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[3/7] media: allegro: correctly scale the bit rate in SPS

Message ID 20210908130355.3295403-4-m.tretter@pengutronix.de (mailing list archive)
State New, archived
Headers show
Series media: allegro: fix and extend non-VCL NAL units | expand

Commit Message

Michael Tretter Sept. 8, 2021, 1:03 p.m. UTC 
The bit rate in the SPS can be scaled by an exponent, which allows to
reduce the number of bits in the SPS in case of high bit rates.

The driver did not scale the bitrate, but used a scaling exponent of 0.
Fix this by properly calculating the scaling factor and writing the bit
rate as value and scaling factor into the SPS.

Signed-off-by: Michael Tretter <m.tretter@pengutronix.de>
---
 drivers/media/platform/allegro-dvt/allegro-core.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/media/platform/allegro-dvt/allegro-core.c b/drivers/media/platform/allegro-dvt/allegro-core.c
index 8bcb40637c93..9cd903bab0ca 100644
--- a/drivers/media/platform/allegro-dvt/allegro-core.c
+++ b/drivers/media/platform/allegro-dvt/allegro-core.c
@@ -1558,8 +1558,9 @@  static ssize_t allegro_h264_write_sps(struct allegro_channel *channel,
 	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;
 	/* See Rec. ITU-T H.264 (04/2017) p. 410 E-53 */
+	sps->vui.vcl_hrd_parameters.bit_rate_scale =
+		ffs(channel->bitrate_peak) - 6;
 	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 */