[FFmpeg-devel,2/2] lavc/vaapi_decode: recreate hw_frames_ctx without destroy va_context

Submitted by Linjie Fu on July 7, 2019, 4:38 p.m.

Details

Message ID 1562517537-1439-1-git-send-email-linjie.fu@intel.com
State New
Headers show

Commit Message

Linjie Fu July 7, 2019, 4:38 p.m.
VP9 allows resolution changes per frame. Currently in VAAPI, resolution
changes leads to va context destroy and reinit. This will cause
reference frame surface lost and produce garbage.

As libva allows re-create surface separately without changing the
context, this issue could be handled by only recreating hw_frames_ctx.

Could be verified by:
ffmpeg -hwaccel vaapi -hwaccel_device /dev/dri/renderD128 -i
./resolutions.ivf
-pix_fmt p010le -f rawvideo -vframes 20 -y vaapi.yuv

Signed-off-by: Linjie Fu <linjie.fu@intel.com>
---
 libavcodec/decode.c       |  8 ++++----
 libavcodec/vaapi_decode.c | 40 ++++++++++++++++++++++------------------
 2 files changed, 26 insertions(+), 22 deletions(-)

Comments

Hendrik Leppkes July 7, 2019, 7:39 a.m.
On Sun, Jul 7, 2019 at 6:41 AM Linjie Fu <linjie.fu@intel.com> wrote:
>
> VP9 allows resolution changes per frame. Currently in VAAPI, resolution
> changes leads to va context destroy and reinit. This will cause
> reference frame surface lost and produce garbage.
>
> As libva allows re-create surface separately without changing the
> context, this issue could be handled by only recreating hw_frames_ctx.
>
> Could be verified by:
> ffmpeg -hwaccel vaapi -hwaccel_device /dev/dri/renderD128 -i
> ./resolutions.ivf
> -pix_fmt p010le -f rawvideo -vframes 20 -y vaapi.yuv
>
> Signed-off-by: Linjie Fu <linjie.fu@intel.com>
> ---
>  libavcodec/decode.c       |  8 ++++----
>  libavcodec/vaapi_decode.c | 40 ++++++++++++++++++++++------------------
>  2 files changed, 26 insertions(+), 22 deletions(-)
>
> diff --git a/libavcodec/decode.c b/libavcodec/decode.c
> index 0863b82..a81b857 100644
> --- a/libavcodec/decode.c
> +++ b/libavcodec/decode.c
> @@ -1254,7 +1254,6 @@ int ff_decode_get_hw_frames_ctx(AVCodecContext *avctx,
>
>      frames_ctx = (AVHWFramesContext*)avctx->hw_frames_ctx->data;
>
> -
>      if (frames_ctx->initial_pool_size) {
>          // We guarantee 4 base work surfaces. The function above guarantees 1
>          // (the absolute minimum), so add the missing count.
> @@ -1333,7 +1332,7 @@ static int hwaccel_init(AVCodecContext *avctx,
>          return AVERROR_PATCHWELCOME;
>      }
>
> -    if (hwaccel->priv_data_size) {
> +    if (hwaccel->priv_data_size && !avctx->internal->hwaccel_priv_data) {
>          avctx->internal->hwaccel_priv_data =
>              av_mallocz(hwaccel->priv_data_size);
>          if (!avctx->internal->hwaccel_priv_data)
> @@ -1397,8 +1396,9 @@ int ff_get_format(AVCodecContext *avctx, const enum AVPixelFormat *fmt)
>
>      for (;;) {
>          // Remove the previous hwaccel, if there was one.
> -        hwaccel_uninit(avctx);
> -
> +        // VAAPI allows reinit hw_frames_ctx only
> +        if (choices[0] != AV_PIX_FMT_VAAPI_VLD)
> +            hwaccel_uninit(avctx);
>          user_choice = avctx->get_format(avctx, choices);

Having VAAPI specific code in this generic code path (or any hwaccel
specific code) seems like a design flaw, and should perhaps be
adressed by a generic improvement, instead of VAAPI specific hacks.

- Hendrik
Mark Thompson July 7, 2019, 11:51 a.m.
On 07/07/2019 17:38, Linjie Fu wrote:
> VP9 allows resolution changes per frame. Currently in VAAPI, resolution
> changes leads to va context destroy and reinit.

Which is correct - it needs to remake the context because the old one is for the wrong resolution.

>                                                 This will cause
> reference frame surface lost and produce garbage.

This isn't right - the reference frame surfaces aren't lost.  See VP9Context.s.refs[], which holds references to the frames (including their hardware frame contexts) until the stream indicates that they can be discarded by overwriting their reference frame slots.

> As libva allows re-create surface separately without changing the
> context, this issue could be handled by only recreating hw_frames_ctx.
> 
> Could be verified by:
> ffmpeg -hwaccel vaapi -hwaccel_device /dev/dri/renderD128 -i
> ./resolutions.ivf
> -pix_fmt p010le -f rawvideo -vframes 20 -y vaapi.yuv
> 
> Signed-off-by: Linjie Fu <linjie.fu@intel.com>
> ---
>  libavcodec/decode.c       |  8 ++++----
>  libavcodec/vaapi_decode.c | 40 ++++++++++++++++++++++------------------
>  2 files changed, 26 insertions(+), 22 deletions(-)
> 
> diff --git a/libavcodec/decode.c b/libavcodec/decode.c
> index 0863b82..a81b857 100644
> --- a/libavcodec/decode.c
> +++ b/libavcodec/decode.c
> @@ -1254,7 +1254,6 @@ int ff_decode_get_hw_frames_ctx(AVCodecContext *avctx,
>  
>      frames_ctx = (AVHWFramesContext*)avctx->hw_frames_ctx->data;
>  
> -
>      if (frames_ctx->initial_pool_size) {
>          // We guarantee 4 base work surfaces. The function above guarantees 1
>          // (the absolute minimum), so add the missing count.
> @@ -1333,7 +1332,7 @@ static int hwaccel_init(AVCodecContext *avctx,
>          return AVERROR_PATCHWELCOME;
>      }
>  
> -    if (hwaccel->priv_data_size) {
> +    if (hwaccel->priv_data_size && !avctx->internal->hwaccel_priv_data) {
>          avctx->internal->hwaccel_priv_data =
>              av_mallocz(hwaccel->priv_data_size);
>          if (!avctx->internal->hwaccel_priv_data)
> @@ -1397,8 +1396,9 @@ int ff_get_format(AVCodecContext *avctx, const enum AVPixelFormat *fmt)
>  
>      for (;;) {
>          // Remove the previous hwaccel, if there was one.
> -        hwaccel_uninit(avctx);
> -
> +        // VAAPI allows reinit hw_frames_ctx only
> +        if (choices[0] != AV_PIX_FMT_VAAPI_VLD)

Including codec-specific conditions in the generic code suggests that something very shady is going on.

