public override Slice GetSample(StreamDataBlockInfo SampleInfo)
{
ADTSDataBlockInfo adtsInfo = (ADTSDataBlockInfo)SampleInfo;
Slice ans = new Slice();
ans.Copy(SampleInfo);
#if ADTS
if (adtsInfo.PESandADTSHeaders == null) // ADTS header may be absent, in which case we use the normal base.GetSample
{
return(base.GetSample(SampleInfo));
}
int headerCount = adtsInfo.PESandADTSHeaders.Length;
ans.SliceBytes = new byte[adtsInfo.SliceSize]; // SampleSize has already been incremented by length of PES + ADTS header
adtsInfo.PESandADTSHeaders.CopyTo(ans.SliceBytes, 0);
//if (ParentStream.Stream.Position != (long)adtsInfo.StreamOffset)
// ParentStream.Stream.Position = (long)adtsInfo.StreamOffset; // this if statement for debugging: just to be able to put a breakpoint here
BinaryReader reader = new BinaryReader(new MemoryStream(adtsInfo.SliceBytes));
//ParentStream.Stream.Read(ans.SliceBytes, headerCount, adtsInfo.SliceSize - headerCount);
reader.Read(ans.SliceBytes, headerCount, adtsInfo.SliceSize - headerCount);
#else
ans.SliceBytes = adtsInfo.SliceBytes;
#endif
return(ans);
}
/// <summary>
/// PrepareSampleReading
/// In MP4, reading of box headers is separate from reading of the H264 and audio bits. This is because the bits are stored
/// in a different place in the file (or may in fact be in a separate file). In a QBox file, however, both headers and bits
/// are stored in the qbox. It makes no sense to separate the two. Therefore, in this implementation of PrepareSampleReading,
/// we actually read the bits together with the headers. The routine WriteSamples doesn't do much.
///
/// There are two signatures for this method: one that accepts qbox indices (this one), and another that accepts ulong start
/// and end times.
///
/// We don't keep the qboxes. QBoxes already processed are disposed of as a last step. If we run out of qboxes, we read-in
/// more.
/// </summary>
/// <param name="inStartSampleIndex">int index to first qbox to be processed</param>
/// <param name="inEndSampleIndex">int index to last qbox to be processed</param>
/// <param name="dummy">not used</param>
/// <returns></returns>
public override List <StreamDataBlockInfo> PrepareSampleReading(int inStartSampleIndex, int inEndSampleIndex,
ref ulong dummy)
{
List <StreamDataBlockInfo> retList = new List <StreamDataBlockInfo>();
if (_qBoxes.Count == 0)
{
return(retList);
}
float scaleFactor = TimeSpan.FromSeconds(1.0).Ticks / this.TimeScale;
bool foundFirstSlice = false;
int boxCount = 0;
// we traverse the _qBoxes list from the beginning;
// can't use foreach because _qBoxes can change;
// box.mIndex is NOT the same as index i.
