pngdec: enable libpng interlaced picture handling

Makes libpng deinterlace Adam7 interlaced pictures
by default. It is the only interlaced format available
and if the picture isn't interlaced the code should behave
as before.

https://bugzilla.gnome.org/show_bug.cgi?id=726161

1 files changed, 9 insertions, 9 deletions

diff --git a/ext/libpng/gstpngdec.c b/ext/libpng/gstpngdec.c
index 0608449e0..d4b8ef1b3 100644
--- a/ext/libpng/gstpngdec.c
+++ b/ext/libpng/gstpngdec.c
@@ -179,15 +179,12 @@ user_endrow_callback (png_structp png_ptr, png_bytep new_row,
 
   pngdec = GST_PNGDEC (png_get_io_ptr (png_ptr));
 
-  /* FIXME: implement interlaced pictures */
-
   /* If buffer_out doesn't exist, it means buffer_alloc failed, which 
    * will already have set the return code */
-  if (GST_IS_BUFFER (pngdec->current_frame->output_buffer)) {
+  if (new_row && GST_IS_BUFFER (pngdec->current_frame->output_buffer)) {
     GstVideoFrame frame;
     GstBuffer *buffer = pngdec->current_frame->output_buffer;
     size_t offset;
-    gint width;
     guint8 *data;
 
     if (!gst_video_frame_map (&frame, &pngdec->output_state->info, buffer,
@@ -198,13 +195,14 @@ user_endrow_callback (png_structp png_ptr, png_bytep new_row,
 
     data = GST_VIDEO_FRAME_COMP_DATA (&frame, 0);
     offset = row_num * GST_VIDEO_FRAME_COMP_STRIDE (&frame, 0);
-    GST_LOG ("got row %u, copying in buffer %p at offset %" G_GSIZE_FORMAT,
-        (guint) row_num, pngdec->current_frame->output_buffer, offset);
-    width = GST_ROUND_UP_4 (png_get_rowbytes (pngdec->png, pngdec->info));
-    memcpy (data + offset, new_row, width);
+    GST_LOG ("got row %u at pass %d, copying in buffer %p at offset %"
+        G_GSIZE_FORMAT, (guint) row_num, pass,
+        pngdec->current_frame->output_buffer, offset);
+    png_progressive_combine_row (pngdec->png, data + offset, new_row);
     gst_video_frame_unmap (&frame);
     pngdec->ret = GST_FLOW_OK;
-  }
+  } else
+    pngdec->ret = GST_FLOW_OK;
 }
 
 static void
@@ -286,6 +284,8 @@ gst_pngdec_caps_create_and_set (GstPngDec * pngdec)
     png_set_palette_to_rgb (pngdec->png);
   }
 
+  png_set_interlace_handling (pngdec->png);
+
   /* Update the info structure */
   png_read_update_info (pngdec->png, pngdec->info);