standard and palette are actually unsigned in v4l2, so let's use that instead of int. Fixes some build warnings

src/zm_local_camera.cpp

@@ -46,7 +46,7 @@ static int vidioctl(int fd, int request, void *arg) {
   return result;
 }
 
-static _AVPIXELFORMAT getFfPixFormatFromV4lPalette(int v4l_version, int palette) {
+static _AVPIXELFORMAT getFfPixFormatFromV4lPalette(int v4l_version, unsigned int palette) {
   _AVPIXELFORMAT pixFormat = AV_PIX_FMT_NONE;
 
   switch (palette) {
@@ -139,7 +139,7 @@ static _AVPIXELFORMAT getFfPixFormatFromV4lPalette(int v4l_version, int palette)
   //case V4L2_PIX_FMT_PJPG :
   //case V4L2_PIX_FMT_YVYU :
   default : {
-    Fatal("Can't find swscale format for palette %d", palette);
+    Fatal("Can't find swscale format for palette %u", palette);
     break;
 #if 0
     // These are all spare and may match some of the above
@@ -226,14 +226,14 @@ LocalCamera::LocalCamera(
   const Monitor *monitor,
   const std::string &p_device,
   int p_channel,
-  int p_standard,
+  v4l2_std_id p_standard,
   bool p_v4l_multi_buffer,
   unsigned int p_v4l_captures_per_frame,
   const std::string &p_method,
   int p_width,
   int p_height,
   int p_colours,
-  int p_palette,
+  unsigned int p_palette,
   int p_brightness,
   int p_contrast,
   int p_hue,
@@ -512,7 +512,7 @@ void LocalCamera::Initialise() {
   }
 
   if ((input.std != V4L2_STD_UNKNOWN) && ((input.std & standard) == V4L2_STD_UNKNOWN)) {
-    Error("Device does not support video standard %d", standard);
+    Error("Device does not support video standard %lld", standard);
   }
 
   if ((vidioctl(vid_fd, VIDIOC_G_STD, &stdId) < 0)) {
@@ -521,7 +521,7 @@ void LocalCamera::Initialise() {
   if (stdId != standard) {
     stdId = standard;
     if ((vidioctl(vid_fd, VIDIOC_S_STD, &stdId) < 0)) {
-      Error("Failed to set video standard %d: %d %s", standard, errno, strerror(errno));
+      Error("Failed to set video standard %lld: %d %s", standard, errno, strerror(errno));
     }
   }
   Debug(3, "Setting up video format");
@@ -715,6 +715,7 @@ void LocalCamera::Initialise() {
     //vid_buf.memory = V4L2_MEMORY_MMAP;
     vid_buf.memory = v4l2_data.reqbufs.memory;
     vid_buf.index = i;
+    Debug(1, "buf_type for %d  %d =? %d, memory %d =? %d", i, vid_buf.type, V4L2_BUF_TYPE_VIDEO_CAPTURE, vid_buf.memory, V4L2_MEMORY_MMAP);
 
     if (vidioctl(vid_fd, VIDIOC_QUERYBUF, &vid_buf) < 0)
       Fatal("Unable to query video buffer: %s", strerror(errno));
@@ -726,6 +727,7 @@ void LocalCamera::Initialise() {
       Fatal("Can't map video buffer %u (%u bytes) to memory: %s(%d)",
             i, vid_buf.length, strerror(errno), errno);
 
+
     capturePictures[i] = av_frame_ptr{av_frame_alloc()};
 
     if (!capturePictures[i])
@@ -1229,6 +1231,31 @@ int LocalCamera::PrimeCapture() {
   if (!device_prime)
     return 1;
 
