Improve detection for hardware capabilities

src/video_core/host1x/ffmpeg/ffmpeg.cpp

@@ -103,6 +103,8 @@ Decoder::Decoder(Tegra::Host1x::NvdecCommon::VideoCodec codec) {
 }
 
 bool Decoder::SupportsDecodingOnDevice(AVPixelFormat* out_pix_fmt, AVHWDeviceType type) const {
+	AVCodec *decoder = avcodec_find_decoder(m_codec);
+	if (decoder) {
 		for (int i = 0;; i++) {
 			const AVCodecHWConfig* config = avcodec_get_hw_config(m_codec, i);
 			if (!config) {
@@ -116,6 +118,7 @@ bool Decoder::SupportsDecodingOnDevice(AVPixelFormat* out_pix_fmt, AVHWDeviceTyp
 				return true;
 			}
 		}
+	}
 
     return false;
 }