Hi, On Thu, May 30, 2019 at 11:15:12PM +0200, Jernej Skrabec wrote: > It seems that for some H264 videos at least one bitstream parsing > trigger must be called in order to be decoded correctly. There is no > explanation why this helps, but it was observed that two sample videos > with this fix are now decoded correctly and there is no regression with > others. > > Signed-off-by: Jernej Skrabec <jernej.skra...@siol.net> > --- > I have two samples which are fixed by this: > http://jernej.libreelec.tv/videos/h264/test.mkv > http://jernej.libreelec.tv/videos/h264/Dredd%20%E2%80%93%20DTS%20Sound%20Check%20DTS-HD%20MA%207.1.m2ts > > Although second one also needs support for multi-slice frames, which is not > yet implemented here. > > .../staging/media/sunxi/cedrus/cedrus_h264.c | 22 ++++++++++++++++--- > 1 file changed, 19 insertions(+), 3 deletions(-) > > diff --git a/drivers/staging/media/sunxi/cedrus/cedrus_h264.c > b/drivers/staging/media/sunxi/cedrus/cedrus_h264.c > index cc8d17f211a1..d0ee3f90ff46 100644 > --- a/drivers/staging/media/sunxi/cedrus/cedrus_h264.c > +++ b/drivers/staging/media/sunxi/cedrus/cedrus_h264.c > @@ -6,6 +6,7 @@ > * Copyright (c) 2018 Bootlin > */ > > +#include <linux/delay.h> > #include <linux/types.h> > > #include <media/videobuf2-dma-contig.h> > @@ -289,6 +290,20 @@ static void cedrus_write_pred_weight_table(struct > cedrus_ctx *ctx, > } > }
We should have a comment here explaining why that is needed
> +static void cedrus_skip_bits(struct cedrus_dev *dev, int num)
> +{
> + for (; num > 32; num -= 32) {
> + cedrus_write(dev, VE_H264_TRIGGER_TYPE, 0x3 | (32 << 8));
Using defines here would be great
> + while (cedrus_read(dev, VE_H264_STATUS) & (1 << 8))
> + udelay(1);
> + }
A new line here would be great
> + if (num > 0) {
> + cedrus_write(dev, VE_H264_TRIGGER_TYPE, 0x3 | (num << 8));
> + while (cedrus_read(dev, VE_H264_STATUS) & (1 << 8))
> + udelay(1);
> + }
Can't we make that a bit simpler by not duplicating the loop?
Something like:
int current = 0;
while (current < num) {
int tmp = min(num - current, 32);
cedrus_write(dev, VE_H264_TRIGGER_TYPE, 0x3 | (current << 8))
while (...)
...
current += tmp;
}
Maxime
--
Maxime Ripard, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
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