Merge "Skip XING/VBRI frame when decoding" (2833eaf0) · Commits · e / os / android_frameworks_base

media/libstagefright/MP3Extractor.cpp

+7 −0

Original line number	Diff line number	Diff line
		@@ -317,6 +317,13 @@ MP3Extractor::MP3Extractor(
		mSeeker = VBRISeeker::CreateFromSource(mDataSource, post_id3_pos);
		}

		if (mSeeker != NULL) {
		// While it is safe to send the XING/VBRI frame to the decoder, this will
		// result in an extra 1152 samples being output. The real first frame to
		// decode is after the XING/VBRI frame, so skip there.
		mFirstFramePos += frame_size;
		}

		int64_t durationUs;

		if (mSeeker == NULL \|\| !mSeeker->getDuration(&durationUs)) {

media/libstagefright/VBRISeeker.cpp

+1 −1

Original line number	Diff line number	Diff line
		@@ -92,7 +92,7 @@ sp<VBRISeeker> VBRISeeker::CreateFromSource(
		}

		sp<VBRISeeker> seeker = new VBRISeeker;
		seeker->mBasePos = post_id3_pos;
		seeker->mBasePos = post_id3_pos + frameSize;
		seeker->mDurationUs = durationUs;

		off64_t offset = post_id3_pos;

media/libstagefright/XINGSeeker.cpp

+51 −106

Original line number	Diff line number	Diff line
		@@ -15,35 +15,13 @@
		*/

		#include "include/XINGSeeker.h"
		#include "include/avc_utils.h"

		#include <media/stagefright/DataSource.h>
		#include <media/stagefright/Utils.h>

		namespace android {

		static bool parse_xing_header(
		const sp<DataSource> &source, off64_t first_frame_pos,
		int32_t frame_number = NULL, int32_t byte_number = NULL,
		unsigned char table_of_contents = NULL, bool toc_is_valid = NULL,
		int32_t quality_indicator = NULL, int64_t duration = NULL);

		// static
		sp<XINGSeeker> XINGSeeker::CreateFromSource(
		const sp<DataSource> &source, off64_t first_frame_pos) {
		sp<XINGSeeker> seeker = new XINGSeeker;

		seeker->mFirstFramePos = first_frame_pos;

		if (!parse_xing_header(
		source, first_frame_pos,
		NULL, &seeker->mSizeBytes, seeker->mTOC, &seeker->mTOCValid,
		NULL, &seeker->mDurationUs)) {
		return NULL;
		}

		return seeker;
		}

		XINGSeeker::XINGSeeker()
		: mDurationUs(-1),
		mSizeBytes(0) {
		@@ -91,60 +69,50 @@ bool XINGSeeker::getOffsetForTime(int64_t timeUs, off64_t pos) {
		return true;
		}

		static bool parse_xing_header(
		const sp<DataSource> &source, off64_t first_frame_pos,
		int32_t frame_number, int32_t byte_number,
		unsigned char table_of_contents, bool toc_valid,
		int32_t *quality_indicator,
		int64_t *duration) {
		if (frame_number) {
		*frame_number = 0;
		}
		if (byte_number) {
		*byte_number = 0;
		}
		if (toc_valid) {
		*toc_valid = false;
		}
		if (quality_indicator) {
		*quality_indicator = 0;
		}
		if (duration) {
		*duration = 0;
		}
		// static
		sp<XINGSeeker> XINGSeeker::CreateFromSource(
		const sp<DataSource> &source, off64_t first_frame_pos) {
		sp<XINGSeeker> seeker = new XINGSeeker;

		seeker->mFirstFramePos = first_frame_pos;

		ALOGI("xingseeker first frame pos: %lld", first_frame_pos);

		seeker->mSizeBytes = 0;
		seeker->mTOCValid = false;
		seeker->mDurationUs = 0;

		uint8_t buffer[4];
		int offset = first_frame_pos;
		if (source->readAt(offset, &buffer, 4) < 4) { // get header
		return false;
		return NULL;
		}
		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;
		int header = U32_AT(buffer);;
		size_t xingframesize = 0;
		int sampling_rate = 0;
		int num_channels;
		int samples_per_frame = 0;
		if (!GetMPEGAudioFrameSize(header, &xingframesize, &sampling_rate, &num_channels,
		NULL, &samples_per_frame)) {
		return NULL;
		}
		seeker->mFirstFramePos += xingframesize;

		uint8_t version = (buffer[1] >> 3) & 3;

		// determine offset of XING header
		if(id&1) { // mpeg1
		if (mode != 3) offset += 32;
		if(version & 1) { // mpeg1
		if (num_channels != 1) offset += 32;
		else offset += 17;
		} else { // mpeg2
		if (mode != 3) offset += 17;
		} else { // mpeg 2 or 2.5
		if (num_channels != 1) offset += 17;
		else offset += 9;
		}

		if (source->readAt(offset, &buffer, 4) < 4) { // XING header ID
		return false;
		return NULL;
		}
		offset += 4;
		// Check XING ID
		@@ -152,73 +120,50 @@ static bool parse_xing_header(
		\|\| (buffer[2] != 'n') \|\| (buffer[3] != 'g')) {
		if ((buffer[0] != 'I') \|\| (buffer[1] != 'n')
		\|\| (buffer[2] != 'f') \|\| (buffer[3] != 'o')) {
		return false;
		return NULL;
		}
		}

		if (source->readAt(offset, &buffer, 4) < 4) { // flags
		return false;
		return NULL;
		}
		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];
		return NULL;
		}
		int32_t frames = U32_AT(buffer);
		seeker->mDurationUs = (int64_t)frames * samples_per_frame * 1000000LL / sampling_rate;
		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);
		return NULL;
		}
		seeker->mSizeBytes = 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;
		}
		if (toc_valid) {
		*toc_valid = true;
		}
		if (source->readAt(offset + 1, seeker->mTOC, 99) < 99) {
		return NULL;
		}
		seeker->mTOCValid = true;
		offset += 100;
		}

		#if 0
		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 NULL;
		}
		// do something with the quality indicator
		offset += 4;
		}
		return true;
		#endif

		return seeker;
		}

		} // namespace android