From 95d4dc7776b0202f22bd743e1e2b86a444a247a3 Mon Sep 17 00:00:00 2001
From: Jeff Tinker <jtinker@google.com>
Date: Wed, 7 Dec 2011 20:28:03 -0800
Subject: [PATCH] Fix ANRs due to Widevine DRM plugin sniff taking too long.

Add a Widevine-specific format sniffer to avoid having to
refetch data from the remote server.

related-to-bug: 5725548

Change-Id: I622e39930f8d243111e4731557b0df17c4e2651d
---
 proprietary/drmwvmplugin/src/WVMDrmPlugin.cpp | 58 +++++--------------
 proprietary/wvm/WVMExtractorImpl.cpp          | 21 +++++++
 proprietary/wvm/include/WVMExtractorImpl.h    |  2 +-
 3 files changed, 36 insertions(+), 45 deletions(-)

diff --git a/proprietary/drmwvmplugin/src/WVMDrmPlugin.cpp b/proprietary/drmwvmplugin/src/WVMDrmPlugin.cpp
index ba7707e7..60b5972f 100644
--- a/proprietary/drmwvmplugin/src/WVMDrmPlugin.cpp
+++ b/proprietary/drmwvmplugin/src/WVMDrmPlugin.cpp
@@ -710,42 +710,14 @@ status_t WVMDrmPlugin::onRemoveAllRights(int uniqueId) {
 status_t WVMDrmPlugin::onOpenDecryptSession(
             int uniqueId, DecryptHandle *decryptHandle, int fd, off64_t offset, off64_t length)
 {
-    status_t result = DRM_ERROR_CANNOT_HANDLE;
+    // For efficiency, we rely on the WVMExtractor's sniff result instead of
+    // setting mimeType and decryptApiType here for the DRMExtractor's sniff.
+    // WVMExtractor's sniff uses the cached data source for the sniff.
+    decryptHandle->decryptInfo = NULL;
+    decryptHandle->status = DRM_NO_ERROR;
 
-    //LOGD("onOpenDecryptSession: fd=%d, offset=%lld, length=%lld", fd, offset, length);
-
-    char buffer[64 * 1024];
-    int dupfd = dup(fd);
-    if (dupfd == -1)
-        return result;
-
-    FILE *f = fdopen(dupfd, "rb");
-    if (f) {
-        fseek(f, 0, SEEK_SET);
-        if (fread(buffer, 1, sizeof(buffer), f) != sizeof(buffer)) {
-            fclose(f);
-            return DRM_ERROR_CANNOT_HANDLE;
-        }
-        fclose(f);
-    } else {
-        close(dupfd);
-        return result;
-    }
-
-    if (WV_IsWidevineMedia(buffer, sizeof(buffer))) {
-        //LOGD("WVMDrmPlugin::onOpenDecryptSession - WV_IsWidevineMedia: true");
-        decryptHandle->mimeType = String8("video/wvm");
-        decryptHandle->decryptApiType = DecryptApiType::WV_BASED;
-        decryptHandle->status = DRM_NO_ERROR;
-        decryptHandle->decryptInfo = NULL;
-
-        mDrmPluginImpl->OpenSession(NULL);
-        result = DRM_NO_ERROR;
-    } else {
-        //LOGD("WVMDrmPlugin::onOpenDecryptSession - not Widevine media");
-    }
-
-    return result;
+    mDrmPluginImpl->OpenSession(NULL);
+    return DRM_NO_ERROR;
 }
 
 /**
@@ -760,21 +732,19 @@ status_t WVMDrmPlugin::onOpenDecryptSession(
 status_t WVMDrmPlugin::onOpenDecryptSession(
     int uniqueId, DecryptHandle* decryptHandle, const char* uri)
 {
+    // For efficiency, we rely on the WVMExtractor's sniff result instead of
+    // setting mimeType and decryptApiType here for the DRMExtractor's sniff.
+    // WVMExtractor's sniff uses the cached data source for the sniff.
     status_t result = DRM_ERROR_CANNOT_HANDLE;
 
     if (!uri)
         return result;
 
-    if (mDrmPluginImpl->IsSupportedMediaType(uri)) {
-        //LOGD("WVMDrmPlugin::onOpenDecryptSession(uri) : %d - match", uniqueId);
-        decryptHandle->mimeType = String8("video/wvm");
-        decryptHandle->decryptApiType = DecryptApiType::WV_BASED;
-        decryptHandle->status = DRM_NO_ERROR;
-        decryptHandle->decryptInfo = NULL;
+    decryptHandle->decryptInfo = NULL;
+    decryptHandle->status = DRM_NO_ERROR;
 
-        if (mDrmPluginImpl->OpenSession(uri)) {
-            result = DRM_NO_ERROR;
-        }
+    if (mDrmPluginImpl->OpenSession(uri)) {
+        result = DRM_NO_ERROR;
     } else {
         //LOGD("WVMDrmPlugin::onOpenDecryptSession(uri) - not Widevine media");
     }
diff --git a/proprietary/wvm/WVMExtractorImpl.cpp b/proprietary/wvm/WVMExtractorImpl.cpp
index 8b27adc3..6af475f3 100644
--- a/proprietary/wvm/WVMExtractorImpl.cpp
+++ b/proprietary/wvm/WVMExtractorImpl.cpp
@@ -80,6 +80,27 @@ WVMLoadableExtractor *GetInstance(sp<DataSource> dataSource) {
     return new WVMExtractorImpl(dataSource);
 }
 
+bool IsWidevineMedia(sp<DataSource> dataSource) {
+    char buffer[64 * 1024];
+
+    String8 uri = dataSource->getUri();
+    if (uri.getPathExtension() == ".m3u8" || uri.find(".m3u8?") != -1) {
+        // can't sniff live streams - check for .m3u8 file extension
+        return true;
+    }
+
+    ssize_t bytesRead = dataSource->readAt(0, buffer, sizeof(buffer));
+    if (bytesRead < (ssize_t)sizeof(buffer)) {
+        LOGW("IsWidevineMedia - insufficient data: %d", (int)bytesRead);
+        return false;
+    }
+
+    bool result = WV_IsWidevineMedia(buffer, sizeof(buffer));
+    return result;
+}
+
+
+
 WVMExtractorImpl::WVMExtractorImpl(sp<DataSource> dataSource)
     : mFileMetaData(new MetaData()),
       mDataSource(dataSource),
diff --git a/proprietary/wvm/include/WVMExtractorImpl.h b/proprietary/wvm/include/WVMExtractorImpl.h
index 63e016c7..c8c9b9b3 100644
--- a/proprietary/wvm/include/WVMExtractorImpl.h
+++ b/proprietary/wvm/include/WVMExtractorImpl.h
@@ -31,7 +31,7 @@
 namespace android {
 
 WVMLoadableExtractor *GetInstance(sp<DataSource> dataSource);
-
+bool IsWidevineMedia(sp<DataSource> dataSource);
 
 class WVMMediaSource;
 class WVMFileSource;