Properly respect NALLengthSize in the AVC Configuration header to determine... (db5d6622) · Commits · e / os / android_frameworks_base

media/libstagefright/MPEG4Extractor.cpp

+51 −12

Original line number	Diff line number	Diff line
		@@ -66,6 +66,8 @@ private:
		uint32_t mCurrentSampleIndex;

		bool mIsAVC;
		size_t mNALLengthSize;

		bool mStarted;

		MediaBufferGroup *mGroup;
		@@ -76,6 +78,8 @@ private:

		uint8_t *mSrcBuffer;

		size_t parseNALSize(const uint8_t *data) const;

		MPEG4Source(const MPEG4Source &);
		MPEG4Source &operator=(const MPEG4Source &);
		};
		@@ -770,6 +774,7 @@ MPEG4Source::MPEG4Source(
		mSampleTable(sampleTable),
		mCurrentSampleIndex(0),
		mIsAVC(false),
		mNALLengthSize(0),
		mStarted(false),
		mGroup(NULL),
		mBuffer(NULL),
		@@ -780,6 +785,21 @@ MPEG4Source::MPEG4Source(
		CHECK(success);

		mIsAVC = !strcasecmp(mime, MEDIA_MIMETYPE_VIDEO_AVC);

		if (mIsAVC) {
		uint32_t type;
		const void *data;
		size_t size;
		CHECK(format->findData(kKeyAVCC, &type, &data, &size));

		const uint8_t ptr = (const uint8_t )data;

		CHECK(size >= 7);
		CHECK_EQ(ptr[0], 1); // configurationVersion == 1

		// The number of bytes used to encode the length of a NAL unit.
		mNALLengthSize = 1 + (ptr[4] & 3);
		}
		}

		MPEG4Source::~MPEG4Source() {
		@@ -837,6 +857,25 @@ sp<MetaData> MPEG4Source::getFormat() {
		return mFormat;
		}

		size_t MPEG4Source::parseNALSize(const uint8_t *data) const {
		switch (mNALLengthSize) {
		case 1:
		return *data;
		case 2:
		return U16_AT(data);
		case 3:
		return ((size_t)data[0] << 16) \| U16_AT(&data[1]);
		case 4:
		return U32_AT(data);
		}

		// This cannot happen, mNALLengthSize springs to life by adding 1 to
		// a 2-bit integer.
		CHECK(!"Should not be here.");

		return 0;
		}

		status_t MPEG4Source::read(
		MediaBuffer *out, const ReadOptions options) {
		CHECK(mStarted);
		@@ -919,21 +958,20 @@ status_t MPEG4Source::read(
		// Each NAL unit is split up into its constituent fragments and
		// each one of them returned in its own buffer.

		CHECK(mBuffer->range_length() >= 2);
		CHECK(mBuffer->range_length() >= mNALLengthSize);

		const uint8_t *src =
		(const uint8_t *)mBuffer->data() + mBuffer->range_offset();

		size_t nal_size = U16_AT(src);

		CHECK(mBuffer->range_length() >= 2 + nal_size);
		size_t nal_size = parseNALSize(src);
		CHECK(mBuffer->range_length() >= mNALLengthSize + nal_size);

		MediaBuffer *clone = mBuffer->clone();
		clone->set_range(mBuffer->range_offset() + 2, nal_size);
		clone->set_range(mBuffer->range_offset() + mNALLengthSize, nal_size);

		mBuffer->set_range(
		mBuffer->range_offset() + 2 + nal_size,
		mBuffer->range_length() - 2 - nal_size);
		mBuffer->range_offset() + mNALLengthSize + nal_size,
		mBuffer->range_length() - mNALLengthSize - nal_size);

		if (mBuffer->range_length() == 0) {
		mBuffer->release();
		@@ -960,12 +998,12 @@ status_t MPEG4Source::read(
		uint8_t dstData = (uint8_t )mBuffer->data();
		size_t srcOffset = 0;
		size_t dstOffset = 0;

		while (srcOffset < size) {
		CHECK(srcOffset + 1 < size);
		size_t nalLength =
		(mSrcBuffer[srcOffset] << 8) \| mSrcBuffer[srcOffset + 1];
		CHECK(srcOffset + 1 + nalLength < size);
		srcOffset += 2;
		CHECK(srcOffset + mNALLengthSize <= size);
		size_t nalLength = parseNALSize(&mSrcBuffer[srcOffset]);
		srcOffset += mNALLengthSize;
		CHECK(srcOffset + nalLength <= size);

		if (nalLength == 0) {
		continue;
		@@ -981,6 +1019,7 @@ status_t MPEG4Source::read(
		srcOffset += nalLength;
		dstOffset += nalLength;
		}
		CHECK_EQ(srcOffset, size);

		mBuffer->set_range(0, dstOffset);
		mBuffer->meta_data()->clear();