UVC Video encoder (zephyr,videoenc) + H264 support + STM32 STM32N6 conf files

boards/st/stm32n6570_dk/stm32n6570_dk_common.dtsi

@@ -534,10 +534,10 @@ csi_interface: &dcmipp {
 	};
 };
 
-&venc {
+zephyr_h264enc: &venc {
 	status = "okay";
 };
 
-&jpeg {
+zephyr_jpegenc: &jpeg {
 	status = "okay";
 };

doc/releases/release-notes-4.3.rst

@@ -324,6 +324,7 @@ New APIs and options
 
   * :c:member:`video_format.size` field
   * :c:func:`video_estimate_fmt_size`
+  * :c:func:`video_transfer_buffer`
 
 .. zephyr-keep-sorted-stop
 

drivers/video/video_common.c

@@ -452,6 +452,7 @@ int video_estimate_fmt_size(struct video_format *fmt)
 
 	switch (fmt->pixelformat) {
 	case VIDEO_PIX_FMT_JPEG:
+	case VIDEO_PIX_FMT_H264:
 		/* Rough estimate for the worst case (quality = 100) */
 		fmt->pitch = 0;
 		fmt->size = fmt->width * fmt->height * 2;
@@ -489,3 +490,20 @@ int video_set_compose_format(const struct device *dev, struct video_format *fmt)
 
 	return video_set_format(dev, fmt);
 }
+
+int video_transfer_buffer(const struct device *src, const struct device *sink,
+			  enum video_buf_type src_type, enum video_buf_type sink_type,
+			  k_timeout_t timeout)
+{
+	struct video_buffer *buf = &(struct video_buffer){.type = src_type};
+	int ret;
+
+	ret = video_dequeue(src, &buf, timeout);
+	if (ret < 0) {
+		return ret;
+	}
+
+	buf->type = sink_type;
+
+	return video_enqueue(sink, buf);
+}

include/zephyr/drivers/video.h

@@ -1003,6 +1003,24 @@ int video_estimate_fmt_size(struct video_format *fmt);
  */
 int video_set_compose_format(const struct device *dev, struct video_format *fmt);
 
+/**
+ * @brief Transfer a buffer between 2 video device
+ *
+ * Helper function which dequeues a buffer from a source device and enqueues it into a
+ * sink device, changing its buffer type between the two.
+ *
+ * @param src		Video device from where buffer is dequeued (source)
+ * @param sink		Video device into which the buffer is queued (sink)
+ * @param src_type	Video buffer type on the source device
+ * @param sink_type	Video buffer type on the sink device
+ * @param timeout	Timeout to be applied on dequeue
+ *
+ * @return 0 on success, otherwise a negative errno code
+ */
+int video_transfer_buffer(const struct device *src, const struct device *sink,
+			  enum video_buf_type src_type, enum video_buf_type sink_type,
+			  k_timeout_t timeout);
+
 /**
  * @defgroup video_pixel_formats Video pixel formats
  * The '|' characters separate the pixels or logical blocks, and spaces separate the bytes.

samples/drivers/video/tcpserversink/src/main.c

@@ -131,7 +131,10 @@ int configure_encoder(void)
 	}
 
 	buffer->type = VIDEO_BUF_TYPE_OUTPUT;
-	video_enqueue(encoder_dev, buffer);
+	if (video_enqueue(encoder_dev, buffer)) {
+		LOG_ERR("Unable to enqueue encoder output buf");
+		return -1;
+	}
 
 	/* Set input format */
 	if (strcmp(CONFIG_VIDEO_PIXEL_FORMAT, "")) {
@@ -165,12 +168,16 @@ int encode_frame(struct video_buffer *in, struct video_buffer **out)
 	int ret;
 
 	in->type = VIDEO_BUF_TYPE_INPUT;
-	video_enqueue(encoder_dev, in);
+	ret = video_enqueue(encoder_dev, in);
+	if (ret) {
+		LOG_ERR("Unable to enqueue encoder input buf");
+		return ret;
+	}
 
