Make the api behavior conform to api spec.

When no more data is available, vpx_codec_decode should
be called with NULL as data and 0 as data_sz.

vpx_codec_get_frame iterates over a list of the frames
available for display. The iterator storage should be initialized
to NULL to start the iteration. Iteration is complete when this
function returns NULL.

Also change the unit test to conform to the api spec.

Change-Id: I4b258b309f5df3d37d10c82f01492c0394181c2a

1 files changed, 9 insertions, 2 deletions

diff --git a/vp9/vp9_dx_iface.c b/vp9/vp9_dx_iface.c
index c52884084..3ff3f6c76 100644
--- a/vp9/vp9_dx_iface.c
+++ b/vp9/vp9_dx_iface.c
@@ -40,6 +40,7 @@ struct vpx_codec_alg_priv {
   void                   *decrypt_state;
   vpx_image_t             img;
   int                     img_avail;
+  int                     flushed;
   int                     invert_tile_order;
   int                     frame_parallel_decode;  // frame-based threading.
 
@@ -69,6 +70,7 @@ static vpx_codec_err_t decoder_init(vpx_codec_ctx_t *ctx,
     ctx->priv->alg_priv = alg_priv;
     ctx->priv->alg_priv->si.sz = sizeof(ctx->priv->alg_priv->si);
     ctx->priv->init_flags = ctx->init_flags;
+    ctx->priv->alg_priv->flushed = 0;
     ctx->priv->alg_priv->frame_parallel_decode =
         (ctx->init_flags & VPX_CODEC_USE_FRAME_THREADING);
 
@@ -403,8 +405,13 @@ static vpx_codec_err_t decoder_decode(vpx_codec_alg_priv_t *ctx,
   uint32_t frame_sizes[8];
   int frame_count;
 
-  if (data == NULL || data_sz == 0)
-    return VPX_CODEC_INVALID_PARAM;
+  if (data == NULL && data_sz == 0) {
+    ctx->flushed = 1;
+    return VPX_CODEC_OK;
+  }
+
+  // Reset flushed when receiving a valid frame.
+  ctx->flushed = 0;
 
   res = parse_superframe_index(data, data_sz, frame_sizes, &frame_count,
                                ctx->decrypt_cb, ctx->decrypt_state);