public void StartDownload(string manifestUrl)
{
GetManifestAndSelectMedia(manifestUrl);
Program.Message("Waiting first fragment...\r");
// downloader already running in UpdateBootstrapInfo()
DetermineAudioVideoPresentInDownloadedFragment();
var DecoderState = new DecoderLastState();
bool useAltAudio = selectedMediaAlt != null;
TagsFilter tagFilter = TagsFilter.ALL;
if (UpdateStatusTimer == null && !Program.isRedirected)
{
UpdateStatusTimer = new Timer(ShowDownloadStatus, null, 0, UpdateStatusInterval);
}
if (useAltAudio)
{
tagFilter = TagsFilter.VIDEO; // only video for main media if alternate media is selected
}
_currentTime = INVALID_TIME;
_mediaTime = INVALID_TIME;
_alternateTime = INVALID_TIME;
droppedAudioFrames = 0;
droppedVideoFrames = 0;
FLVTag mediaTag = null;
FLVTag alternateTag = null;
bool needSynchronizationAudio = true;
if (!Program.ConsolePresent && Program.isRedirected)
{
Program.Message("Processing...");
}
// --------------- MAIN LOOP DECODE FRAGMENTS ----------------
while (Downloader.TagsAvaliable(selectedMedia) || selectedMedia.Bootstrap.live)
{
if (mediaTag == null)
{
mediaTag = Downloader.GetNextTag(selectedMedia);
if (mediaTag == null)
{
Thread.Sleep(100); // for decrease CPU load
}
}
if (useAltAudio && _mediaTime != INVALID_TIME && Downloader.TagsAvaliable(selectedMediaAlt))
{
if (alternateTag == null)
{
alternateTag = Downloader.GetNextTag(selectedMediaAlt);
}
if (useAltAudio && alternateTag != null && alternateTag.IsAkamaiEncrypted)
{
if (AD2 == null) // create and init only if need
{
AD2 = new AkamaiDecryptor();
}
AD2.DecryptFLVTag(alternateTag, manifest.baseURL, auth);
}
if (needSynchronizationAudio && (_mediaTime != INVALID_TIME || _alternateTime != INVALID_TIME))
{
uint alternateSynchronizationTime = _alternateTime != INVALID_TIME ? _alternateTime : _mediaTime;
alternateTag = Downloader.SeekAudioByTime(selectedMediaAlt, alternateSynchronizationTime);
if (alternateTag != null)
{
needSynchronizationAudio = false;
}
}
}
if (mediaTag != null && mediaTag.IsAkamaiEncrypted)
{
if (AD1 == null) // create and init only if need
{
AD1 = new AkamaiDecryptor();
}
AD1.DecryptFLVTag(mediaTag, manifest.baseURL, auth);
}
if (useAltAudio && alternateTag != null && alternateTag.IsAkamaiEncrypted)
{
if (AD2 == null) // create and init only if need
{
AD2 = new AkamaiDecryptor();
}
AD2.DecryptFLVTag(alternateTag, manifest.baseURL, auth);
}
if (ShouldFilterTag(mediaTag, tagFilter))
{
if (mediaTag != null)
{
if (mediaTag is FLVTagVideo)
{
droppedVideoFrames++;
}
totalDroppedFrames++;
}
mediaTag = null;
}
else
{
UpdateTimes(mediaTag);
}
if (ShouldFilterTag(alternateTag, TagsFilter.AUDIO))
{
if (alternateTag != null)
{
droppedAudioFrames++;
totalDroppedFrames++;
}
alternateTag = null;
}
else
{
UpdateTimes(alternateTag);
}
if (!useAltAudio)
{
if (mediaTag != null)
{
_currentTime = mediaTag.Timestamp;
FLVFile.Write(mediaTag);
mediaTag = null;
}
}
else
{