> +            hwaccel_uninit(avctx);>          user_choice = avctx->get_format(avctx, choices);
>          if (user_choice == AV_PIX_FMT_NONE) {
>              // Explicitly chose nothing, give up.
> diff --git a/libavcodec/vaapi_decode.c b/libavcodec/vaapi_decode.c
> index 69512e1..13f0cf0 100644
> --- a/libavcodec/vaapi_decode.c
> +++ b/libavcodec/vaapi_decode.c
> @@ -613,8 +613,10 @@ int ff_vaapi_decode_init(AVCodecContext *avctx)
>      VAStatus vas;
>      int err;
>  
> -    ctx->va_config  = VA_INVALID_ID;
> -    ctx->va_context = VA_INVALID_ID;
> +    if (!ctx->va_config && !ctx->va_context){
> +        ctx->va_config  = VA_INVALID_ID;
> +        ctx->va_context = VA_INVALID_ID;
> +    }
>  
>  #if FF_API_STRUCT_VAAPI_CONTEXT
>      if (avctx->hwaccel_context) {
> @@ -642,7 +644,6 @@ int ff_vaapi_decode_init(AVCodecContext *avctx)
>          // present, so set it here to avoid the behaviour changing.
>          ctx->hwctx->driver_quirks =
>              AV_VAAPI_DRIVER_QUIRK_RENDER_PARAM_BUFFERS;
> -
>      }
>  #endif
>  
> @@ -655,7 +656,8 @@ int ff_vaapi_decode_init(AVCodecContext *avctx)
>                 "context: %#x/%#x.\n", ctx->va_config, ctx->va_context);
>      } else {
>  #endif
> -
> +    // Get a new hw_frames_ctx even if there is already one
> +    // recreate surface without reconstuct va_context
>      err = ff_decode_get_hw_frames_ctx(avctx, AV_HWDEVICE_TYPE_VAAPI);
>      if (err < 0)
>          goto fail;
> @@ -670,21 +672,23 @@ int ff_vaapi_decode_init(AVCodecContext *avctx)
>      if (err)
>          goto fail;
>  
> -    vas = vaCreateContext(ctx->hwctx->display, ctx->va_config,
> -                          avctx->coded_width, avctx->coded_height,
> -                          VA_PROGRESSIVE,
> -                          ctx->hwfc->surface_ids,
> -                          ctx->hwfc->nb_surfaces,
> -                          &ctx->va_context);
> -    if (vas != VA_STATUS_SUCCESS) {
> -        av_log(avctx, AV_LOG_ERROR, "Failed to create decode "
> -               "context: %d (%s).\n", vas, vaErrorStr(vas));
> -        err = AVERROR(EIO);
> -        goto fail;
> -    }
> +    if (ctx->va_context == VA_INVALID_ID) {
> +        vas = vaCreateContext(ctx->hwctx->display, ctx->va_config,
> +                              avctx->coded_width, avctx->coded_height,
> +                              VA_PROGRESSIVE,
> +                              ctx->hwfc->surface_ids,
> +                              ctx->hwfc->nb_surfaces,
> +                              &ctx->va_context);
> +        if (vas != VA_STATUS_SUCCESS) {
> +            av_log(avctx, AV_LOG_ERROR, "Failed to create decode "
> +                   "context: %d (%s).\n", vas, vaErrorStr(vas));
> +            err = AVERROR(EIO);
> +            goto fail;
> +        }
>  
> -    av_log(avctx, AV_LOG_DEBUG, "Decode context initialised: "
> -           "%#x/%#x.\n", ctx->va_config, ctx->va_context);
> +        av_log(avctx, AV_LOG_DEBUG, "Decode context initialised: "
> +               "%#x/%#x.\n", ctx->va_config, ctx->va_context);
> +    }

If I'm reading this correctly, this changes to only creating one context ever even when the resolution changes.

How can that work if the resolution increases?  For example you start decoding at 1280x720 and create a context for that, then the resolution changes to 3840x2160 and it tries to decode using the 1280x720 context.

>  #if FF_API_STRUCT_VAAPI_CONTEXT
>      }
>  #endif
> 

- Mark
Linjie Fu July 7, 2019, 1:49 p.m.
> -----Original Message-----

> From: ffmpeg-devel [mailto:ffmpeg-devel-bounces@ffmpeg.org] On Behalf

> Of Mark Thompson

> Sent: Sunday, July 7, 2019 19:51

> To: ffmpeg-devel@ffmpeg.org

> Subject: Re: [FFmpeg-devel] [PATCH 2/2] lavc/vaapi_decode: recreate

> hw_frames_ctx without destroy va_context

> 

> On 07/07/2019 17:38, Linjie Fu wrote:

> > VP9 allows resolution changes per frame. Currently in VAAPI, resolution

> > changes leads to va context destroy and reinit.

> 

> Which is correct - it needs to remake the context because the old one is for

> the wrong resolution.


It seems that we don't need to remake context, remaking the surface is enough
for resolution changing.
Currently in libva, surface is able to be recreated separately without remaking context.
And this way is used in libyami to cope with resolution changing cases.

> 

> >                                                 This will cause

> > reference frame surface lost and produce garbage.

> 

> This isn't right - the reference frame surfaces aren't lost.  See

> VP9Context.s.refs[], which holds references to the frames (including their

> hardware frame contexts) until the stream indicates that they can be

> discarded by overwriting their reference frame slots.


I'm not quite sure about this, at least the result shows they are not used correctly
in current way. 
Will look deeper into it.

> 

> > As libva allows re-create surface separately without changing the

> > context, this issue could be handled by only recreating hw_frames_ctx.

> >

> > Could be verified by:

> > ffmpeg -hwaccel vaapi -hwaccel_device /dev/dri/renderD128 -i

> > ./resolutions.ivf

> > -pix_fmt p010le -f rawvideo -vframes 20 -y vaapi.yuv

> >

> > Signed-off-by: Linjie Fu <linjie.fu@intel.com>

> > ---

> >  libavcodec/decode.c       |  8 ++++----

> >  libavcodec/vaapi_decode.c | 40 ++++++++++++++++++++++----------------

> --

> >  2 files changed, 26 insertions(+), 22 deletions(-)

> >

> > diff --git a/libavcodec/decode.c b/libavcodec/decode.c

> > index 0863b82..a81b857 100644

> > --- a/libavcodec/decode.c

> > +++ b/libavcodec/decode.c

> > @@ -1254,7 +1254,6 @@ int

> ff_decode_get_hw_frames_ctx(AVCodecContext *avctx,

> >

> >      frames_ctx = (AVHWFramesContext*)avctx->hw_frames_ctx->data;

> >

> > -

> >      if (frames_ctx->initial_pool_size) {

> >          // We guarantee 4 base work surfaces. The function above guarantees

> 1

> >          // (the absolute minimum), so add the missing count.

> > @@ -1333,7 +1332,7 @@ static int hwaccel_init(AVCodecContext *avctx,

> >          return AVERROR_PATCHWELCOME;

> >      }

> >

> > -    if (hwaccel->priv_data_size) {

> > +    if (hwaccel->priv_data_size && !avctx->internal->hwaccel_priv_data) {

> >          avctx->internal->hwaccel_priv_data =

> >              av_mallocz(hwaccel->priv_data_size);

> >          if (!avctx->internal->hwaccel_priv_data)

> > @@ -1397,8 +1396,9 @@ int ff_get_format(AVCodecContext *avctx, const

> enum AVPixelFormat *fmt)

> >

> >      for (;;) {

> >          // Remove the previous hwaccel, if there was one.

> > -        hwaccel_uninit(avctx);

> > -

> > +        // VAAPI allows reinit hw_frames_ctx only

> > +        if (choices[0] != AV_PIX_FMT_VAAPI_VLD)

> 

> Including codec-specific conditions in the generic code suggests that

> something very shady is going on.


Yes, will try to avoid this.

> > +            hwaccel_uninit(avctx);>          user_choice = avctx-

> >get_format(avctx, choices);

> >          if (user_choice == AV_PIX_FMT_NONE) {

> >              // Explicitly chose nothing, give up.

> > diff --git a/libavcodec/vaapi_decode.c b/libavcodec/vaapi_decode.c

> > index 69512e1..13f0cf0 100644

> > --- a/libavcodec/vaapi_decode.c

> > +++ b/libavcodec/vaapi_decode.c

> > @@ -613,8 +613,10 @@ int ff_vaapi_decode_init(AVCodecContext *avctx)

> >      VAStatus vas;

> >      int err;

> >

> > -    ctx->va_config  = VA_INVALID_ID;

> > -    ctx->va_context = VA_INVALID_ID;

> > +    if (!ctx->va_config && !ctx->va_context){

> > +        ctx->va_config  = VA_INVALID_ID;

> > +        ctx->va_context = VA_INVALID_ID;

> > +    }

> >

> >  #if FF_API_STRUCT_VAAPI_CONTEXT

> >      if (avctx->hwaccel_context) {

> > @@ -642,7 +644,6 @@ int ff_vaapi_decode_init(AVCodecContext *avctx)

> >          // present, so set it here to avoid the behaviour changing.

