Adding param checking for encoder

Author: djthorpe

encoder.go

@@ -69,24 +69,47 @@ func newEncoder(ctx *ff.AVFormatContext, stream_id int, param Parameters) (*enco
 	switch codec.Type() {
 	case ff.AVMEDIA_TYPE_AUDIO:
 		encoder.t = AUDIO
-		// TODO: Check codec supports this configuration
 
-		// Set codec parameters
-		if err := codecctx.SetChannelLayout(par.audiopar.Ch); err != nil {
+		// Choose sample format
+		if sampleformat, err := ff.AVCodec_supported_sampleformat(codec, par.audiopar.SampleFormat); err != nil {
+			ff.AVCodec_free_context(codecctx)
+			return nil, err
+		} else {
+			codecctx.SetSampleFormat(sampleformat)
+		}
+
+		// Choose sample rate
+		if samplerate, err := ff.AVCodec_supported_samplerate(codec, par.audiopar.Samplerate); err != nil {
+			ff.AVCodec_free_context(codecctx)
+			return nil, err
+		} else {
+			codecctx.SetSampleRate(samplerate)
+		}
+
+		// Choose channel layout
+		if channellayout, err := ff.AVCodec_supported_channellayout(codec, par.audiopar.Ch); err != nil {
+			ff.AVCodec_free_context(codecctx)
+			return nil, err
+		} else if err := codecctx.SetChannelLayout(channellayout); err != nil {
 			ff.AVCodec_free_context(codecctx)
 			return nil, err
 		}
-		codecctx.SetSampleFormat(par.audiopar.SampleFormat)
-		codecctx.SetSampleRate(par.audiopar.Samplerate)
 
 		// Set stream parameters
 		encoder.stream.SetTimeBase(ff.AVUtil_rational(1, par.audiopar.Samplerate))
+
 	case ff.AVMEDIA_TYPE_VIDEO:
 		encoder.t = VIDEO
-		// TODO: Check codec supports this configuration
+
+		// Choose pixel format
+		if pixelformat, err := ff.AVCodec_supported_pixelformat(codec, par.videopar.PixelFormat); err != nil {
+			ff.AVCodec_free_context(codecctx)
+			return nil, err
+		} else {
+			codecctx.SetPixFmt(pixelformat)
+		}
 
 		// Set codec parameters
-		codecctx.SetPixFmt(par.videopar.PixelFormat)
 		codecctx.SetWidth(par.videopar.Width)
 		codecctx.SetHeight(par.videopar.Height)
 

sys/ffmpeg61/avcodec_core.go

@@ -1,6 +1,9 @@
 package ffmpeg
 
-import "unsafe"
+import (
+	"fmt"
+	"unsafe"
+)
 
 ////////////////////////////////////////////////////////////////////////////////
 // CGO
@@ -99,3 +102,45 @@ func AVCodec_is_encoder(codec *AVCodec) bool {
 func AVCodec_is_decoder(codec *AVCodec) bool {
 	return C.av_codec_is_decoder((*C.struct_AVCodec)(codec)) != 0
 }
+
+// Return a supported sample format that is closest to the given sample format.
+func AVCodec_supported_sampleformat(codec *AVCodec, samplefmt AVSampleFormat) (AVSampleFormat, error) {
+	for _, fmt := range codec.SampleFormats() {
+		if fmt == samplefmt {
+			return samplefmt, nil
+		}
+	}
+	return AVSampleFormat(AV_SAMPLE_FMT_NONE), fmt.Errorf("sample format %v is not supported by codec %q", samplefmt, codec.Name())
+}
+
+// Return a supported sample rate that is closest to the given sample rate.
+func AVCodec_supported_samplerate(codec *AVCodec, samplerate int) (int, error) {
+	max := 0
+	for _, rate := range codec.SupportedSamplerates() {
+		if rate == samplerate {
+			return samplerate, nil
+		}
+		if rate > max {
+			max = rate
+		}
+	}
+	if max > 0 {
+		return max, nil
+	} else {
+		return 0, fmt.Errorf("sample rate %v is not supported by codec %q", samplerate, codec.Name())
+	}
+}
+
+// Return a supported channel layout that is closest to the given channel layout.
+func AVCodec_supported_channellayout(codec *AVCodec, channellayout AVChannelLayout) (AVChannelLayout, error) {
+	for _, layout := range codec.ChannelLayouts() {
+		if C.av_channel_layout_compare(&layout, &channellayout) == 0 {
+			return channellayout, nil
+		}
+	}
+}
+
+// Return a supported pixel format that is closest to the given pixel format.
+func AVCodec_supported_pixelformat(AVCodec *codec, AVPixelFormat pixelformat) (AVPixelFormat, error) {
+
+}