webmdec: Fix read_frame return value for calls after EOS

webm_read_frame assumes that it won't be called once end of file
is reached. But for frame parallel mode that turns out to be not
true. this patch fixes that behavior by checking for EOS and
returning the appropriate value for subsequent calls.

Change-Id: Ie2fddbe00493a0f96c4172c67be1eb719f0fe8ed

diff --git a/webmdec.cc b/webmdec.cc
index d591f3e..60b01ad 100644 (file)
--- a/webmdec.cc
+++ b/webmdec.cc
@@ -63,6 +63,7 @@ int file_is_webm(struct WebmInputContext *webm_ctx,
                  struct VpxInputContext *vpx_ctx) {
   mkvparser::MkvReader *const reader = new mkvparser::MkvReader(vpx_ctx->file);
   webm_ctx->reader = reader;
+  webm_ctx->reached_eos = 0;
 
   mkvparser::EBMLHeader header;
   long long pos = 0;
@@ -121,6 +122,11 @@ int webm_read_frame(struct WebmInputContext *webm_ctx,
                     uint8_t **buffer,
                     size_t *bytes_in_buffer,
                     size_t *buffer_size) {
+  // This check is needed for frame parallel decoding, in which case this
+  // function could be called even after it has reached end of input stream.
+  if (webm_ctx->reached_eos) {
+    return 1;
+  }
   mkvparser::Segment *const segment =
       reinterpret_cast<mkvparser::Segment*>(webm_ctx->segment);
   const mkvparser::Cluster* cluster =
@@ -140,6 +146,7 @@ int webm_read_frame(struct WebmInputContext *webm_ctx,
       cluster = segment->GetNext(cluster);
       if (cluster == NULL || cluster->EOS()) {
         *bytes_in_buffer = 0;
+        webm_ctx->reached_eos = 1;
         return 1;
       }
       status = cluster->GetFirst(block_entry);

diff --git a/webmdec.h b/webmdec.h
index 1cd35d4..7d16380 100644 (file)
--- a/webmdec.h
+++ b/webmdec.h
@@ -29,6 +29,7 @@ struct WebmInputContext {
   int video_track_index;
   uint64_t timestamp_ns;
   int is_key_frame;
+  int reached_eos;
 };
 
 // Checks if the input is a WebM file. If so, initializes WebMInputContext so