// we use a for loop only because we are adding qboxes to _qBoxes as part of the loop
for (int i = 0; i < _qBoxes.Count; i++)
{
QBox box = _qBoxes[i];
boxCount++;
// reject qboxes with sample size zero (no data)
if (box.mSampleSize == 0)
{
continue;
}
// we shouldn't be searching for the first box of interest, because it should always be the first one
// it should always be the first one because we threw away all boxes already processed
if (((ulong)inStartSampleIndex > (box.mFrameCounter - 1)) ||
((!foundFirstSlice) && (((uint)box.mSampleFlags & QBox.QBOX_SAMPLE_FLAGS_SYNC_POINT) == 0)))
{
continue; // skip
}
else if ((ulong)inStartSampleIndex == (box.mFrameCounter - 1))
{
foundFirstSlice = true;
}
else if (!foundFirstSlice)
{
_qBoxes.Clear();
base.GetNextBatch(0, inStartSampleIndex); // throw new Exception("First IFrame not found");
i = -1; // this gets incremented to zero
boxCount = 0; // start all over
continue;
}
StreamDataBlockInfo datBlock = new Slice();
switch (box.SampleStreamTypeString())
{
case "AAC":
datBlock = new ADTSDataBlockInfo();
datBlock.SliceType = SliceType.AAC;
break;
case "Q711":
case "PCM":
datBlock.SliceType = SliceType.Unknown; // FIXME: add sample type for PCM
break;
case "MP2A":
datBlock.SliceType = SliceType.MP4A;
break;
case "Q722": // ADPCM
case "Q726":
case "Q728":
datBlock.SliceType = SliceType.Unknown; // FIXME: add sample type for ADPCM
break;
case "H264":
case "H264_SLICE":
datBlock = new NaluDelimiterBlockInfo();
if (((uint)box.mSampleFlags & QBox.QBOX_SAMPLE_FLAGS_SYNC_POINT) == 0)
{
datBlock.SliceType = SliceType.DFrame;
}
else
{
datBlock.SliceType = SliceType.IFrame;
}
if ((box.mSample != null) && (box.mSample.v != null))
{
NaluDelimiterBlockInfo blockInfo = datBlock as NaluDelimiterBlockInfo;
blockInfo.AccessUnitDelimiter = box.mSample.v.aud;
}
break;
case "JPEG":
datBlock.SliceType = SliceType.JPEG;
break;
case "MPEG2_ELEMENTARY":
datBlock.SliceType = SliceType.Unknown; // FIXME: add sample type for MPEG2
break;
case "VIN_STATS_GLOBAL":
case "VIN_STATS_MB":
case "USER_METADATA":
case "DEBUG":
default:
System.Diagnostics.Debug.WriteLine("Unknown QBox: {0}", box.SampleStreamTypeString());
break;
}
datBlock.CTS = (ulong)((box.mSampleCTS - (box.mStreamDuration - box.mSampleDuration)) * scaleFactor);
datBlock.SliceDuration = (uint)(scaleFactor * box.mSampleDuration);
if (box.mFrameCounter == 0 && box.mStreamDuration == 0)
{
datBlock.TimeStampNew = 0;
}
else if (box.mStreamDuration == 0)
{
datBlock.TimeStampNew = null;
}
else
{
datBlock.TimeStampNew = (ulong)(scaleFactor * (box.mStreamDuration - box.mSampleDuration));
}
datBlock.SliceSize = box.mSampleSize;
datBlock.index = (int)box.mFrameCounter - 1; // boxCount;
// NOTE! For qbox, StreamOffset has a different meaning than in MP4.
// Here, StreamOffset is the offset to the qbox itself; whereas in
// MP4, StreamOffset is the offset to the H264 payload.
// In GenericMediaTrack.GetSample, StreamOffset is used as in MP4, but
// this method is overriden by another in QBoxVideoTrack that does not use StreamOffset.
// For flashback to work for both MP4 and qbox files, the caching mechanism
// is different in MP4 from than in qbox.
datBlock.StreamOffset = (ulong)box.mHeaderPosition; // needed for flashback to work
// set payload
Slice slice = datBlock as Slice;
slice.SliceBytes = box.mSample.mPayload;
#if ADTS
if (box.mSampleStreamType == QBox.QBOX_SAMPLE_TYPE_AAC)
{
QMed.QMedAAC qmedaac = (QMed.QMedAAC)box.mSample.qmed;
#if PES
datBlock.PESandADTSHeaders = new byte[qmedaac.pesHeader.Length + qmedaac.adtsHeader.Length];
qmedaac.pesHeader.CopyTo(datBlock.PESandADTSHeaders, 0);
qmedaac.adtsHeader.CopyTo(datBlock.PESandADTSHeaders, qmedaac.pesHeader.Length);
#else
datBlock.PESandADTSHeaders = new byte[qmedaac.adtsHeader.Length];
qmedaac.adtsHeader.CopyTo(datBlock.PESandADTSHeaders, 0);
#endif
datBlock.SampleSize += datBlock.PESandADTSHeaders.Length;
}
#endif
if (datBlock.SliceDuration == 0)
{
datBlock.SliceDuration = (uint)(scaleFactor * box.mSampleDuration); // any non-zero duration is better
}
if ((((uint)box.mSampleFlags & QBox.QBOX_SAMPLE_FLAGS_SYNC_POINT) != 0) && ((box.mFrameCounter - 1) >= (ulong)inEndSampleIndex))
{
boxCount--;
break; // don't put last IFrame box in return list
}
retList.Add(datBlock);
if (box == _qBoxes.Last())
{
base.GetNextBatch(GenericMediaStream.MAX_BOXES_TO_READ, 0);
// callee should set end FIXME: is box.mCurrentPosition being set?
