subject:"\[FFmpeg\-devel\] \[PATCH 3\/4\] ituh263dec\: Optimize new RL

Re: [FFmpeg-devel] [PATCH 3/4] ituh263dec: Optimize new RL_VLC based decoding.

2014-08-31 Thread Reimar Döffinger

On Sun, Aug 31, 2014 at 08:14:04PM +0200, Michael Niedermayer wrote:
> On Sun, Aug 31, 2014 at 08:06:54PM +0200, Reimar Döffinger wrote:
> > On Sun, Aug 31, 2014 at 07:09:13PM +0200, Michael Niedermayer wrote:
> > > On Sun, Aug 31, 2014 at 04:48:43PM +0200, Reimar Döffinger wrote:
> > > > @@ -549,11 +549,8 @@ retry:
> > > >  av_log(s->avctx, AV_LOG_ERROR, "run overflow at %dx%d 
> > > > i:%d\n", s->mb_x, s->mb_y, s->mb_intra);
> > > >  return -1;
> > > >  }
> > > > -j = scan_table[i];
> > > > +j = scan_table[i-1];
> > > 
> > > the - 1 feels avoidable
> > 
> > I have no good idea how so far.
> 
> cant i be offset at entry & exit of the loop ?
> or
> scan_table be offset by -1 ?

*facepalm*. Yes, something like that should be possible.

> anyway not really important, its faster as is than before so this is
> maybe better in a seperate later patch

Considering how many bugs I had in this one, yes,
I rather have this one out and tested before I break
it again :)
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Re: [FFmpeg-devel] [PATCH 3/4] ituh263dec: Optimize new RL_VLC based decoding.

2014-08-31 Thread Michael Niedermayer

On Sun, Aug 31, 2014 at 08:06:54PM +0200, Reimar Döffinger wrote:
> On Sun, Aug 31, 2014 at 07:09:13PM +0200, Michael Niedermayer wrote:
> > On Sun, Aug 31, 2014 at 04:48:43PM +0200, Reimar Döffinger wrote:
> > > @@ -549,11 +549,8 @@ retry:
> > >  av_log(s->avctx, AV_LOG_ERROR, "run overflow at %dx%d 
> > > i:%d\n", s->mb_x, s->mb_y, s->mb_intra);
> > >  return -1;
> > >  }
> > > -j = scan_table[i];
> > > +j = scan_table[i-1];
> > 
> > the - 1 feels avoidable
> 
> I have no good idea how so far.

cant i be offset at entry & exit of the loop ?
or
scan_table be offset by -1 ?

anyway not really important, its faster as is than before so this is
maybe better in a seperate later patch


> Note that it is not really an extra cost: we save on a i++ at this place
> exchange...
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No snowflake in an avalanche ever feels responsible. -- Voltaire


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Re: [FFmpeg-devel] [PATCH 3/4] ituh263dec: Optimize new RL_VLC based decoding.

2014-08-31 Thread Reimar Döffinger

On Sun, Aug 31, 2014 at 07:09:13PM +0200, Michael Niedermayer wrote:
> On Sun, Aug 31, 2014 at 04:48:43PM +0200, Reimar Döffinger wrote:
> > @@ -549,11 +549,8 @@ retry:
> >  av_log(s->avctx, AV_LOG_ERROR, "run overflow at %dx%d i:%d\n", 
> > s->mb_x, s->mb_y, s->mb_intra);
> >  return -1;
> >  }
> > -j = scan_table[i];
> > +j = scan_table[i-1];
> 
> the - 1 feels avoidable

I have no good idea how so far.
Note that it is not really an extra cost: we save on a i++ at this place
exchange...
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Re: [FFmpeg-devel] [PATCH 3/4] ituh263dec: Optimize new RL_VLC based decoding.