if (_mediaTime != INVALID_TIME || _alternateTime != INVALID_TIME)
{
if (alternateTag != null && (alternateTag.Timestamp >= _currentTime || _currentTime == INVALID_TIME) && (alternateTag.Timestamp <= _mediaTime))
{
_currentTime = alternateTag.Timestamp;
FLVFile.Write(alternateTag);
alternateTag = null;
}
else if (mediaTag != null && (mediaTag.Timestamp >= _currentTime || _currentTime == INVALID_TIME) && (mediaTag.Timestamp <= _alternateTime))
{
_currentTime = mediaTag.Timestamp;
FLVFile.Write(mediaTag);
mediaTag = null;
}
}
}
if ((duration > 0) && (FLVFile.LastTimestamp >= duration))
{
Status = "Duration limit reached"; break;
}
if ((filesize > 0) && (FLVFile.Filesize >= filesize))
{
Status = "File size limit reached"; break;
}
}
DestroyUpdateStatusTimer();
ShowDownloadStatus();
}
public static void FixTimestamp(DecoderLastState DecoderState, FLVTag tag)
{
uint lastTS = DecoderState.prevVideoTS >= DecoderState.prevAudioTS ? DecoderState.prevVideoTS : DecoderState.prevAudioTS;
uint fixedTS = lastTS + (uint)fixWindow;
if ((DecoderState.baseTS == DecoderLastState.INVALID_TIMESTAMP) && ((tag.Type == FLVTag.TagType.AUDIO) || (tag.Type == FLVTag.TagType.VIDEO)))
{
DecoderState.baseTS = tag.Timestamp;
}
if ((DecoderState.baseTS > fixWindow) && (tag.Timestamp >= DecoderState.baseTS))
{
tag.Timestamp -= DecoderState.baseTS;
}
if (lastTS != DecoderLastState.INVALID_TIMESTAMP)
{
int timeShift = (int)(tag.Timestamp - lastTS);
if (timeShift > fixWindow)
{
Program.DebugLog(string.Format("Timestamp gap detected: PacketTS={0} LastTS={1} Timeshift={2}", tag.Timestamp, lastTS, timeShift));
if (DecoderState.baseTS < tag.Timestamp)
{
DecoderState.baseTS += (uint)(timeShift - fixWindow);
}
else
{
DecoderState.baseTS = (uint)(timeShift - fixWindow);
}
tag.Timestamp = fixedTS;
}
else
{
lastTS = tag.Type == FLVTag.TagType.VIDEO ? DecoderState.prevVideoTS : DecoderState.prevAudioTS;
if ((lastTS != DecoderLastState.INVALID_TIMESTAMP) && (int)tag.Timestamp < (lastTS - fixWindow))
{
if ((DecoderState.negTS != DecoderLastState.INVALID_TIMESTAMP) && ((tag.Timestamp + DecoderState.negTS) < (lastTS - fixWindow)))
{
DecoderState.negTS = DecoderLastState.INVALID_TIMESTAMP;
}
if (DecoderState.negTS == DecoderLastState.INVALID_TIMESTAMP)
{
DecoderState.negTS = fixedTS - tag.Timestamp;
Program.DebugLog(string.Format("Negative timestamp detected: PacketTS={0} LastTS={1} NegativeTS={2}", tag.Timestamp, lastTS, DecoderState.negTS));
tag.Timestamp = (uint)fixedTS;
}
else
{
if ((tag.Timestamp + DecoderState.negTS) <= (lastTS + fixWindow))
{
tag.Timestamp += (uint)DecoderState.negTS;
}
else
{
DecoderState.negTS = fixedTS - tag.Timestamp;
Program.DebugLog(string.Format("Negative timestamp override: PacketTS={0} LastTS={1} NegativeTS={2}", tag.Timestamp, lastTS, DecoderState.negTS));
tag.Timestamp = (uint)fixedTS;
}
}
}
}
}
if (tag is FLVTagAudio)
{
DecoderState.prevAudioTS = tag.Timestamp;
}
else
{
DecoderState.prevVideoTS = tag.Timestamp;
}
}