Added transition from LFF to interlaced merged

src/rtp/video_decoders.cpp

@@ -109,7 +109,7 @@ struct state_video_decoder;
  * Interlacing changing function protoype. The function should be able to change buffer
  * in place, that is when dst and src are the same.
  */
-typedef void (*change_il_t)(char *dst, char *src, int linesize, int height);
+typedef void (*change_il_t)(char *dst, char *src, int linesize, int height, void **state);
 
 // prototypes
 static bool reconfigure_decoder(struct state_video_decoder *decoder,
@@ -216,6 +216,7 @@ struct state_video_decoder
 
         unsigned int      max_substreams; ///< maximal number of expected substreams
         change_il_t       change_il;      ///< function to change interlacing, if needed. Otherwise NULL.
+        vector<void *>    change_il_state;
 
         mutex lock;
 
@@ -526,7 +527,7 @@ static void *decompress_thread(void *args) {
                         for(i = 0; i < decoder->frame->tile_count; ++i) {
                                 struct tile *tile = vf_get_tile(decoder->frame, i);
                                 decoder->change_il(tile->data, tile->data, vc_get_linesize(tile->width,
-                                                        decoder->out_codec), tile->height);
+                                                        decoder->out_codec), tile->height, &decoder->change_il_state[i]);
                         }
                 }
 
@@ -782,6 +783,11 @@ static void cleanup(struct state_video_decoder *decoder)
                 free(decoder->line_decoder);
                 decoder->line_decoder = NULL;
         }
+
+        for (auto && item : decoder->change_il_state) {
+                free(item);
+        }
+        decoder->change_il_state.resize(0);
 }
 
 #define PRINT_STATISTICS fprintf(stderr, "Video decoder statistics: %lu total: %lu displayed / %lu "\
@@ -1039,6 +1045,7 @@ static change_il_t select_il_func(enum interlacing_t in_il, enum interlacing_t *
         struct transcode_t { enum interlacing_t in; enum interlacing_t out; change_il_t func; };
 
         struct transcode_t transcode[] = {
+                {LOWER_FIELD_FIRST, INTERLACED_MERGED, il_lower_to_merged},
                 {UPPER_FIELD_FIRST, INTERLACED_MERGED, il_upper_to_merged},
                 {INTERLACED_MERGED, UPPER_FIELD_FIRST, il_merged_to_upper}
         };
@@ -1062,6 +1069,8 @@ static change_il_t select_il_func(enum interlacing_t in_il, enum interlacing_t *
                 }
         }
 
+        fprintf(stderr, "[Warning] Cannot find transition between incoming and display "
+                        "interlacing modes!\n");
         return NULL;
 }
 
@@ -1146,6 +1155,7 @@ static bool reconfigure_decoder(struct state_video_decoder *decoder,
 
         decoder->change_il = select_il_func(desc.interlacing, decoder->disp_supported_il,
                         decoder->disp_supported_il_cnt, &display_il);
+        decoder->change_il_state.resize(decoder->max_substreams);
 
         if (!decoder->postprocess || !pp_does_change_tiling_mode) { /* otherwise we need postprocessor mode, which we obtained before */
                 render_mode = display_mode;

src/video_frame.c

@@ -211,9 +211,62 @@ const char *get_interlacing_suffix(enum interlacing_t interlacing)
         return NULL;
 }
 
-/* TODO: rewrite following 2 functions in more efficient way */
-void il_upper_to_merged(char *dst, char *src, int linesize, int height)
+/**
+ * @todo
+ * Needs to be more efficient
+ */
+void il_lower_to_merged(char *dst, char *src, int linesize, int height, void **stored_state)
 {
+        struct il_lower_to_merged_state {
+                size_t field_len;
+                char field[];
+        };
+        struct il_lower_to_merged_state *last_field = (struct il_lower_to_merged_state *) *stored_state;
+
+        int y;
+        char *tmp = malloc(linesize * height);
+        char *line1, *line2;
+
+        // upper field
+        line1 = tmp;
+        int field_len = linesize * (height / 2);
+        // first check if we have field from last frame
+        if (last_field == NULL) {
+                last_field = (struct il_lower_to_merged_state *)
+                        malloc(sizeof(struct il_lower_to_merged_state) + field_len);
+                last_field->field_len = field_len;
+                *stored_state = last_field;
+                // if no, use current one
+                line2 = src + linesize * ((height + 1) / 2);
+        } else {
+                // otherwise use field from last "frame"
+                line2 = last_field->field;
+        }
+        for(y = 0; y < height / 2; y ++) {
+                memcpy(line1, line2, linesize);
+                line1 += linesize * 2;
+                line2 += linesize;
+        }
+        // store
+        assert ((int) last_field->field_len == field_len);
+        memcpy(last_field->field, src + linesize * ((height + 1) / 2), field_len);
+
+        // lower field
+        line1 = tmp + linesize;
+        line2 = src;
+        for(y = 0; y < (height + 1) / 2; y ++) {
+                memcpy(line1, line2, linesize);
+                line1 += linesize * 2;
+                line2 += linesize;
+        }
+        memcpy(dst, tmp, linesize * height);
+        free(tmp);
+}
+
+/* TODO: rewrite following 2 functions in more efficient way */
+void il_upper_to_merged(char *dst, char *src, int linesize, int height, void **state)
+{
+        UNUSED(state);
         int y;
         char *tmp = malloc(linesize * height);
         char *line1, *line2;
@@ -237,8 +290,9 @@ void il_upper_to_merged(char *dst, char *src, int linesize, int height)
         free(tmp);
 }
 
-void il_merged_to_upper(char *dst, char *src, int linesize, int height)
+void il_merged_to_upper(char *dst, char *src, int linesize, int height, void **state)
 {
+        UNUSED(state);
         int y;
         char *tmp = malloc(linesize * height);
         char *line1, *line2;

src/video_frame.h

@@ -151,15 +151,16 @@ const char *get_interlacing_description(enum interlacing_t interlacing);
  */
 const char *get_interlacing_suffix(enum interlacing_t interlacing);
 
+void il_lower_to_merged(char *dst, char *src, int linesize, int height, void **stored_state);
 /* these functions transcode one interlacing format to another */
 /**
  * @brief Converts upper-field-first to interlaced merged.
  */
-void il_upper_to_merged(char *dst, char *src, int linesize, int height);
+void il_upper_to_merged(char *dst, char *src, int linesize, int height, void **stored_state);
 /**
  * @brief Converts interlaced merged to upper-field-first.
  */
-void il_merged_to_upper(char *dst, char *src, int linesize, int height);
+void il_merged_to_upper(char *dst, char *src, int linesize, int height, void **stored_state);
 
 /**
  * @brief Computes FPS as a double from packet fields.