> >          ctx->hwctx->driver_quirks =

> >              AV_VAAPI_DRIVER_QUIRK_RENDER_PARAM_BUFFERS;

> > -

> >      }

> >  #endif

> >

> > @@ -655,7 +656,8 @@ int ff_vaapi_decode_init(AVCodecContext *avctx)

> >                 "context: %#x/%#x.\n", ctx->va_config, ctx->va_context);

> >      } else {

> >  #endif

> > -

> > +    // Get a new hw_frames_ctx even if there is already one

> > +    // recreate surface without reconstuct va_context

> >      err = ff_decode_get_hw_frames_ctx(avctx,

> AV_HWDEVICE_TYPE_VAAPI);

> >      if (err < 0)

> >          goto fail;

> > @@ -670,21 +672,23 @@ int ff_vaapi_decode_init(AVCodecContext *avctx)

> >      if (err)

> >          goto fail;

> >

> > -    vas = vaCreateContext(ctx->hwctx->display, ctx->va_config,

> > -                          avctx->coded_width, avctx->coded_height,

> > -                          VA_PROGRESSIVE,

> > -                          ctx->hwfc->surface_ids,

> > -                          ctx->hwfc->nb_surfaces,

> > -                          &ctx->va_context);

> > -    if (vas != VA_STATUS_SUCCESS) {

> > -        av_log(avctx, AV_LOG_ERROR, "Failed to create decode "

> > -               "context: %d (%s).\n", vas, vaErrorStr(vas));

> > -        err = AVERROR(EIO);

> > -        goto fail;

> > -    }

> > +    if (ctx->va_context == VA_INVALID_ID) {

> > +        vas = vaCreateContext(ctx->hwctx->display, ctx->va_config,

> > +                              avctx->coded_width, avctx->coded_height,

> > +                              VA_PROGRESSIVE,

> > +                              ctx->hwfc->surface_ids,

> > +                              ctx->hwfc->nb_surfaces,

> > +                              &ctx->va_context);

> > +        if (vas != VA_STATUS_SUCCESS) {

> > +            av_log(avctx, AV_LOG_ERROR, "Failed to create decode "

> > +                   "context: %d (%s).\n", vas, vaErrorStr(vas));

> > +            err = AVERROR(EIO);

> > +            goto fail;

> > +        }

> >

> > -    av_log(avctx, AV_LOG_DEBUG, "Decode context initialised: "

> > -           "%#x/%#x.\n", ctx->va_config, ctx->va_context);

> > +        av_log(avctx, AV_LOG_DEBUG, "Decode context initialised: "

> > +               "%#x/%#x.\n", ctx->va_config, ctx->va_context);

> > +    }

> 

> If I'm reading this correctly, this changes to only creating one context ever

> even when the resolution changes.

> 

> How can that work if the resolution increases?  For example you start

> decoding at 1280x720 and create a context for that, then the resolution

> changes to 3840x2160 and it tries to decode using the 1280x720 context.

> 

Recreating hw_frame_ctx can cope with this.
Verified in one case with resolution increasing:
Resolution changes from 495x168 -> 328 x 307 -> 395 x376, the pipeline works
and the output image is good.
It's not increasing on both width and height, but as long as one of them increases,
current pipeline will be broken ff we don’t reinit the context(or just don't recreate
hw_frame_ctx). 
(also did experiment as a contrast that we use the same context without recreate
hw_frame_ctx, the pipeline will be blocked when mapping surface in resolution increase)

ffmpeg -hwaccel vaapi -hwaccel_device /dev/dri/renderD128 -v verbose -i ./test3232.ivf
-pix_fmt p010le -f rawvideo -vf scale=w=416:h=168 -vframes 10 -y md5.yuv

log is attached.

Thanks.
Linjie Fu July 7, 2019, 1:52 p.m.
> -----Original Message-----

> From: ffmpeg-devel [mailto:ffmpeg-devel-bounces@ffmpeg.org] On Behalf

> Of Hendrik Leppkes

> Sent: Sunday, July 7, 2019 15:39

> To: FFmpeg development discussions and patches <ffmpeg-

> devel@ffmpeg.org>

> Subject: Re: [FFmpeg-devel] [PATCH 2/2] lavc/vaapi_decode: recreate

> hw_frames_ctx without destroy va_context

> 

> On Sun, Jul 7, 2019 at 6:41 AM Linjie Fu <linjie.fu@intel.com> wrote:

> >

> > VP9 allows resolution changes per frame. Currently in VAAPI, resolution

> > changes leads to va context destroy and reinit. This will cause

> > reference frame surface lost and produce garbage.

> >

> > As libva allows re-create surface separately without changing the

> > context, this issue could be handled by only recreating hw_frames_ctx.

> >

> > Could be verified by:

> > ffmpeg -hwaccel vaapi -hwaccel_device /dev/dri/renderD128 -i

> > ./resolutions.ivf

> > -pix_fmt p010le -f rawvideo -vframes 20 -y vaapi.yuv

> >

> > Signed-off-by: Linjie Fu <linjie.fu@intel.com>

> > ---

> >  libavcodec/decode.c       |  8 ++++----

> >  libavcodec/vaapi_decode.c | 40 ++++++++++++++++++++++----------------

> --

> >  2 files changed, 26 insertions(+), 22 deletions(-)

> >

> > diff --git a/libavcodec/decode.c b/libavcodec/decode.c

> > index 0863b82..a81b857 100644

> > --- a/libavcodec/decode.c

> > +++ b/libavcodec/decode.c

> > @@ -1254,7 +1254,6 @@ int

> ff_decode_get_hw_frames_ctx(AVCodecContext *avctx,

> >

> >      frames_ctx = (AVHWFramesContext*)avctx->hw_frames_ctx->data;

> >

> > -

> >      if (frames_ctx->initial_pool_size) {

> >          // We guarantee 4 base work surfaces. The function above guarantees

> 1

> >          // (the absolute minimum), so add the missing count.

> > @@ -1333,7 +1332,7 @@ static int hwaccel_init(AVCodecContext *avctx,

> >          return AVERROR_PATCHWELCOME;

> >      }

> >

> > -    if (hwaccel->priv_data_size) {

> > +    if (hwaccel->priv_data_size && !avctx->internal->hwaccel_priv_data) {

> >          avctx->internal->hwaccel_priv_data =

> >              av_mallocz(hwaccel->priv_data_size);

> >          if (!avctx->internal->hwaccel_priv_data)

> > @@ -1397,8 +1396,9 @@ int ff_get_format(AVCodecContext *avctx, const

> enum AVPixelFormat *fmt)

> >

> >      for (;;) {

> >          // Remove the previous hwaccel, if there was one.

> > -        hwaccel_uninit(avctx);

> > -

> > +        // VAAPI allows reinit hw_frames_ctx only

> > +        if (choices[0] != AV_PIX_FMT_VAAPI_VLD)

> > +            hwaccel_uninit(avctx);

> >          user_choice = avctx->get_format(avctx, choices);

> 

> Having VAAPI specific code in this generic code path (or any hwaccel

> specific code) seems like a design flaw, and should perhaps be

> adressed by a generic improvement, instead of VAAPI specific hacks.

> 


Yes, a better solution(maybe a flag set by reinit in vaapi) should be applied.
Thanks for your response.
Linjie Fu July 7, 2019, 2:15 p.m.
> -----Original Message-----

> From: ffmpeg-devel [mailto:ffmpeg-devel-bounces@ffmpeg.org] On Behalf

> Of Fu, Linjie

> Sent: Sunday, July 7, 2019 21:49

> To: FFmpeg development discussions and patches <ffmpeg-

> devel@ffmpeg.org>

> Cc: Mark Thompson <sw@jkqxz.net>

> Subject: Re: [FFmpeg-devel] [PATCH 2/2] lavc/vaapi_decode: recreate

> hw_frames_ctx without destroy va_context

> 

> > -----Original Message-----

> > From: ffmpeg-devel [mailto:ffmpeg-devel-bounces@ffmpeg.org] On

> Behalf

> > Of Mark Thompson

> > Sent: Sunday, July 7, 2019 19:51

> > To: ffmpeg-devel@ffmpeg.org

> > Subject: Re: [FFmpeg-devel] [PATCH 2/2] lavc/vaapi_decode: recreate

> > hw_frames_ctx without destroy va_context

> >

> > On 07/07/2019 17:38, Linjie Fu wrote:

> > > VP9 allows resolution changes per frame. Currently in VAAPI, resolution

> > > changes leads to va context destroy and reinit.

> >

> > Which is correct - it needs to remake the context because the old one is for

> > the wrong resolution.

> 

> It seems that we don't need to remake context, remaking the surface is

> enough

> for resolution changing.

> Currently in libva, surface is able to be recreated separately without

> remaking context.

> And this way is used in libyami to cope with resolution changing cases.

> 

> >

> > >                                                 This will cause

> > > reference frame surface lost and produce garbage.

> >

> > This isn't right - the reference frame surfaces aren't lost.  See

> > VP9Context.s.refs[], which holds references to the frames (including their

> > hardware frame contexts) until the stream indicates that they can be

> > discarded by overwriting their reference frame slots.

> 

> I'm not quite sure about this, at least the result shows they are not used

> correctly

> in current way.

> Will look deeper into it.

> 

> >

> > > As libva allows re-create surface separately without changing the

> > > context, this issue could be handled by only recreating hw_frames_ctx.

