libvpx/vp8/vp8_dx_iface.c

/*
 *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */

#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include "./vp8_rtcd.h"
#include "./vpx_dsp_rtcd.h"
#include "./vpx_scale_rtcd.h"
#include "vpx/vpx_decoder.h"
#include "vpx/vp8dx.h"
#include "vpx/internal/vpx_codec_internal.h"
#include "vpx_version.h"
#include "common/alloccommon.h"
#include "common/common.h"
#include "common/onyxd.h"
#include "decoder/onyxd_int.h"
#include "vpx_dsp/vpx_dsp_common.h"
#include "vpx_mem/vpx_mem.h"
#include "vpx_ports/system_state.h"
#if CONFIG_ERROR_CONCEALMENT
#include "decoder/error_concealment.h"
#endif
#include "decoder/decoderthreading.h"

#define VP8_CAP_POSTPROC (CONFIG_POSTPROC ? VPX_CODEC_CAP_POSTPROC : 0)
#define VP8_CAP_ERROR_CONCEALMENT \
  (CONFIG_ERROR_CONCEALMENT ? VPX_CODEC_CAP_ERROR_CONCEALMENT : 0)

typedef vpx_codec_stream_info_t vp8_stream_info_t;

/* Structures for handling memory allocations */
typedef enum { VP8_SEG_ALG_PRIV = 256, VP8_SEG_MAX } mem_seg_id_t;
#define NELEMENTS(x) ((int)(sizeof(x) / sizeof(x[0])))

struct vpx_codec_alg_priv {
  vpx_codec_priv_t base;
  vpx_codec_dec_cfg_t cfg;
  vp8_stream_info_t si;
  int decoder_init;
  int postproc_cfg_set;
  vp8_postproc_cfg_t postproc_cfg;
  vpx_decrypt_cb decrypt_cb;
  void *decrypt_state;
  vpx_image_t img;
  int img_setup;
  struct frame_buffers yv12_frame_buffers;
  void *user_priv;
  FRAGMENT_DATA fragments;
};

static int vp8_init_ctx(vpx_codec_ctx_t *ctx) {
  vpx_codec_alg_priv_t *priv =
      (vpx_codec_alg_priv_t *)vpx_calloc(1, sizeof(*priv));
  if (!priv) return 1;

  ctx->priv = (vpx_codec_priv_t *)priv;
  ctx->priv->init_flags = ctx->init_flags;

  priv->si.sz = sizeof(priv->si);
  priv->decrypt_cb = NULL;
  priv->decrypt_state = NULL;

  if (ctx->config.dec) {
    /* Update the reference to the config structure to an internal copy. */
    priv->cfg = *ctx->config.dec;
    ctx->config.dec = &priv->cfg;
  }

  return 0;
}

static vpx_codec_err_t vp8_init(vpx_codec_ctx_t *ctx,
                                vpx_codec_priv_enc_mr_cfg_t *data) {
  vpx_codec_err_t res = VPX_CODEC_OK;
  vpx_codec_alg_priv_t *priv = NULL;
  (void)data;

  vp8_rtcd();
  vpx_dsp_rtcd();
  vpx_scale_rtcd();

  /* This function only allocates space for the vpx_codec_alg_priv_t
   * structure. More memory may be required at the time the stream
   * information becomes known.
   */
  if (!ctx->priv) {
    if (vp8_init_ctx(ctx)) return VPX_CODEC_MEM_ERROR;
    priv = (vpx_codec_alg_priv_t *)ctx->priv;

    /* initialize number of fragments to zero */
    priv->fragments.count = 0;
    /* is input fragments enabled? */
    priv->fragments.enabled =
        (priv->base.init_flags & VPX_CODEC_USE_INPUT_FRAGMENTS);

    /*post processing level initialized to do nothing */
  } else {
    priv = (vpx_codec_alg_priv_t *)ctx->priv;
  }

  return res;
}

static vpx_codec_err_t vp8_destroy(vpx_codec_alg_priv_t *ctx) {
  vp8_remove_decoder_instances(&ctx->yv12_frame_buffers);

  vpx_free(ctx);

  return VPX_CODEC_OK;
}

static vpx_codec_err_t vp8_peek_si_internal(const uint8_t *data,
                                            unsigned int data_sz,
                                            vpx_codec_stream_info_t *si,
                                            vpx_decrypt_cb decrypt_cb,
                                            void *decrypt_state) {
  vpx_codec_err_t res = VPX_CODEC_OK;

  assert(data != NULL);

  if (data + data_sz <= data) {
    res = VPX_CODEC_INVALID_PARAM;
  } else {
    /* Parse uncompresssed part of key frame header.
     * 3 bytes:- including version, frame type and an offset
     * 3 bytes:- sync code (0x9d, 0x01, 0x2a)
     * 4 bytes:- including image width and height in the lowest 14 bits
     *           of each 2-byte value.
     */
    uint8_t clear_buffer[10];
    const uint8_t *clear = data;
    if (decrypt_cb) {
      int n = VPXMIN(sizeof(clear_buffer), data_sz);
      decrypt_cb(decrypt_state, data, clear_buffer, n);
      clear = clear_buffer;
    }
    si->is_kf = 0;

    if (data_sz >= 10 && !(clear[0] & 0x01)) /* I-Frame */
    {
      si->is_kf = 1;

