/// <summary>
/// If necessary, disposes the existing filtergraph and creates a new one based on the frame arguments.
/// </summary>
/// <param name="frame">The frame.</param>
/// <exception cref="MediaContainerException">
/// avfilter_graph_create_filter
/// or
/// avfilter_graph_create_filter
/// or
/// avfilter_link
/// or
/// avfilter_graph_parse
/// or
/// avfilter_graph_config
/// </exception>
private void InitializeFilterGraph(AVFrame *frame)
{
/*
* References:
* https://www.ffmpeg.org/doxygen/2.0/doc_2examples_2filtering_audio_8c-example.html
*/
var frameArguments = ComputeFilterArguments(frame);
if (string.IsNullOrWhiteSpace(CurrentFilterArguments) || frameArguments.Equals(CurrentFilterArguments) == false)
{
DestroyFiltergraph();
}
else
{
return;
}
FilterGraph = ffmpeg.avfilter_graph_alloc();
RC.Current.Add(FilterGraph, $"264: {nameof(AudioComponent)}.{nameof(InitializeFilterGraph)}()");
CurrentFilterArguments = frameArguments;
try
{
var result = 0;
fixed(AVFilterContext **source = &SourceFilter)
fixed(AVFilterContext **sink = &SinkFilter)
{
result = ffmpeg.avfilter_graph_create_filter(source, ffmpeg.avfilter_get_by_name("abuffer"), "audio_buffer", CurrentFilterArguments, null, FilterGraph);
if (result != 0)
{
throw new MediaContainerException(
$"{nameof(ffmpeg.avfilter_graph_create_filter)} (audio_buffer) failed. Error {result}: {FFmpegEx.GetErrorMessage(result)}");
}
result = ffmpeg.avfilter_graph_create_filter(sink, ffmpeg.avfilter_get_by_name("abuffersink"), "audio_buffersink", null, null, FilterGraph);
if (result != 0)
{
throw new MediaContainerException(
$"{nameof(ffmpeg.avfilter_graph_create_filter)} (audio_buffersink) failed. Error {result}: {FFmpegEx.GetErrorMessage(result)}");
}
}
if (string.IsNullOrWhiteSpace(FilterString))
{
result = ffmpeg.avfilter_link(SourceFilter, 0, SinkFilter, 0);
if (result != 0)
{
throw new MediaContainerException($"{nameof(ffmpeg.avfilter_link)} failed. Error {result}: {FFmpegEx.GetErrorMessage(result)}");
}
}
else
{
var initFilterCount = FilterGraph->nb_filters;
SourceOutput = ffmpeg.avfilter_inout_alloc();
SourceOutput->name = ffmpeg.av_strdup("in");
SourceOutput->filter_ctx = SourceFilter;
SourceOutput->pad_idx = 0;
SourceOutput->next = null;
SinkInput = ffmpeg.avfilter_inout_alloc();
SinkInput->name = ffmpeg.av_strdup("out");
SinkInput->filter_ctx = SinkFilter;
SinkInput->pad_idx = 0;
SinkInput->next = null;
result = ffmpeg.avfilter_graph_parse(FilterGraph, FilterString, SinkInput, SourceOutput, null);
if (result != 0)
{
throw new MediaContainerException($"{nameof(ffmpeg.avfilter_graph_parse)} failed. Error {result}: {FFmpegEx.GetErrorMessage(result)}");
}
// Reorder the filters to ensure that inputs of the custom filters are merged first
for (var i = 0; i < FilterGraph->nb_filters - initFilterCount; i++)
{
var sourceAddress = FilterGraph->filters[i];
var targetAddress = FilterGraph->filters[i + initFilterCount];
FilterGraph->filters[i] = targetAddress;
FilterGraph->filters[i + initFilterCount] = sourceAddress;
}
}
result = ffmpeg.avfilter_graph_config(FilterGraph, null);
if (result != 0)
{
throw new MediaContainerException($"{nameof(ffmpeg.avfilter_graph_config)} failed. Error {result}: {FFmpegEx.GetErrorMessage(result)}");
}
}
catch (Exception ex)
{
Container.Logger?.Log(MediaLogMessageType.Error, $"Audio filter graph could not be built: {FilterString}.\r\n{ex.Message}");
DestroyFiltergraph();
}
}
/// <summary>
/// If necessary, disposes the existing filtergraph and creates a new one based on the frame arguments.