> > >

> > > Could be verified by:

> > > ffmpeg -hwaccel vaapi -hwaccel_device /dev/dri/renderD128 -i

> > > ./resolutions.ivf

> > > -pix_fmt p010le -f rawvideo -vframes 20 -y vaapi.yuv

> > >

> > > Signed-off-by: Linjie Fu <linjie.fu@intel.com>

> > > ---

> > >  libavcodec/decode.c       |  8 ++++----

> > >  libavcodec/vaapi_decode.c | 40 ++++++++++++++++++++++--------------

> --

> > --

> > >  2 files changed, 26 insertions(+), 22 deletions(-)

> > >

> > > diff --git a/libavcodec/decode.c b/libavcodec/decode.c

> > > index 0863b82..a81b857 100644

> > > --- a/libavcodec/decode.c

> > > +++ b/libavcodec/decode.c

> > > @@ -1254,7 +1254,6 @@ int

> > ff_decode_get_hw_frames_ctx(AVCodecContext *avctx,

> > >

> > >      frames_ctx = (AVHWFramesContext*)avctx->hw_frames_ctx->data;

> > >

> > > -

> > >      if (frames_ctx->initial_pool_size) {

> > >          // We guarantee 4 base work surfaces. The function above

> guarantees

> > 1

> > >          // (the absolute minimum), so add the missing count.

> > > @@ -1333,7 +1332,7 @@ static int hwaccel_init(AVCodecContext *avctx,

> > >          return AVERROR_PATCHWELCOME;

> > >      }

> > >

> > > -    if (hwaccel->priv_data_size) {

> > > +    if (hwaccel->priv_data_size && !avctx->internal->hwaccel_priv_data)

> {

> > >          avctx->internal->hwaccel_priv_data =

> > >              av_mallocz(hwaccel->priv_data_size);

> > >          if (!avctx->internal->hwaccel_priv_data)

> > > @@ -1397,8 +1396,9 @@ int ff_get_format(AVCodecContext *avctx,

> const

> > enum AVPixelFormat *fmt)

> > >

> > >      for (;;) {

> > >          // Remove the previous hwaccel, if there was one.

> > > -        hwaccel_uninit(avctx);

> > > -

> > > +        // VAAPI allows reinit hw_frames_ctx only

> > > +        if (choices[0] != AV_PIX_FMT_VAAPI_VLD)

> >

> > Including codec-specific conditions in the generic code suggests that

> > something very shady is going on.

> 

> Yes, will try to avoid this.

> 

> > > +            hwaccel_uninit(avctx);>          user_choice = avctx-

> > >get_format(avctx, choices);

> > >          if (user_choice == AV_PIX_FMT_NONE) {

> > >              // Explicitly chose nothing, give up.

> > > diff --git a/libavcodec/vaapi_decode.c b/libavcodec/vaapi_decode.c

> > > index 69512e1..13f0cf0 100644

> > > --- a/libavcodec/vaapi_decode.c

> > > +++ b/libavcodec/vaapi_decode.c

> > > @@ -613,8 +613,10 @@ int ff_vaapi_decode_init(AVCodecContext

> *avctx)

> > >      VAStatus vas;

> > >      int err;

> > >

> > > -    ctx->va_config  = VA_INVALID_ID;

> > > -    ctx->va_context = VA_INVALID_ID;

> > > +    if (!ctx->va_config && !ctx->va_context){

> > > +        ctx->va_config  = VA_INVALID_ID;

> > > +        ctx->va_context = VA_INVALID_ID;

> > > +    }

> > >

> > >  #if FF_API_STRUCT_VAAPI_CONTEXT

> > >      if (avctx->hwaccel_context) {

> > > @@ -642,7 +644,6 @@ int ff_vaapi_decode_init(AVCodecContext *avctx)

> > >          // present, so set it here to avoid the behaviour changing.

> > >          ctx->hwctx->driver_quirks =

> > >              AV_VAAPI_DRIVER_QUIRK_RENDER_PARAM_BUFFERS;

> > > -

> > >      }

> > >  #endif

> > >

> > > @@ -655,7 +656,8 @@ int ff_vaapi_decode_init(AVCodecContext *avctx)

> > >                 "context: %#x/%#x.\n", ctx->va_config, ctx->va_context);

> > >      } else {

> > >  #endif

> > > -

> > > +    // Get a new hw_frames_ctx even if there is already one

> > > +    // recreate surface without reconstuct va_context

> > >      err = ff_decode_get_hw_frames_ctx(avctx,

> > AV_HWDEVICE_TYPE_VAAPI);

> > >      if (err < 0)

> > >          goto fail;

> > > @@ -670,21 +672,23 @@ int ff_vaapi_decode_init(AVCodecContext

> *avctx)

> > >      if (err)

> > >          goto fail;

> > >

> > > -    vas = vaCreateContext(ctx->hwctx->display, ctx->va_config,

> > > -                          avctx->coded_width, avctx->coded_height,

> > > -                          VA_PROGRESSIVE,

> > > -                          ctx->hwfc->surface_ids,

> > > -                          ctx->hwfc->nb_surfaces,

> > > -                          &ctx->va_context);

> > > -    if (vas != VA_STATUS_SUCCESS) {

> > > -        av_log(avctx, AV_LOG_ERROR, "Failed to create decode "

> > > -               "context: %d (%s).\n", vas, vaErrorStr(vas));

> > > -        err = AVERROR(EIO);

> > > -        goto fail;

> > > -    }

> > > +    if (ctx->va_context == VA_INVALID_ID) {

> > > +        vas = vaCreateContext(ctx->hwctx->display, ctx->va_config,

> > > +                              avctx->coded_width, avctx->coded_height,

> > > +                              VA_PROGRESSIVE,

> > > +                              ctx->hwfc->surface_ids,

> > > +                              ctx->hwfc->nb_surfaces,

> > > +                              &ctx->va_context);

> > > +        if (vas != VA_STATUS_SUCCESS) {

> > > +            av_log(avctx, AV_LOG_ERROR, "Failed to create decode "

> > > +                   "context: %d (%s).\n", vas, vaErrorStr(vas));

> > > +            err = AVERROR(EIO);

> > > +            goto fail;

> > > +        }

> > >

> > > -    av_log(avctx, AV_LOG_DEBUG, "Decode context initialised: "

> > > -           "%#x/%#x.\n", ctx->va_config, ctx->va_context);

> > > +        av_log(avctx, AV_LOG_DEBUG, "Decode context initialised: "

> > > +               "%#x/%#x.\n", ctx->va_config, ctx->va_context);

> > > +    }

> >

> > If I'm reading this correctly, this changes to only creating one context ever

> > even when the resolution changes.

> >

> > How can that work if the resolution increases?  For example you start

> > decoding at 1280x720 and create a context for that, then the resolution

> > changes to 3840x2160 and it tries to decode using the 1280x720 context.

> >

> Recreating hw_frame_ctx can cope with this.

> Verified in one case with resolution increasing:

> Resolution changes from 495x168 -> 328 x 307 -> 395 x376, the pipeline works

> and the output image is good.

> It's not increasing on both width and height, but as long as one of them

> increases,

> current pipeline will be broken ff we don’t reinit the context(or just don't

> recreate

> hw_frame_ctx).

> (also did experiment as a contrast that we use the same context without

> recreate

> hw_frame_ctx, the pipeline will be blocked when mapping surface in

> resolution increase)

> 

> ffmpeg -hwaccel vaapi -hwaccel_device /dev/dri/renderD128 -v verbose -

> i ./test3232.ivf

> -pix_fmt p010le -f rawvideo -vf scale=w=416:h=168 -vframes 10 -y md5.yuv

> 

> log is attached.


Update the log, sorry for the inconvenience.

- Linjie
Yan Wang July 8, 2019, 6:45 a.m.
On 7/7/2019 9:49 PM, Fu, Linjie wrote:
>> -----Original Message-----
>> From: ffmpeg-devel [mailto:ffmpeg-devel-bounces@ffmpeg.org] On Behalf
>> Of Mark Thompson
>> Sent: Sunday, July 7, 2019 19:51
>> To: ffmpeg-devel@ffmpeg.org
>> Subject: Re: [FFmpeg-devel] [PATCH 2/2] lavc/vaapi_decode: recreate
>> hw_frames_ctx without destroy va_context
>>
>> On 07/07/2019 17:38, Linjie Fu wrote:
>>> VP9 allows resolution changes per frame. Currently in VAAPI, resolution
>>> changes leads to va context destroy and reinit.
>> Which is correct - it needs to remake the context because the old one is for
>> the wrong resolution.
> It seems that we don't need to remake context, remaking the surface is enough
> for resolution changing.
> Currently in libva, surface is able to be recreated separately without remaking context.
> And this way is used in libyami to cope with resolution changing cases.
>
>>>                                                  This will cause
>>> reference frame surface lost and produce garbage.
>> This isn't right - the reference frame surfaces aren't lost.  See
>> VP9Context.s.refs[], which holds references to the frames (including their
>> hardware frame contexts) until the stream indicates that they can be
>> discarded by overwriting their reference frame slots.
> I'm not quite sure about this, at least the result shows they are not used correctly
> in current way.
> Will look deeper into it.

