From: Steinar H. Gunderson <sgunderson@bigfoot.com>
Date: Sat, 20 Apr 2019 14:12:59 +0000 (+0200)
Subject: Add a --disable-audio option to Kaeru, to transcode streams with no audio.
X-Git-Tag: 1.9.0~49
X-Git-Url: https://git.sesse.net/?p=nageru;a=commitdiff_plain;h=0aab96d4c270758b72cb09606ce183b41588c746

Add a --disable-audio option to Kaeru, to transcode streams with no audio.
---

diff --git a/nageru/flags.cpp b/nageru/flags.cpp
index 57e58ae..ed52dc8 100644
--- a/nageru/flags.cpp
+++ b/nageru/flags.cpp
@@ -37,6 +37,7 @@ enum LongOption {
 	OPTION_HTTP_AUDIO_BITRATE,
 	OPTION_HTTP_PORT,
 	OPTION_NO_TRANSCODE_AUDIO,
+	OPTION_DISABLE_AUDIO,
 	OPTION_FLAT_AUDIO,
 	OPTION_GAIN_STAGING,
 	OPTION_DISABLE_LOCUT,
@@ -170,6 +171,7 @@ void usage(Program program)
 	if (program == PROGRAM_KAERU) {
 		fprintf(stderr, "      --no-transcode-audio        copy encoded audio raw from the source stream\n");
 		fprintf(stderr, "                                    (requires --http-audio-codec= to be set)\n");
+		fprintf(stderr, "      --disable-audio             do not include any audio in the stream\n");
 	}
 	if (program == PROGRAM_NAGERU) {
 		fprintf(stderr, "      --flat-audio                start with most audio processing turned off\n");
@@ -252,6 +254,7 @@ void parse_flags(Program program, int argc, char * const argv[])
 		{ "http-audio-bitrate", required_argument, 0, OPTION_HTTP_AUDIO_BITRATE },
 		{ "http-port", required_argument, 0, OPTION_HTTP_PORT },
 		{ "no-transcode-audio", no_argument, 0, OPTION_NO_TRANSCODE_AUDIO },
+		{ "disable-audio", no_argument, 0, OPTION_DISABLE_AUDIO },
 		{ "flat-audio", no_argument, 0, OPTION_FLAT_AUDIO },
 		{ "gain-staging", required_argument, 0, OPTION_GAIN_STAGING },
 		{ "disable-locut", no_argument, 0, OPTION_DISABLE_LOCUT },
@@ -367,6 +370,10 @@ void parse_flags(Program program, int argc, char * const argv[])
 		case OPTION_NO_TRANSCODE_AUDIO:
 			global_flags.transcode_audio = false;
 			break;
+		case OPTION_DISABLE_AUDIO:
+			global_flags.transcode_audio = false;
+			global_flags.enable_audio = false;
+			break;
 		case OPTION_HTTP_X264_VIDEO:
 			global_flags.x264_video_to_http = true;
 			break;
@@ -570,7 +577,7 @@ void parse_flags(Program program, int argc, char * const argv[])
 		fprintf(stderr, "ERROR: --output-card points to a nonexistant card\n");
 		exit(1);
 	}
-	if (!global_flags.transcode_audio && global_flags.stream_audio_codec_name.empty()) {
+	if (global_flags.enable_audio && !global_flags.transcode_audio && global_flags.stream_audio_codec_name.empty()) {
 		fprintf(stderr, "ERROR: If not transcoding audio, you must specify ahead-of-time what audio codec is in use\n");
 		fprintf(stderr, "       (using --http-audio-codec).\n");
 		exit(1);
diff --git a/nageru/flags.h b/nageru/flags.h
index 3586500..a401dbf 100644
--- a/nageru/flags.h
+++ b/nageru/flags.h
@@ -63,6 +63,7 @@ struct Flags {
 	bool ten_bit_output = false;  // Implies x264_video_to_disk == true and x264_bit_depth == 10.
 	YCbCrInterpretation ycbcr_interpretation[MAX_VIDEO_CARDS];
 	bool transcode_audio = true;  // Kaeru only.
+	bool enable_audio = true;  // Kaeru only. If false, then transcode_audio is also false.
 	int x264_bit_depth = 8;  // Not user-settable.
 	bool use_zerocopy = false;  // Not user-settable.
 	bool can_disable_srgb_decoder = false;  // Not user-settable.
diff --git a/nageru/kaeru.cpp b/nageru/kaeru.cpp
index 32b497d..b10324c 100644
--- a/nageru/kaeru.cpp
+++ b/nageru/kaeru.cpp
@@ -71,8 +71,13 @@ unique_ptr<Mux> create_mux(HTTPD *httpd, AVOutputFormat *oformat, X264Encoder *x
 
 	string video_extradata = x264_encoder->get_global_headers();
 
+	// If audio is disabled (ie., we won't ever see any audio packets),
+	// set nullptr here to also not include the stream in the mux.
+	AVCodecParameters *audio_codecpar =
+		global_flags.enable_audio ? audio_encoder->get_codec_parameters().get() : nullptr;
+
 	unique_ptr<Mux> mux;
-	mux.reset(new Mux(avctx, global_flags.width, global_flags.height, Mux::CODEC_H264, video_extradata, audio_encoder->get_codec_parameters().get(),
+	mux.reset(new Mux(avctx, global_flags.width, global_flags.height, Mux::CODEC_H264, video_extradata, audio_codecpar,
 		get_color_space(global_flags.ycbcr_rec709_coefficients), COARSE_TIMEBASE,
 	        /*write_callback=*/nullptr, Mux::WRITE_FOREGROUND, { &stream_mux_metrics }));
 	stream_mux_metrics.init({{ "destination", "http" }});
@@ -205,7 +210,7 @@ int main(int argc, char *argv[])
 	FFmpegCapture video(argv[optind], global_flags.width, global_flags.height);
 	video.set_pixel_format(FFmpegCapture::PixelFormat_NV12);
 	video.set_frame_callback(bind(video_frame_callback, &video, x264_encoder.get(), audio_encoder.get(), _1, _2, _3, _4, _5, _6, _7, _8, _9, _10, _11));
-	if (!global_flags.transcode_audio) {
+	if (!global_flags.transcode_audio && global_flags.enable_audio) {
 		video.set_audio_callback(bind(audio_frame_callback, http_mux.get(), _1, _2));
 	}
 	video.configure_card();