[Libva] [PATCH v4 intel-driver 11/11] decoder: h264: fix frame store logic for MVC.

Gwenole Beauchesne gb.devel at gmail.com
Fri Jun 6 01:02:04 PDT 2014


2014-06-06 9:59 GMT+02:00 Gwenole Beauchesne <gb.devel at gmail.com>:
> Hi,
>
> 2014-06-06 8:27 GMT+02:00 Zhao, Yakui <yakui.zhao at intel.com>:
>> On Thu, 2014-06-05 at 17:46 -0600, Gwenole Beauchesne wrote:
>>> In strict MVC decoding mode, when only the necessary set of inter-view
>>> reference pictures are passed to the ReferenceFrames array for decoding
>>> the current picture, we should not re-use a frame store id that might
>>> be needed for decoding another view component in the same access unit.
>>>
>>> One way to solve this problem is to track when the VA surface in a
>>> specified frame store id was last referenced. So, a "ref_poc" (RefPOC)
>>> field is introduced to the GenFrameStore struct and is updated whenever
>>> the surface is being referenced.
>>>
>>
>> The purpose of this patch is to sort the retired free slots so that it
>> can defer the usage of reference picture later used to hold another new
>> reference picture in DPB although it is not used when decoding current
>> frame.
>>
>> But I don't think that the POC delta is good way to sort the retired
>> free_slot.
>
> Agreed, my initial intention behind the GenFrameStoreContext was to
> store a serial id in it, and use it incrementally (on POC change). But
> using the POC could still be fine. We are only interested in relative
> difference in this algorithm.
>
>>> Additionally, the list of retired refs candidates (free_refs) is kept
>>> ordered by increasing RefPOC. That way, we can immediately know what
>>> is the oldest frame store id to recycle.
>>>
>>> Let dPOC = |RefPOC - CurrPOC|
>>
>> Why not uses the concept of POC difference in H264 spec?
>>
>>> If dPOC > 1, we know for sure that the VA surface is gone ;
>>
>> Why do you mean that the VA surface is gone when the dPOC > 1 ? Is it
>> from the spec?
>
> No, it's from my algorithm. :)
> I think I will go back to the initial GenFrameSoreContext struct as
> otherwise, the Frame Store logic data is going to be spread over
> various data structures. Here, for instance, if I want to use a
> serial, I'd need to add it in the decode_state. Though, that approach
> would have the benefit to pre-initialize less data for each
> generation, since it would be fine to have the "age" (s/ref_poc/age
> BTW) starting off zero, which is the case when the decode_state is
> calloc()'ed.
>
> So, that second option would be a better interim solution. I will test
> this right now.

BTW, I mean age, but that's just a name that could be anything you
would prefer (DTS, etc.).

>
> Regards,
> Gwenole.
>
>> BTW: For one I P B B sequence, the corresponding POC can also be "0, 12,
>> 4, 8" based on the spec.
>>
>>
>>> If dPOC = 1, the surface could be re-used for inter prediction ;
>>> If dPOC = 0, the surface could be re-used for inter-view prediction.
>>>
>>> In practice, we are only interested in keeping the relative order.
>>> The exact difference is not maintained due to possible wrap arounds
>>> that would complicate the algorithm for no benefit.
