media: allegro: add SPS/PPS nal unit writer

The allegro hardware encoder does not write SPS/PPS nal units into the
encoded video stream. Therefore, we need to write the units in software.

The implementation follows Rec. ITU-T H.264 (04/2017) to allow to
convert between a C struct and the RBSP representation of the SPS and
PPS nal units.

The allegro driver writes the nal units into the v4l2 capture buffer in
front of the actual video data which is written at an offset by the IP
core. The remaining gap is filled with a filler nal unit.

[hverkuil-cisco@xs4all.nl: added missing @dev description for nal_h264_read_sps()]
[mchehab+samsung@kernel.org: removed uneeded "-ccflags-y $(src)" from Makefile]

Signed-off-by: Michael Tretter <m.tretter@pengutronix.de>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

1 files changed, 181 insertions, 0 deletions

diff --git a/drivers/staging/media/allegro-dvt/allegro-core.c b/drivers/staging/media/allegro-dvt/allegro-core.c
index a6d42dc16d91..d007d1778f0e 100644
--- a/drivers/staging/media/allegro-dvt/allegro-core.c
+++ b/drivers/staging/media/allegro-dvt/allegro-core.c
@@ -26,6 +26,8 @@
 #include <media/videobuf2-dma-contig.h>
 #include <media/videobuf2-v4l2.h>
 
+#include "nal-h264.h"
+
 /*
  * Support up to 4k video streams. The hardware actually supports higher
  * resolutions, which are specified in PG252 June 6, 2018 (H.264/H.265 Video
@@ -1301,6 +1303,131 @@ static int allocate_reference_buffers(struct allegro_channel *channel,
 					 n, PAGE_ALIGN(size));
 }
 
+static ssize_t allegro_h264_write_sps(struct allegro_channel *channel,
+				      void *dest, size_t n)
+{
+	struct allegro_dev *dev = channel->dev;
+	struct nal_h264_sps *sps;
+	ssize_t size;
+	unsigned int size_mb = SIZE_MACROBLOCK;
+	/* Calculation of crop units in Rec. ITU-T H.264 (04/2017) p. 76 */
+	unsigned int crop_unit_x = 2;
+	unsigned int crop_unit_y = 2;
+
+	sps = kzalloc(sizeof(*sps), GFP_KERNEL);
+	if (!sps)
+		return -ENOMEM;
+
+	sps->profile_idc = nal_h264_profile_from_v4l2(channel->profile);
+	sps->constraint_set0_flag = 0;
+	sps->constraint_set1_flag = 1;
+	sps->constraint_set2_flag = 0;
+	sps->constraint_set3_flag = 0;
+	sps->constraint_set4_flag = 0;
+	sps->constraint_set5_flag = 0;
+	sps->level_idc = nal_h264_level_from_v4l2(channel->level);
+	sps->seq_parameter_set_id = 0;
+	sps->log2_max_frame_num_minus4 = 0;
+	sps->pic_order_cnt_type = 0;
+	sps->log2_max_pic_order_cnt_lsb_minus4 = 6;
+	sps->max_num_ref_frames = 3;
+	sps->gaps_in_frame_num_value_allowed_flag = 0;
+	sps->pic_width_in_mbs_minus1 =
+		DIV_ROUND_UP(channel->width, size_mb) - 1;
+	sps->pic_height_in_map_units_minus1 =
+		DIV_ROUND_UP(channel->height, size_mb) - 1;
+	sps->frame_mbs_only_flag = 1;
+	sps->mb_adaptive_frame_field_flag = 0;
+	sps->direct_8x8_inference_flag = 1;
+	sps->frame_cropping_flag =
+		(channel->width % size_mb) || (channel->height % size_mb);
+	if (sps->frame_cropping_flag) {
+		sps->crop_left = 0;
+		sps->crop_right = (round_up(channel->width, size_mb) - channel->width) / crop_unit_x;
+		sps->crop_top = 0;
+		sps->crop_bottom = (round_up(channel->height, size_mb) - channel->height) / crop_unit_y;
+	}
+	sps->vui_parameters_present_flag = 1;
+	sps->vui.aspect_ratio_info_present_flag = 0;
+	sps->vui.overscan_info_present_flag = 0;
+	sps->vui.video_signal_type_present_flag = 1;
+	sps->vui.video_format = 1;
+	sps->vui.video_full_range_flag = 0;
+	sps->vui.colour_description_present_flag = 1;
+	sps->vui.colour_primaries = 5;
+	sps->vui.transfer_characteristics = 5;
+	sps->vui.matrix_coefficients = 5;
+	sps->vui.chroma_loc_info_present_flag = 1;
+	sps->vui.chroma_sample_loc_type_top_field = 0;
+	sps->vui.chroma_sample_loc_type_bottom_field = 0;
+	sps->vui.timing_info_present_flag = 1;
+	sps->vui.num_units_in_tick = 1;
+	sps->vui.time_scale = 50;
+	sps->vui.fixed_frame_rate_flag = 1;
+	sps->vui.nal_hrd_parameters_present_flag = 0;
+	sps->vui.vcl_hrd_parameters_present_flag = 1;
+	sps->vui.vcl_hrd_parameters.cpb_cnt_minus1 = 0;
+	sps->vui.vcl_hrd_parameters.bit_rate_scale = 0;
+	sps->vui.vcl_hrd_parameters.cpb_size_scale = 1;
+	/* See Rec. ITU-T H.264 (04/2017) p. 410 E-53 */
+	sps->vui.vcl_hrd_parameters.bit_rate_value_minus1[0] =
+		channel->bitrate_peak / (1 << (6 + sps->vui.vcl_hrd_parameters.bit_rate_scale)) - 1;
+	/* See Rec. ITU-T H.264 (04/2017) p. 410 E-54 */
+	sps->vui.vcl_hrd_parameters.cpb_size_value_minus1[0] =
+		(channel->cpb_size * 1000) / (1 << (4 + sps->vui.vcl_hrd_parameters.cpb_size_scale)) - 1;
+	sps->vui.vcl_hrd_parameters.cbr_flag[0] = 1;
+	sps->vui.vcl_hrd_parameters.initial_cpb_removal_delay_length_minus1 = 31;
+	sps->vui.vcl_hrd_parameters.cpb_removal_delay_length_minus1 = 31;
+	sps->vui.vcl_hrd_parameters.dpb_output_delay_length_minus1 = 31;
+	sps->vui.vcl_hrd_parameters.time_offset_length = 0;
+	sps->vui.low_delay_hrd_flag = 0;
+	sps->vui.pic_struct_present_flag = 1;
+	sps->vui.bitstream_restriction_flag = 0;
+
+	size = nal_h264_write_sps(&dev->plat_dev->dev, dest, n, sps);
+
+	kfree(sps);
+
+	return size;
+}
+
+static ssize_t allegro_h264_write_pps(struct allegro_channel *channel,
+				      void *dest, size_t n)
+{
+	struct allegro_dev *dev = channel->dev;
+	struct nal_h264_pps *pps;
+	ssize_t size;
+
+	pps = kzalloc(sizeof(*pps), GFP_KERNEL);
+	if (!pps)
+		return -ENOMEM;
+
+	pps->pic_parameter_set_id = 0;
+	pps->seq_parameter_set_id = 0;
+	pps->entropy_coding_mode_flag = 0;
+	pps->bottom_field_pic_order_in_frame_present_flag = 0;
+	pps->num_slice_groups_minus1 = 0;
+	pps->num_ref_idx_l0_default_active_minus1 = 2;
+	pps->num_ref_idx_l1_default_active_minus1 = 2;
+	pps->weighted_pred_flag = 0;
+	pps->weighted_bipred_idc = 0;
+	pps->pic_init_qp_minus26 = 0;
+	pps->pic_init_qs_minus26 = 0;
+	pps->chroma_qp_index_offset = 0;
+	pps->deblocking_filter_control_present_flag = 1;
+	pps->constrained_intra_pred_flag = 0;
+	pps->redundant_pic_cnt_present_flag = 0;
+	pps->transform_8x8_mode_flag = 0;
+	pps->pic_scaling_matrix_present_flag = 0;
+	pps->second_chroma_qp_index_offset = 0;
+
+	size = nal_h264_write_pps(&dev->plat_dev->dev, dest, n, pps);
+
+	kfree(pps);
+
+	return size;
+}
+
 static bool allegro_channel_is_at_eos(struct allegro_channel *channel)
 {
 	bool is_at_eos = false;
@@ -1350,6 +1477,9 @@ static void allegro_channel_finish_frame(struct allegro_channel *channel,
 		u32 size;
 	} *partition;
 	enum vb2_buffer_state state = VB2_BUF_STATE_ERROR;
+	char *curr;
+	ssize_t len;
+	ssize_t free;
 
