fix scaling preset and update docs for rk hwaccel

docs/docs/configuration/ffmpeg_presets.md

@@ -22,6 +22,8 @@ See [the hwaccel docs](/configuration/hardware_acceleration.md) for more info on
 | preset-nvidia-mjpeg   | Nvidia GPU with mjpeg stream   | Recommend restreaming mjpeg and using nvidia-h264     |
 | preset-jetson-h264    | Nvidia Jetson with h264 stream |                                                       |
 | preset-jetson-h265    | Nvidia Jetson with h265 stream |                                                       |
+| preset-rk-h264        | Nvidia Jetson with h264 stream | Use image with *-rk suffix and privileged mode        |
+| preset-rk-h265        | Nvidia Jetson with h265 stream | Use image with *-rk suffix and privileged mode        |
 
 ### Input Args Presets
 

docs/docs/configuration/hardware_acceleration.md

@@ -319,3 +319,25 @@ ffmpeg:
 If everything is working correctly, you should see a significant reduction in ffmpeg CPU load and power consumption.
 Verify that hardware decoding is working by running `jtop` (`sudo pip3 install -U jetson-stats`), which should show
 that NVDEC/NVDEC1 are in use.
+
+## Rockchip platform
+
+Hardware accelerated video de-/encoding is supported on all Rockchip SoCs.
+
+### Setup
+
+Use a frigate docker image with `-rk` suffix and enable privileged mode by adding the `--privileged` flag to your docker run command or `privileged: true` to your `docker-compose.yml` file.
+
+### Configuration
+
+Add one of the following ffmpeg presets to your `config.yaml` to enable hardware acceleration:
+
+```yaml
+# if you try to decode a h264 encoded stream
+ffmpeg:
+  hwaccel_args: preset-rk-h264
+
+# if you try to decode a h265 (hevc) encoded stream
+ffmpeg:
+  hwaccel_args: preset-rk-h265
+```

frigate/ffmpeg_presets.py

@@ -77,8 +77,8 @@ PRESETS_HW_ACCEL_SCALE = {
     "preset-nvidia-h265": "-r {0} -vf fps={0},scale_cuda=w={1}:h={2}:format=nv12,hwdownload,format=nv12,format=yuv420p",
     "preset-jetson-h264": "-r {0}",  # scaled in decoder
     "preset-jetson-h265": "-r {0}",  # scaled in decoder
-    "preset-rk-h264": "-r {0} -width {1} -height {2}",
+    "preset-rk-h264": "-r {0} -vf fps={0},scale={1}:{2}",
-    "preset-rk-h265": "-r {0} -width {1} -height {2}",
+    "preset-rk-h265": "-r {0} -vf fps={0},scale={1}:{2}",
     "default": "-r {0} -vf fps={0},scale={1}:{2}",
 }