Android/frameworks_base
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Merge "Bug 5156756 Fix AAC ADTS header size computation"

Browse Source
This commit is contained in:
Jean-Michel Trivi
2011-08-30 09:06:36 -07:00
committed by Android (Google) Code Review
parent 7c267b24c6 59fe406b3a
commit c5d0fac081
1 changed files with 24 additions and 9 deletions
Download Patch File Download Diff File Expand all files Collapse all files

33
media/libstagefright/AACExtractor.cpp
View File

@@ -33,8 +33,6 @@
namespace android {
#define ADTS_HEADER_LENGTH 7
class AACSource : public MediaSource {
public:
AACSource(const sp<DataSource> &source,
@@ -88,7 +86,16 @@ uint32_t get_sample_rate(const uint8_t sf_index)
return 0;
}
static size_t getFrameSize(const sp<DataSource> &source, off64_t offset) {
// Returns the frame length in bytes as described in an ADTS header starting at the given offset,
// or 0 if the size can't be read due to an error in the header or a read failure.
// The returned value is the AAC frame size with the ADTS header length (regardless of
// the presence of the CRC).
// If headerSize is non-NULL, it will be used to return the size of the header of this ADTS frame.
static size_t getAdtsFrameLength(const sp<DataSource> &source, off64_t offset, size_t* headerSize) {
const size_t kAdtsHeaderLengthNoCrc = 7;
const size_t kAdtsHeaderLengthWithCrc = 9;
size_t frameSize = 0;
uint8_t syncword[2];
@@ -111,7 +118,15 @@ static size_t getFrameSize(const sp<DataSource> &source, off64_t offset) {
}
frameSize = (header[0] & 0x3) << 11 | header[1] << 3 | header[2] >> 5;
frameSize += ADTS_HEADER_LENGTH + protectionAbsent ? 0 : 2;
// protectionAbsent is 0 if there is CRC
size_t headSize = protectionAbsent ? kAdtsHeaderLengthNoCrc : kAdtsHeaderLengthWithCrc;
if (headSize > frameSize) {
return 0;
}
if (headerSize != NULL) {
*headerSize = headSize;
}
return frameSize;
}
@@ -148,7 +163,7 @@ AACExtractor::AACExtractor(const sp<DataSource> &source)
if (mDataSource->getSize(&streamSize) == OK) {
while (offset < streamSize) {
if ((frameSize = getFrameSize(source, offset)) == 0) {
if ((frameSize = getAdtsFrameLength(source, offset, NULL)) == 0) {
return;
}
@@ -268,8 +283,8 @@ status_t AACSource::read(
}
}
size_t frameSize, frameSizeWithoutHeader;
if ((frameSize = getFrameSize(mDataSource, mOffset)) == 0) {
size_t frameSize, frameSizeWithoutHeader, headerSize;
if ((frameSize = getAdtsFrameLength(mDataSource, mOffset, &headerSize)) == 0) {
return ERROR_END_OF_STREAM;
}
@@ -279,8 +294,8 @@ status_t AACSource::read(
return err;
}
frameSizeWithoutHeader = frameSize - ADTS_HEADER_LENGTH;
if (mDataSource->readAt(mOffset + ADTS_HEADER_LENGTH, buffer->data(),
frameSizeWithoutHeader = frameSize - headerSize;
if (mDataSource->readAt(mOffset + headerSize, buffer->data(),
frameSizeWithoutHeader) != (ssize_t)frameSizeWithoutHeader) {
buffer->release();
buffer = NULL;