[PATCH v3 2/4] qcap: Calculate image size and pitch when setting format.

[Jeff Smith]

Signed-off-by: Jeff Smith <whydoubt at gmail.com>
---
By calculating and recording the image size when the V4L format is set,
the current_caps field can be ignored by functions that are used with
streaming.  Looking ahead to later patches, this avoids most of the
cases where we would need to check whether current_caps has been set.

 dlls/qcap/v4l.c | 31 ++++++++++++-------------------
 1 file changed, 12 insertions(+), 19 deletions(-)

diff --git a/dlls/qcap/v4l.c b/dlls/qcap/v4l.c
index d8c5e168e1..dade5a51e0 100644
--- a/dlls/qcap/v4l.c
+++ b/dlls/qcap/v4l.c
@@ -96,6 +96,9 @@ struct v4l_device
     struct caps *caps;
     LONG caps_count;
 
+    int image_size;
+    int image_pitch;
+
     struct strmbase_source *pin;
     int fd, mmap;
 
@@ -194,6 +197,8 @@ static BOOL set_caps(struct v4l_device *device, const struct caps *caps)
     }
 
     device->current_caps = caps;
+    device->image_size = width * height * caps->video_info.bmiHeader.biBitCount / 8;
+    device->image_pitch = width * caps->video_info.bmiHeader.biBitCount / 8;
 
     return TRUE;
 }
@@ -304,15 +309,11 @@ static HRESULT v4l_device_set_prop(struct video_capture_device *iface,
 static void reverse_image(struct v4l_device *device, LPBYTE output, const BYTE *input)
 {
     int inoffset, outoffset, pitch;
-    UINT width, height, depth;
 
-    width = device->current_caps->video_info.bmiHeader.biWidth;
-    height = device->current_caps->video_info.bmiHeader.biHeight;
-    depth = device->current_caps->video_info.bmiHeader.biBitCount / 8;
     /* the whole image needs to be reversed,
        because the dibs are messed up in windows */
-    outoffset = width * height * depth;
-    pitch = width * depth;
+    outoffset = device->image_size;
+    pitch = device->image_pitch;
     inoffset = 0;
     while (outoffset > 0)
     {
@@ -330,14 +331,8 @@ static DWORD WINAPI ReadThread(void *arg)
     HRESULT hr;
     IMediaSample *pSample = NULL;
     unsigned char *pTarget, *image_data;
-    unsigned int image_size;
-    UINT width, height, depth;
-
-    width = device->current_caps->video_info.bmiHeader.biWidth;
-    height = device->current_caps->video_info.bmiHeader.biHeight;
-    depth = device->current_caps->video_info.bmiHeader.biBitCount / 8;
-    image_size = width * height * depth;
-    if (!(image_data = heap_alloc(image_size)))
+
+    if (!(image_data = heap_alloc(device->image_size)))
     {
         ERR("Failed to allocate memory.\n");
         return 0;
@@ -363,15 +358,14 @@ static DWORD WINAPI ReadThread(void *arg)
         {
             int len;
             
-            len = width * height * depth;
-            IMediaSample_SetActualDataLength(pSample, len);
+            IMediaSample_SetActualDataLength(pSample, device->image_size);
 
             len = IMediaSample_GetActualDataLength(pSample);
             TRACE("Data length: %d KB\n", len / 1024);
 
             IMediaSample_GetPointer(pSample, &pTarget);
 
-            while (video_read(device->fd, image_data, image_size) == -1)
+            while (video_read(device->fd, image_data, device->image_size) == -1)
             {
                 if (errno != EAGAIN)
                 {
@@ -403,8 +397,7 @@ static void v4l_device_init_stream(struct video_capture_device *iface)
     HRESULT hr;
 
     req_props.cBuffers = 3;
-    req_props.cbBuffer = device->current_caps->video_info.bmiHeader.biWidth * device->current_caps->video_info.bmiHeader.biHeight;
-    req_props.cbBuffer = (req_props.cbBuffer * device->current_caps->video_info.bmiHeader.biBitCount) / 8;
+    req_props.cbBuffer = device->image_size;
     req_props.cbAlign = 1;
     req_props.cbPrefix = 0;
 
-- 
2.23.0