}
} // end of for loop
_qBoxes.RemoveRange(0, boxCount);
return(retList);
}
/// <summary>
/// PrepareSampleReading
/// In MP4, reading of box headers is separate from reading of the H264 and audio bits. This is because the bits are stored
/// in a different place in the file (or may in fact be in a separate file). In a QBox file, however, both headers and bits
/// are stored in the qbox. It makes no sense to separate the two. Therefore, in this implementation of PrepareSampleReading,
/// we actually read the bits together with the headers. The routine WriteSamples doesn't do much.
///
/// There are two signatures for this method: one that accepts qbox indices (this one), and another that accepts ulong start
/// and end times.
///
/// We don't keep the qboxes. QBoxes already processed are disposed of as a last step. If we run out of qboxes, we read-in
/// more.
/// </summary>
/// <param name="inStartSampleIndex">int index to first qbox to be processed</param>
/// <param name="inEndSampleIndex">int index to last qbox to be processed</param>
/// <param name="dummy">not used</param>
/// <returns></returns>
public override List<StreamDataBlockInfo> PrepareSampleReading(int inStartSampleIndex, int inEndSampleIndex,
ref ulong dummy)
{
List<StreamDataBlockInfo> retList = new List<StreamDataBlockInfo>();
if (_qBoxes.Count == 0)
return retList;
float scaleFactor = TimeSpan.FromSeconds(1.0).Ticks/this.TimeScale;
bool foundFirstSlice = false;
int boxCount = 0;
// we traverse the _qBoxes list from the beginning;
// can't use foreach because _qBoxes can change;
// box.mIndex is NOT the same as index i.
// we use a for loop only because we are adding qboxes to _qBoxes as part of the loop
for (int i = 0; i < _qBoxes.Count; i++) {
QBox box = _qBoxes[i];
boxCount++;
// reject qboxes with sample size zero (no data)
if (box.mSampleSize == 0) {
continue;
}
// we shouldn't be searching for the first box of interest, because it should always be the first one
// it should always be the first one because we threw away all boxes already processed
if (((ulong)inStartSampleIndex > (box.mFrameCounter - 1)) ||
((!foundFirstSlice) && (((uint) box.mSampleFlags & QBox.QBOX_SAMPLE_FLAGS_SYNC_POINT) == 0))) {
continue; // skip
}
else if ((ulong)inStartSampleIndex == (box.mFrameCounter - 1))
{
foundFirstSlice = true;
}
else if (!foundFirstSlice) {
_qBoxes.Clear();
base.GetNextBatch(0, inStartSampleIndex); // throw new Exception("First IFrame not found");
i = -1; // this gets incremented to zero
boxCount = 0; // start all over
continue;
}
StreamDataBlockInfo datBlock = new Slice();
switch (box.SampleStreamTypeString()) {
case "AAC":
datBlock = new ADTSDataBlockInfo();
datBlock.SliceType = SliceType.AAC;
break;
case "Q711":
case "PCM":
datBlock.SliceType = SliceType.Unknown; // FIXME: add sample type for PCM
break;
case "MP2A":
datBlock.SliceType = SliceType.MP4A;
break;
case "Q722": // ADPCM
case "Q726":
case "Q728":
datBlock.SliceType = SliceType.Unknown; // FIXME: add sample type for ADPCM
break;
case "H264":
case "H264_SLICE":
