media: allegro: correctly scale the bit rate in SPS

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>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
This commit is contained in:
Michael Tretter 2021-09-08 14:03:51 +01:00 committed by Mauro Carvalho Chehab
parent c0a3753c5a
commit 89091e1246

View File

@ -1639,8 +1639,9 @@ 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 */