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

3 files changed, 38 insertions, 13 deletions

diff --git a/test/decode_test_driver.cc b/test/decode_test_driver.cc
index 3e4ef0ad1..99610ebc5 100644
--- a/test/decode_test_driver.cc
+++ b/test/decode_test_driver.cc
@@ -67,24 +67,33 @@ void DecoderTest::RunLoop(CompressedVideoSource *video,
                           const vpx_codec_dec_cfg_t &dec_cfg) {
   Decoder* const decoder = codec_->CreateDecoder(dec_cfg, 0);
   ASSERT_TRUE(decoder != NULL);
+  bool end_of_file = false;
 
   // Decode frames.
-  for (video->Begin(); !::testing::Test::HasFailure() && video->cxdata();
+  for (video->Begin(); !::testing::Test::HasFailure() && !end_of_file;
        video->Next()) {
     PreDecodeFrameHook(*video, decoder);
 
     vpx_codec_stream_info_t stream_info;
     stream_info.sz = sizeof(stream_info);
-    const vpx_codec_err_t res_peek = decoder->PeekStream(video->cxdata(),
-                                                         video->frame_size(),
-                                                         &stream_info);
-    HandlePeekResult(decoder, video, res_peek);
-    ASSERT_FALSE(::testing::Test::HasFailure());
-
-    vpx_codec_err_t res_dec = decoder->DecodeFrame(video->cxdata(),
-                                                   video->frame_size());
-    if (!HandleDecodeResult(res_dec, *video, decoder))
-      break;
+
+    if (video->cxdata() != NULL) {
+      const vpx_codec_err_t res_peek = decoder->PeekStream(video->cxdata(),
+                                                           video->frame_size(),
+                                                           &stream_info);
+      HandlePeekResult(decoder, video, res_peek);
+      ASSERT_FALSE(::testing::Test::HasFailure());
+
+      vpx_codec_err_t res_dec = decoder->DecodeFrame(video->cxdata(),
+                                                     video->frame_size());
+      if (!HandleDecodeResult(res_dec, *video, decoder))
+        break;
+    } else {
+      // Signal end of the file to the decoder.
+      const vpx_codec_err_t res_dec = decoder->DecodeFrame(NULL, 0);
+      ASSERT_EQ(VPX_CODEC_OK, res_dec) << decoder->DecodeError();
+      end_of_file = true;
+    }
 
     DxDataIterator dec_iter = decoder->GetDxData();
     const vpx_image_t *img = NULL;
diff --git a/vp8/vp8_dx_iface.c b/vp8/vp8_dx_iface.c
index f768b5c47..ccc0afbe3 100644
--- a/vp8/vp8_dx_iface.c
+++ b/vp8/vp8_dx_iface.c
@@ -60,6 +60,7 @@ struct vpx_codec_alg_priv
     vpx_decrypt_cb          decrypt_cb;
     void                    *decrypt_state;
     vpx_image_t             img;
+    int                     flushed;
     int                     img_setup;
     struct frame_buffers    yv12_frame_buffers;
     void                    *user_priv;
@@ -88,6 +89,7 @@ static void vp8_init_ctx(vpx_codec_ctx_t *ctx)
     ctx->priv->alg_priv->si.sz = sizeof(ctx->priv->alg_priv->si);
     ctx->priv->alg_priv->decrypt_cb = NULL;
     ctx->priv->alg_priv->decrypt_state = NULL;
+    ctx->priv->alg_priv->flushed = 0;
     ctx->priv->init_flags = ctx->init_flags;
 
     if (ctx->config.dec)
@@ -328,6 +330,13 @@ static vpx_codec_err_t vp8_decode(vpx_codec_alg_priv_t  *ctx,
     unsigned int resolution_change = 0;
     unsigned int w, h;
 
+    if (data == NULL && data_sz == 0) {
+      ctx->flushed = 1;
+      return VPX_CODEC_OK;
+    }
+
+    /* Reset flushed when receiving a valid frame */
+    ctx->flushed = 0;
 
     /* Update the input fragment data */
     if(update_fragments(ctx, data, data_sz, &res) <= 0)
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);