Extend WAV extractor for multichannel (63ffeeb6) · Commits · e / os / android_frameworks_base

media/libstagefright/WAVExtractor.cpp

+72 −10

Original line number	Diff line number	Diff line
		@@ -28,15 +28,22 @@
		#include <media/stagefright/MediaSource.h>
		#include <media/stagefright/MetaData.h>
		#include <utils/String8.h>
		#include <cutils/bitops.h>

		#define CHANNEL_MASK_USE_CHANNEL_ORDER 0

		namespace android {

		enum {
		WAVE_FORMAT_PCM = 1,
		WAVE_FORMAT_ALAW = 6,
		WAVE_FORMAT_MULAW = 7,
		WAVE_FORMAT_PCM = 0x0001,
		WAVE_FORMAT_ALAW = 0x0006,
		WAVE_FORMAT_MULAW = 0x0007,
		WAVE_FORMAT_EXTENSIBLE = 0xFFFE
		};

		static const char* WAVEEXT_SUBFORMAT = "\x00\x00\x00\x00\x10\x00\x80\x00\x00\xAA\x00\x38\x9B\x71";


		static uint32_t U32_LE_AT(const uint8_t *ptr) {
		return ptr[3] << 24 \| ptr[2] << 16 \| ptr[1] << 8 \| ptr[0];
		}
		@@ -84,7 +91,8 @@ private:

		WAVExtractor::WAVExtractor(const sp<DataSource> &source)
		: mDataSource(source),
		mValidFormat(false) {
		mValidFormat(false),
		mChannelMask(CHANNEL_MASK_USE_CHANNEL_ORDER) {
		mInitCheck = init();
		}

		@@ -161,22 +169,38 @@ status_t WAVExtractor::init() {
		return NO_INIT;
		}

		uint8_t formatSpec[16];
		if (mDataSource->readAt(offset, formatSpec, 16) < 16) {
		uint8_t formatSpec[40];
		if (mDataSource->readAt(offset, formatSpec, 2) < 2) {
		return NO_INIT;
		}

		mWaveFormat = U16_LE_AT(formatSpec);
		if (mWaveFormat != WAVE_FORMAT_PCM
		&& mWaveFormat != WAVE_FORMAT_ALAW
		&& mWaveFormat != WAVE_FORMAT_MULAW) {
		&& mWaveFormat != WAVE_FORMAT_MULAW
		&& mWaveFormat != WAVE_FORMAT_EXTENSIBLE) {
		return ERROR_UNSUPPORTED;
		}

		uint8_t fmtSize = 16;
		if (mWaveFormat == WAVE_FORMAT_EXTENSIBLE) {
		fmtSize = 40;
		}
		if (mDataSource->readAt(offset, formatSpec, fmtSize) < fmtSize) {
		return NO_INIT;
		}

		mNumChannels = U16_LE_AT(&formatSpec[2]);
		if (mWaveFormat != WAVE_FORMAT_EXTENSIBLE) {
		if (mNumChannels != 1 && mNumChannels != 2) {
		ALOGW("More than 2 channels (%d) in non-WAVE_EXT, unknown channel mask",
		mNumChannels);
		}
		} else {
		if (mNumChannels < 1 && mNumChannels > 8) {
		return ERROR_UNSUPPORTED;
		}
		}

		mSampleRate = U32_LE_AT(&formatSpec[4]);

		@@ -186,7 +210,8 @@ status_t WAVExtractor::init() {

		mBitsPerSample = U16_LE_AT(&formatSpec[14]);

		if (mWaveFormat == WAVE_FORMAT_PCM) {
		if (mWaveFormat == WAVE_FORMAT_PCM
		\|\| mWaveFormat == WAVE_FORMAT_EXTENSIBLE) {
		if (mBitsPerSample != 8 && mBitsPerSample != 16
		&& mBitsPerSample != 24) {
		return ERROR_UNSUPPORTED;
		@@ -199,6 +224,42 @@ status_t WAVExtractor::init() {
		}
		}

		if (mWaveFormat == WAVE_FORMAT_EXTENSIBLE) {
		uint16_t validBitsPerSample = U16_LE_AT(&formatSpec[18]);
		if (validBitsPerSample != mBitsPerSample) {
		ALOGE("validBits(%d) != bitsPerSample(%d) are not supported",
		validBitsPerSample, mBitsPerSample);
		return ERROR_UNSUPPORTED;
		}

		mChannelMask = U32_LE_AT(&formatSpec[20]);
		ALOGV("numChannels=%d channelMask=0x%x", mNumChannels, mChannelMask);
		if ((mChannelMask >> 18) != 0) {
		ALOGE("invalid channel mask 0x%x", mChannelMask);
		return ERROR_MALFORMED;
		}

		if ((mChannelMask != CHANNEL_MASK_USE_CHANNEL_ORDER)
		&& (popcount(mChannelMask) != mNumChannels)) {
		ALOGE("invalid number of channels (%d) in channel mask (0x%x)",
		popcount(mChannelMask), mChannelMask);
		return ERROR_MALFORMED;
		}

		// In a WAVE_EXT header, the first two bytes of the GUID stored at byte 24 contain
		// the sample format, using the same definitions as a regular WAV header
		mWaveFormat = U16_LE_AT(&formatSpec[24]);
		if (mWaveFormat != WAVE_FORMAT_PCM
		&& mWaveFormat != WAVE_FORMAT_ALAW
		&& mWaveFormat != WAVE_FORMAT_MULAW) {
		return ERROR_UNSUPPORTED;
		}
		if (memcmp(&formatSpec[26], WAVEEXT_SUBFORMAT, 14)) {
		ALOGE("unsupported GUID");
		return ERROR_UNSUPPORTED;
		}
		}

		mValidFormat = true;
		} else if (!memcmp(chunkHeader, "data", 4)) {
		if (mValidFormat) {
		@@ -224,6 +285,7 @@ status_t WAVExtractor::init() {
		}

		mTrackMeta->setInt32(kKeyChannelCount, mNumChannels);
		mTrackMeta->setInt32(kKeyChannelMask, mChannelMask);
		mTrackMeta->setInt32(kKeySampleRate, mSampleRate);

		size_t bytesPerSample = mBitsPerSample >> 3;

media/libstagefright/include/WAVExtractor.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -47,6 +47,7 @@ private:
		bool mValidFormat;
		uint16_t mWaveFormat;
		uint16_t mNumChannels;
		uint32_t mChannelMask;
		uint32_t mSampleRate;
		uint16_t mBitsPerSample;
		off64_t mDataOffset;