encoder: Add logic to auto-detect H.264 encoder type

Add a function to automatically select the H.264 codec based on the
platform availability.  The hardware H.264 codec is preferred over the
sofware x264/libav codec.

The "auto" codec option is now the default.

Signed-off-by: Naushir Patuck <naush@raspberrypi.com>

encoder/encoder.cpp

@@ -6,6 +6,11 @@
  */
 
 #include <cstring>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+
+#include <linux/videodev2.h>
 
 #include "encoder.hpp"
 #include "h264_encoder.hpp"
@@ -16,12 +21,34 @@
 #include "libav_encoder.hpp"
 #endif
 
-Encoder *Encoder::Create(VideoOptions const *options, const StreamInfo &info)
+Encoder *h264_codec_select(VideoOptions *options, const StreamInfo &info)
+{
+ const char hw_codec[] = "/dev/video11";
+ struct v4l2_capability caps;
+ memset(&caps, 0, sizeof(caps));
+ int fd = open(hw_codec, O_RDWR, 0);
+ if (fd)
+ {
+ int ret = ioctl(fd, VIDIOC_QUERYCAP, &caps);
+ if (!ret && !strncmp((char *)caps.card, "bcm2835-codec-encode", sizeof(caps.card)))
+ return new H264Encoder(options, info);
+ }
+
+#if LIBAV_PRESENT
+ // No hardware codec available, use x264 through libav.
+ options->libav_video_codec = "libx264";
+ return new LibAvEncoder(options, info);
+#endif
+
+ throw std::runtime_error("Unable to find an appropriate H.264 codec");
+}
+
+Encoder *Encoder::Create(VideoOptions *options, const StreamInfo &info)
 {
  if (strcasecmp(options->codec.c_str(), "yuv420") == 0)
  return new NullEncoder(options);
  else if (strcasecmp(options->codec.c_str(), "h264") == 0)
- return new H264Encoder(options, info);
+ return h264_codec_select(options, info);
 #if LIBAV_PRESENT
  else if (strcasecmp(options->codec.c_str(), "libav") == 0)
  return new LibAvEncoder(options, info);

encoder/encoder.hpp

@@ -18,7 +18,7 @@ typedef std::function<void(void *, size_t, int64_t, bool)> OutputReadyCallback;
 class Encoder
 {
 public:
- static Encoder *Create(VideoOptions const *options, StreamInfo const &info);
+ static Encoder *Create(VideoOptions *options, StreamInfo const &info);
 
  Encoder(VideoOptions const *options) : options_(options) {}
  virtual ~Encoder() {}