Merge change Ibac388a3 into eclair-mr2 (791c626a) · Commits · e / os / android_frameworks_base

media/libstagefright/MP3Extractor.cpp

+182 −11

Original line number	Diff line number	Diff line
		@@ -173,6 +173,133 @@ static bool get_mp3_frame_size(
		return true;
		}

		static bool parse_xing_header(
		const sp<DataSource> &source, off_t first_frame_pos,
		int32_t frame_number = NULL, int32_t byte_number = NULL,
		char table_of_contents = NULL, int32_t quality_indicator = NULL,
		int64_t *duration = NULL) {

		if (frame_number) {
		*frame_number = 0;
		}
		if (byte_number) {
		*byte_number = 0;
		}
		if (table_of_contents) {
		table_of_contents[0] = 0;
		}
		if (quality_indicator) {
		*quality_indicator = 0;
		}
		if (duration) {
		*duration = 0;
		}

		uint8_t buffer[4];
		int offset = first_frame_pos;
		if (source->readAt(offset, &buffer, 4) < 4) { // get header
		return false;
		}
		offset += 4;

		uint8_t id, layer, sr_index, mode;
		layer = (buffer[1] >> 1) & 3;
		id = (buffer[1] >> 3) & 3;
		sr_index = (buffer[2] >> 2) & 3;
		mode = (buffer[3] >> 6) & 3;
		if (layer == 0) {
		return false;
		}
		if (id == 1) {
		return false;
		}
		if (sr_index == 3) {
		return false;
		}
		// determine offset of XING header
		if(id&1) { // mpeg1
		if (mode != 3) offset += 32;
		else offset += 17;
		} else { // mpeg2
		if (mode != 3) offset += 17;
		else offset += 9;
		}

		if (source->readAt(offset, &buffer, 4) < 4) { // XING header ID
		return false;
		}
		offset += 4;
		// Check XING ID
		if ((buffer[0] != 'X') \|\| (buffer[1] != 'i')
		\|\| (buffer[2] != 'n') \|\| (buffer[3] != 'g')) {
		if ((buffer[0] != 'I') \|\| (buffer[1] != 'n')
		\|\| (buffer[2] != 'f') \|\| (buffer[3] != 'o')) {
		return false;
		}
		}

		if (source->readAt(offset, &buffer, 4) < 4) { // flags
		return false;
		}
		offset += 4;
		uint32_t flags = U32_AT(buffer);

		if (flags & 0x0001) { // Frames field is present
		if (source->readAt(offset, buffer, 4) < 4) {
		return false;
		}
		if (frame_number) {
		*frame_number = U32_AT(buffer);
		}
		int32_t frame = U32_AT(buffer);
		// Samples per Frame: 1. index = MPEG Version ID, 2. index = Layer
		const int samplesPerFrames[2][3] =
		{
		{ 384, 1152, 576 }, // MPEG 2, 2.5: layer1, layer2, layer3
		{ 384, 1152, 1152 }, // MPEG 1: layer1, layer2, layer3
		};
		// sampling rates in hertz: 1. index = MPEG Version ID, 2. index = sampling rate index
		const int samplingRates[4][3] =
		{
		{ 11025, 12000, 8000, }, // MPEG 2.5
		{ 0, 0, 0, }, // reserved
		{ 22050, 24000, 16000, }, // MPEG 2
		{ 44100, 48000, 32000, } // MPEG 1
		};
		if (duration) {
		duration = (int64_t)frame samplesPerFrames[id&1][3-layer] * 1000000LL
		/ samplingRates[id][sr_index];
		}
		offset += 4;
		}
		if (flags & 0x0002) { // Bytes field is present
		if (byte_number) {
		if (source->readAt(offset, buffer, 4) < 4) {
		return false;
		}
		*byte_number = U32_AT(buffer);
		}
		offset += 4;
		}
		if (flags & 0x0004) { // TOC field is present
		if (table_of_contents) {
		if (source->readAt(offset + 1, table_of_contents, 99) < 99) {
		return false;
		}
		}
		offset += 100;
		}
		if (flags & 0x0008) { // Quality indicator field is present
		if (quality_indicator) {
		if (source->readAt(offset, buffer, 4) < 4) {
		return false;
		}
		*quality_indicator = U32_AT(buffer);
		}
		}
		return true;
		}

		static bool Resync(
		const sp<DataSource> &source, uint32_t match_header,
		off_t inout_pos, uint32_t out_header) {
		@@ -314,7 +441,8 @@ class MP3Source : public MediaSource {
		public:
		MP3Source(
		const sp<MetaData> &meta, const sp<DataSource> &source,
		off_t first_frame_pos, uint32_t fixed_header);
		off_t first_frame_pos, uint32_t fixed_header,
		int32_t byte_number, const char *table_of_contents);

		virtual status_t start(MetaData *params = NULL);
		virtual status_t stop();
		@@ -335,7 +463,9 @@ private:
		off_t mCurrentPos;
		int64_t mCurrentTimeUs;
		bool mStarted;

		int32_t mByteNumber; // total number of bytes in this MP3
		// TOC entries in XING header. Skip the first one since it's always 0.
		char mTableOfContents[99];
		MediaBufferGroup *mGroup;

