From 5c6163ad5daa01b486e44c394dd7cc9878ec5df5 Mon Sep 17 00:00:00 2001
From: "Steinar H. Gunderson" <sgunderson@bigfoot.com>
Date: Sun, 1 May 2016 22:11:05 +0200
Subject: [PATCH] Add an option --map-signal= to override the default
 signal-to-card mapping.

---
 NEWS      |  3 +++
 flags.cpp | 31 +++++++++++++++++++++++++++++++
 flags.h   |  2 ++
 theme.cpp |  3 ++-
 4 files changed, 38 insertions(+), 1 deletion(-)

diff --git a/NEWS b/NEWS
index 0efd48c..9e57829 100644
--- a/NEWS
+++ b/NEWS
@@ -17,6 +17,9 @@ Nageru 1.3.0, not released yet
    is now done in a background thread, in order to not disturb the external
    stream. The audio still goes into a somewhat random stream, though.
 
+ - You can now override the default stream-to-card mapping with --map-signal=
+   on the command line.
+
 
 Nageru 1.2.1, April 15th, 2016
 
diff --git a/flags.cpp b/flags.cpp
index f782c76..7e8beaf 100644
--- a/flags.cpp
+++ b/flags.cpp
@@ -3,6 +3,11 @@
 #include <getopt.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
+
+#include <utility>
+
+using namespace std;
 
 Flags global_flags;
 
@@ -15,6 +20,7 @@ void usage()
 	fprintf(stderr, "  -t, --theme=FILE                choose theme (default theme.lua)\n");
 	fprintf(stderr, "  -v, --va-display=SPEC           VA-API device for H.264 encoding\n");
 	fprintf(stderr, "                                    ($DISPLAY spec or /dev/dri/render* path)\n");
+	fprintf(stderr, "  -m, --map-signal=SIGNAL,CARD    set a default card mapping (can be given multiple times)\n");
 	fprintf(stderr, "      --http-uncompressed-video   send uncompressed NV12 video to HTTP clients\n");
 	fprintf(stderr, "      --http-x264-video           send x264-compressed video to HTTP clients\n");
 	fprintf(stderr, "      --x264-preset               x264 quality preset (default " X264_DEFAULT_PRESET ")\n");
@@ -46,6 +52,7 @@ void parse_flags(int argc, char * const argv[])
 		{ "help", no_argument, 0, 'h' },
 		{ "num-cards", required_argument, 0, 'c' },
 		{ "theme", required_argument, 0, 't' },
+		{ "map-signal", required_argument, 0, 'm' },
 		{ "va-display", required_argument, 0, 1000 },
 		{ "http-uncompressed-video", no_argument, 0, 1001 },
 		{ "http-x264-video", no_argument, 0, 1008 },
@@ -77,6 +84,23 @@ void parse_flags(int argc, char * const argv[])
 		case 't':
 			global_flags.theme_filename = optarg;
 			break;
+		case 'm': {
+			char *ptr = strchr(optarg, ',');
+			if (ptr == nullptr) {
+				fprintf(stderr, "ERROR: Invalid argument '%s' to --map-signal (needs a signal and a card number, separated by comma)\n", optarg);
+				exit(1);
+			}
+			*ptr = '\0';
+			const int signal_num = atoi(optarg);
+			const int card_num = atoi(ptr + 1);
+			if (global_flags.default_stream_mapping.count(signal_num)) {
+				fprintf(stderr, "ERROR: Signal %d already mapped to card %d\n",
+					signal_num, global_flags.default_stream_mapping[signal_num]);
+				exit(1);
+			}
+			global_flags.default_stream_mapping[signal_num] = card_num;
+			break;
+		}
 		case 1000:
 			global_flags.va_display = optarg;
 			break;
@@ -138,4 +162,11 @@ void parse_flags(int argc, char * const argv[])
 		fprintf(stderr, "ERROR: --http-uncompressed-video and --http-x264-video are mutually incompatible\n");
 		exit(1);
 	}
+	for (pair<int, int> mapping : global_flags.default_stream_mapping) {
+		if (mapping.second >= global_flags.num_cards) {
+			fprintf(stderr, "ERROR: Signal %d mapped to card %d, which doesn't exist (try adjusting --num-cards)\n",
+				mapping.first, mapping.second);
+			exit(1);
+		}
+	}
 }
diff --git a/flags.h b/flags.h
index 0c01ab1..c3ea0fc 100644
--- a/flags.h
+++ b/flags.h
@@ -1,6 +1,7 @@
 #ifndef _FLAGS_H
 #define _FLAGS_H
 
+#include <map>
 #include <string>
 
 #include "defs.h"
@@ -23,6 +24,7 @@ struct Flags {
 	int x264_vbv_max_bitrate = -1;  // In kilobits. 0 = no limit, -1 = same as <x264_bitrate> (CBR).
 	int x264_vbv_buffer_size = -1;  // In kilobits. 0 = one-frame VBV, -1 = same as <x264_bitrate> (one-second VBV).
 	bool enable_alsa_output = true;
+	std::map<int, int> default_stream_mapping;
 };
 extern Flags global_flags;
 
diff --git a/theme.cpp b/theme.cpp
index 1d0cd2d..2b5c5b4 100644
--- a/theme.cpp
+++ b/theme.cpp
@@ -24,6 +24,7 @@
 #include <memory>
 
 #include "defs.h"
+#include "flags.h"
 #include "image_input.h"
 #include "mixer.h"
 
@@ -695,7 +696,7 @@ int call_num_channels(lua_State *L)
 }  // namespace
 
 Theme::Theme(const char *filename, ResourcePool *resource_pool, unsigned num_cards)
-	: resource_pool(resource_pool), num_cards(num_cards)
+	: resource_pool(resource_pool), num_cards(num_cards), signal_to_card_mapping(global_flags.default_stream_mapping)
 {
 	L = luaL_newstate();
         luaL_openlibs(L);
-- 
2.39.2