/// <summary>
/// Initializes a new instance of the <see cref="MediaComponent"/> class.
/// </summary>
/// <param name="container">The container.</param>
/// <param name="streamIndex">Index of the stream.</param>
/// <exception cref="ArgumentNullException">container.</exception>
/// <exception cref="MediaContainerException">The container exception.</exception>
public MediaComponent(MediaContainer container, int streamIndex)
{
// Ported from: https://github.com/FFmpeg/FFmpeg/blob/master/fftools/ffplay.c#L2559
Container = container ?? throw new ArgumentNullException(nameof(container));
m_LoggingHandler = ((ILoggingSource)Container).LoggingHandler;
m_CodecContext = new IntPtr(ffmpeg.avcodec_alloc_context3(null));
RC.Current.Add(CodecContext);
StreamIndex = streamIndex;
m_Stream = new IntPtr(container.InputContext->streams[streamIndex]);
StreamInfo = container.MediaInfo.Streams[streamIndex];
// Set default codec context options from probed stream
var setCodecParamsResult = ffmpeg.avcodec_parameters_to_context(CodecContext, Stream->codecpar);
if (setCodecParamsResult < 0)
{
this.LogWarning(Aspects.Component,
$"Could not set codec parameters. Error code: {setCodecParamsResult}");
}
// We set the packet timebase in the same timebase as the stream as opposed to the typical AV_TIME_BASE
if (this is VideoComponent && Container.MediaOptions.VideoForcedFps > 0)
{
var fpsRational = ffmpeg.av_d2q(Container.MediaOptions.VideoForcedFps, 1000000);
Stream->r_frame_rate = fpsRational;
CodecContext->pkt_timebase = new AVRational {
num = fpsRational.den, den = fpsRational.num
};
}
else
{
CodecContext->pkt_timebase = Stream->time_base;
}
// Find the default decoder codec from the stream and set it.
var defaultCodec = ffmpeg.avcodec_find_decoder(Stream->codec->codec_id);
AVCodec *forcedCodec = null;
// If set, change the codec to the forced codec.
if (Container.MediaOptions.DecoderCodec.ContainsKey(StreamIndex) &&
string.IsNullOrWhiteSpace(Container.MediaOptions.DecoderCodec[StreamIndex]) == false)
{
var forcedCodecName = Container.MediaOptions.DecoderCodec[StreamIndex];
forcedCodec = ffmpeg.avcodec_find_decoder_by_name(forcedCodecName);
if (forcedCodec == null)
{
this.LogWarning(Aspects.Component,
$"COMP {MediaType.ToString().ToUpperInvariant()}: " +
$"Unable to set decoder codec to '{forcedCodecName}' on stream index {StreamIndex}");
}
}
// Check we have a valid codec to open and process the stream.
if (defaultCodec == null && forcedCodec == null)
{
var errorMessage = $"Fatal error. Unable to find suitable decoder for {Stream->codec->codec_id.ToString()}";
CloseComponent();
throw new MediaContainerException(errorMessage);
}
var codecCandidates = new[] { forcedCodec, defaultCodec };
AVCodec *selectedCodec = null;
var codecOpenResult = 0;
foreach (var codec in codecCandidates)
{
if (codec == null)
{
continue;
}
// Pass default codec stuff to the codec context
CodecContext->codec_id = codec->id;
// Process the decoder options
{
var decoderOptions = Container.MediaOptions.DecoderParams;
// Configure the codec context flags
if (decoderOptions.EnableFastDecoding)
{
CodecContext->flags2 |= ffmpeg.AV_CODEC_FLAG2_FAST;
}
if (decoderOptions.EnableLowDelayDecoding)
{
CodecContext->flags |= ffmpeg.AV_CODEC_FLAG_LOW_DELAY;
}
// process the low res option
if (decoderOptions.LowResolutionIndex != VideoResolutionDivider.Full && codec->max_lowres > 0)
{
var lowResOption = Math.Min((byte)decoderOptions.LowResolutionIndex, codec->max_lowres)
.ToString(CultureInfo.InvariantCulture);
decoderOptions.LowResIndexOption = lowResOption;
}
// Ensure ref counted frames for audio and video decoding
if (CodecContext->codec_type == AVMediaType.AVMEDIA_TYPE_VIDEO || CodecContext->codec_type == AVMediaType.AVMEDIA_TYPE_AUDIO)
{
decoderOptions.RefCountedFrames = "1";
}
CodecContext->thread_count = 4;
}
// Setup additional settings. The most important one is Threads -- Setting it to 1 decoding is very slow. Setting it to auto
// decoding is very fast in most scenarios.
