ enum v4l2_mpeg_video_h264_hierarchical_coding_type - > > > > > :stub-columns: 0 > > > > > :widths: 1 1 2 > > > > > > > > > > - * - __u32 > > > > > - - ``size`` > > > > > - - > > > > > * - __u32 > > > > > - ``start_byte_offset`` > > > > > Offset (in bytes) from the beginning of the OUTPUT buffer to the start > > > > > diff --git a/drivers/staging/media/sunxi/cedrus/cedrus_h264.c b/drivers/staging/media/sunxi/cedrus/cedrus_h264.c > > > > > index a9ba78b15907..8b6f05aadbe8 100644 > > > > > --- a/drivers/staging/media/sunxi/cedrus/cedrus_h264.c > > > > > +++ b/drivers/staging/media/sunxi/cedrus/cedrus_h264.c > > > > > @@ -324,17 +324,16 @@ static void cedrus_set_params(struct cedrus_ctx *ctx, > > > > > struct vb2_buffer *src_buf = &run->src->vb2_buf; > > > > > struct cedrus_dev *dev = ctx->dev; > > > > > dma_addr_t src_buf_addr; > > > > > - u32 len = slice->size * 8; > > > > > + size_t slice_bytes = vb2_get_plane_payload(src_buf, 0); > > > > > unsigned int pic_width_in_mbs; > > > > > bool mbaff_pic; > > > > > u32 reg; > > > > > > > > > > - cedrus_write(dev, VE_H264_VLD_LEN, len); > > > > > + cedrus_write(dev, VE_H264_VLD_LEN, slice_bytes * 8); > > > > > cedrus_write(dev, VE_H264_VLD_OFFSET, 0); > > > > > > > > > > src_buf_addr = vb2_dma_contig_plane_dma_addr(src_buf, 0); > > > > > - cedrus_write(dev, VE_H264_VLD_END, > > > > > - src_buf_addr + vb2_get_plane_payload(src_buf, 0)); > > > > > + cedrus_write(dev, VE_H264_VLD_END, src_buf_addr + slice_bytes); > > > > > cedrus_write(dev, VE_H264_VLD_ADDR, > > > > > VE_H264_VLD_ADDR_VAL(src_buf_addr) | > > > > > VE_H264_VLD_ADDR_FIRST | VE_H264_VLD_ADDR_VALID | > > > > > diff --git a/include/media/h264-ctrls.h b/include/media/h264-ctrls.h > > > > > index 4f05ee265997..f74736fcfa00 100644 > > > > > --- a/include/media/h264-ctrls.h > > > > > +++ b/include/media/h264-ctrls.h > > > > > @@ -158,9 +158,6 @@ struct v4l2_h264_reference { > > > > > }; > > > > > > > > > > struct v4l2_ctrl_h264_slice_params { > > > > > - /* Size in bytes, including header */ > > > > > - __u32 size; > > > > > - > > > > > /* Offset in bytes to the start of slice in the OUTPUT buffer. */ > > > > > __u32 start_byte_offset; > > > > > > > > > > -- > > > > > 2.27.0 > > > > > > >
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