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.skrabec@xxxxxxxx> > --- > 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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