Improved cache RAM usage... a lot

If clip is smaller than allowed cache (a few GB in most cases), just enough for the clip will be allocated instead of maximum. Also if cache size is set before a clip is opened, memory will not be allocated.

src/mlv/frame_caching.c

@@ -20,14 +20,14 @@ void setMlvRawCacheLimitMegaBytes(mlvObject_t * video, uint64_t megaByteLimit)
     video->cache_limit_mb = megaByteLimit;
     video->cache_limit_bytes = bytes_limit;
 
-    /* Resize cache block */
-    video->cache_memory_block = realloc(video->cache_memory_block, bytes_limit);
 
     /* Protection against zero division, cuz that causes "Floating point exception: 8"... 
      * ...LOL there's not even a floating point in sight */
-    if (frame_size != 0 && video->is_active)
+    if (video->is_active && frame_size != 0)
     {
         uint64_t frame_limit = (uint64_t)bytes_limit / (uint64_t)frame_size;
+        uint64_t cache_whole = frame_size * getMlvFrames(video);
+
         video->cache_limit_frames = frame_limit;
 
         printf("\nEnough memory allowed to cache %i frames (%i MiB)\n\n", (int)frame_limit, (int)megaByteLimit);
@@ -37,25 +37,32 @@ void setMlvRawCacheLimitMegaBytes(mlvObject_t * video, uint64_t megaByteLimit)
         {
             pthread_create(&video->cache_thread, NULL, (void *)cache_mlv_frames, (void *)video);
         }
+
+        /* Resize cache block - to maximum allowed or enough to fit whole clip if it is smaller */
+        video->cache_memory_block = realloc(video->cache_memory_block, MIN(bytes_limit, cache_whole));
     }
+
+    /* No else - if video is not active we won't waste RAM */
 }
 
+/* Not recommended */
 void setMlvRawCacheLimitFrames(mlvObject_t * video, uint64_t frameLimit)
 {
     uint64_t frame_size = getMlvWidth(video) * getMlvHeight(video) * sizeof(uint16_t) * 3;
 
     /* Do only if clip is loaded */
-    if (frame_size != 0 && video->is_active)
+    if (video->is_active && frame_size != 0)
     {
         uint64_t bytes_limit = frame_size * frameLimit;
         uint64_t mbyte_limit = bytes_limit / (1 << 20);
+        uint64_t cache_whole = frame_size * getMlvFrames(video);
 
         video->cache_limit_bytes = bytes_limit;
         video->cache_limit_mb = mbyte_limit;
         video->cache_limit_frames = frameLimit;
 
-        /* Resize cache block */
-        video->cache_memory_block = realloc(video->cache_memory_block, bytes_limit);
+        /* Resize cache block - to maximum allowed or enough to fit whole clip if it is smaller */
+        video->cache_memory_block = realloc(video->cache_memory_block, MIN(bytes_limit, cache_whole));
 
         /* Begin updating cached frames */
         if (!video->is_caching)
@@ -131,4 +138,4 @@ void get_mlv_raw_frame_debayered( mlvObject_t * video,
         /* Debayer quickly (bilinearly) */
         debayerBasic(output_frame, temp_memory, width, height, 1);
     }
-}
+}