private void AddOutputStreams(Uri source, MediaMuxer muxer, out AVStream *vidOutStream,
out AVStream *audioOutStream, out IDictionary <MediaStreamType, int> streamMap)
{
vidOutStream = audioOutStream = null;
using var audioDecoder = new MediaDecoder(source, HardwareDevice);
using var videoDecoder = new MediaDecoder(source, HardwareDevice);
var hasAudio = audioDecoder.SelectStream(AVMediaType.AVMEDIA_TYPE_AUDIO);
var hasVideo = videoDecoder.SelectStream(AVMediaType.AVMEDIA_TYPE_VIDEO);
var streamIndex = 0;
streamMap = new Dictionary <MediaStreamType, int>();
var decoders = new List <MediaDecoder>();
if (hasVideo)
{
decoders.Add(videoDecoder);
}
if (hasAudio)
{
decoders.Add(audioDecoder);
}
foreach (var decoder in decoders)
{
var targetCodec = decoder.CodecId;
var decoderCodec = decoder.CodecContext;
AVStream *stream;
var encoder = ffmpeg.avcodec_find_encoder(targetCodec);
stream = muxer.AddStream(encoder);
if (decoder == videoDecoder)
{
vidOutStream = stream;
streamMap.Add(MediaStreamType.Video, streamIndex);
}
else if (decoder == audioDecoder)
{
audioOutStream = stream;
streamMap.Add(MediaStreamType.Audio, streamIndex);
}
else
{
throw new NotImplementedException("Unknown decoder type.");
}
streamIndex++;
//streams[streamIndex] = stream;
var param = stream->codecpar;
ffmpeg.avcodec_parameters_from_context(param, decoder.GetStream()->codec).ThrowOnError();
stream->codecpar->codec_tag = 0;
}
}
private Dictionary <MediaStreamType, MediaDecoder> MakeDecoders()
{
var decoders = new Dictionary <MediaStreamType, MediaDecoder>();
foreach (var source in _sources.Values)
{
var decoder = new MediaDecoder(source.Path, HardwareDevice);
switch (source.StreamType)
{
case MediaStreamType.Audio:
decoder.SelectStream(AVMediaType.AVMEDIA_TYPE_AUDIO);
break;
case MediaStreamType.Video:
decoder.SelectStream(AVMediaType.AVMEDIA_TYPE_VIDEO);
break;
default:
throw new NotSupportedException($"Media stream type of {source.StreamType} is not supported.");
}
decoders.Add(source.StreamType, decoder);
}
return(decoders);
}
private void ConcatFile(Uri source, ConcatContext context)
{
using var videoDecoder = new MediaDecoder(source, HardwareDevice);
using var audioDecoder = new MediaDecoder(source, HardwareDevice);
var hasVideo = new Reference <bool>(videoDecoder.SelectStream(AVMediaType.AVMEDIA_TYPE_VIDEO));
var hasAudio = new Reference <bool>(audioDecoder.SelectStream(AVMediaType.AVMEDIA_TYPE_AUDIO));
var audioDts = new Reference <long>();
var videoDts = new Reference <long>();
while (hasVideo || hasAudio)
{
MediaStreamType type;
if (!hasAudio)
{
type = MediaStreamType.Video;
}
else if (!hasVideo)
{
type = MediaStreamType.Audio;
}
else
{
type = audioDts.Value < videoDts.Value ? MediaStreamType.Audio : MediaStreamType.Video;
}
AVStream * outStream;
MediaDecoder decoder;
Reference <long> dts;
Reference <bool> has;
switch (type)
{
case MediaStreamType.Audio:
outStream = context.AudioOutStream;
decoder = audioDecoder;
dts = audioDts;
has = hasAudio;
break;
case MediaStreamType.Video:
outStream = context.VideoOutStream;
decoder = videoDecoder;
dts = videoDts;
has = hasVideo;
break;
default:
throw new NotSupportedException();
}
using var packet = decoder.ReadPacket();
if (packet == null)
{
has.Value = false;
continue;
}
var pck = packet.Pointer;
ffmpeg.av_packet_rescale_ts(pck, decoder.TimeBase, outStream->time_base);
pck->stream_index = context.StreamMap[type];
dts.Value = pck->dts;
context.Muxer.WritePacket(pck);
}
}