 	src_buf = v4l2_m2m_src_buf_remove(channel->fh.m2m_ctx);
 
@@ -1400,6 +1530,57 @@ static void allegro_channel_finish_frame(struct allegro_channel *channel,
 	vb2_set_plane_payload(&dst_buf->vb2_buf, 0,
 			      partition->offset + partition->size);
 
+	curr = vb2_plane_vaddr(&dst_buf->vb2_buf, 0);
+	free = partition->offset;
+	if (msg->is_idr) {
+		len = allegro_h264_write_sps(channel, curr, free);
+		if (len < 0) {
+			v4l2_err(&dev->v4l2_dev,
+				 "not enough space for sequence parameter set: %zd left\n",
+				 free);
+			goto err;
+		}
+		curr += len;
+		free -= len;
+		v4l2_dbg(1, debug, &dev->v4l2_dev,
+			 "channel %d: wrote %zd byte SPS nal unit\n",
+			 channel->mcu_channel_id, len);
+	}
+
+	if (msg->slice_type == AL_ENC_SLICE_TYPE_I) {
+		len = allegro_h264_write_pps(channel, curr, free);
+		if (len < 0) {
+			v4l2_err(&dev->v4l2_dev,
+				 "not enough space for picture parameter set: %zd left\n",
+				 free);
+			goto err;
+		}
+		curr += len;
+		free -= len;
+		v4l2_dbg(1, debug, &dev->v4l2_dev,
+			 "channel %d: wrote %zd byte PPS nal unit\n",
+			 channel->mcu_channel_id, len);
+	}
+
+	len = nal_h264_write_filler(&dev->plat_dev->dev, curr, free);
+	if (len < 0) {
+		v4l2_err(&dev->v4l2_dev,
+			 "failed to write %zd filler data\n", free);
+		goto err;
+	}
+	curr += len;
+	free -= len;
+	v4l2_dbg(2, debug, &dev->v4l2_dev,
+		 "channel %d: wrote %zd bytes filler nal unit\n",
+		 channel->mcu_channel_id, len);
+
+	if (free != 0) {
+		v4l2_err(&dev->v4l2_dev,
+			 "non-VCL NAL units do not fill space until VCL NAL unit: %zd bytes left\n",
+			 free);
+		goto err;
+	}
+
 	state = VB2_BUF_STATE_DONE;
 
 	v4l2_m2m_buf_copy_metadata(src_buf, dst_buf, false);