2014-08-31 Thread Michael Niedermayer

On Sun, Aug 31, 2014 at 04:48:43PM +0200, Reimar Döffinger wrote:
> Signed-off-by: Reimar Döffinger 
> ---
>  libavcodec/ituh263dec.c | 39 ++-
>  1 file changed, 18 insertions(+), 21 deletions(-)
> 
> diff --git a/libavcodec/ituh263dec.c b/libavcodec/ituh263dec.c
> index 26f0ec5..083f5ae 100644
> --- a/libavcodec/ituh263dec.c
> +++ b/libavcodec/ituh263dec.c
> @@ -418,7 +418,7 @@ static void h263_decode_dquant(MpegEncContext *s){
>  static int h263_decode_block(MpegEncContext * s, int16_t * block,
>   int n, int coded)
>  {
> -int level, i, j, last, run;
> +int level, i, j, run;
>  RLTable *rl = &ff_h263_rl_inter;
>  const uint8_t *scan_table;
>  GetBitContext gb= s->gb;
> @@ -493,26 +493,22 @@ retry:
>  if (CONFIG_FLV_DECODER && s->h263_flv > 1) {
>  int is11 = SHOW_UBITS(re, &s->gb, 1);
>  SKIP_CACHE(re, &s->gb, 1);
> -last = SHOW_UBITS(re, &s->gb, 1);
> -SKIP_CACHE(re, &s->gb, 1);
> -run = SHOW_UBITS(re, &s->gb, 6);
> +run = SHOW_UBITS(re, &s->gb, 7) + 1;
>  if (is11) {
> -SKIP_COUNTER(re, &s->gb, 6);
> +SKIP_COUNTER(re, &s->gb, 1 + 7);
>  UPDATE_CACHE(re, &s->gb);
>  level = SHOW_SBITS(re, &s->gb, 11);
> -SKIP_COUNTER(re, &s->gb, 1 + 1 + 6 + 11);
> +SKIP_COUNTER(re, &s->gb, 11);
>  } else {
> -SKIP_CACHE(re, &s->gb, 6);
> +SKIP_CACHE(re, &s->gb, 7);
>  level = SHOW_SBITS(re, &s->gb, 7);
> -SKIP_COUNTER(re, &s->gb, 1 + 1 + 6 + 7);
> +SKIP_COUNTER(re, &s->gb, 1 + 7 + 7);
>  }
>  } else {
> -last = SHOW_UBITS(re, &s->gb, 1);
> -SKIP_CACHE(re, &s->gb, 1);
> -run = SHOW_UBITS(re, &s->gb, 6);
> -SKIP_CACHE(re, &s->gb, 6);
> +run = SHOW_UBITS(re, &s->gb, 7) + 1;
> +SKIP_CACHE(re, &s->gb, 7);
>  level = (int8_t)SHOW_UBITS(re, &s->gb, 8);
> -SKIP_COUNTER(re, &s->gb, 1 + 6 + 8);
> +SKIP_COUNTER(re, &s->gb, 7 + 8);
>  if(level == -128){
>  UPDATE_CACHE(re, &s->gb);
>  if (s->codec_id == AV_CODEC_ID_RV10) {
> @@ -528,15 +524,19 @@ retry:
>  }
>  }
>  } else {
> -run--;
> -last = run >= 192;
> -run &= 63;
>  if (SHOW_UBITS(re, &s->gb, 1))
>  level = -level;
>  SKIP_COUNTER(re, &s->gb, 1);
>  }
>  i += run;
> -if (i >= 64){
> +if (i > 64){
> +// redo update without last flag
> +i = i - run + ((run-1)&63);
> +if (i < 64) {
> +// only last marker, no overrun
> +block[scan_table[i]] = level;
> +break;
> +}
>  if(s->alt_inter_vlc && rl == &ff_h263_rl_inter && !s->mb_intra){
>  CLOSE_READER(re, &s->gb);
>  //Looks like a hack but no, it's the way it is supposed to 
> work ...

> @@ -549,11 +549,8 @@ retry:
>  av_log(s->avctx, AV_LOG_ERROR, "run overflow at %dx%d i:%d\n", 
> s->mb_x, s->mb_y, s->mb_intra);
>  return -1;
>  }
> -j = scan_table[i];
> +j = scan_table[i-1];

the - 1 feels avoidable

patch should be ok


[...]

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Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

I have often repented speaking, but never of holding my tongue.
-- Xenocrates


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[FFmpeg-devel] [PATCH 3/4] ituh263dec: Optimize new RL_VLC based decoding.