In vaapi_vp9_start_frame() of libavcodec/vaapi_vp9.c, it only passes 
VASurfaceID into pic_param.reference_frames[i].

But when destroy va_context, the surface/render target based on this 
VASurfaceID has been destroyed.

So the new va_context cannot find the corresponding surface based on 
this surface ID.

IMHO, one possible solution is to create one the VA surfaces including 
VP9Context.s.refs[] data which is AVFrame in fact and pass them into 
libva when re-creating new va_context.

Thanks.

Yan Wang

>
>>> As libva allows re-create surface separately without changing the
>>> context, this issue could be handled by only recreating hw_frames_ctx.
>>>
>>> Could be verified by:
>>> ffmpeg -hwaccel vaapi -hwaccel_device /dev/dri/renderD128 -i
>>> ./resolutions.ivf
>>> -pix_fmt p010le -f rawvideo -vframes 20 -y vaapi.yuv
>>>
>>> Signed-off-by: Linjie Fu <linjie.fu@intel.com>
>>> ---
>>>   libavcodec/decode.c       |  8 ++++----
>>>   libavcodec/vaapi_decode.c | 40 ++++++++++++++++++++++----------------
>> --
>>>   2 files changed, 26 insertions(+), 22 deletions(-)
>>>
>>> diff --git a/libavcodec/decode.c b/libavcodec/decode.c
>>> index 0863b82..a81b857 100644
>>> --- a/libavcodec/decode.c
>>> +++ b/libavcodec/decode.c
>>> @@ -1254,7 +1254,6 @@ int
>> ff_decode_get_hw_frames_ctx(AVCodecContext *avctx,
>>>       frames_ctx = (AVHWFramesContext*)avctx->hw_frames_ctx->data;
>>>
>>> -
>>>       if (frames_ctx->initial_pool_size) {
>>>           // We guarantee 4 base work surfaces. The function above guarantees
>> 1
>>>           // (the absolute minimum), so add the missing count.
>>> @@ -1333,7 +1332,7 @@ static int hwaccel_init(AVCodecContext *avctx,
>>>           return AVERROR_PATCHWELCOME;
>>>       }
>>>
>>> -    if (hwaccel->priv_data_size) {
>>> +    if (hwaccel->priv_data_size && !avctx->internal->hwaccel_priv_data) {
>>>           avctx->internal->hwaccel_priv_data =
>>>               av_mallocz(hwaccel->priv_data_size);
>>>           if (!avctx->internal->hwaccel_priv_data)
>>> @@ -1397,8 +1396,9 @@ int ff_get_format(AVCodecContext *avctx, const
>> enum AVPixelFormat *fmt)
>>>       for (;;) {
>>>           // Remove the previous hwaccel, if there was one.
>>> -        hwaccel_uninit(avctx);
>>> -
>>> +        // VAAPI allows reinit hw_frames_ctx only
>>> +        if (choices[0] != AV_PIX_FMT_VAAPI_VLD)
>> Including codec-specific conditions in the generic code suggests that
>> something very shady is going on.
> Yes, will try to avoid this.
>
>>> +            hwaccel_uninit(avctx);>          user_choice = avctx-
>>> get_format(avctx, choices);
>>>           if (user_choice == AV_PIX_FMT_NONE) {
>>>               // Explicitly chose nothing, give up.
>>> diff --git a/libavcodec/vaapi_decode.c b/libavcodec/vaapi_decode.c
>>> index 69512e1..13f0cf0 100644
>>> --- a/libavcodec/vaapi_decode.c
>>> +++ b/libavcodec/vaapi_decode.c
>>> @@ -613,8 +613,10 @@ int ff_vaapi_decode_init(AVCodecContext *avctx)
>>>       VAStatus vas;
>>>       int err;
>>>
>>> -    ctx->va_config  = VA_INVALID_ID;
>>> -    ctx->va_context = VA_INVALID_ID;
>>> +    if (!ctx->va_config && !ctx->va_context){
>>> +        ctx->va_config  = VA_INVALID_ID;
>>> +        ctx->va_context = VA_INVALID_ID;
>>> +    }
>>>
>>>   #if FF_API_STRUCT_VAAPI_CONTEXT
>>>       if (avctx->hwaccel_context) {
>>> @@ -642,7 +644,6 @@ int ff_vaapi_decode_init(AVCodecContext *avctx)
>>>           // present, so set it here to avoid the behaviour changing.
>>>           ctx->hwctx->driver_quirks =
>>>               AV_VAAPI_DRIVER_QUIRK_RENDER_PARAM_BUFFERS;
>>> -
>>>       }
>>>   #endif
>>>
>>> @@ -655,7 +656,8 @@ int ff_vaapi_decode_init(AVCodecContext *avctx)
>>>                  "context: %#x/%#x.\n", ctx->va_config, ctx->va_context);
>>>       } else {
>>>   #endif
>>> -
>>> +    // Get a new hw_frames_ctx even if there is already one
>>> +    // recreate surface without reconstuct va_context
>>>       err = ff_decode_get_hw_frames_ctx(avctx,
>> AV_HWDEVICE_TYPE_VAAPI);
>>>       if (err < 0)
>>>           goto fail;
>>> @@ -670,21 +672,23 @@ int ff_vaapi_decode_init(AVCodecContext *avctx)
>>>       if (err)
>>>           goto fail;
>>>
>>> -    vas = vaCreateContext(ctx->hwctx->display, ctx->va_config,
>>> -                          avctx->coded_width, avctx->coded_height,
>>> -                          VA_PROGRESSIVE,
>>> -                          ctx->hwfc->surface_ids,
>>> -                          ctx->hwfc->nb_surfaces,
>>> -                          &ctx->va_context);
>>> -    if (vas != VA_STATUS_SUCCESS) {
>>> -        av_log(avctx, AV_LOG_ERROR, "Failed to create decode "
>>> -               "context: %d (%s).\n", vas, vaErrorStr(vas));
>>> -        err = AVERROR(EIO);
>>> -        goto fail;
>>> -    }
>>> +    if (ctx->va_context == VA_INVALID_ID) {
>>> +        vas = vaCreateContext(ctx->hwctx->display, ctx->va_config,
>>> +                              avctx->coded_width, avctx->coded_height,
>>> +                              VA_PROGRESSIVE,
>>> +                              ctx->hwfc->surface_ids,
>>> +                              ctx->hwfc->nb_surfaces,
>>> +                              &ctx->va_context);
>>> +        if (vas != VA_STATUS_SUCCESS) {
>>> +            av_log(avctx, AV_LOG_ERROR, "Failed to create decode "
>>> +                   "context: %d (%s).\n", vas, vaErrorStr(vas));
>>> +            err = AVERROR(EIO);
>>> +            goto fail;
>>> +        }
>>>
>>> -    av_log(avctx, AV_LOG_DEBUG, "Decode context initialised: "
>>> -           "%#x/%#x.\n", ctx->va_config, ctx->va_context);
>>> +        av_log(avctx, AV_LOG_DEBUG, "Decode context initialised: "
>>> +               "%#x/%#x.\n", ctx->va_config, ctx->va_context);
>>> +    }
>> If I'm reading this correctly, this changes to only creating one context ever
>> even when the resolution changes.
>>
>> How can that work if the resolution increases?  For example you start
>> decoding at 1280x720 and create a context for that, then the resolution
>> changes to 3840x2160 and it tries to decode using the 1280x720 context.
>>
> Recreating hw_frame_ctx can cope with this.
> Verified in one case with resolution increasing:
> Resolution changes from 495x168 -> 328 x 307 -> 395 x376, the pipeline works
> and the output image is good.

As my understanding, you decoding output should be 495x168 always for 
every frame. Right?

When the resolution of the decoded frame is different with the first 
frame, the scaling is fired.

The scaling should come from media driver VP pipeline because ffmpeg use 
vaGetImage() to get decoded frame.

This is dependent on ffmpeg requirement. If ffmpeg hopes to get original 
decoded frame, this behavior should be changed.

Thanks.