>>>
>>> Signed-off-by: Gwenole Beauchesne <gwenole.beauchesne at intel.com>
>>> ---
>>>  src/gen6_mfd.c           |   2 +
>>>  src/gen75_mfd.c          |   2 +
>>>  src/gen7_mfd.c           |   2 +
>>>  src/gen8_mfd.c           |   7 ++--
>>>  src/i965_avc_bsd.c       |   1 +
>>>  src/i965_decoder.h       |   1 +
>>>  src/i965_decoder_utils.c | 103 +++++++++++++++++++++++++++++++----------------
>>>  src/i965_media_h264.c    |   8 +---
>>>  src/intel_media.h        |   1 +
>>>  src/sysdeps.h            |   1 +
>>>  10 files changed, 83 insertions(+), 45 deletions(-)
>>>
>>> diff --git a/src/gen6_mfd.c b/src/gen6_mfd.c
>>> index 437ad3b..ebf13e5 100755
>>> --- a/src/gen6_mfd.c
>>> +++ b/src/gen6_mfd.c
>>> @@ -61,6 +61,7 @@ gen6_mfd_init_avc_surface(VADriverContextP ctx,
>>>
>>>      if (!gen6_avc_surface) {
>>>          gen6_avc_surface = calloc(sizeof(GenAvcSurface), 1);
>>> +        gen6_avc_surface->frame_store_id = -1;
>>>          assert((obj_surface->size & 0x3f) == 0);
>>>          obj_surface->private_data = gen6_avc_surface;
>>>      }
>>> @@ -1926,6 +1927,7 @@ gen6_dec_hw_context_init(VADriverContextP ctx, struct object_config *obj_config)
>>>          gen6_mfd_context->reference_surface[i].surface_id = VA_INVALID_ID;
>>>          gen6_mfd_context->reference_surface[i].frame_store_id = -1;
>>>          gen6_mfd_context->reference_surface[i].obj_surface = NULL;
>>> +        gen6_mfd_context->reference_surface[i].ref_poc = INT_MAX;
>>>      }
>>>
>>>      gen6_mfd_context->wa_mpeg2_slice_vertical_position = -1;
>>> diff --git a/src/gen75_mfd.c b/src/gen75_mfd.c
>>> index 67d4c51..2ebc25b 100644
>>> --- a/src/gen75_mfd.c
>>> +++ b/src/gen75_mfd.c
>>> @@ -67,6 +67,7 @@ gen75_mfd_init_avc_surface(VADriverContextP ctx,
>>>
>>>      if (!gen7_avc_surface) {
>>>          gen7_avc_surface = calloc(sizeof(GenAvcSurface), 1);
>>> +        gen7_avc_surface->frame_store_id = -1;
>>>          assert((obj_surface->size & 0x3f) == 0);
>>>          obj_surface->private_data = gen7_avc_surface;
>>>      }
>>> @@ -3233,6 +3234,7 @@ gen75_dec_hw_context_init(VADriverContextP ctx, struct object_config *obj_config
>>>          gen7_mfd_context->reference_surface[i].surface_id = VA_INVALID_ID;
>>>          gen7_mfd_context->reference_surface[i].frame_store_id = -1;
>>>          gen7_mfd_context->reference_surface[i].obj_surface = NULL;
>>> +        gen7_mfd_context->reference_surface[i].ref_poc = INT_MAX;
>>>      }
>>>
>>>      gen7_mfd_context->jpeg_wa_surface_id = VA_INVALID_SURFACE;
>>> diff --git a/src/gen7_mfd.c b/src/gen7_mfd.c
>>> index bda104e..fab83e7 100755
>>> --- a/src/gen7_mfd.c
>>> +++ b/src/gen7_mfd.c
>>> @@ -65,6 +65,7 @@ gen7_mfd_init_avc_surface(VADriverContextP ctx,
>>>
>>>      if (!gen7_avc_surface) {
>>>          gen7_avc_surface = calloc(sizeof(GenAvcSurface), 1);
>>> +        gen7_avc_surface->frame_store_id = -1;
>>>          assert((obj_surface->size & 0x3f) == 0);
>>>          obj_surface->private_data = gen7_avc_surface;
>>>      }
>>> @@ -2678,6 +2679,7 @@ gen7_dec_hw_context_init(VADriverContextP ctx, struct object_config *obj_config)
>>>          gen7_mfd_context->reference_surface[i].surface_id = VA_INVALID_ID;
>>>          gen7_mfd_context->reference_surface[i].frame_store_id = -1;
>>>          gen7_mfd_context->reference_surface[i].obj_surface = NULL;