+
+  // *** VERIFY FORMAT HASN'T CHANGED ***
+  struct v4l2_format current_fmt;
+  memset(&current_fmt, 0, sizeof(current_fmt));
+  current_fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+
+  if (vidioctl(vid_fd, VIDIOC_G_FMT, &current_fmt) < 0) {
+    Error("Failed to get current format: %s", strerror(errno));
+  } else {
+    Debug(1, "Format at PrimeCapture: %dx%d, format=0x%x, bytesperline=%d, sizeimage=%d",
+          current_fmt.fmt.pix. width, current_fmt.fmt. pix.height,
+          current_fmt.fmt.pix. pixelformat, current_fmt. fmt.pix.bytesperline,
+          current_fmt. fmt.pix.sizeimage);
+    Debug(1, "Expected format: %dx%d, format=0x%x, bytesperline=%d, sizeimage=%d",
+          v4l2_data.fmt.fmt. pix.width, v4l2_data.fmt.fmt. pix.height,
+          v4l2_data.fmt. fmt.pix.pixelformat, v4l2_data. fmt.fmt.pix.bytesperline,
+          v4l2_data.fmt.fmt.pix.sizeimage);
+
+    if (current_fmt.fmt.pix.sizeimage != v4l2_data.fmt.fmt.pix.sizeimage) {
+      Error("FORMAT MISMATCH! Current sizeimage %d != expected %d",
+            current_fmt.fmt.pix.sizeimage, v4l2_data.fmt.fmt.pix. sizeimage);
+    }
+  }
+  // *** END DIAGNOSTIC ***
+
   Debug(3, "Queueing (%d) buffers", v4l2_data.reqbufs.count);
   for (unsigned int frame = 0; frame < v4l2_data.reqbufs.count; frame++) {
     struct v4l2_buffer vid_buf;
@@ -1242,8 +1269,16 @@ int LocalCamera::PrimeCapture() {
     vid_buf.memory = v4l2_data.reqbufs.memory;
     vid_buf.index = frame;
 
+     // *** ADD MORE DIAGNOSTICS FOR THE FAILING QBUF ***
+    Debug(3, "Attempting QBUF: index=%d, type=%d, memory=%d, reqbufs.count=%d",
+          vid_buf.index, vid_buf.type, vid_buf.memory, v4l2_data. reqbufs.count);
+
     if (vidioctl(vid_fd, VIDIOC_QBUF, &vid_buf) < 0) {
       Error("Failed to queue buffer %d: %s", frame, strerror(errno));
+        Error("  vid_buf: type=%d, memory=%d, index=%d", vid_buf.type, vid_buf.memory, vid_buf.index);
+      Error("  reqbufs: count=%d, type=%d, memory=%d",
+            v4l2_data.reqbufs.count, v4l2_data.reqbufs.type, v4l2_data.reqbufs.memory);
+
       return 0;
     }
   }
@@ -1284,7 +1319,6 @@ int LocalCamera::Capture(std::shared_ptr<ZMPacket> &zm_packet) {
     static struct v4l2_buffer vid_buf;
 
     memset(&vid_buf, 0, sizeof(vid_buf));
-
     vid_buf.type = v4l2_data.fmt.type;
     vid_buf.memory = v4l2_data.reqbufs.memory;
 

src/zm_local_camera.h

@@ -50,8 +50,8 @@ class LocalCamera : public Camera {
  protected:
   std::string device;
   int channel;
-  int standard;
-  int palette;
+  v4l2_std_id standard;
+  unsigned int palette;
   bool device_prime;
   bool channel_prime;
   int channel_index;
@@ -86,14 +86,14 @@ class LocalCamera : public Camera {
     const Monitor *monitor,
     const std::string &device,
     int p_channel,
-    int p_format,
+    v4l2_std_id p_standard,
     bool v4lmultibuffer,
     unsigned int v4lcapturesperframe,
     const std::string &p_method,
     int p_width,
     int p_height,
     int p_colours,
-    int p_palette,
+    unsigned int p_palette,
     int p_brightness,
     int p_contrast,
     int p_hue,
@@ -110,7 +110,7 @@ class LocalCamera : public Camera {
 
   int Channel() const { return channel; }
   int Standard() const { return standard; }
-  int Palette() const { return palette; }
+  unsigned int Palette() const { return palette; }
   int Extras() const { return extras; }
 
   int Control(int vid_id, int newvalue=-1 );