		MP3Source(const MP3Source &);
		@@ -345,7 +475,8 @@ private:
		MP3Extractor::MP3Extractor(const sp<DataSource> &source)
		: mDataSource(source),
		mFirstFramePos(-1),
		mFixedHeader(0) {
		mFixedHeader(0),
		mByteNumber(0) {
		off_t pos = 0;
		uint32_t header;
		bool success = Resync(mDataSource, 0, &pos, &header);
		@@ -369,6 +500,13 @@ MP3Extractor::MP3Extractor(const sp<DataSource> &source)
		mMeta->setInt32(kKeyBitRate, bitrate * 1000);
		mMeta->setInt32(kKeyChannelCount, num_channels);

		int64_t duration;
		parse_xing_header(
		mDataSource, mFirstFramePos, NULL, &mByteNumber,
		mTableOfContents, NULL, &duration);
		if (duration > 0) {
		mMeta->setInt64(kKeyDuration, duration);
		} else {
		off_t fileSize;
		if (mDataSource->getSize(&fileSize) == OK) {
		mMeta->setInt64(
		@@ -377,6 +515,7 @@ MP3Extractor::MP3Extractor(const sp<DataSource> &source)
		}
		}
		}
		}

		MP3Extractor::~MP3Extractor() {
		}
		@@ -391,7 +530,8 @@ sp<MediaSource> MP3Extractor::getTrack(size_t index) {
		}

		return new MP3Source(
		mMeta, mDataSource, mFirstFramePos, mFixedHeader);
		mMeta, mDataSource, mFirstFramePos, mFixedHeader,
		mByteNumber, mTableOfContents);
		}

		sp<MetaData> MP3Extractor::getTrackMetaData(size_t index, uint32_t flags) {
		@@ -406,7 +546,8 @@ sp<MetaData> MP3Extractor::getTrackMetaData(size_t index, uint32_t flags) {

		MP3Source::MP3Source(
		const sp<MetaData> &meta, const sp<DataSource> &source,
		off_t first_frame_pos, uint32_t fixed_header)
		off_t first_frame_pos, uint32_t fixed_header,
		int32_t byte_number, const char *table_of_contents)
		: mMeta(meta),
		mDataSource(source),
		mFirstFramePos(first_frame_pos),
		@@ -414,7 +555,9 @@ MP3Source::MP3Source(
		mCurrentPos(0),
		mCurrentTimeUs(0),
		mStarted(false),
		mByteNumber(byte_number),
		mGroup(NULL) {
		memcpy (mTableOfContents, table_of_contents, strlen(table_of_contents));
		}

		MP3Source::~MP3Source() {
		@@ -469,8 +612,36 @@ status_t MP3Source::read(
		}

		mCurrentTimeUs = seekTimeUs;
		// interpolate in TOC to get file seek point in bytes
		int64_t duration;
		if ((mByteNumber > 0) && (mTableOfContents[0] > 0)
		&& mMeta->findInt64(kKeyDuration, &duration)) {
		float percent = (float)seekTimeUs * 100 / duration;
		float fx;
		if( percent <= 0.0f ) {
		fx = 0.0f;
		} else if( percent >= 100.0f ) {
		fx = 256.0f;
		} else {
		int a = (int)percent;
		float fa, fb;
		if ( a == 0 ) {
		fa = 0.0f;
		} else {
		fa = (float)mTableOfContents[a-1];
		}
		if ( a < 99 ) {
		fb = (float)mTableOfContents[a];
		} else {
		fb = 256.0f;
		}
		fx = fa + (fb-fa)*(percent-a);
		}
		mCurrentPos = mFirstFramePos + (int)((1.0f/256.0f)fxmByteNumber);
		} else {
		mCurrentPos = mFirstFramePos + seekTimeUs * bitrate / 8000000;
		}
		}

		MediaBuffer *buffer;
		status_t err = mGroup->acquire_buffer(&buffer);

media/libstagefright/include/MP3Extractor.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -42,6 +42,8 @@ private:
		off_t mFirstFramePos;
		sp<MetaData> mMeta;
		uint32_t mFixedHeader;
		int32_t mByteNumber; // total number of bytes in this MP3
		char mTableOfContents[99]; // TOC entries in XING header

		MP3Extractor(const MP3Extractor &);
		MP3Extractor &operator=(const MP3Extractor &);