Hi,
this is the third version of the i.MX mem2mem scaler series.
The driver patch has been moved to the beginning, as Steve suggested.
I've added his warning patch to catch alignment bugs to the series,
seam position selection has been fixed for more corner cases, the
alignment restriction relaxation patches have been merged into one
patch, and support for tiling with three rows or columns has been added
to avoid unnecessary overhead.
Changes since v2:
- Rely on ipu_image_convert_adjust() in mem2mem_try_fmt() for format
adjustments. This makes the mem2mem driver mostly a V4L2 mem2mem API
wrapper around the IPU image converter, and independent of the
internal image converter implementation.
- Remove the source and destination buffers on error in device_run().
Otherwise the conversion is re-attempted apparently over and over
again (with WARN() backtraces).
- Allow subscribing to control changes.
- Fix seam position selection for more corner cases:
- Switch width/height properly and align tile top left positions to 8x8
IRT block size when rotating.
- Align input width to input burst length in case the scaling step
flips horizontally.
- Fix bottom edge calculation.
Changes since v1:
- Fix inverted allow_overshoot logic
- Correctly switch horizontal / vertical tile alignment when
determining seam positions with the 90° rotator active.
- Fix SPDX-License-Identifier and remove superfluous license
text.
- Fix uninitialized walign in try_fmt
Previous cover letter:
we have image conversion code for scaling and colorspace conversion in
the IPUv3 base driver for a while. Since the IC hardware can only write
up to 1024x1024 pixel buffers, it scales to larger output buffers by
splitting the input and output frame into similarly sized tiles.
This causes the issue that the bilinear interpolation resets at the tile
boundary: instead of smoothly interpolating across the seam, there is a
jump in the input sample position that is very apparent for high
upscaling factors. This can be avoided by slightly changing the scaling
coefficients to let the left/top tiles overshoot their input sampling
into the first pixel / line of their right / bottom neighbors. The error
can be further reduced by letting tiles be differently sized and by
selecting seam positions that minimize the input sampling position error
at tile boundaries.
This is complicated by different DMA start address, burst size, and
rotator block size alignment requirements, depending on the input and
output pixel formats, and the fact that flipping happens in different
places depending on the rotation.
This series implements optimal seam position selection and seam hiding
with per-tile resizing coefficients and adds a scaling mem2mem device
to the imx-media driver.
regards
Philipp
Philipp Zabel (15):
media: imx: add mem2mem device
gpu: ipu-v3: ipu-ic: allow to manually set resize coefficients
gpu: ipu-v3: image-convert: prepare for per-tile configuration
gpu: ipu-v3: image-convert: calculate per-tile resize coefficients
gpu: ipu-v3: image-convert: reconfigure IC per tile
gpu: ipu-v3: image-convert: store tile top/left position
gpu: ipu-v3: image-convert: calculate tile dimensions and offsets
outside fill_image
gpu: ipu-v3: image-convert: move tile alignment helpers
gpu: ipu-v3: image-convert: select optimal seam positions
gpu: ipu-v3: image-convert: fix debug output for varying tile sizes
gpu: ipu-v3: image-convert: relax alignment restrictions
gpu: ipu-v3: image-convert: fix bytesperline adjustment
gpu: ipu-v3: image-convert: add some ASCII art to the exposition
gpu: ipu-v3: image-convert: disable double buffering if necessary
gpu: ipu-v3: image-convert: allow three rows or columns
Steve Longerbeam (1):
gpu: ipu-cpmem: add WARN_ON_ONCE() for unaligned dma buffers
drivers/gpu/ipu-v3/ipu-cpmem.c | 6 +
drivers/gpu/ipu-v3/ipu-ic.c | 52 +-
drivers/gpu/ipu-v3/ipu-image-convert.c | 919 +++++++++++++++---
drivers/staging/media/imx/Kconfig | 1 +
drivers/staging/media/imx/Makefile | 1 +
drivers/staging/media/imx/imx-media-dev.c | 11 +
drivers/staging/media/imx/imx-media-mem2mem.c | 873 +++++++++++++++++
drivers/staging/media/imx/imx-media.h | 10 +
include/video/imx-ipu-v3.h | 6 +
9 files changed, 1727 insertions(+), 152 deletions(-)
create mode 100644 drivers/staging/media/imx/imx-media-mem2mem.c
--
2.19.0
