Allow to compile without ffmpeg

Makefile

@@ -4,7 +4,14 @@ HEADERS := $(wildcard **/*.h)
 HTML := $(wildcard html/*.js html/*.html)
 
 CFLAGS := -Werror -g -I$(PWD)
-LDLIBS := -lpthread -lavcodec -lavformat -lavutil
+LDLIBS := -lpthread
+
+USE_FFMPEG ?= $(shell pkg-config libavutil libavformat libavcodec && echo 1)
+
+ifeq (1,$(USE_FFMPEG))
+CFLAGS += -DUSE_FFMPEG
+LDLIBS += -lavcodec -lavformat -lavutil
+endif
 
 HTML_SRC = $(addsuffix .c,$(HTML))
 OBJS = $(subst .c,.o,$(SRC) $(HTML_SRC))

cmd/main.c

@@ -16,9 +16,11 @@ http_method_t http_methods[] = {
   { "GET /?action=stream", http_stream },
   { "GET /video?", http_video_html },
   { "GET /video.h264?", http_h264_video },
+#ifdef USE_FFMPEG
   { "GET /video.mkv?", http_mkv_video },
   { "GET /video.mp4?", http_mp4_video },
   { "GET /jmuxer.min.js?", http_jmuxer_js },
+#endif // USE_FFMPEG
   { "GET /?", http_index },
   { }
 };

http/http_ffmpeg.c

@@ -1,3 +1,5 @@
+#ifdef USE_FFMPEG
+
 #include <stdio.h>
 #include <stdlib.h>
 
@@ -330,3 +332,5 @@ void http_mp4_video(http_worker_t *worker, FILE *stream)
 {
   http_ffmpeg_video(worker, stream, "video/mp4", "mp4");
 }
+
+#endif // USE_FFMPEG