Merge pull request #90 from gabivlj/master

Fix bug where if you used WithInput before Output you would lose the context.

ffmpeg.go

@@ -13,12 +13,12 @@ import (
 	"github.com/aws/aws-sdk-go/service/s3/s3manager"
 )
 
-// Input file URL (ffmpeg ``-i`` option)
+// Input file URL (ffmpeg “-i“ option)
 //
-// Any supplied kwargs are passed to ffmpeg verbatim (e.g. ``t=20``,
-// ``f='mp4'``, ``acodec='pcm'``, etc.).
+// Any supplied kwargs are passed to ffmpeg verbatim (e.g. “t=20“,
+// “f='mp4'“, “acodec='pcm'“, etc.).
 //
-// To tell ffmpeg to read from stdin, use ``pipe:`` as the filename.
+// To tell ffmpeg to read from stdin, use “pipe:“ as the filename.
 //
 // Official documentation: `Main options <https://ffmpeg.org/ffmpeg.html#Main-options>`__
 func Input(filename string, kwargs ...KwArgs) *Stream {
@@ -33,15 +33,15 @@ func Input(filename string, kwargs ...KwArgs) *Stream {
 	return NewInputNode("input", nil, args).Stream("", "")
 }
 
-// Add extra global command-line argument(s), e.g. ``-progress``.
+// Add extra global command-line argument(s), e.g. “-progress“.
 func (s *Stream) GlobalArgs(args ...string) *Stream {
 	if s.Type != "OutputStream" {
 		panic("cannot overwrite outputs on non-OutputStream")
 	}
 	return NewGlobalNode("global_args", []*Stream{s}, args, nil).Stream("", "")
 }
 
-// Overwrite output files without asking (ffmpeg ``-y`` option)
+// Overwrite output files without asking (ffmpeg “-y“ option)
 //
 // Official documentation: `Main options <https://ffmpeg.org/ffmpeg.html#Main-options>`_
 func (s *Stream) OverwriteOutput(stream *Stream) *Stream {
@@ -56,28 +56,28 @@ func MergeOutputs(streams ...*Stream) *Stream {
 	return NewMergeOutputsNode("merge_output", streams).Stream("", "")
 }
 
-//Output file URL
+// Output file URL
 //
-//    Syntax:
-//        `ffmpeg.Output([]*Stream{stream1, stream2, stream3...}, filename, kwargs)`
+//	Syntax:
+//	    `ffmpeg.Output([]*Stream{stream1, stream2, stream3...}, filename, kwargs)`
 //
-//    Any supplied keyword arguments are passed to ffmpeg verbatim (e.g.
-//    ``t=20``, ``f='mp4'``, ``acodec='pcm'``, ``vcodec='rawvideo'``,
-//    etc.).  Some keyword-arguments are handled specially, as shown below.
+//	Any supplied keyword arguments are passed to ffmpeg verbatim (e.g.
+//	``t=20``, ``f='mp4'``, ``acodec='pcm'``, ``vcodec='rawvideo'``,
+//	etc.).  Some keyword-arguments are handled specially, as shown below.
 //
-//    Args:
-//        video_bitrate: parameter for ``-b:v``, e.g. ``video_bitrate=1000``.
-//        audio_bitrate: parameter for ``-b:a``, e.g. ``audio_bitrate=200``.
-//        format: alias for ``-f`` parameter, e.g. ``format='mp4'``
-//            (equivalent to ``f='mp4'``).
+//	Args:
+//	    video_bitrate: parameter for ``-b:v``, e.g. ``video_bitrate=1000``.
+//	    audio_bitrate: parameter for ``-b:a``, e.g. ``audio_bitrate=200``.
+//	    format: alias for ``-f`` parameter, e.g. ``format='mp4'``
+//	        (equivalent to ``f='mp4'``).
 //
-//    If multiple streams are provided, they are mapped to the same
-//    output.
+//	If multiple streams are provided, they are mapped to the same
+//	output.
 //
-//    To tell ffmpeg to write to stdout, use ``pipe:`` as the filename.
+//	To tell ffmpeg to write to stdout, use ``pipe:`` as the filename.
 //
-//    Official documentation: `Synopsis <https://ffmpeg.org/ffmpeg.html#Synopsis>`__
-//    """
+//	Official documentation: `Synopsis <https://ffmpeg.org/ffmpeg.html#Synopsis>`__
+//	"""
 func Output(streams []*Stream, fileName string, kwargs ...KwArgs) *Stream {
 	args := MergeKwArgs(kwargs)
 	if !args.HasKey("filename") {
@@ -90,14 +90,42 @@ func Output(streams []*Stream, fileName string, kwargs ...KwArgs) *Stream {
 	return NewOutputNode("output", streams, nil, args).Stream("", "")
 }
 
+// Output file URL
+//
+//	Syntax:
+//	    `ffmpeg.Output(ctx, []*Stream{stream1, stream2, stream3...}, filename, kwargs)`
+//
+//	Any supplied keyword arguments are passed to ffmpeg verbatim (e.g.
+//	``t=20``, ``f='mp4'``, ``acodec='pcm'``, ``vcodec='rawvideo'``,
+//	etc.).  Some keyword-arguments are handled specially, as shown below.
+//
+//	Args:
+//	    video_bitrate: parameter for ``-b:v``, e.g. ``video_bitrate=1000``.
+//	    audio_bitrate: parameter for ``-b:a``, e.g. ``audio_bitrate=200``.
+//	    format: alias for ``-f`` parameter, e.g. ``format='mp4'``
+//	        (equivalent to ``f='mp4'``).
+//
+//	If multiple streams are provided, they are mapped to the same
+//	output.
+//
+//	To tell ffmpeg to write to stdout, use ``pipe:`` as the filename.
+//
+//	Official documentation: `Synopsis <https://ffmpeg.org/ffmpeg.html#Synopsis>`__
+//	"""
+func OutputContext(ctx context.Context, streams []*Stream, fileName string, kwargs ...KwArgs) *Stream {
+	output := Output(streams, fileName, kwargs...)
+	output.Context = ctx
+	return output
+}
+
 func (s *Stream) Output(fileName string, kwargs ...KwArgs) *Stream {
 	if s.Type != "FilterableStream" {
 		log.Panic("cannot output on non-FilterableStream")
 	}
 	if strings.HasPrefix(fileName, "s3://") {
 		return s.outputS3Stream(fileName, kwargs...)
 	}
-	return Output([]*Stream{s}, fileName, kwargs...)
+	return OutputContext(s.Context, []*Stream{s}, fileName, kwargs...)
 }
 
 func (s *Stream) outputS3Stream(fileName string, kwargs ...KwArgs) *Stream {