 	(*out)->type = VIDEO_BUF_TYPE_OUTPUT;
 	ret = video_dequeue(encoder_dev, out, K_FOREVER);
 	if (ret) {
-		LOG_ERR("Unable to dequeue encoder buf");
+		LOG_ERR("Unable to dequeue encoder output buf");
 		return ret;
 	}
 
@@ -422,7 +429,11 @@ int main(void)
 
 		/* Enqueue Buffers */
 		for (i = 0; i < ARRAY_SIZE(buffers); i++) {
-			video_enqueue(video_dev, buffers[i]);
+			ret = video_enqueue(video_dev, buffers[i]);
+			if (ret) {
+				LOG_ERR("Unable to enqueue video buf");
+				return 0;
+			}
 		}
 
 		/* Start video capture */
@@ -452,7 +463,12 @@ int main(void)
 			ret = sendall(client, vbuf_out->buffer, vbuf_out->bytesused);
 
 			vbuf_out->type = VIDEO_BUF_TYPE_OUTPUT;
-			video_enqueue(encoder_dev, vbuf_out);
+			ret = video_enqueue(encoder_dev, vbuf_out);
+			if (ret) {
+				LOG_ERR("Unable to enqueue encoder output buf");
+				return 0;
+			}
+
 #else
 			LOG_INF("Sending frame %d", i++);
 			/* Send video buffer to TCP client */
@@ -465,7 +481,11 @@ int main(void)
 			}
 
 			vbuf->type = VIDEO_BUF_TYPE_INPUT;
-			(void)video_enqueue(video_dev, vbuf);
+			ret = video_enqueue(video_dev, vbuf);
+			if (ret) {
+				LOG_ERR("Unable to enqueue video buf");
+				return 0;
+			}
 		} while (!ret);
 
 		/* stop capture */

samples/subsys/usb/uvc/app_h264enc.overlay

@@ -0,0 +1,13 @@
+/*
+ * Copyright (c) 2025 STMicroelectronics
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include "app.overlay"
+
+/ {
+	chosen {
+		zephyr,videoenc = &zephyr_h264enc;
+	};
+};

samples/subsys/usb/uvc/app_jpegenc.overlay

@@ -0,0 +1,13 @@
+/*
+ * Copyright (c) 2025 STMicroelectronics
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include "app.overlay"
+
+/ {
+	chosen {
+		zephyr,videoenc = &zephyr_jpegenc;
+	};
+};

samples/subsys/usb/uvc/sample.yaml

@@ -27,3 +27,27 @@ tests:
     filter: dt_chosen_enabled("zephyr,camera")
     integration_platforms:
       - arduino_nicla_vision/stm32h747xx/m7
+  sample.subsys.usb.uvc.encoder.h264:
+    depends_on:
+      - usbd
+    tags: usb video
+    extra_configs:
+      - CONFIG_VIDEO_ENCODER_H264=y
+    extra_args:
+      - EXTRA_DTC_OVERLAY_FILE="app_h264enc.overlay"
+      - SHIELD=st_b_cams_imx_mb1854
+    filter: dt_chosen_enabled("zephyr,camera")
+    integration_platforms:
+      - stm32n6570_dk/stm32n657xx/sb
+  sample.subsys.usb.uvc.encoder.jpeg:
+    depends_on:
+      - usbd
+    tags: usb video
+    extra_configs:
+      - CONFIG_VIDEO_ENCODER_JPEG=y
+    extra_args:
+      - EXTRA_DTC_OVERLAY_FILE="app_jpegenc.overlay"
+      - SHIELD=st_b_cams_imx_mb1854
+    filter: dt_chosen_enabled("zephyr,camera")
+    integration_platforms:
+      - stm32n6570_dk/stm32n657xx/sb