datBlock = new NaluDelimiterBlockInfo();
if (((uint) box.mSampleFlags & QBox.QBOX_SAMPLE_FLAGS_SYNC_POINT) == 0)
datBlock.SliceType = SliceType.DFrame;
else {
datBlock.SliceType = SliceType.IFrame;
}
if ((box.mSample != null) && (box.mSample.v != null)) {
NaluDelimiterBlockInfo blockInfo = datBlock as NaluDelimiterBlockInfo;
blockInfo.AccessUnitDelimiter = box.mSample.v.aud;
}
break;
case "JPEG":
datBlock.SliceType = SliceType.JPEG;
break;
case "MPEG2_ELEMENTARY":
datBlock.SliceType = SliceType.Unknown; // FIXME: add sample type for MPEG2
break;
case "VIN_STATS_GLOBAL":
case "VIN_STATS_MB":
case "USER_METADATA":
case "DEBUG":
default:
System.Diagnostics.Debug.WriteLine("Unknown QBox: {0}", box.SampleStreamTypeString());
break;
}
datBlock.CTS = (ulong)((box.mSampleCTS - (box.mStreamDuration - box.mSampleDuration)) * scaleFactor);
datBlock.SliceDuration = (uint)(scaleFactor * box.mSampleDuration);
if (box.mFrameCounter == 0 && box.mStreamDuration == 0) {
datBlock.TimeStampNew = 0;
} else if (box.mStreamDuration == 0) {
datBlock.TimeStampNew = null;
} else {
datBlock.TimeStampNew = (ulong) (scaleFactor*(box.mStreamDuration - box.mSampleDuration));
}
datBlock.SliceSize = box.mSampleSize;
datBlock.index = (int)box.mFrameCounter - 1; // boxCount;
// NOTE! For qbox, StreamOffset has a different meaning than in MP4.
// Here, StreamOffset is the offset to the qbox itself; whereas in
// MP4, StreamOffset is the offset to the H264 payload.
// In GenericMediaTrack.GetSample, StreamOffset is used as in MP4, but
// this method is overriden by another in QBoxVideoTrack that does not use StreamOffset.
// For flashback to work for both MP4 and qbox files, the caching mechanism
// is different in MP4 from than in qbox.
datBlock.StreamOffset = (ulong) box.mHeaderPosition; // needed for flashback to work
// set payload
Slice slice = datBlock as Slice;
slice.SliceBytes = box.mSample.mPayload;
#if ADTS
if (box.mSampleStreamType == QBox.QBOX_SAMPLE_TYPE_AAC)
{
QMed.QMedAAC qmedaac = (QMed.QMedAAC)box.mSample.qmed;
#if PES
datBlock.PESandADTSHeaders = new byte[qmedaac.pesHeader.Length + qmedaac.adtsHeader.Length];
qmedaac.pesHeader.CopyTo(datBlock.PESandADTSHeaders, 0);
qmedaac.adtsHeader.CopyTo(datBlock.PESandADTSHeaders, qmedaac.pesHeader.Length);
#else
datBlock.PESandADTSHeaders = new byte[qmedaac.adtsHeader.Length];
qmedaac.adtsHeader.CopyTo(datBlock.PESandADTSHeaders, 0);
#endif
datBlock.SampleSize += datBlock.PESandADTSHeaders.Length;
}
#endif
if (datBlock.SliceDuration == 0) {
datBlock.SliceDuration = (uint) (scaleFactor*box.mSampleDuration); // any non-zero duration is better
}
if ((((uint) box.mSampleFlags & QBox.QBOX_SAMPLE_FLAGS_SYNC_POINT) != 0) && ((box.mFrameCounter - 1) >= (ulong)inEndSampleIndex)) {
boxCount--;
break; // don't put last IFrame box in return list
}
retList.Add(datBlock);
if (box == _qBoxes.Last()) {
base.GetNextBatch(GenericMediaStream.MAX_BOXES_TO_READ, 0);
// callee should set end FIXME: is box.mCurrentPosition being set?
}
} // end of for loop
_qBoxes.RemoveRange(0, boxCount);
return retList;
}