obs-ffmpeg: Add PCM and ALAC encoders

plugins/obs-ffmpeg/data/locale/en-US.ini

@@ -1,6 +1,9 @@
 FFmpegOutput="FFmpeg Output"
 FFmpegAAC="FFmpeg AAC"
 FFmpegOpus="FFmpeg Opus"
+FFmpegALAC="FFmpeg ALAC (24-bit)"
+FFmpegPCM16Bit="FFmpeg PCM (16-bit)"
+FFmpegPCM24Bit="FFmpeg PCM (24-bit)"
 FFmpegOpts="FFmpeg Options"
 FFmpegOpts.ToolTip.Source="Allows you to set FFmpeg options. This only accepts options in the option=value format.\nMultiple options can be set by separating them with a space.\nExample: rtsp_transport=tcp rtsp_flags=prefer_tcp"
 Bitrate="Bitrate"

plugins/obs-ffmpeg/obs-ffmpeg-audio-encoders.c

@@ -95,6 +95,24 @@ static const char *opus_getname(void *unused)
 	return obs_module_text("FFmpegOpus");
 }
 
+static const char *pcm_getname(void *unused)
+{
+	UNUSED_PARAMETER(unused);
+	return obs_module_text("FFmpegPCM16Bit");
+}
+
+static const char *pcm24_getname(void *unused)
+{
+	UNUSED_PARAMETER(unused);
+	return obs_module_text("FFmpegPCM24Bit");
+}
+
+static const char *alac_getname(void *unused)
+{
+	UNUSED_PARAMETER(unused);
+	return obs_module_text("FFmpegALAC");
+}
+
 static void enc_destroy(void *data)
 {
 	struct enc_encoder *enc = data;
@@ -207,9 +225,17 @@ static void *enc_create(obs_data_t *settings, obs_encoder_t *encoder,
 		goto fail;
 	}
 
-	if (!bitrate) {
+	const AVCodecDescriptor *codec_desc =
+		avcodec_descriptor_get(enc->codec->id);
+
+	if (!codec_desc) {
+		warn("Failed to get codec descriptor");
+		goto fail;
+	}
+
+	if (!bitrate && !(codec_desc->props & AV_CODEC_PROP_LOSSLESS)) {
 		warn("Invalid bitrate specified");
-		return NULL;
+		goto fail;
 	}
 
 	enc->context = avcodec_alloc_context3(enc->codec);
@@ -218,7 +244,12 @@ static void *enc_create(obs_data_t *settings, obs_encoder_t *encoder,
 		goto fail;
 	}
 
-	enc->context->bit_rate = bitrate * 1000;
+	if (codec_desc->props & AV_CODEC_PROP_LOSSLESS)
+		// Set by encoder on init, not known at this time
+		enc->context->bit_rate = -1;
+	else
+		enc->context->bit_rate = bitrate * 1000;
+
 	const struct audio_output_info *aoi;
 	aoi = audio_output_get_info(audio);
 
@@ -300,6 +331,21 @@ static void *opus_create(obs_data_t *settings, obs_encoder_t *encoder)
 	return enc_create(settings, encoder, "libopus", "opus");
 }
 
+static void *pcm_create(obs_data_t *settings, obs_encoder_t *encoder)
+{
+	return enc_create(settings, encoder, "pcm_s16le", NULL);
+}
+
+static void *pcm24_create(obs_data_t *settings, obs_encoder_t *encoder)
+{
+	return enc_create(settings, encoder, "pcm_s24le", NULL);
+}
+
+static void *alac_create(obs_data_t *settings, obs_encoder_t *encoder)
+{
+	return enc_create(settings, encoder, "alac", NULL);
+}
+
 static bool do_encode(struct enc_encoder *enc, struct encoder_packet *packet,
 		      bool *received_packet)
 {
@@ -453,3 +499,48 @@ struct obs_encoder_info opus_encoder_info = {
 	.get_extra_data = enc_extra_data,
 	.get_audio_info = enc_audio_info,
 };
+
+struct obs_encoder_info pcm_encoder_info = {
+	.id = "ffmpeg_pcm_s16le",
+	.type = OBS_ENCODER_AUDIO,
+	.codec = "pcm_s16le",
+	.get_name = pcm_getname,
+	.create = pcm_create,
+	.destroy = enc_destroy,
+	.encode = enc_encode,
+	.get_frame_size = enc_frame_size,
+	.get_defaults = enc_defaults,
+	.get_properties = enc_properties,
+	.get_extra_data = enc_extra_data,
+	.get_audio_info = enc_audio_info,
+};
+
+struct obs_encoder_info pcm24_encoder_info = {
+	.id = "ffmpeg_pcm_s24le",
+	.type = OBS_ENCODER_AUDIO,
+	.codec = "pcm_s24le",
+	.get_name = pcm24_getname,
+	.create = pcm24_create,
+	.destroy = enc_destroy,
+	.encode = enc_encode,
+	.get_frame_size = enc_frame_size,
+	.get_defaults = enc_defaults,
+	.get_properties = enc_properties,
+	.get_extra_data = enc_extra_data,
+	.get_audio_info = enc_audio_info,
+};
+
+struct obs_encoder_info alac_encoder_info = {
+	.id = "ffmpeg_alac",
+	.type = OBS_ENCODER_AUDIO,
+	.codec = "alac",
+	.get_name = alac_getname,
+	.create = alac_create,
+	.destroy = enc_destroy,
+	.encode = enc_encode,
+	.get_frame_size = enc_frame_size,
+	.get_defaults = enc_defaults,
+	.get_properties = enc_properties,
+	.get_extra_data = enc_extra_data,
+	.get_audio_info = enc_audio_info,
+};

plugins/obs-ffmpeg/obs-ffmpeg.c

@@ -36,6 +36,9 @@ extern struct obs_output_info replay_buffer;
 extern struct obs_output_info ffmpeg_hls_muxer;
 extern struct obs_encoder_info aac_encoder_info;
 extern struct obs_encoder_info opus_encoder_info;
+extern struct obs_encoder_info pcm_encoder_info;
+extern struct obs_encoder_info pcm24_encoder_info;
+extern struct obs_encoder_info alac_encoder_info;
 extern struct obs_encoder_info h264_nvenc_encoder_info;
 #ifdef ENABLE_HEVC
 extern struct obs_encoder_info hevc_nvenc_encoder_info;
@@ -387,6 +390,9 @@ bool obs_module_load(void)
 	register_encoder_if_available(&svt_av1_encoder_info, "libsvtav1");
 	register_encoder_if_available(&aom_av1_encoder_info, "libaom-av1");
 	obs_register_encoder(&opus_encoder_info);
+	obs_register_encoder(&pcm_encoder_info);
+	obs_register_encoder(&pcm24_encoder_info);
+	obs_register_encoder(&alac_encoder_info);
 #ifndef __APPLE__
 	bool h264 = false;
 	bool hevc = false;