Hi Nicolas,

On 8/11/2025 9:12 PM, Nicolas Dufresne wrote:

Le dimanche 10 août 2025 à 21:24 +0000, Jonas Karlman a écrit :

quoted

The Rockchip VDEC supports the HEVC codec with the Main and Main10
Profile up to Level 5.1 High tier: 4096x2304@60 fps.

Add the backend for HEVC format to the decoder.

Signed-off-by: Alex Bee <redacted>
Signed-off-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Signed-off-by: Sebastian Fricke <redacted>
Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
---
Changes in v2:
- Use new_value in transpose_and_flatten_matrices()
- Add NULL check for ctrl->new_elems in rkvdec_hevc_run_preamble()
- Set RKVDEC_WR_DDR_ALIGN_EN for RK3328
---
 .../media/platform/rockchip/rkvdec/Makefile   |    2 +-
 .../rockchip/rkvdec/rkvdec-hevc-data.c        | 1848 +++++++++++++++++
 .../platform/rockchip/rkvdec/rkvdec-hevc.c    |  817 ++++++++
 .../platform/rockchip/rkvdec/rkvdec-regs.h    |    2 +
 .../media/platform/rockchip/rkvdec/rkvdec.c   |   76 +
 .../media/platform/rockchip/rkvdec/rkvdec.h   |    1 +
 6 files changed, 2745 insertions(+), 1 deletion(-)
 create mode 100644 drivers/media/platform/rockchip/rkvdec/rkvdec-hevc-data.c
 create mode 100644 drivers/media/platform/rockchip/rkvdec/rkvdec-hevc.c

diff --git a/drivers/media/platform/rockchip/rkvdec/Makefile

b/drivers/media/platform/rockchip/rkvdec/Makefile
index cb86b429cfaa..a77122641d14 100644

--- a/drivers/media/platform/rockchip/rkvdec/Makefile
+++ b/drivers/media/platform/rockchip/rkvdec/Makefile

@@ -1,3 +1,3 @@

 obj-$(CONFIG_VIDEO_ROCKCHIP_VDEC) += rockchip-vdec.o
 
-rockchip-vdec-y += rkvdec.o rkvdec-h264.o rkvdec-vp9.o
+rockchip-vdec-y += rkvdec.o rkvdec-h264.o rkvdec-hevc.o rkvdec-vp9.o

diff --git a/drivers/media/platform/rockchip/rkvdec/rkvdec-hevc-data.c

b/drivers/media/platform/rockchip/rkvdec/rkvdec-hevc-data.c
new file mode 100644
index 000000000000..eac4ea604949

--- /dev/null
+++ b/drivers/media/platform/rockchip/rkvdec/rkvdec-hevc-data.c

@@ -0,0 +1,1848 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Rockchip Video Decoder driver
+ *
+ * Copyright (C) 2023 Collabora, Ltd.
+ *	Sebastian Fricke <sebastian.fricke@collabora.com>
+ */
+
+#include <linux/types.h>
+
+#define RKV_CABAC_TABLE_SIZE		27456
+
+/*
+ * This file is #include from rkvdec-hevc.c and not compiled.
+ */
+static const u8 rkvdec_hevc_cabac_table[RKV_CABAC_TABLE_SIZE] = {
+	0x07, 0x0f, 0x48, 0x58, 0x58, 0x40, 0x40, 0x40, 0x40, 0x40, 0x0f,

0x40, 0x40, 0x40, 0x0f,

Nit, in H.264 case, we managed to fill the CABAC based on the spect with macros,
didn't we figure-out this one ? I didn't check in Detlev tree, I'm just asking
here.

As hinted at in the cover letter: in the initial implementation used for
LibreELEC I just shamelessly copied the cabac data 1:1 from the Rockchip
mpp library, for this series it was replaced with the cabac table from
Sebastian Fricke prior series to add a HEVC backend [1]. Sebastian
mentioned following regarding the cabac table:

"""
Notable design decisions:
- The giant static array of cabac values is moved to a separate c file,
I did so because a separate .h file would be incorrect as it doesn't
expose anything of any value for any other file than the rkvdec-hevc.c
file. Other options were:
  - Calculating the values instead of storing the results (No clear pattern
    found for the calculation using the static array and the formulas from the
    specification)
  - Supply them via firmware (Adding firmware makes the whole software
    way more complicated and the usage of the driver less obvious)
"""

I have not explored any other way to handle the cabac table based on
these design decisions.

[1] https://lore.kernel.org/linux-media/20230101-patch-series-v2-6-2-rc1-v2-0-fa1897efac14@collabora.com/ (local)

Regards,
Jonas

Nicolas

[snip]