On 01/03/2019 04:15 PM, Dafna Hirschfeld wrote:
> On Wed, Jan 2, 2019 at 12:22 PM Hans Verkuil <[email protected]> wrote:
<snip>
>>> > if (frm->components_num >= 3) {
>>> > - u32 chroma_h = frm->height / frm->height_div;
>>> > - u32 chroma_w = frm->width / frm->width_div;
>>> > + u32 chroma_h = height / frm->height_div;
>>> > + u32 chroma_w = width / frm->width_div;
>>> > + u32 chroma_coded_width = frm->coded_width /
>>> frm->width_div;
>>>
>>> chroma_stride = frm->stride / frm->width_div;
>
> This calculation of chroma_stride does not work for formats such as
> YUYV where frm->width_div = 2 but the chromas are not in separate
> planes.
> How do I calculate the stride in general ?
For interleaved formats like YUYV the stride is equal to bytesperline.
To be more precise: bytesperline is the stride for the first plane. Since YUYV
formats have only one plane, that stride is valid for all color components.
> For yuv420 for example, where the chromas are in separate planes, is
> 'chroma_stride = stride / 2' ?
Yes.
>
>>>
>>> > unsigned int chroma_size = chroma_h * chroma_w;
>>> >
>>> > rlco_max = rlco + chroma_size / 2 - 256;
>>> > encoding |= encode_plane(frm->cb, ref_frm->cb, &rlco,
>>> rlco_max,
>>> > cf, chroma_h, chroma_w,
>>> > - frm->chroma_step,
>>> > + chroma_coded_width,
>>> frm->chroma_step,
>>> > is_intra, next_is_intra);
>>> > if (encoding & FWHT_FRAME_UNENCODED)
>>> > encoding |= FWHT_CB_UNENCODED;
>>> > @@ -778,7 +784,7 @@ u32 fwht_encode_frame(struct fwht_raw_frame *frm,
>>> > rlco_max = rlco + chroma_size / 2 - 256;
>>> > encoding |= encode_plane(frm->cr, ref_frm->cr, &rlco,
>>> rlco_max,
>>> > cf, chroma_h, chroma_w,
>>> > - frm->chroma_step,
>>> > + chroma_coded_width,
>>> frm->chroma_step,
>>> > is_intra, next_is_intra);
>>> > if (encoding & FWHT_FRAME_UNENCODED)
>>> > encoding |= FWHT_CR_UNENCODED;
>>> > @@ -788,8 +794,8 @@ u32 fwht_encode_frame(struct fwht_raw_frame *frm,
>>> > if (frm->components_num == 4) {
>>> > rlco_max = rlco + size / 2 - 256;
>>> > encoding |= encode_plane(frm->alpha, ref_frm->alpha,
>>> &rlco,
>>> > - rlco_max, cf, frm->height,
>>> frm->width,
>>> > - frm->luma_alpha_step,
>>> > + rlco_max, cf, height, width,
>>> > + frm->coded_width,
>>> frm->luma_alpha_step,
>>> > is_intra, next_is_intra);
>>> > if (encoding & FWHT_FRAME_UNENCODED)
>>> > encoding |= FWHT_ALPHA_UNENCODED;
>>> > @@ -801,7 +807,7 @@ u32 fwht_encode_frame(struct fwht_raw_frame *frm,
>>> > }
>>> >
>>> > static void decode_plane(struct fwht_cframe *cf, const __be16
>>> **rlco, u8 *ref,
>>> > - u32 height, u32 width, bool uncompressed)
>>> > + u32 height, u32 width, u32 coded_width, bool
>>> uncompressed)
>>>
>>> coded_width is OK here since you are writing into 'ref' and not the vb2
>>> capture buffer.
>
>
> Actually I think coded_width is not needed at all for the decoder
> because it only use the internal ref_frame buffer.
> So the width and height are enough.
I'm not 100% certain. Specifically for 4:2:0 formats where the width/height
has to be a multiple of 16 instead of 8. So you might need the
coded_width/height
to handle that correctly. You would have to check this carefully.
Regards,
Hans
