Fix support for per-frame unsynchronization in ID3V2.4 tags. (8735f898) · Commits · e / os / android_frameworks_base

media/libstagefright/id3/ID3.cpp

+84 −4

Original line number	Diff line number	Diff line
		@@ -142,11 +142,22 @@ struct id3_header {
		mSize = size;

		if (source->readAt(sizeof(header), mData, mSize) != (ssize_t)mSize) {
		free(mData);
		mData = NULL;

		return false;
		}

		if (header.flags & 0x80) {
		if (header.version_major == 4) {
		if (!removeUnsynchronizationV2_4()) {
		free(mData);
		mData = NULL;

		return false;
		}
		} else if (header.flags & 0x80) {
		LOGV("removing unsynchronization");

		removeUnsynchronization();
		}

		@@ -243,6 +254,74 @@ void ID3::removeUnsynchronization() {
		}
		}

		static void WriteSyncsafeInteger(uint8_t *dst, size_t x) {
		for (size_t i = 0; i < 4; ++i) {
		dst[3 - i] = (x & 0x7f);
		x >>= 7;
		}
		}

		bool ID3::removeUnsynchronizationV2_4() {
		size_t oldSize = mSize;

		size_t offset = 0;
		while (offset + 10 <= mSize) {
		if (!memcmp(&mData[offset], "\0\0\0\0", 4)) {
		break;
		}

		size_t dataSize;
		if (!ParseSyncsafeInteger(&mData[offset + 4], &dataSize)) {
		return false;
		}

		if (offset + dataSize + 10 > mSize) {
		return false;
		}

		uint16_t flags = U16_AT(&mData[offset + 8]);
		uint16_t prevFlags = flags;

		if (flags & 1) {
		// Strip data length indicator

		memmove(&mData[offset + 10], &mData[offset + 14], mSize - offset - 14);
		mSize -= 4;
		dataSize -= 4;

		flags &= ~1;
		}

		if (flags & 2) {
		// Unsynchronization added.

		for (size_t i = 0; i + 1 < dataSize; ++i) {
		if (mData[offset + 10 + i] == 0xff
		&& mData[offset + 11 + i] == 0x00) {
		memmove(&mData[offset + 11 + i], &mData[offset + 12 + i],
		mSize - offset - 12 - i);
		--mSize;
		--dataSize;
		}
		}

		flags &= ~2;
		}

		if (flags != prevFlags) {
		WriteSyncsafeInteger(&mData[offset + 4], dataSize);
		mData[offset + 8] = flags >> 8;
		mData[offset + 9] = flags & 0xff;
		}

		offset += 10 + dataSize;
		}

		memset(&mData[mSize], 0, oldSize - mSize);

		return true;
		}

		ID3::Iterator::Iterator(const ID3 &parent, const char *id)
		: mParent(parent),
		mID(NULL),
		@@ -529,10 +608,11 @@ void ID3::Iterator::findFrame() {

		uint16_t flags = U16_AT(&mParent.mData[mOffset + 8]);

		if ((mParent.mVersion == ID3_V2_4 && (flags & 0x000e))
		if ((mParent.mVersion == ID3_V2_4 && (flags & 0x000c))
		\|\| (mParent.mVersion == ID3_V2_3 && (flags & 0x00c0))) {
		// Compression, Encryption or per-Frame unsynchronization
		// are not supported at this time.
		// Compression or encryption are not supported at this time.
		// Per-frame unsynchronization and data-length indicator
		// have already been taken care of.

		LOGV("Skipping unsupported frame (compression, encryption "
		"or per-frame unsynchronization flagged");

media/libstagefright/include/ID3.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -80,6 +80,7 @@ private:
		bool parseV1(const sp<DataSource> &source);
		bool parseV2(const sp<DataSource> &source);
		void removeUnsynchronization();
		bool removeUnsynchronizationV2_4();

		static bool ParseSyncsafeInteger(const uint8_t encoded[4], size_t *x);