support CFG_EXAMPLE_VIDEO_READONLY for stream0 for small mcu

Author: hathach

examples/device/video_capture_2ch/src/images.h

@@ -1,6 +1,8 @@
-#if defined(CFG_EXAMPLE_VIDEO_DISABLE_MJPEG)
-// uncopmressed frame
-static const unsigned char frame_buffer[128 * (96 + 1) * 2] = {
+#if defined(CFG_EXAMPLE_VIDEO_READONLY)
+//--------------------------------------------------------------------+
+// YUY2 Uncompressed Frame (fixed)
+//--------------------------------------------------------------------+
+static const unsigned char framebuf_yuy2_readonly[128 * (96 + 1) * 2] = {
   /* 0 */
   0xeb, 0x80, 0xeb, 0x80, 0xeb, 0x80, 0xeb, 0x80, 0xeb, 0x80, 0xeb, 0x80, 0xeb, 0x80, 0xeb, 0x80,
   0xeb, 0x80, 0xeb, 0x80, 0xeb, 0x80, 0xeb, 0x80, 0xeb, 0x80, 0xeb, 0x80, 0xeb, 0x80, 0xeb, 0x80,
@@ -1654,9 +1656,10 @@ static const unsigned char frame_buffer[128 * (96 + 1) * 2] = {
 
 #endif
 
-#if 1
+//--------------------------------------------------------------------+
+// MPEG Compressed Frame (fixed)
+//--------------------------------------------------------------------+
 
-// mpeg compressed data (not CFG_EXAMPLE_VIDEO_DISABLE_MJPEG)
 unsigned char color_bar_0_jpg[] = {
   0xff, 0xd8, 0xff, 0xdb, 0x00, 0x43, 0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
   0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
@@ -1929,7 +1932,3 @@ unsigned char color_bar_7_jpg[] = {
   0x42, 0x51, 0x59, 0x8c, 0xb1, 0x45, 0x00, 0x25, 0x15, 0x98, 0xc4, 0xa2, 0xb5, 0x32, 0x12, 0x8a,
   0xcc, 0x63, 0x68, 0xad, 0x8d, 0x84, 0xa2, 0xb3, 0x18, 0x94, 0x56, 0xa6, 0x47, 0xff, 0xd9
 };
-
-
-
-#endif

examples/device/video_capture_2ch/src/main.c

@@ -112,6 +112,8 @@ void tud_resume_cb(void) {
 //--------------------------------------------------------------------+
 // USB Video
 //--------------------------------------------------------------------+
+#define FRAMEBUF_SIZE (FRAME_WIDTH * FRAME_HEIGHT * 16 / 8)
+
 static unsigned frame_num[CFG_TUD_VIDEO_STREAMING] = {1};
 static unsigned tx_busy = 0;
 static unsigned interval_ms[CFG_TUD_VIDEO_STREAMING] = {1000 / FRAME_RATE};
@@ -134,8 +136,8 @@ static struct {
     {sizeof(color_bar_7_jpg), color_bar_7_jpg},
 };
 
+#if !defined(CFG_EXAMPLE_VIDEO_READONLY)
 // YUY2 frame buffer
-#define FRAMEBUF_SIZE (FRAME_WIDTH * FRAME_HEIGHT * 16 / 8)
 static uint8_t framebuf_yuy2[FRAMEBUF_SIZE];
 
 static void fill_color_bar(uint8_t* buffer, unsigned start_position) {
@@ -174,14 +176,20 @@ static void fill_color_bar(uint8_t* buffer, unsigned start_position) {
     p += FRAME_WIDTH * 2;
   }
 }
+#endif
 
 size_t get_framebuf(uint_fast8_t ctl_idx, uint_fast8_t stm_idx, size_t fnum, void **fb) {
   uint32_t idx = ctl_idx + stm_idx;
 
   if (idx == 0) {
     // stream 0 use uncompressed YUY2 frame
+    #if defined(CFG_EXAMPLE_VIDEO_READONLY)
+    *fb = (void*)(uintptr_t ) framebuf_yuy2_readonly[(fnum % (FRAME_WIDTH / 2)) * 4];
+    #else
     fill_color_bar(framebuf_yuy2, frame_num[idx]);
     *fb = framebuf_yuy2;
+    #endif
+
     return FRAMEBUF_SIZE;
   }else {
     // stream 1 use MJPEG frame