From 366e8fbcf5052cdce34c6ff1de4383720a3130ce Mon Sep 17 00:00:00 2001
From: Leandro Moreira <leandro.ribeiro.moreira@gmail.com>
Date: Sun, 19 May 2024 19:16:24 -0300
Subject: [PATCH] move filters and add codec context setters

---
 .../engine/donut_engine_controller.go         | 12 ++++++--
 .../controllers/streamers/libav_ffmpeg.go     | 15 ++++++----
 internal/entities/entities.go                 | 28 +++++++++++++++++++
 3 files changed, 47 insertions(+), 8 deletions(-)

diff --git a/internal/controllers/engine/donut_engine_controller.go b/internal/controllers/engine/donut_engine_controller.go
index da1511a..82c2d40 100644
--- a/internal/controllers/engine/donut_engine_controller.go
+++ b/internal/controllers/engine/donut_engine_controller.go
@@ -114,14 +114,20 @@ func (d *donutEngine) RecipeFor(server, client *entities.StreamInfo) (*entities.
 	r := &entities.DonutRecipe{
 		Input: appetizer,
 		Video: entities.DonutMediaTask{
+			// Action:               entities.DonutTranscode,
 			Action:               entities.DonutBypass,
 			Codec:                entities.H264,
 			DonutBitStreamFilter: &entities.DonutH264AnnexB,
+			// CodecContextOptions: []entities.LibAVOptionsCodecContext{
+			// 	entities.SetBitRate(100_000),
+			// 	entities.SetBaselineProfile(),
+			// 	entities.SetGopSize(30),
+			// },
 		},
 		Audio: entities.DonutMediaTask{
-			Action: entities.DonutTranscode,
-			Codec:  entities.Opus,
-			// TODO: create method list options per Codec
+			Action:            entities.DonutTranscode,
+			Codec:             entities.Opus,
+			DonutStreamFilter: entities.AudioResamplerFilter(48000),
 			CodecContextOptions: []entities.LibAVOptionsCodecContext{
 				entities.SetSampleRate(48000),
 				entities.SetSampleFormat("fltp"),
diff --git a/internal/controllers/streamers/libav_ffmpeg.go b/internal/controllers/streamers/libav_ffmpeg.go
index cfbc676..7599fd2 100644
--- a/internal/controllers/streamers/libav_ffmpeg.go
+++ b/internal/controllers/streamers/libav_ffmpeg.go
@@ -391,10 +391,11 @@ func (c *LibAVFFmpegStreamer) prepareFilters(p *libAVParams, closer *astikit.Clo
 			}
 			buffersrc = astiav.FindFilterByName("abuffer")
 			buffersink = astiav.FindFilterByName("abuffersink")
-			content = fmt.Sprintf(
-				"aresample=%s", // necessary for opus
-				strconv.Itoa(s.encCodecContext.SampleRate()),
-			)
+			if donut.Recipe.Audio.DonutStreamFilter != nil {
+				content = string(*donut.Recipe.Audio.DonutStreamFilter)
+			} else {
+				content = "anull" /* passthrough (dummy) filter for audio */
+			}
 		}
 
 		if isVideo {
@@ -406,7 +407,11 @@ func (c *LibAVFFmpegStreamer) prepareFilters(p *libAVParams, closer *astikit.Clo
 			}
 			buffersrc = astiav.FindFilterByName("buffer")
 			buffersink = astiav.FindFilterByName("buffersink")
-			content = fmt.Sprintf("format=pix_fmts=%s", s.encCodecContext.PixelFormat().Name())
+			if donut.Recipe.Video.DonutStreamFilter != nil {
+				content = string(*donut.Recipe.Video.DonutStreamFilter)
+			} else {
+				content = "null" /* passthrough (dummy) filter for video */
+			}
 		}
 
 		if buffersrc == nil {
diff --git a/internal/entities/entities.go b/internal/entities/entities.go
index c31566d..f89cf49 100644
--- a/internal/entities/entities.go
+++ b/internal/entities/entities.go
@@ -156,6 +156,13 @@ type DonutBitStreamFilter string
 
 var DonutH264AnnexB DonutBitStreamFilter = "h264_mp4toannexb"
 
+type DonutStreamFilter string
+
+func AudioResamplerFilter(sampleRate int) *DonutStreamFilter {
+	filter := DonutStreamFilter(fmt.Sprintf("aresample=%d", sampleRate))
+	return &filter
+}
+
 // TODO: split entities per domain or files avoiding name collision.
 
 // DonutMediaTask is a transformation template to apply over a media.
@@ -171,6 +178,9 @@ type DonutMediaTask struct {
 
 	// DonutBitStreamFilter is the bitstream filter
 	DonutBitStreamFilter *DonutBitStreamFilter
+
+	// DonutStreamFilter is a regular filter
+	DonutStreamFilter *DonutStreamFilter
 }
 
 type DonutInputOptionKey string
@@ -220,6 +230,24 @@ func SetTimeBase(num, den int) LibAVOptionsCodecContext {
 	}
 }
 
+func SetBitRate(bitRate int64) LibAVOptionsCodecContext {
+	return func(c *astiav.CodecContext) {
+		c.SetBitRate(bitRate)
+	}
+}
+
+func SetBaselineProfile() LibAVOptionsCodecContext {
+	return func(c *astiav.CodecContext) {
+		c.SetProfile(astiav.ProfileH264Baseline)
+	}
+}
+
+func SetGopSize(gopSize int) LibAVOptionsCodecContext {
+	return func(c *astiav.CodecContext) {
+		c.SetGopSize(gopSize)
+	}
+}
+
 // SetSampleFormat sets sample format,
 // CAUTION it only contains partial list of fmt
 // TODO: move it to mappers