>>> +        gen7_mfd_context->reference_surface[i].ref_poc = INT_MAX;
>>>      }
>>>
>>>      gen7_mfd_context->jpeg_wa_surface_id = VA_INVALID_SURFACE;
>>> diff --git a/src/gen8_mfd.c b/src/gen8_mfd.c
>>> index 065302d..3800fd2 100644
>>> --- a/src/gen8_mfd.c
>>> +++ b/src/gen8_mfd.c
>>> @@ -27,10 +27,7 @@
>>>   *
>>>   */
>>>
>>> -#include <stdio.h>
>>> -#include <stdlib.h>
>>> -#include <string.h>
>>> -#include <assert.h>
>>> +#include "sysdeps.h"
>>>  #include <math.h>
>>>  #include <va/va_dec_jpeg.h>
>>>  #include <va/va_dec_vp8.h>
>>> @@ -74,6 +71,7 @@ gen8_mfd_init_avc_surface(VADriverContextP ctx,
>>>
>>>      if (!gen7_avc_surface) {
>>>          gen7_avc_surface = calloc(sizeof(GenAvcSurface), 1);
>>> +        gen7_avc_surface->frame_store_id = -1;
>>>          assert((obj_surface->size & 0x3f) == 0);
>>>          obj_surface->private_data = gen7_avc_surface;
>>>      }
>>> @@ -3160,6 +3158,7 @@ gen8_dec_hw_context_init(VADriverContextP ctx, struct object_config *obj_config)
>>>      for (i = 0; i < ARRAY_ELEMS(gen7_mfd_context->reference_surface); i++) {
>>>          gen7_mfd_context->reference_surface[i].surface_id = VA_INVALID_ID;
>>>          gen7_mfd_context->reference_surface[i].frame_store_id = -1;
>>> +        gen7_mfd_context->reference_surface[i].ref_poc = INT_MAX;
>>>      }
>>>
>>>      gen7_mfd_context->jpeg_wa_surface_id = VA_INVALID_SURFACE;
>>> diff --git a/src/i965_avc_bsd.c b/src/i965_avc_bsd.c
>>> index aca3c01..09f7591 100644
>>> --- a/src/i965_avc_bsd.c
>>> +++ b/src/i965_avc_bsd.c
>>> @@ -51,6 +51,7 @@ i965_avc_bsd_init_avc_bsd_surface(VADriverContextP ctx,
>>>
>>>      if (!avc_bsd_surface) {
>>>          avc_bsd_surface = calloc(sizeof(GenAvcSurface), 1);
>>> +        avc_bsd_surface->frame_store_id = -1;
>>>          assert((obj_surface->size & 0x3f) == 0);
>>>          obj_surface->private_data = avc_bsd_surface;
>>>      }
>>> diff --git a/src/i965_decoder.h b/src/i965_decoder.h
>>> index 01c093f..c568417 100644
>>> --- a/src/i965_decoder.h
>>> +++ b/src/i965_decoder.h
>>> @@ -38,6 +38,7 @@ typedef struct gen_frame_store GenFrameStore;
>>>  struct gen_frame_store {
>>>      VASurfaceID surface_id;
>>>      int         frame_store_id;
>>> +    int         ref_poc; /* only used for H.264 on earlier generations (<HSW) */
>>>      struct      object_surface *obj_surface;
>>>  };
>>>
>>> diff --git a/src/i965_decoder_utils.c b/src/i965_decoder_utils.c
>>> index 7833919..4accbc9 100644
>>> --- a/src/i965_decoder_utils.c
>>> +++ b/src/i965_decoder_utils.c
>>> @@ -26,6 +26,7 @@
>>>  #include <alloca.h>
>>>
>>>  #include "intel_batchbuffer.h"
>>> +#include "intel_media.h"
>>>  #include "i965_drv_video.h"
>>>  #include "i965_decoder_utils.h"
>>>  #include "i965_defines.h"
>>> @@ -254,6 +255,21 @@ avc_gen_default_iq_matrix(VAIQMatrixBufferH264 *iq_matrix)
>>>      memset(&iq_matrix->ScalingList8x8, 16, sizeof(iq_matrix->ScalingList8x8));
>>>  }
>>>
>>> +/* Returns the POC of the supplied VA picture */
>>> +static int
>>> +avc_get_picture_poc(const VAPictureH264 *va_pic)
>>> +{
>>> +    int structure, field_poc[2];
>>> +
>>> +    structure = va_pic->flags &
>>> +        (VA_PICTURE_H264_TOP_FIELD | VA_PICTURE_H264_BOTTOM_FIELD);
>>> +    field_poc[0] = structure != VA_PICTURE_H264_BOTTOM_FIELD ?
>>> +        va_pic->TopFieldOrderCnt : INT_MAX;
>>> +    field_poc[1] = structure != VA_PICTURE_H264_TOP_FIELD ?
