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improve IPF writing

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This commit is contained in:
Christian R. Helmrich
2021-02-28 19:00:03 +01:00
parent 7d2b818e5a
commit 86f24988e2
8 changed files with 84 additions and 28 deletions
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34
src/lib/bitStreamWriter.cpp
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@ -715,7 +715,10 @@ unsigned BitStreamWriter::createAudioConfig (const char samplingFrequencyIndex,
{
const uint8_t fli = (sbrRatioShiftValue == 0 ? 1 /*no SBR*/ : __min (2, sbrRatioShiftValue) + 2);
const int8_t usfi = __max (0, samplingFrequencyIndex - 3 * sbrRatioShiftValue); // TODO: non-standard sampling rates
unsigned bitCount = 37;
unsigned bitCount = 37, auLen;
#ifndef NO_PREROLL_DATA
unsigned ucOffset = (samplingFrequencyIndex < AAC_NUM_SAMPLE_RATES ? 2 : 5);
#endif
if ((elementType == nullptr) || (audioConfig == nullptr) || (chConfigurationIndex >= USAC_MAX_NUM_ELCONFIGS) ||
#if !RESTRICT_TO_AAC
@ -816,8 +819,12 @@ unsigned BitStreamWriter::createAudioConfig (const char samplingFrequencyIndex,
bitCount += (8 - m_auBitStream.heldBitCount) & 7;
writeByteAlignment (); // flush bytes
memcpy (audioConfig, &m_auBitStream.stream.front (), __min (17u + fli, bitCount >> 3));
auLen = __min (18u + fli, bitCount >> 3);
#ifndef NO_PREROLL_DATA
m_usacConfigLen = uint16_t (__max (9, auLen - ucOffset)); // excl. ASC payload
memcpy (m_usacConfig, &m_auBitStream.stream.at (ucOffset), auLen - ucOffset);
#endif
memcpy (audioConfig, &m_auBitStream.stream.front (), auLen);
return (bitCount >> 3); // byte count
}
@ -854,7 +861,7 @@ unsigned BitStreamWriter::createAudioFrame (CoreCoderData** const elementData,
if ((ipf == 2) || (ipf == 1 && (numElements > 1 || !noiseFilling[0])))
{
bitCount = __min (nSamplesInFrame << 2, (uint32_t) m_auBitStream.stream.size ());
memcpy (tempBuffer, &m_auBitStream.stream.front (), bitCount);
memcpy (tempBuffer, &m_auBitStream.stream.front (), bitCount); // prev fr AU
}
#endif
m_auBitStream.reset ();
@ -869,19 +876,28 @@ unsigned BitStreamWriter::createAudioFrame (CoreCoderData** const elementData,
{
const uint16_t idxPreRollExt = elementData[0]->elementType & 1;
const bool lowRatePreRollExt = (ipf == 1 && numElements == 1 && noiseFilling[0]);
const unsigned payloadLength = (lowRatePreRollExt ? (8 + idxPreRollExt * 6) >> (sbrRatioShiftValue > 0 ? 0 : 1) : bitCount) + 3; // in bytes!
const unsigned extraLength = (m_usacConfigLen > 14 ? 4 : 3) + m_usacConfigLen;
const unsigned payloadLength = (lowRatePreRollExt ? (8 + idxPreRollExt * 6) >> (sbrRatioShiftValue > 0 ? 0 : 1) : bitCount) + extraLength; // in bytes
m_auBitStream.write (0, 1); // usacExtElementUseDefaultLength = 0 (variable)
m_auBitStream.write (CLIP_UCHAR (payloadLength), 8);
if (payloadLength > 254) m_auBitStream.write (payloadLength - 253, 16);
m_auBitStream.write (0, 6); // start AudioPreRoll - configLen = reserved = 0
m_auBitStream.write (__min (15, m_usacConfigLen), 4); // configLen (part #1)
if (m_usacConfigLen > 14) m_auBitStream.write (m_usacConfigLen - 15, 4);
m_auBitStream.write (m_usacConfig[ci++] & 31, 5); // 1st 3 bits are from ASC
while (ci < m_usacConfigLen) m_auBitStream.write (m_usacConfig[ci++], 8);
ci = 0;
m_auBitStream.write (0, 8 - 5); // pad end of UsacConfig() data
m_auBitStream.write (0, 2); // applyCrossfade = 0 and reserved = 0 (part #2)
m_auBitStream.write (1, 2); // numPreRollFrames, only one supported for now!
m_auBitStream.write (payloadLength - 3, 16); // auLen
m_auBitStream.write (payloadLength - extraLength, 16); // auLen
if (lowRatePreRollExt)
{
bitCount = payloadLength - 3;
bitCount = payloadLength - extraLength;
memcpy (tempBuffer, zeroAu[idxPreRollExt], bitCount);
if (elementData[0]->elementType < ID_USAC_LFE) // correct window_sequence
{
@ -893,6 +909,8 @@ unsigned BitStreamWriter::createAudioFrame (CoreCoderData** const elementData,
}
while (ci < bitCount) m_auBitStream.write (tempBuffer[ci++], 8); // write AU
ci = 0;
if (m_usacConfigLen > 14) m_auBitStream.write (0, 4); // pad end of ext data
bitCount = (payloadLength > 254 ? 26 : 10) + (payloadLength << 3); // for PR
}
bitCount++; // for ElementPresent flag