samples: video: tcpserversink: N-buffering configuration

Allow to configure the number of allocated capture frames.
This allows to make tradeof between framerate versus memory usage.
2 buffers allows to capture while sending data (optimal framerate).
1 buffer allows to reduce memory usage but capture framerate is lower.

Signed-off-by: Hugues Fruchet <[email protected]>

Author: hfruchet-st

samples/drivers/video/tcpserversink/Kconfig

@@ -1,4 +1,5 @@
 # Copyright (c) 2024 Espressif Systems (Shanghai) Co., Ltd.
+# Copyright (c) 2025 STMicroelectronics.
 # SPDX-License-Identifier: Apache-2.0
 
 mainmenu "TCP camera streaming sample application"
@@ -48,6 +49,15 @@ config VIDEO_PIXEL_FORMAT
 	help
 	  Pixel format of the video frame. If not set, the default pixel format is used.
 
+config VIDEO_NUM_FRAMES
+	int "Capture N-buffering"
+	default 2
+	help
+	  Framerate versus memory usage tradeoff.
+	  "2" allows to capture while sending data (optimal framerate).
+	  "1" allows to reduce memory usage but capture framerate is lower.
+	  If not set defaults to "2".
+
 config VIDEO_CTRL_HFLIP
 	bool "Mirror the video frame horizontally"
 	help

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

@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2019 Linaro Limited
+ * Copyright (c) 2025 STMicroelectronics.
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -141,7 +142,7 @@ int main(void)
 {
 	struct sockaddr_in addr, client_addr;
 	socklen_t client_addr_len = sizeof(client_addr);
-	struct video_buffer *buffers[2];
+	struct video_buffer *buffers[CONFIG_VIDEO_NUM_FRAMES];
 	struct video_buffer *vbuf = &(struct video_buffer){};
 	struct video_buffer *vbuf_out = &(struct video_buffer){};
 	int ret, sock, client;