>>> +        va_pic->BottomFieldOrderCnt : INT_MAX;
>>> +    return MIN(field_poc[0], field_poc[1]);
>>> +}
>>> +
>>>  /* Returns a unique picture ID that represents the supplied VA surface object */
>>>  int
>>>  avc_get_picture_id(struct object_surface *obj_surface)
>>> @@ -471,6 +487,20 @@ gen6_send_avc_ref_idx_state(
>>>      );
>>>  }
>>>
>>> +/* Comparison function for sorting out the array of free frame store entries */
>>> +static int
>>> +compare_avc_ref_store_func(const void *p1, const void *p2)
>>> +{
>>> +    const GenFrameStore * const fs1 = *((GenFrameStore **)p1);
>>> +    const GenFrameStore * const fs2 = *((GenFrameStore **)p2);
>>> +
>>> +    if (fs1->ref_poc == INT_MAX)
>>> +        return -1;
>>> +    if (fs2->ref_poc == INT_MAX)
>>> +        return 1;
>>> +    return fs1->ref_poc - fs2->ref_poc;
>>> +}
>>> +
>>>  void
>>>  intel_update_avc_frame_store_index(
>>>      VADriverContextP              ctx,
>>> @@ -480,59 +510,62 @@ intel_update_avc_frame_store_index(
>>>  )
>>>  {
>>>      GenFrameStore *free_refs[MAX_GEN_REFERENCE_FRAMES];
>>> -    int i, j, n, num_free_refs;
>>> +    uint32_t used_refs = 0, add_refs = 0;
>>> +    int i, n, num_free_refs;
>>>
>>> -    /* Remove obsolete entries from the internal DPB */
>>> -    for (i = 0, n = 0; i < MAX_GEN_REFERENCE_FRAMES; i++) {
>>> -        GenFrameStore * const fs = &frame_store[i];
>>> -        if (fs->surface_id == VA_INVALID_ID || !fs->obj_surface) {
>>> -            free_refs[n++] = fs;
>>> +    const int poc = avc_get_picture_poc(&pic_param->CurrPic);
>>> +
>>> +    /* Tag entries that are still available in our Frame Store */
>>> +    for (i = 0; i < ARRAY_ELEMS(decode_state->reference_objects); i++) {
>>> +        struct object_surface * const obj_surface =
>>> +            decode_state->reference_objects[i];
>>> +        if (!obj_surface)
>>>              continue;
>>> -        }
>>>
>>> -        // Find whether the current entry is still a valid reference frame
>>> -        for (j = 0; j < ARRAY_ELEMS(decode_state->reference_objects); j++) {
>>> -            struct object_surface * const obj_surface =
>>> -                decode_state->reference_objects[j];
>>> -            if (obj_surface && obj_surface == fs->obj_surface)
>>> -                break;
>>> +        GenAvcSurface * const avc_surface = obj_surface->private_data;
>>> +        if (avc_surface->frame_store_id >= 0) {
>>> +            GenFrameStore * const fs =
>>> +                &frame_store[avc_surface->frame_store_id];
>>> +            if (fs->surface_id == obj_surface->base.id) {
>>> +                fs->obj_surface = obj_surface;
>>> +                fs->ref_poc = poc;
>>> +                used_refs |= 1 << fs->frame_store_id;
>>> +                continue;
>>> +            }
>>>          }
>>> +        add_refs |= 1 << i;
>>> +    }
>>>
>>> -        // ... or remove it
>>> -        if (j == ARRAY_ELEMS(decode_state->reference_objects)) {
>>> -            fs->surface_id = VA_INVALID_ID;
>>> +    /* Build and sort out the list of retired candidates. The resulting
>>> +       list is ordered by increasing POC when they were last used */
>>> +    for (i = 0, n = 0; i < MAX_GEN_REFERENCE_FRAMES; i++) {
>>> +        if (!(used_refs & (1 << i))) {
>>> +            GenFrameStore * const fs = &frame_store[i];
>>>              fs->obj_surface = NULL;
>>> -            fs->frame_store_id = -1;
>>>              free_refs[n++] = fs;
>>>          }