Yan Wang

> It's not increasing on both width and height, but as long as one of them increases,
> current pipeline will be broken ff we don’t reinit the context(or just don't recreate
> hw_frame_ctx).
> (also did experiment as a contrast that we use the same context without recreate
> hw_frame_ctx, the pipeline will be blocked when mapping surface in resolution increase)
>
> ffmpeg -hwaccel vaapi -hwaccel_device /dev/dri/renderD128 -v verbose -i ./test3232.ivf
> -pix_fmt p010le -f rawvideo -vf scale=w=416:h=168 -vframes 10 -y md5.yuv
>
> log is attached.
>
> Thanks.
>
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel@ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
Yan Wang July 8, 2019, 7:54 a.m.
On 7/8/2019 2:45 PM, Yan Wang wrote:
>
> On 7/7/2019 9:49 PM, Fu, Linjie wrote:
>>> -----Original Message-----
>>> From: ffmpeg-devel [mailto:ffmpeg-devel-bounces@ffmpeg.org] On Behalf
>>> Of Mark Thompson
>>> Sent: Sunday, July 7, 2019 19:51
>>> To: ffmpeg-devel@ffmpeg.org
>>> Subject: Re: [FFmpeg-devel] [PATCH 2/2] lavc/vaapi_decode: recreate
>>> hw_frames_ctx without destroy va_context
>>>
>>> On 07/07/2019 17:38, Linjie Fu wrote:
>>>> VP9 allows resolution changes per frame. Currently in VAAPI, 
>>>> resolution
>>>> changes leads to va context destroy and reinit.
>>> Which is correct - it needs to remake the context because the old 
>>> one is for
>>> the wrong resolution.
>> It seems that we don't need to remake context, remaking the surface 
>> is enough
>> for resolution changing.
>> Currently in libva, surface is able to be recreated separately 
>> without remaking context.
>> And this way is used in libyami to cope with resolution changing cases.
>>
>>>> This will cause
>>>> reference frame surface lost and produce garbage.
>>> This isn't right - the reference frame surfaces aren't lost. See
>>> VP9Context.s.refs[], which holds references to the frames (including 
>>> their
>>> hardware frame contexts) until the stream indicates that they can be
>>> discarded by overwriting their reference frame slots.
>> I'm not quite sure about this, at least the result shows they are not 
>> used correctly
>> in current way.
>> Will look deeper into it.
>
> In vaapi_vp9_start_frame() of libavcodec/vaapi_vp9.c, it only passes 
> VASurfaceID into pic_param.reference_frames[i].
>
> But when destroy va_context, the surface/render target based on this 
> VASurfaceID has been destroyed.

Update: the surface isn't destroyed when destroy va_context. But every 
va_context maintains one independent map table: m_ddiDecodeCtx->RTtbl.

So the new context cannot find this surface in its map table.

My previous suggested solution should be available still.

Thanks.

Yan Wang

>
> So the new va_context cannot find the corresponding surface based on 
> this surface ID.
>
> IMHO, one possible solution is to create one the VA surfaces including 
> VP9Context.s.refs[] data which is AVFrame in fact and pass them into 
> libva when re-creating new va_context.
>
> Thanks.
>
> Yan Wang
>
>>
>>>> As libva allows re-create surface separately without changing the
>>>> context, this issue could be handled by only recreating hw_frames_ctx.
>>>>
>>>> Could be verified by:
>>>> ffmpeg -hwaccel vaapi -hwaccel_device /dev/dri/renderD128 -i
>>>> ./resolutions.ivf
>>>> -pix_fmt p010le -f rawvideo -vframes 20 -y vaapi.yuv
>>>>
>>>> Signed-off-by: Linjie Fu <linjie.fu@intel.com>
>>>> ---
>>>>   libavcodec/decode.c       |  8 ++++----
>>>>   libavcodec/vaapi_decode.c | 40 
>>>> ++++++++++++++++++++++----------------
>>> -- 
>>>>   2 files changed, 26 insertions(+), 22 deletions(-)
>>>>
>>>> diff --git a/libavcodec/decode.c b/libavcodec/decode.c
>>>> index 0863b82..a81b857 100644
>>>> --- a/libavcodec/decode.c
>>>> +++ b/libavcodec/decode.c
>>>> @@ -1254,7 +1254,6 @@ int
>>> ff_decode_get_hw_frames_ctx(AVCodecContext *avctx,
>>>>       frames_ctx = (AVHWFramesContext*)avctx->hw_frames_ctx->data;
>>>>
>>>> -
>>>>       if (frames_ctx->initial_pool_size) {
>>>>           // We guarantee 4 base work surfaces. The function above 
>>>> guarantees
>>> 1
>>>>           // (the absolute minimum), so add the missing count.
>>>> @@ -1333,7 +1332,7 @@ static int hwaccel_init(AVCodecContext *avctx,
>>>>           return AVERROR_PATCHWELCOME;
>>>>       }
>>>>
>>>> -    if (hwaccel->priv_data_size) {
>>>> +    if (hwaccel->priv_data_size && 
>>>> !avctx->internal->hwaccel_priv_data) {
>>>>           avctx->internal->hwaccel_priv_data =
>>>>               av_mallocz(hwaccel->priv_data_size);
>>>>           if (!avctx->internal->hwaccel_priv_data)
>>>> @@ -1397,8 +1396,9 @@ int ff_get_format(AVCodecContext *avctx, const
>>> enum AVPixelFormat *fmt)
>>>>       for (;;) {
>>>>           // Remove the previous hwaccel, if there was one.
>>>> -        hwaccel_uninit(avctx);
>>>> -
>>>> +        // VAAPI allows reinit hw_frames_ctx only
>>>> +        if (choices[0] != AV_PIX_FMT_VAAPI_VLD)
>>> Including codec-specific conditions in the generic code suggests that
>>> something very shady is going on.
>> Yes, will try to avoid this.
>>
>>>> + hwaccel_uninit(avctx);>          user_choice = avctx-
>>>> get_format(avctx, choices);
>>>>           if (user_choice == AV_PIX_FMT_NONE) {
>>>>               // Explicitly chose nothing, give up.
>>>> diff --git a/libavcodec/vaapi_decode.c b/libavcodec/vaapi_decode.c
>>>> index 69512e1..13f0cf0 100644
>>>> --- a/libavcodec/vaapi_decode.c
>>>> +++ b/libavcodec/vaapi_decode.c
>>>> @@ -613,8 +613,10 @@ int ff_vaapi_decode_init(AVCodecContext *avctx)
>>>>       VAStatus vas;
>>>>       int err;
>>>>
>>>> -    ctx->va_config  = VA_INVALID_ID;
>>>> -    ctx->va_context = VA_INVALID_ID;
>>>> +    if (!ctx->va_config && !ctx->va_context){
>>>> +        ctx->va_config  = VA_INVALID_ID;
>>>> +        ctx->va_context = VA_INVALID_ID;
>>>> +    }
>>>>
>>>>   #if FF_API_STRUCT_VAAPI_CONTEXT
>>>>       if (avctx->hwaccel_context) {
>>>> @@ -642,7 +644,6 @@ int ff_vaapi_decode_init(AVCodecContext *avctx)
>>>>           // present, so set it here to avoid the behaviour changing.
>>>>           ctx->hwctx->driver_quirks =
>>>>               AV_VAAPI_DRIVER_QUIRK_RENDER_PARAM_BUFFERS;
>>>> -
>>>>       }
>>>>   #endif
>>>>
>>>> @@ -655,7 +656,8 @@ int ff_vaapi_decode_init(AVCodecContext *avctx)
>>>>                  "context: %#x/%#x.\n", ctx->va_config, 
>>>> ctx->va_context);
>>>>       } else {
>>>>   #endif
>>>> -
>>>> +    // Get a new hw_frames_ctx even if there is already one
>>>> +    // recreate surface without reconstuct va_context
>>>>       err = ff_decode_get_hw_frames_ctx(avctx,
>>> AV_HWDEVICE_TYPE_VAAPI);
>>>>       if (err < 0)
>>>>           goto fail;
>>>> @@ -670,21 +672,23 @@ int ff_vaapi_decode_init(AVCodecContext *avctx)
>>>>       if (err)
>>>>           goto fail;
>>>>
>>>> -    vas = vaCreateContext(ctx->hwctx->display, ctx->va_config,
>>>> -                          avctx->coded_width, avctx->coded_height,
>>>> -                          VA_PROGRESSIVE,
>>>> -                          ctx->hwfc->surface_ids,
>>>> -                          ctx->hwfc->nb_surfaces,
>>>> -                          &ctx->va_context);
>>>> -    if (vas != VA_STATUS_SUCCESS) {
>>>> -        av_log(avctx, AV_LOG_ERROR, "Failed to create decode "
>>>> -               "context: %d (%s).\n", vas, vaErrorStr(vas));
>>>> -        err = AVERROR(EIO);
>>>> -        goto fail;
>>>> -    }
>>>> +    if (ctx->va_context == VA_INVALID_ID) {
>>>> +        vas = vaCreateContext(ctx->hwctx->display, ctx->va_config,
>>>> +                              avctx->coded_width, 
>>>> avctx->coded_height,
>>>> +                              VA_PROGRESSIVE,
>>>> +                              ctx->hwfc->surface_ids,
>>>> +                              ctx->hwfc->nb_surfaces,
>>>> +                              &ctx->va_context);
>>>> +        if (vas != VA_STATUS_SUCCESS) {
>>>> +            av_log(avctx, AV_LOG_ERROR, "Failed to create decode "
>>>> +                   "context: %d (%s).\n", vas, vaErrorStr(vas));
>>>> +            err = AVERROR(EIO);
>>>> +            goto fail;
>>>> +        }
>>>>
>>>> -    av_log(avctx, AV_LOG_DEBUG, "Decode context initialised: "
>>>> -           "%#x/%#x.\n", ctx->va_config, ctx->va_context);
>>>> +        av_log(avctx, AV_LOG_DEBUG, "Decode context initialised: "
>>>> +               "%#x/%#x.\n", ctx->va_config, ctx->va_context);
>>>> +    }
>>> If I'm reading this correctly, this changes to only creating one 
>>> context ever
>>> even when the resolution changes.
>>>
>>> How can that work if the resolution increases?  For example you start
>>> decoding at 1280x720 and create a context for that, then the resolution
>>> changes to 3840x2160 and it tries to decode using the 1280x720 context.
>>>
>> Recreating hw_frame_ctx can cope with this.
>> Verified in one case with resolution increasing:
>> Resolution changes from 495x168 -> 328 x 307 -> 395 x376, the 
>> pipeline works
>> and the output image is good.
>
> As my understanding, you decoding output should be 495x168 always for 
> every frame. Right?
>
> When the resolution of the decoded frame is different with the first 
> frame, the scaling is fired.
>
> The scaling should come from media driver VP pipeline because ffmpeg 
> use vaGetImage() to get decoded frame.
>
> This is dependent on ffmpeg requirement. If ffmpeg hopes to get 
> original decoded frame, this behavior should be changed.
>
> Thanks.
>
> Yan Wang
>
>> It's not increasing on both width and height, but as long as one of 
>> them increases,
>> current pipeline will be broken ff we don’t reinit the context(or 
>> just don't recreate
>> hw_frame_ctx).
>> (also did experiment as a contrast that we use the same context 
>> without recreate
>> hw_frame_ctx, the pipeline will be blocked when mapping surface in 
>> resolution increase)
>>
>> ffmpeg -hwaccel vaapi -hwaccel_device /dev/dri/renderD128 -v verbose 
>> -i ./test3232.ivf
>> -pix_fmt p010le -f rawvideo -vf scale=w=416:h=168 -vframes 10 -y md5.yuv
>>
>> log is attached.
>>
>> Thanks.
>>
>> _______________________________________________
>> ffmpeg-devel mailing list
>> ffmpeg-devel@ffmpeg.org
>> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>>
>> To unsubscribe, visit link above, or email
>> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel@ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
Linjie Fu July 8, 2019, 8:10 a.m.
> -----Original Message-----

