From ebeae6d869d32bfd1a4d16573dc82ef30e003ed3 Mon Sep 17 00:00:00 2001 From: Guillaume Desmottes Date: Thu, 29 Jun 2017 14:16:19 +0200 Subject: [PATCH] omxh264enc: add 'b-frames' property Add a property to control the number of B-frames produced by the encoder using the OMX_VIDEO_PARAM_AVCTYPE OMX API. https://bugzilla.gnome.org/show_bug.cgi?id=784379 --- omx/gstomxh264enc.c | 66 ++++++++++++++++++++++++++++++++++++++++++++++++----- omx/gstomxh264enc.h | 1 + 2 files changed, 61 insertions(+), 6 deletions(-) diff --git a/omx/gstomxh264enc.c b/omx/gstomxh264enc.c index 77f89ed..7f202a5 100644 --- a/omx/gstomxh264enc.c +++ b/omx/gstomxh264enc.c @@ -55,7 +55,8 @@ enum PROP_INLINESPSPPSHEADERS, #endif PROP_PERIODICITYOFIDRFRAMES, - PROP_INTERVALOFCODINGINTRAFRAMES + PROP_INTERVALOFCODINGINTRAFRAMES, + PROP_B_FRAMES, }; #ifdef USE_OMX_TARGET_RPI @@ -63,6 +64,7 @@ enum #endif #define GST_OMX_H264_VIDEO_ENC_PERIODICITY_OF_IDR_FRAMES_DEFAULT (0xffffffff) #define GST_OMX_H264_VIDEO_ENC_INTERVAL_OF_CODING_INTRA_FRAMES_DEFAULT (0xffffffff) +#define GST_OMX_H264_VIDEO_ENC_B_FRAMES_DEFAULT (0xffffffff) /* class initialization */ @@ -117,6 +119,13 @@ gst_omx_h264_enc_class_init (GstOMXH264EncClass * klass) G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS | GST_PARAM_MUTABLE_READY)); + g_object_class_install_property (gobject_class, PROP_B_FRAMES, + g_param_spec_uint ("b-frames", "Number of B-frames", + "Number of B-frames between two consecutive I-frames (0xffffffff=component default)", + 0, G_MAXUINT, GST_OMX_H264_VIDEO_ENC_B_FRAMES_DEFAULT, + G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS | + GST_PARAM_MUTABLE_READY)); + basevideoenc_class->flush = gst_omx_h264_enc_flush; basevideoenc_class->stop = gst_omx_h264_enc_stop; @@ -152,6 +161,9 @@ gst_omx_h264_enc_set_property (GObject * object, guint prop_id, case PROP_INTERVALOFCODINGINTRAFRAMES: self->interval_intraframes = g_value_get_uint (value); break; + case PROP_B_FRAMES: + self->b_frames = g_value_get_uint (value); + break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); break; @@ -176,6 +188,9 @@ gst_omx_h264_enc_get_property (GObject * object, guint prop_id, GValue * value, case PROP_INTERVALOFCODINGINTRAFRAMES: g_value_set_uint (value, self->interval_intraframes); break; + case PROP_B_FRAMES: + g_value_set_uint (value, self->b_frames); + break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); break; @@ -193,6 +208,7 @@ gst_omx_h264_enc_init (GstOMXH264Enc * self) GST_OMX_H264_VIDEO_ENC_PERIODICITY_OF_IDR_FRAMES_DEFAULT; self->interval_intraframes = GST_OMX_H264_VIDEO_ENC_INTERVAL_OF_CODING_INTRA_FRAMES_DEFAULT; + self->b_frames = GST_OMX_H264_VIDEO_ENC_B_FRAMES_DEFAULT; } static gboolean @@ -357,6 +373,37 @@ update_param_avc (GstOMXH264Enc * self, if (level != OMX_VIDEO_AVCLevelMax) param.eLevel = level; + /* GOP pattern */ + if (self->interval_intraframes != + GST_OMX_H264_VIDEO_ENC_INTERVAL_OF_CODING_INTRA_FRAMES_DEFAULT) { + param.nPFrames = self->interval_intraframes; + + /* If user specified a specific number of B-frames, reduce the number of + * P-frames by this amount. If not ensure there is no B-frame to have the + * requested GOP length. */ + if (self->b_frames != GST_OMX_H264_VIDEO_ENC_B_FRAMES_DEFAULT) { + if (self->b_frames > self->interval_intraframes) { + GST_ERROR_OBJECT (self, + "The interval_intraframes perdiod (%u) needs to be higher than the number of B-frames (%u)", + self->interval_intraframes, self->b_frames); + return FALSE; + } + param.nPFrames -= self->b_frames; + } else { + param.nBFrames = 0; + } + } + + if (self->b_frames != GST_OMX_H264_VIDEO_ENC_B_FRAMES_DEFAULT) { + if (profile == OMX_VIDEO_AVCProfileBaseline && self->b_frames > 0) { + GST_ERROR_OBJECT (self, + "Baseline profile doesn't support B-frames (%u requested)", + self->b_frames); + return FALSE; + } + param.nBFrames = self->b_frames; + } + err = gst_omx_component_set_parameter (GST_OMX_VIDEO_ENC (self)->enc, OMX_IndexParamVideoAvc, ¶m); @@ -405,7 +452,12 @@ set_avc_intra_period (GstOMXH264Enc * self) if (self->interval_intraframes != GST_OMX_H264_VIDEO_ENC_INTERVAL_OF_CODING_INTRA_FRAMES_DEFAULT) { - config_avcintraperiod.nPFrames = self->interval_intraframes; + /* This OMX API doesn't allow us to specify the number of B-frames. + * So if user requested one we have to rely on update_param_avc() + * to configure the intraframes interval so it can take the + * B-frames into account. */ + if (self->b_frames == GST_OMX_H264_VIDEO_ENC_B_FRAMES_DEFAULT) + config_avcintraperiod.nPFrames = self->interval_intraframes; } err = @@ -565,15 +617,17 @@ gst_omx_h264_enc_set_format (GstOMXVideoEnc * enc, GstOMXPort * port, gst_caps_unref (peercaps); if (profile != OMX_VIDEO_AVCProfileMax || level != OMX_VIDEO_AVCLevelMax) { - /* OMX provides 2 API to set the profile and level so try using both */ + /* OMX provides 2 API to set the profile and level. We try using the + * generic on here and the H264 specific when calling + * update_param_avc() */ if (!update_param_profile_level (self, profile, level)) return FALSE; - - if (!update_param_avc (self, profile, level)) - return FALSE; } } + if (!update_param_avc (self, profile, level)) + return FALSE; + return TRUE; unsupported_profile: diff --git a/omx/gstomxh264enc.h b/omx/gstomxh264enc.h index 03326e1..43ab079 100644 --- a/omx/gstomxh264enc.h +++ b/omx/gstomxh264enc.h @@ -51,6 +51,7 @@ struct _GstOMXH264Enc #endif guint32 periodicty_idr; guint32 interval_intraframes; + guint32 b_frames; GList *headers; }; -- 2.7.4