Remove RefBase from the extractor API

- Add MetaDataBase base class that MetaData derives from, but which
  does not derive from RefBase.
- MediaBuffer::meta_data() now returns a MetaDataBase& rather than an
  sp<MetaData>
- Rename MediaSourceBase to MediaTrack.
- MediaSource no longer derives from MediaSourceBase (or MediaTrack)
- MediaTrack::getFormat(), MediaExtractor::getTrackMetaData() and
  MediaExtractor::getMetaData() all take a MetaDataBase& parameter that
  they fill out, rather than returning a MetaData directly (the
  corresponding methods on MediaSource and RemoteMediaExtractor continue
  to return MetaData)

Bug: 67908544
Test: CTS MediaPlayerTest, DecoderTest, EncodeDecodeTest, manually record video

Change-Id: Ib531ab309061290be33d40d6100c9a8127e22083
diff --git a/media/libmediaextractor/VorbisComment.cpp b/media/libmediaextractor/VorbisComment.cpp
new file mode 100644
index 0000000..fabaf51
--- /dev/null
+++ b/media/libmediaextractor/VorbisComment.cpp
@@ -0,0 +1,153 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+//#define LOG_NDEBUG 0
+#define LOG_TAG "VorbisComment"
+#include <utils/Log.h>
+
+#include "media/VorbisComment.h"
+
+#include <media/stagefright/foundation/base64.h>
+#include <media/stagefright/foundation/ABuffer.h>
+#include <media/stagefright/foundation/AString.h>
+#include <media/stagefright/foundation/ByteUtils.h>
+#include <media/stagefright/MetaDataBase.h>
+
+namespace android {
+
+static void extractAlbumArt(
+        MetaDataBase *fileMeta, const void *data, size_t size) {
+    ALOGV("extractAlbumArt from '%s'", (const char *)data);
+
+    sp<ABuffer> flacBuffer = decodeBase64(AString((const char *)data, size));
+    if (flacBuffer == NULL) {
+        ALOGE("malformed base64 encoded data.");
+        return;
+    }
+
+    size_t flacSize = flacBuffer->size();
+    uint8_t *flac = flacBuffer->data();
+    ALOGV("got flac of size %zu", flacSize);
+
+    uint32_t picType;
+    uint32_t typeLen;
+    uint32_t descLen;
+    uint32_t dataLen;
+    char type[128];
+
+    if (flacSize < 8) {
+        return;
+    }
+
+    picType = U32_AT(flac);
+
+    if (picType != 3) {
+        // This is not a front cover.
+        return;
+    }
+
+    typeLen = U32_AT(&flac[4]);
+    if (typeLen > sizeof(type) - 1) {
+        return;
+    }
+
+    // we've already checked above that flacSize >= 8
+    if (flacSize - 8 < typeLen) {
+        return;
+    }
+
+    memcpy(type, &flac[8], typeLen);
+    type[typeLen] = '\0';
+
+    ALOGV("picType = %d, type = '%s'", picType, type);
+
+    if (!strcmp(type, "-->")) {
+        // This is not inline cover art, but an external url instead.
+        return;
+    }
+
+    if (flacSize < 32 || flacSize - 32 < typeLen) {
+        return;
+    }
+
+    descLen = U32_AT(&flac[8 + typeLen]);
+    if (flacSize - 32 - typeLen < descLen) {
+        return;
+    }
+
+    dataLen = U32_AT(&flac[8 + typeLen + 4 + descLen + 16]);
+
+    // we've already checked above that (flacSize - 32 - typeLen - descLen) >= 0
+    if (flacSize - 32 - typeLen - descLen < dataLen) {
+        return;
+    }
+
+    ALOGV("got image data, %zu trailing bytes",
+         flacSize - 32 - typeLen - descLen - dataLen);
+
+    fileMeta->setData(
+            kKeyAlbumArt, 0, &flac[8 + typeLen + 4 + descLen + 20], dataLen);
+
+    fileMeta->setCString(kKeyAlbumArtMIME, type);
+}
+
+void parseVorbisComment(
+        MetaDataBase *fileMeta, const char *comment, size_t commentLength)
+{
+    struct {
+        const char *const mTag;
+        uint32_t mKey;
+    } kMap[] = {
+        { "TITLE", kKeyTitle },
+        { "ARTIST", kKeyArtist },
+        { "ALBUMARTIST", kKeyAlbumArtist },
+        { "ALBUM ARTIST", kKeyAlbumArtist },
+        { "COMPILATION", kKeyCompilation },
+        { "ALBUM", kKeyAlbum },
+        { "COMPOSER", kKeyComposer },
+        { "GENRE", kKeyGenre },
+        { "AUTHOR", kKeyAuthor },
+        { "TRACKNUMBER", kKeyCDTrackNumber },
+        { "DISCNUMBER", kKeyDiscNumber },
+        { "DATE", kKeyDate },
+        { "YEAR", kKeyYear },
+        { "LYRICIST", kKeyWriter },
+        { "METADATA_BLOCK_PICTURE", kKeyAlbumArt },
+        { "ANDROID_LOOP", kKeyAutoLoop },
+    };
+
+        for (size_t j = 0; j < sizeof(kMap) / sizeof(kMap[0]); ++j) {
+            size_t tagLen = strlen(kMap[j].mTag);
+            if (!strncasecmp(kMap[j].mTag, comment, tagLen)
+                    && comment[tagLen] == '=') {
+                if (kMap[j].mKey == kKeyAlbumArt) {
+                    extractAlbumArt(
+                            fileMeta,
+                            &comment[tagLen + 1],
+                            commentLength - tagLen - 1);
+                } else if (kMap[j].mKey == kKeyAutoLoop) {
+                    if (!strcasecmp(&comment[tagLen + 1], "true")) {
+                        fileMeta->setInt32(kKeyAutoLoop, true);
+                    }
+                } else {
+                    fileMeta->setCString(kMap[j].mKey, &comment[tagLen + 1]);
+                }
+            }
+        }
+
+}
+
+}  // namespace android