/// </summary>
/// <param name="frame">The frame.</param>
/// <exception cref="MediaContainerException">
/// avfilter_graph_create_filter
/// or
/// avfilter_graph_create_filter
/// or
/// avfilter_link
/// or
/// avfilter_graph_parse
/// or
/// avfilter_graph_config
/// </exception>
private void InitializeFilterGraph(AVFrame *frame)
{
/*
* References:
* http://libav-users.943685.n4.nabble.com/Libav-user-yadif-deinterlace-how-td3606561.html
* https://www.ffmpeg.org/doxygen/trunk/filtering_8c-source.html
* https://raw.githubusercontent.com/FFmpeg/FFmpeg/release/3.2/ffplay.c
*/
var frameArguments = ComputeFilterArguments(frame);
if (string.IsNullOrWhiteSpace(CurrentFilterArguments) || frameArguments.Equals(CurrentFilterArguments) == false)
{
DestroyFiltergraph();
}
else
{
return;
}
FilterGraph = ffmpeg.avfilter_graph_alloc();
RC.Current.Add(FilterGraph, $"144: {nameof(VideoComponent)}.{nameof(InitializeFilterGraph)}()");
CurrentFilterArguments = frameArguments;
try
{
var result = 0;
fixed(AVFilterContext **source = &SourceFilter)
fixed(AVFilterContext **sink = &SinkFilter)
{
result = ffmpeg.avfilter_graph_create_filter(source, ffmpeg.avfilter_get_by_name("buffer"), "video_buffer", CurrentFilterArguments, null, FilterGraph);
if (result != 0)
{
throw new MediaContainerException($"{nameof(ffmpeg.avfilter_graph_create_filter)} (buffer) failed. Error {result}: {FFmpegEx.GetErrorMessage(result)}");
}
result = ffmpeg.avfilter_graph_create_filter(sink, ffmpeg.avfilter_get_by_name("buffersink"), "video_buffersink", null, null, FilterGraph);
if (result != 0)
{
throw new MediaContainerException($"{nameof(ffmpeg.avfilter_graph_create_filter)} (buffersink) failed. Error {result}: {FFmpegEx.GetErrorMessage(result)}");
}
// TODO: from ffplay, ffmpeg.av_opt_set_int_list(sink, "pix_fmts", (byte*)&f0, 1, ffmpeg.AV_OPT_SEARCH_CHILDREN);
}
if (string.IsNullOrWhiteSpace(FilterString))
{
result = ffmpeg.avfilter_link(SourceFilter, 0, SinkFilter, 0);
if (result != 0)
{
throw new MediaContainerException($"{nameof(ffmpeg.avfilter_link)} failed. Error {result}: {FFmpegEx.GetErrorMessage(result)}");
}
}
else
{
var initFilterCount = FilterGraph->nb_filters;
SourceOutput = ffmpeg.avfilter_inout_alloc();
SourceOutput->name = ffmpeg.av_strdup("in");
SourceOutput->filter_ctx = SourceFilter;
SourceOutput->pad_idx = 0;
SourceOutput->next = null;
SinkInput = ffmpeg.avfilter_inout_alloc();
SinkInput->name = ffmpeg.av_strdup("out");
SinkInput->filter_ctx = SinkFilter;
SinkInput->pad_idx = 0;
SinkInput->next = null;
result = ffmpeg.avfilter_graph_parse(FilterGraph, FilterString, SinkInput, SourceOutput, null);
if (result != 0)
{
throw new MediaContainerException($"{nameof(ffmpeg.avfilter_graph_parse)} failed. Error {result}: {FFmpegEx.GetErrorMessage(result)}");
}
// Reorder the filters to ensure that inputs of the custom filters are merged first
for (var i = 0; i < FilterGraph->nb_filters - initFilterCount; i++)
{
var sourceAddress = FilterGraph->filters[i];
var targetAddress = FilterGraph->filters[i + initFilterCount];
FilterGraph->filters[i] = targetAddress;
FilterGraph->filters[i + initFilterCount] = sourceAddress;
}
}
result = ffmpeg.avfilter_graph_config(FilterGraph, null);
if (result != 0)
{
throw new MediaContainerException($"{nameof(ffmpeg.avfilter_graph_config)} failed. Error {result}: {FFmpegEx.GetErrorMessage(result)}");
}
}
catch (Exception ex)
{
Container.Logger?.Log(MediaLogMessageType.Error, $"Video filter graph could not be built: {FilterString}.\r\n{ex.Message}");
DestroyFiltergraph();
}
}