var codecOptions = Container.MediaOptions.DecoderParams.GetStreamCodecOptions(Stream->index);
// Enable Hardware acceleration if requested
(this as VideoComponent)?.AttachHardwareDevice(container.MediaOptions.VideoHardwareDevice);
// Open the CodecContext. This requires exclusive FFmpeg access
lock (CodecLock)
{
var codecOptionsRef = codecOptions.Pointer;
codecOpenResult = ffmpeg.avcodec_open2(CodecContext, codec, &codecOptionsRef);
codecOptions.UpdateReference(codecOptionsRef);
}
// Check if the codec opened successfully
if (codecOpenResult < 0)
{
this.LogWarning(Aspects.Component,
$"Unable to open codec '{Utilities.PtrToStringUTF8(codec->name)}' on stream {streamIndex}");
continue;
}
// If there are any codec options left over from passing them, it means they were not consumed
var currentEntry = codecOptions.First();
while (currentEntry?.Key != null)
{
this.LogWarning(Aspects.Component,
$"Invalid codec option: '{currentEntry.Key}' for codec '{Utilities.PtrToStringUTF8(codec->name)}', stream {streamIndex}");
currentEntry = codecOptions.Next(currentEntry);
}
selectedCodec = codec;
break;
}
if (selectedCodec == null)
{
CloseComponent();
throw new MediaContainerException($"Unable to find suitable decoder codec for stream {streamIndex}. Error code {codecOpenResult}");
}
// Startup done. Set some options.
Stream->discard = AVDiscard.AVDISCARD_DEFAULT;
MediaType = (MediaType)CodecContext->codec_type;
switch (MediaType)
{
case MediaType.Audio:
case MediaType.Video:
BufferCountThreshold = 25;
BufferDurationThreshold = TimeSpan.FromSeconds(1);
DecodePacketFunction = DecodeNextAVFrame;
break;
default:
throw new NotSupportedException($"A component of MediaType '{MediaType}' is not supported");
}
var contentDisposition = StreamInfo.Disposition;
IsStillPictures = MediaType == MediaType.Video &&
((contentDisposition & ffmpeg.AV_DISPOSITION_ATTACHED_PIC) != 0 ||
(contentDisposition & ffmpeg.AV_DISPOSITION_STILL_IMAGE) != 0 ||
(contentDisposition & ffmpeg.AV_DISPOSITION_TIMED_THUMBNAILS) != 0);
if (IsStillPictures)
{
BufferCountThreshold = 0;
BufferDurationThreshold = TimeSpan.Zero;
}
// Compute the start time
StartTime = Stream->start_time == ffmpeg.AV_NOPTS_VALUE
? Container.MediaInfo.StartTime == TimeSpan.MinValue ? TimeSpan.Zero : Container.MediaInfo.StartTime
: Stream->start_time.ToTimeSpan(Stream->time_base);
// Compute the duration
Duration = (Stream->duration == ffmpeg.AV_NOPTS_VALUE || Stream->duration <= 0)
? Container.MediaInfo.Duration
: Stream->duration.ToTimeSpan(Stream->time_base);
CodecId = Stream->codec->codec_id;
CodecName = Utilities.PtrToStringUTF8(selectedCodec->name);
BitRate = Stream->codec->bit_rate < 0 ? 0 : Stream->codec->bit_rate;
this.LogDebug(Aspects.Component,
$"{MediaType.ToString().ToUpperInvariant()} - Start Time: {StartTime.Format()}; Duration: {Duration.Format()}");
// Begin processing with a flush packet
SendFlushPacket();
}
/// <inheritdoc />
public override string ToString() =>
$"IX: {StreamIndex} | TB: {StreamTimeBase.num}/{StreamTimeBase.den} | ST: {StartTime.Format()} | PTS: {PresentationTime} | DTS: {DecodingTime}";