> From: ffmpeg-devel [mailto:ffmpeg-devel-bounces@ffmpeg.org] On Behalf

> Of Yan Wang

> Sent: Monday, July 8, 2019 15:54

> To: ffmpeg-devel@ffmpeg.org

> Subject: Re: [FFmpeg-devel] [PATCH 2/2] lavc/vaapi_decode: recreate

> hw_frames_ctx without destroy va_context

> 

> 

> On 7/8/2019 2:45 PM, Yan Wang wrote:

> >

> > On 7/7/2019 9:49 PM, Fu, Linjie wrote:

> >>> -----Original Message-----

> >>> From: ffmpeg-devel [mailto:ffmpeg-devel-bounces@ffmpeg.org] On

> Behalf

> >>> Of Mark Thompson

> >>> Sent: Sunday, July 7, 2019 19:51

> >>> To: ffmpeg-devel@ffmpeg.org

> >>> Subject: Re: [FFmpeg-devel] [PATCH 2/2] lavc/vaapi_decode: recreate

> >>> hw_frames_ctx without destroy va_context

> >>>

> >>> On 07/07/2019 17:38, Linjie Fu wrote:

> >>>> VP9 allows resolution changes per frame. Currently in VAAPI,

> >>>> resolution

> >>>> changes leads to va context destroy and reinit.

> >>> Which is correct - it needs to remake the context because the old

> >>> one is for

> >>> the wrong resolution.

> >> It seems that we don't need to remake context, remaking the surface

> >> is enough

> >> for resolution changing.

> >> Currently in libva, surface is able to be recreated separately

> >> without remaking context.

> >> And this way is used in libyami to cope with resolution changing cases.

> >>

> >>>> This will cause

> >>>> reference frame surface lost and produce garbage.

> >>> This isn't right - the reference frame surfaces aren't lost. See

> >>> VP9Context.s.refs[], which holds references to the frames (including

> >>> their

> >>> hardware frame contexts) until the stream indicates that they can be

> >>> discarded by overwriting their reference frame slots.

> >> I'm not quite sure about this, at least the result shows they are not

> >> used correctly

> >> in current way.

> >> Will look deeper into it.

> >

> > In vaapi_vp9_start_frame() of libavcodec/vaapi_vp9.c, it only passes

> > VASurfaceID into pic_param.reference_frames[i].

> >

> > But when destroy va_context, the surface/render target based on this

> > VASurfaceID has been destroyed.

> 

> Update: the surface isn't destroyed when destroy va_context. But every

> va_context maintains one independent map table: m_ddiDecodeCtx->RTtbl.

> 

> So the new context cannot find this surface in its map table.

> 

> My previous suggested solution should be available still.

>


Yes, tracing the code and could find that:

1.  surface is not destroyed until the decode finishes and calls avcodec_close;
2. refs[i] is passed to driver, however in DdiMediaBase::GetRenderTargetID, driver failed to
find the expected surface in the re-created m_ddiDecodeCtx->RTtbl, and returns invalid.
		if(rtTbl->pRT[i] == surface) {
			return i;
		}
 		return DDI_CODEC_INVALID_FRAME_INDEX;

One possible way is to register the refs[] surfaces in the new created context ->RTtbl and make it
findable.

Thanks for reviews and all comments.
linjie
Linjie Fu July 11, 2019, 7:32 a.m.
> -----Original Message-----

> From: ffmpeg-devel [mailto:ffmpeg-devel-bounces@ffmpeg.org] On Behalf

> Of Fu, Linjie

> Sent: Monday, July 8, 2019 16:11

> To: FFmpeg development discussions and patches <ffmpeg-

> devel@ffmpeg.org>

> Subject: Re: [FFmpeg-devel] [PATCH 2/2] lavc/vaapi_decode: recreate

> hw_frames_ctx without destroy va_context

> 

> > -----Original Message-----

> > From: ffmpeg-devel [mailto:ffmpeg-devel-bounces@ffmpeg.org] On

> Behalf

> > Of Yan Wang

> > Sent: Monday, July 8, 2019 15:54

> > To: ffmpeg-devel@ffmpeg.org

> > Subject: Re: [FFmpeg-devel] [PATCH 2/2] lavc/vaapi_decode: recreate

> > hw_frames_ctx without destroy va_context

> >

> >

> > On 7/8/2019 2:45 PM, Yan Wang wrote:

> > >

> > > On 7/7/2019 9:49 PM, Fu, Linjie wrote:

> > >>> -----Original Message-----

> > >>> From: ffmpeg-devel [mailto:ffmpeg-devel-bounces@ffmpeg.org] On

> > Behalf

> > >>> Of Mark Thompson

> > >>> Sent: Sunday, July 7, 2019 19:51

> > >>> To: ffmpeg-devel@ffmpeg.org

> > >>> Subject: Re: [FFmpeg-devel] [PATCH 2/2] lavc/vaapi_decode: recreate

> > >>> hw_frames_ctx without destroy va_context

> > >>>

> > >>> On 07/07/2019 17:38, Linjie Fu wrote:

> > >>>> VP9 allows resolution changes per frame. Currently in VAAPI,

> > >>>> resolution

> > >>>> changes leads to va context destroy and reinit.

