Add support for h.264 codec profiles

Both hardware and libav h.264 encoders are updated. The hardware will
support baseline, constrained baseline, main and high. libav will
support, well, what libav supports (which is a much wider selection).

libav users can also change the encoder "preset" for higher quality
encode when there is sufficient CPU available.

Signed-off-by: David Plowman <[email protected]>

picamera2/encoders/h264_encoder.py

@@ -4,9 +4,14 @@
                   V4L2_CID_MPEG_VIDEO_H264_LEVEL,
                   V4L2_CID_MPEG_VIDEO_H264_MAX_QP,
                   V4L2_CID_MPEG_VIDEO_H264_MIN_QP,
+                  V4L2_CID_MPEG_VIDEO_H264_PROFILE,
                   V4L2_CID_MPEG_VIDEO_REPEAT_SEQ_HEADER,
                   V4L2_MPEG_VIDEO_H264_LEVEL_4_1,
-                  V4L2_MPEG_VIDEO_H264_LEVEL_4_2, V4L2_PIX_FMT_H264)
+                  V4L2_MPEG_VIDEO_H264_LEVEL_4_2,
+                  V4L2_MPEG_VIDEO_H264_PROFILE_BASELINE,
+                  V4L2_MPEG_VIDEO_H264_PROFILE_CONSTRAINED_BASELINE,
+                  V4L2_MPEG_VIDEO_H264_PROFILE_HIGH,
+                  V4L2_MPEG_VIDEO_H264_PROFILE_MAIN, V4L2_PIX_FMT_H264)
 
 from picamera2.encoders import Quality
 from picamera2.encoders.v4l2_encoder import V4L2Encoder
@@ -15,7 +20,8 @@
 class H264Encoder(V4L2Encoder):
     """Uses functionality from V4L2Encoder"""
 
-    def __init__(self, bitrate=None, repeat=True, iperiod=None, framerate=None, enable_sps_framerate=False, qp=None):
+    def __init__(self, bitrate=None, repeat=True, iperiod=None, framerate=None, enable_sps_framerate=False,
+                 qp=None, profile=None):
         """H264 Encoder
 
         :param bitrate: Bitrate, default None
@@ -33,6 +39,7 @@ def __init__(self, bitrate=None, repeat=True, iperiod=None, framerate=None, enab
         self.iperiod = iperiod
         self.repeat = repeat
         self.qp = qp
+        self.profile = profile
         # The framerate can be reported in the sequence headers if enable_sps_framerate is set,
         # but there's no guarantee that frames will be delivered to the codec at that rate!
         self.framerate = framerate
@@ -41,6 +48,19 @@ def __init__(self, bitrate=None, repeat=True, iperiod=None, framerate=None, enab
     def _start(self):
         self._controls = []
 
+        # These names match what FFmpeg uses.
+        profile_lookup = {"baseline": V4L2_MPEG_VIDEO_H264_PROFILE_BASELINE,
+                          "constrained baseline": V4L2_MPEG_VIDEO_H264_PROFILE_CONSTRAINED_BASELINE,
+                          "main": V4L2_MPEG_VIDEO_H264_PROFILE_MAIN,
+                          "high": V4L2_MPEG_VIDEO_H264_PROFILE_HIGH}
+        if self.profile:
+            if not isinstance(self.profile, str):
+                raise RuntimeError("Profile should be a string value")
+            profile = self.profile.lower()
+            if profile in profile_lookup:
+                self._controls += [(V4L2_CID_MPEG_VIDEO_H264_PROFILE, profile_lookup[profile])]
+            else:
+                raise RuntimeError("Profile " + self.profile + " not recognised")
         if self.iperiod is not None:
             self._controls += [(V4L2_CID_MPEG_VIDEO_H264_I_PERIOD, self.iperiod)]
         if self.repeat:

picamera2/encoders/libav_h264_encoder.py

@@ -13,7 +13,7 @@
 class LibavH264Encoder(Encoder):
     """Encoder class that uses libx264 for h.264 encoding."""
 
-    def __init__(self, bitrate=None, repeat=True, iperiod=30, framerate=30, qp=None):
+    def __init__(self, bitrate=None, repeat=True, iperiod=30, framerate=30, qp=None, profile=None):
         """Initialise"""
         super().__init__()
         self._codec = "h264"  # for now only support h264
@@ -22,6 +22,8 @@ def __init__(self, bitrate=None, repeat=True, iperiod=30, framerate=30, qp=None)
         self.iperiod = iperiod
         self.framerate = framerate
         self.qp = qp
+        self.profile = profile
+        self.preset = None
 
     def _setup(self, quality):
         # If an explicit quality was specified, use it, otherwise try to preserve any bitrate/qp
@@ -45,20 +47,39 @@ def _start(self):
         self._stream = self._container.add_stream(self._codec, rate=self.framerate)
 
         self._stream.codec_context.thread_count = 8
-        self._stream.codec_context.thread_type = av.codec.context.ThreadType.FRAME
+        self._stream.codec_context.thread_type = av.codec.context.ThreadType.FRAME  # noqa
 
         self._stream.width = self.width
         self._stream.height = self.height
         self._stream.pix_fmt = "yuv420p"
 
+        preset = "ultrafast"
+        if self.profile is not None:
+            if not isinstance(self.profile, str):
+                raise RuntimeError("Profile should be a string value")
+            # Much more helpful to compare profile names case insensitively!
+            available_profiles = {k.lower(): v for k, v in self._stream.codec.profiles.items()}
+            profile = self.profile.lower()
+            if profile not in available_profiles:
+                raise RuntimeError("Profile " + self.profile + " not recognised")
+            self._stream.codec_context.profile = available_profiles[profile]
+            # The "ultrafast" preset always produces baseline, so:
+            if "baseline" not in profile:
+                preset = "superfast"
+
         if self.bitrate is not None:
             self._stream.codec_context.bit_rate = self.bitrate
         self._stream.codec_context.gop_size = self.iperiod
-        self._stream.codec_context.options["preset"] = "ultrafast"
+
+        # For those who know what they're doing, let them override the "preset".
+        if self.preset:
+            preset = self.preset
+        self._stream.codec_context.options["preset"] = preset
+
         self._stream.codec_context.options["deblock"] = "1"
         # Absence of the "global header" flags means that SPS/PPS headers get repeated.
         if not self.repeat:
-            self._stream.codec_context.flags |= av.codec.context.Flags.GLOBAL_HEADER
+            self._stream.codec_context.flags |= av.codec.context.Flags.GLOBAL_HEADER  # noqa
         if self.qp is not None:
             self._stream.codec_context.qmin = self.qp
             self._stream.codec_context.qmax = self.qp