MediaCodecList: handle errors gracefully

Handle missing OMX codecs, and codecs that do not load.
Fix NULL dereference when initializing codec with no type.

Bug: 16907578
Bug: 16905025
Change-Id: I5d103db36ebb029d1aab03222bf6e9324beb1566

3 files changed, 30 insertions, 5 deletions

diff --git a/include/media/MediaCodecInfo.h b/include/media/MediaCodecInfo.h
index 29315ce..fc340c8 100644
--- a/include/media/MediaCodecInfo.h
+++ b/include/media/MediaCodecInfo.h
@@ -107,6 +107,7 @@ private:
     status_t initializeCapabilities(const CodecCapabilities &caps);
     void addDetail(const AString &key, const AString &value);
     void addFeature(const AString &key, int32_t value);
+    void removeMime(const char *mime);
     void complete();
 
     DISALLOW_EVIL_CONSTRUCTORS(MediaCodecInfo);
diff --git a/media/libmedia/MediaCodecInfo.cpp b/media/libmedia/MediaCodecInfo.cpp
index 7900eae..8f47292 100644
--- a/media/libmedia/MediaCodecInfo.cpp
+++ b/media/libmedia/MediaCodecInfo.cpp
@@ -206,6 +206,14 @@ status_t MediaCodecInfo::addMime(const char *mime) {
     return OK;
 }
 
+void MediaCodecInfo::removeMime(const char *mime) {
+    ssize_t ix = getCapabilityIndex(mime);
+    if (ix >= 0) {
+        mCaps.removeItemsAt(ix);
+        // mCurrentCaps will be removed when completed
+    }
+}
+
 status_t MediaCodecInfo::initializeCapabilities(const CodecCapabilities &caps) {
     mCurrentCaps->mProfileLevels.clear();
     mCurrentCaps->mColorFormats.clear();
diff --git a/media/libstagefright/MediaCodecList.cpp b/media/libstagefright/MediaCodecList.cpp
index 7f8b7f5..2f2a0b3 100644
--- a/media/libstagefright/MediaCodecList.cpp
+++ b/media/libstagefright/MediaCodecList.cpp
@@ -482,11 +482,21 @@ status_t MediaCodecList::addMediaCodecFromAttributes(
     }
 
     mCurrentInfo = new MediaCodecInfo(name, encoder, type);
-    mCodecInfos.push_back(mCurrentInfo);
-    return initializeCapabilities(type);
+    // The next step involves trying to load the codec, which may
+    // fail.  Only list the codec if this succeeds.
+    // However, keep mCurrentInfo object around until parsing
+    // of full codec info is completed.
+    if (initializeCapabilities(type) == OK) {
+        mCodecInfos.push_back(mCurrentInfo);
+    }
+    return OK;
 }
 
 status_t MediaCodecList::initializeCapabilities(const char *type) {
+    if (type == NULL) {
+        return OK;
+    }
+
     ALOGV("initializeCapabilities %s:%s",
             mCurrentInfo->mName.c_str(), type);
 
@@ -553,10 +563,16 @@ status_t MediaCodecList::addTypeFromAttributes(const char **attrs) {
     }
 
     status_t ret = mCurrentInfo->addMime(name);
-    if (ret == OK) {
-        ret = initializeCapabilities(name);
+    if (ret != OK) {
+        return ret;
     }
-    return ret;
+
+    // The next step involves trying to load the codec, which may
+    // fail.  Handle this gracefully (by not reporting such mime).
+    if (initializeCapabilities(name) != OK) {
+        mCurrentInfo->removeMime(name);
+    }
+    return OK;
 }
 
 // legacy method for non-advanced codecs