> > >>> Which is correct - it needs to remake the context because the old

> > >>> one is for

> > >>> the wrong resolution.

> > >> It seems that we don't need to remake context, remaking the surface

> > >> is enough

> > >> for resolution changing.

> > >> Currently in libva, surface is able to be recreated separately

> > >> without remaking context.

> > >> And this way is used in libyami to cope with resolution changing cases.

> > >>

> > >>>> This will cause

> > >>>> reference frame surface lost and produce garbage.

> > >>> This isn't right - the reference frame surfaces aren't lost. See

> > >>> VP9Context.s.refs[], which holds references to the frames (including

> > >>> their

> > >>> hardware frame contexts) until the stream indicates that they can be

> > >>> discarded by overwriting their reference frame slots.

> > >> I'm not quite sure about this, at least the result shows they are not

> > >> used correctly

> > >> in current way.

> > >> Will look deeper into it.

> > >

> > > In vaapi_vp9_start_frame() of libavcodec/vaapi_vp9.c, it only passes

> > > VASurfaceID into pic_param.reference_frames[i].

> > >

> > > But when destroy va_context, the surface/render target based on this

> > > VASurfaceID has been destroyed.

> >

> > Update: the surface isn't destroyed when destroy va_context. But every

> > va_context maintains one independent map table: m_ddiDecodeCtx-

> >RTtbl.

> >

> > So the new context cannot find this surface in its map table.

> >

> > My previous suggested solution should be available still.

> >

> 

> Yes, tracing the code and could find that:

> 

> 1.  surface is not destroyed until the decode finishes and calls avcodec_close;

> 2. refs[i] is passed to driver, however in DdiMediaBase::GetRenderTargetID,

> driver failed to

> find the expected surface in the re-created m_ddiDecodeCtx->RTtbl, and

> returns invalid.

> 		if(rtTbl->pRT[i] == surface) {

> 			return i;

> 		}

>  		return DDI_CODEC_INVALID_FRAME_INDEX;

> 

> One possible way is to register the refs[] surfaces in the new created context

> ->RTtbl and make it

> findable.


Attempt  to register refs[] surface when re-creating context, and observed that refs[] surface
has been registered into RTtbl and is able to accessed in driver.
https://github.com/fulinjie/ffmpeg/commit/9ed1a309786d2e395753ed327b511e6d9779986f

However, the decode still failed to get the correct image.

Working together with  Wang Yan to investigate more in driver.

And Yan found iHD driver will maintain some internal variables and reference link list
(CodeclhalDecodeVp9::m_vp9RefList) in Codec HAL layer which will be destroyed
when destroy VAAPI context.

CodechalDecodeVp9:SetFrameStates() will set resRefPic/dwFrameWidth/dwFrameHeight
of CodeclhalDecodeVp9::m_vp9RefList. And CodechalDecodeVp9::~ CodechalDecodeVp9()
will destroy it when VAAPI context is destroyed. So the new VAAPI context will only include
an empty CodeclhalDecodeVp9::m_vp9RefList.

It seems that passing surface ids to driver when recreate context could not fix the dynamic
resolution changing issue simply.

Refined a new patch to be less hacky.
And it fixes more than 1000 dynamic resolution changing cases during my test.

It's obvious that currently context in driver is not designed for remap internal variable
from previous context. 
If driver could not cope with this easily, I think we may make it more robust in ffmpeg vaapi vp9.

- linjie

Patch hide | download patch | download mbox

diff --git a/libavcodec/decode.c b/libavcodec/decode.c
index 0863b82..a81b857 100644
--- a/libavcodec/decode.c
+++ b/libavcodec/decode.c
@@ -1254,7 +1254,6 @@  int ff_decode_get_hw_frames_ctx(AVCodecContext *avctx,
 
     frames_ctx = (AVHWFramesContext*)avctx->hw_frames_ctx->data;
 
-
     if (frames_ctx->initial_pool_size) {
         // We guarantee 4 base work surfaces. The function above guarantees 1
         // (the absolute minimum), so add the missing count.
@@ -1333,7 +1332,7 @@  static int hwaccel_init(AVCodecContext *avctx,
         return AVERROR_PATCHWELCOME;
     }
 
-    if (hwaccel->priv_data_size) {
+    if (hwaccel->priv_data_size && !avctx->internal->hwaccel_priv_data) {
         avctx->internal->hwaccel_priv_data =
             av_mallocz(hwaccel->priv_data_size);
         if (!avctx->internal->hwaccel_priv_data)
@@ -1397,8 +1396,9 @@  int ff_get_format(AVCodecContext *avctx, const enum AVPixelFormat *fmt)
 
     for (;;) {
         // Remove the previous hwaccel, if there was one.
-        hwaccel_uninit(avctx);
-
+        // VAAPI allows reinit hw_frames_ctx only
+        if (choices[0] != AV_PIX_FMT_VAAPI_VLD)
+            hwaccel_uninit(avctx);
         user_choice = avctx->get_format(avctx, choices);
         if (user_choice == AV_PIX_FMT_NONE) {
             // Explicitly chose nothing, give up.
diff --git a/libavcodec/vaapi_decode.c b/libavcodec/vaapi_decode.c
index 69512e1..13f0cf0 100644
--- a/libavcodec/vaapi_decode.c
+++ b/libavcodec/vaapi_decode.c
@@ -613,8 +613,10 @@  int ff_vaapi_decode_init(AVCodecContext *avctx)
     VAStatus vas;
     int err;
 
-    ctx->va_config  = VA_INVALID_ID;
-    ctx->va_context = VA_INVALID_ID;
+    if (!ctx->va_config && !ctx->va_context){
+        ctx->va_config  = VA_INVALID_ID;
+        ctx->va_context = VA_INVALID_ID;
+    }
 
 #if FF_API_STRUCT_VAAPI_CONTEXT
     if (avctx->hwaccel_context) {
@@ -642,7 +644,6 @@  int ff_vaapi_decode_init(AVCodecContext *avctx)
         // present, so set it here to avoid the behaviour changing.
         ctx->hwctx->driver_quirks =
             AV_VAAPI_DRIVER_QUIRK_RENDER_PARAM_BUFFERS;
-
     }
 #endif
 
@@ -655,7 +656,8 @@  int ff_vaapi_decode_init(AVCodecContext *avctx)
                "context: %#x/%#x.\n", ctx->va_config, ctx->va_context);
     } else {
 #endif
-
+    // Get a new hw_frames_ctx even if there is already one
+    // recreate surface without reconstuct va_context
     err = ff_decode_get_hw_frames_ctx(avctx, AV_HWDEVICE_TYPE_VAAPI);
     if (err < 0)
         goto fail;
@@ -670,21 +672,23 @@  int ff_vaapi_decode_init(AVCodecContext *avctx)
     if (err)
         goto fail;
 
-    vas = vaCreateContext(ctx->hwctx->display, ctx->va_config,
-                          avctx->coded_width, avctx->coded_height,
-                          VA_PROGRESSIVE,
-                          ctx->hwfc->surface_ids,
-                          ctx->hwfc->nb_surfaces,
-                          &ctx->va_context);
-    if (vas != VA_STATUS_SUCCESS) {
-        av_log(avctx, AV_LOG_ERROR, "Failed to create decode "
-               "context: %d (%s).\n", vas, vaErrorStr(vas));
-        err = AVERROR(EIO);
-        goto fail;
-    }
+    if (ctx->va_context == VA_INVALID_ID) {
+        vas = vaCreateContext(ctx->hwctx->display, ctx->va_config,
+                              avctx->coded_width, avctx->coded_height,
+                              VA_PROGRESSIVE,
+                              ctx->hwfc->surface_ids,
+                              ctx->hwfc->nb_surfaces,
+                              &ctx->va_context);
+        if (vas != VA_STATUS_SUCCESS) {
+            av_log(avctx, AV_LOG_ERROR, "Failed to create decode "
+                   "context: %d (%s).\n", vas, vaErrorStr(vas));
+            err = AVERROR(EIO);
+            goto fail;
+        }
 
-    av_log(avctx, AV_LOG_DEBUG, "Decode context initialised: "
-           "%#x/%#x.\n", ctx->va_config, ctx->va_context);
+        av_log(avctx, AV_LOG_DEBUG, "Decode context initialised: "
+               "%#x/%#x.\n", ctx->va_config, ctx->va_context);
+    }
 #if FF_API_STRUCT_VAAPI_CONTEXT
     }
 #endif