>>>      }
>>>      num_free_refs = n;
>>> +    qsort(&free_refs[0], n, sizeof(free_refs[0]), compare_avc_ref_store_func);
>>>
>>>      /* Append the new reference frames */
>>>      for (i = 0, n = 0; i < ARRAY_ELEMS(decode_state->reference_objects); i++) {
>>>          struct object_surface * const obj_surface =
>>>              decode_state->reference_objects[i];
>>> -        if (!obj_surface)
>>> +        if (!obj_surface || !(add_refs & (1 << i)))
>>>              continue;
>>>
>>> -        // Find whether the current frame is not already in our frame store
>>> -        for (j = 0; j < MAX_GEN_REFERENCE_FRAMES; j++) {
>>> -            GenFrameStore * const fs = &frame_store[j];
>>> -            if (fs->obj_surface == obj_surface)
>>> -                break;
>>> -        }
>>> -
>>> -        // ... or add it
>>> -        if (j == MAX_GEN_REFERENCE_FRAMES) {
>>> -            if (n < num_free_refs) {
>>> -                GenFrameStore * const fs = free_refs[n++];
>>> -                fs->surface_id = obj_surface->base.id;
>>> -                fs->obj_surface = obj_surface;
>>> -                fs->frame_store_id = fs - frame_store;
>>> -                continue;
>>> -            }
>>> -            WARN_ONCE("No free slot found for DPB reference list!!!\n");
>>> +        GenAvcSurface * const avc_surface = obj_surface->private_data;
>>> +        if (n < num_free_refs) {
>>> +            GenFrameStore * const fs = free_refs[n++];
>>> +            fs->surface_id = obj_surface->base.id;
>>> +            fs->obj_surface = obj_surface;
>>> +            fs->frame_store_id = fs - frame_store;
>>> +            fs->ref_poc = poc;
>>> +            avc_surface->frame_store_id = fs->frame_store_id;
>>> +            continue;
>>>          }
>>> +        WARN_ONCE("No free slot found for DPB reference list!!!\n");
>>>      }
>>>  }
>>>
>>> diff --git a/src/i965_media_h264.c b/src/i965_media_h264.c
>>> index 8ec7e4f..4b37fcb 100644
>>> --- a/src/i965_media_h264.c
>>> +++ b/src/i965_media_h264.c
>>> @@ -1,9 +1,4 @@
>>> -#include <stdlib.h>
>>> -#include <stdio.h>
>>> -#include <string.h>
>>> -#include <assert.h>
>>> -
>>> -
>>> +#include "sysdeps.h"
>>>  #include "intel_batchbuffer.h"
>>>  #include "intel_driver.h"
>>>
>>> @@ -870,6 +865,7 @@ i965_media_h264_dec_context_init(VADriverContextP ctx, struct i965_media_context
>>>      for (i = 0; i < 16; i++) {
>>>          i965_h264_context->fsid_list[i].surface_id = VA_INVALID_ID;
>>>          i965_h264_context->fsid_list[i].frame_store_id = -1;
>>> +        i965_h264_context->fsid_list[i].ref_poc = INT_MAX;
>>>      }
>>>
>>>      i965_h264_context->batch = media_context->base.batch;
>>> diff --git a/src/intel_media.h b/src/intel_media.h
>>> index b30740a..55136d6 100644
>>> --- a/src/intel_media.h
>>> +++ b/src/intel_media.h
>>> @@ -39,6 +39,7 @@ struct gen_avc_surface
>>>      dri_bo *dmv_top;
>>>      dri_bo *dmv_bottom;
>>>      int dmv_bottom_flag;
>>> +    int frame_store_id; /* only used for H.264 on earlier generations (<HSW) */
>>>  };
>>>
>>>  extern void gen_free_avc_surface(void **data);
>>> diff --git a/src/sysdeps.h b/src/sysdeps.h
>>> index 71bfb4d..cc7144a 100644
>>> --- a/src/sysdeps.h
>>> +++ b/src/sysdeps.h
>>> @@ -43,5 +43,6 @@
>>>  #include <string.h>
>>>  #include <stdint.h>
>>>  #include <assert.h>
>>> +#include <limits.h>
>>>
>>>  #endif /* SYSDEPS_H */
>>
>>


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