Give struct members more sensible names:

[ffmpeg] / libavcodec / mpegvideo_xvmc.c

diff --git a/libavcodec/mpegvideo_xvmc.c b/libavcodec/mpegvideo_xvmc.c
index 1310c92bbfe985fb622368427cf19719f29742bd..51dcb8cfa7fb0f90fe9cac213f941ea737b7d299 100644 (file)
--- a/libavcodec/mpegvideo_xvmc.c
+++ b/libavcodec/mpegvideo_xvmc.c
@@ -34,15 +34,22 @@
 /**
  * Initializes the block field of the MpegEncContext pointer passed as
  * parameter after making sure that the data is not corrupted.
+ * In order to implement something like direct rendering instead of decoding
+ * coefficients in s->blocks and then copying them, copy them directly
+ * into the data_blocks array provided by xvmc.
  */
 void ff_xvmc_init_block(MpegEncContext *s)
 {
     struct xvmc_pix_fmt *render = (struct xvmc_pix_fmt*)s->current_picture.data[2];
-    assert(render && render->unique_id == AV_XVMC_RENDER_MAGIC);
+    assert(render && render->xvmc_id == AV_XVMC_ID);
 
     s->block = (DCTELEM *)(render->data_blocks + render->next_free_data_block_num * 64);
 }
 
+/**
+ * Fill individual block pointers, so there are no gaps in the data_block array
+ * in case not all blocks in MB are coded.
+ */
 void ff_xvmc_pack_pblocks(MpegEncContext *s, int cbp)
 {
     int i, j = 0;
@@ -59,6 +66,7 @@ void ff_xvmc_pack_pblocks(MpegEncContext *s, int cbp)
 }
 
 /**
+ * Find and store the surfaces that are used as reference frames.
  * This function should be called for every new field and/or frame.
  * It should be safe to call the function a few times for the same field.
  */
@@ -68,7 +76,7 @@ int ff_xvmc_field_start(MpegEncContext*s, AVCodecContext *avctx)
     const int mb_block_count = 4 + (1 << s->chroma_format);
 
     assert(avctx);
-    if (!render || render->unique_id != AV_XVMC_RENDER_MAGIC ||
+    if (!render || render->xvmc_id != AV_XVMC_ID ||
         !render->data_blocks || !render->mv_blocks) {
         av_log(avctx, AV_LOG_ERROR,
                "Render token doesn't look as expected.\n");
@@ -81,8 +89,8 @@ int ff_xvmc_field_start(MpegEncContext*s, AVCodecContext *avctx)
                render->filled_mv_blocks_num);
         return -1;
     }
-    if (render->total_number_of_mv_blocks   < 1 ||
-        render->total_number_of_data_blocks < mb_block_count) {
+    if (render->allocated_mv_blocks   < 1 ||
+        render->allocated_data_blocks < mb_block_count) {
         av_log(avctx, AV_LOG_ERROR,
                "Rendering surface doesn't provide enough block structures to work with.\n");
         return -1;
@@ -100,7 +108,7 @@ int ff_xvmc_field_start(MpegEncContext*s, AVCodecContext *avctx)
             next = (struct xvmc_pix_fmt*)s->next_picture.data[2];
             if (!next)
                 return -1;
-            if (next->unique_id != AV_XVMC_RENDER_MAGIC)
+            if (next->xvmc_id != AV_XVMC_ID)
                 return -1;
             render->p_future_surface = next->p_surface;
             // no return here, going to set forward prediction
@@ -108,7 +116,7 @@ int ff_xvmc_field_start(MpegEncContext*s, AVCodecContext *avctx)
             last = (struct xvmc_pix_fmt*)s->last_picture.data[2];
             if (!last)
                 last = render; // predict second field from the first
-            if (last->unique_id != AV_XVMC_RENDER_MAGIC)
+            if (last->xvmc_id != AV_XVMC_ID)
                 return -1;
             render->p_past_surface = last->p_surface;
             return 0;
@@ -118,7 +126,9 @@ return -1;
 }
 
 /**
- * This function should be called for every new field and/or frame.
+ * Complete frame/field rendering by passing any remaining blocks.
+ * Normally ff_draw_horiz_band() is called for each slice, however,
+ * some leftover blocks, for example from error_resilience(), may remain.
  * It should be safe to call the function a few times for the same field.
  */
 void ff_xvmc_field_end(MpegEncContext *s)
@@ -130,6 +140,10 @@ void ff_xvmc_field_end(MpegEncContext *s)
         ff_draw_horiz_band(s, 0, 0);
 }
 
+/**
+ * Synthesize the data needed by XvMC to render one macroblock of data.
+ * Fill all relevant fields, if necessary do IDCT.
+ */
 void ff_xvmc_decode_mb(MpegEncContext *s)
 {
     XvMCMacroBlock *mv_block;
@@ -162,7 +176,7 @@ void ff_xvmc_decode_mb(MpegEncContext *s)
     // start of XVMC-specific code
     render = (struct xvmc_pix_fmt*)s->current_picture.data[2];
     assert(render);
-    assert(render->unique_id == AV_XVMC_RENDER_MAGIC);
+    assert(render->xvmc_id == AV_XVMC_ID);
     assert(render->mv_blocks);
 
     // take the next free macroblock
@@ -298,13 +312,13 @@ void ff_xvmc_decode_mb(MpegEncContext *s)
     }
     render->filled_mv_blocks_num++;
 
-    assert(render->filled_mv_blocks_num     <= render->total_number_of_mv_blocks);
-    assert(render->next_free_data_block_num <= render->total_number_of_data_blocks);
+    assert(render->filled_mv_blocks_num     <= render->allocated_mv_blocks);
+    assert(render->next_free_data_block_num <= render->allocated_data_blocks);
     /* The above conditions should not be able to fail as long as this function
      * is used and the following 'if ()' automatically calls a callback to free
      * blocks. */
 
 
-    if (render->filled_mv_blocks_num == render->total_number_of_mv_blocks)
+    if (render->filled_mv_blocks_num == render->allocated_mv_blocks)
         ff_draw_horiz_band(s, 0, 0);
 }