2014-08-31 Thread Reimar Döffinger

Signed-off-by: Reimar Döffinger 
---
 libavcodec/ituh263dec.c | 39 ++-
 1 file changed, 18 insertions(+), 21 deletions(-)

diff --git a/libavcodec/ituh263dec.c b/libavcodec/ituh263dec.c
index 26f0ec5..083f5ae 100644
--- a/libavcodec/ituh263dec.c
+++ b/libavcodec/ituh263dec.c
@@ -418,7 +418,7 @@ static void h263_decode_dquant(MpegEncContext *s){
 static int h263_decode_block(MpegEncContext * s, int16_t * block,
  int n, int coded)
 {
-int level, i, j, last, run;
+int level, i, j, run;
 RLTable *rl = &ff_h263_rl_inter;
 const uint8_t *scan_table;
 GetBitContext gb= s->gb;
@@ -493,26 +493,22 @@ retry:
 if (CONFIG_FLV_DECODER && s->h263_flv > 1) {
 int is11 = SHOW_UBITS(re, &s->gb, 1);
 SKIP_CACHE(re, &s->gb, 1);
-last = SHOW_UBITS(re, &s->gb, 1);
-SKIP_CACHE(re, &s->gb, 1);
-run = SHOW_UBITS(re, &s->gb, 6);
+run = SHOW_UBITS(re, &s->gb, 7) + 1;
 if (is11) {
-SKIP_COUNTER(re, &s->gb, 6);
+SKIP_COUNTER(re, &s->gb, 1 + 7);
 UPDATE_CACHE(re, &s->gb);
 level = SHOW_SBITS(re, &s->gb, 11);
-SKIP_COUNTER(re, &s->gb, 1 + 1 + 6 + 11);
+SKIP_COUNTER(re, &s->gb, 11);
 } else {
-SKIP_CACHE(re, &s->gb, 6);
+SKIP_CACHE(re, &s->gb, 7);
 level = SHOW_SBITS(re, &s->gb, 7);
-SKIP_COUNTER(re, &s->gb, 1 + 1 + 6 + 7);
+SKIP_COUNTER(re, &s->gb, 1 + 7 + 7);
 }
 } else {
-last = SHOW_UBITS(re, &s->gb, 1);
-SKIP_CACHE(re, &s->gb, 1);
-run = SHOW_UBITS(re, &s->gb, 6);
-SKIP_CACHE(re, &s->gb, 6);
+run = SHOW_UBITS(re, &s->gb, 7) + 1;
+SKIP_CACHE(re, &s->gb, 7);
 level = (int8_t)SHOW_UBITS(re, &s->gb, 8);
-SKIP_COUNTER(re, &s->gb, 1 + 6 + 8);
+SKIP_COUNTER(re, &s->gb, 7 + 8);
 if(level == -128){
 UPDATE_CACHE(re, &s->gb);
 if (s->codec_id == AV_CODEC_ID_RV10) {
@@ -528,15 +524,19 @@ retry:
 }
 }
 } else {
-run--;
-last = run >= 192;
-run &= 63;
 if (SHOW_UBITS(re, &s->gb, 1))
 level = -level;
 SKIP_COUNTER(re, &s->gb, 1);
 }
 i += run;
-if (i >= 64){
+if (i > 64){
+// redo update without last flag
+i = i - run + ((run-1)&63);
+if (i < 64) {
+// only last marker, no overrun
+block[scan_table[i]] = level;
+break;
+}
 if(s->alt_inter_vlc && rl == &ff_h263_rl_inter && !s->mb_intra){
 CLOSE_READER(re, &s->gb);
 //Looks like a hack but no, it's the way it is supposed to 
work ...
@@ -549,11 +549,8 @@ retry:
 av_log(s->avctx, AV_LOG_ERROR, "run overflow at %dx%d i:%d\n", 
s->mb_x, s->mb_y, s->mb_intra);
 return -1;
 }
-j = scan_table[i];
+j = scan_table[i-1];
 block[j] = level;
-if (last)
-break;
-i++;
 }
 CLOSE_READER(re, &s->gb);
 }
-- 
2.1.0

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Re: [FFmpeg-devel] [PATCH 3/4] ituh263dec: Optimize new RL_VLC based decoding.

Re: [FFmpeg-devel] [PATCH 3/4] ituh263dec: Optimize new RL_VLC based decoding.

Re: [FFmpeg-devel] [PATCH 3/4] ituh263dec: Optimize new RL_VLC based decoding.

Re: [FFmpeg-devel] [PATCH 3/4] ituh263dec: Optimize new RL_VLC based decoding.

[FFmpeg-devel] [PATCH 3/4] ituh263dec: Optimize new RL_VLC based decoding.

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