      /* vet via sync code */
      if (clear[3] != 0x9d || clear[4] != 0x01 || clear[5] != 0x2a) {
        return VPX_CODEC_UNSUP_BITSTREAM;
      }

      si->w = (clear[6] | (clear[7] << 8)) & 0x3fff;
      si->h = (clear[8] | (clear[9] << 8)) & 0x3fff;

      /*printf("w=%d, h=%d\n", si->w, si->h);*/
      if (!(si->h && si->w)) res = VPX_CODEC_CORRUPT_FRAME;
    } else {
      res = VPX_CODEC_UNSUP_BITSTREAM;
    }
  }

  return res;
}

static vpx_codec_err_t vp8_peek_si(const uint8_t *data, unsigned int data_sz,
                                   vpx_codec_stream_info_t *si) {
  return vp8_peek_si_internal(data, data_sz, si, NULL, NULL);
}

static vpx_codec_err_t vp8_get_si(vpx_codec_alg_priv_t *ctx,
                                  vpx_codec_stream_info_t *si) {
  unsigned int sz;

  if (si->sz >= sizeof(vp8_stream_info_t)) {
    sz = sizeof(vp8_stream_info_t);
  } else {
    sz = sizeof(vpx_codec_stream_info_t);
  }

  memcpy(si, &ctx->si, sz);
  si->sz = sz;

  return VPX_CODEC_OK;
}

static vpx_codec_err_t update_error_state(
    vpx_codec_alg_priv_t *ctx, const struct vpx_internal_error_info *error) {
  vpx_codec_err_t res;

  if ((res = error->error_code)) {
    ctx->base.err_detail = error->has_detail ? error->detail : NULL;
  }

  return res;
}

static void yuvconfig2image(vpx_image_t *img, const YV12_BUFFER_CONFIG *yv12,
                            void *user_priv) {
  /** vpx_img_wrap() doesn't allow specifying independent strides for
    * the Y, U, and V planes, nor other alignment adjustments that
    * might be representable by a YV12_BUFFER_CONFIG, so we just
    * initialize all the fields.*/
  img->fmt = VPX_IMG_FMT_I420;
  img->w = yv12->y_stride;
  img->h = (yv12->y_height + 2 * VP8BORDERINPIXELS + 15) & ~15;
  img->d_w = img->r_w = yv12->y_width;
  img->d_h = img->r_h = yv12->y_height;
  img->x_chroma_shift = 1;
  img->y_chroma_shift = 1;
  img->planes[VPX_PLANE_Y] = yv12->y_buffer;
  img->planes[VPX_PLANE_U] = yv12->u_buffer;
  img->planes[VPX_PLANE_V] = yv12->v_buffer;
  img->planes[VPX_PLANE_ALPHA] = NULL;
  img->stride[VPX_PLANE_Y] = yv12->y_stride;
  img->stride[VPX_PLANE_U] = yv12->uv_stride;
  img->stride[VPX_PLANE_V] = yv12->uv_stride;
  img->stride[VPX_PLANE_ALPHA] = yv12->y_stride;
  img->bit_depth = 8;
  img->bps = 12;
  img->user_priv = user_priv;
  img->img_data = yv12->buffer_alloc;
  img->img_data_owner = 0;
  img->self_allocd = 0;
}

static int update_fragments(vpx_codec_alg_priv_t *ctx, const uint8_t *data,
                            unsigned int data_sz, vpx_codec_err_t *res) {
  *res = VPX_CODEC_OK;

  if (ctx->fragments.count == 0) {
    /* New frame, reset fragment pointers and sizes */
    memset((void *)ctx->fragments.ptrs, 0, sizeof(ctx->fragments.ptrs));
    memset(ctx->fragments.sizes, 0, sizeof(ctx->fragments.sizes));
  }
  if (ctx->fragments.enabled && !(data == NULL && data_sz == 0)) {
    /* Store a pointer to this fragment and return. We haven't
     * received the complete frame yet, so we will wait with decoding.
     */
    ctx->fragments.ptrs[ctx->fragments.count] = data;
    ctx->fragments.sizes[ctx->fragments.count] = data_sz;
    ctx->fragments.count++;
    if (ctx->fragments.count > (1 << EIGHT_PARTITION) + 1) {
      ctx->fragments.count = 0;
      *res = VPX_CODEC_INVALID_PARAM;
      return -1;
    }
    return 0;
  }

  if (!ctx->fragments.enabled && (data == NULL && data_sz == 0)) {
    return 0;
  }

  if (!ctx->fragments.enabled) {
    ctx->fragments.ptrs[0] = data;
    ctx->fragments.sizes[0] = data_sz;
    ctx->fragments.count = 1;
  }

  return 1;
}

static vpx_codec_err_t vp8_decode(vpx_codec_alg_priv_t *ctx,
                                  const uint8_t *data, unsigned int data_sz,
                                  void *user_priv, long deadline) {
  vpx_codec_err_t res = VPX_CODEC_OK;
  unsigned int resolution_change = 0;
  unsigned int w, h;

  if (!ctx->fragments.enabled && (data == NULL && data_sz == 0)) {
    return 0;
  }

  /* Update the input fragment data */
  if (update_fragments(ctx, data, data_sz, &res) <= 0) return res;

  /* Determine the stream parameters. Note that we rely on peek_si to
   * validate that we have a buffer that does not wrap around the top
   * of the heap.
   */
  w = ctx->si.w;
  h = ctx->si.h;

  res = vp8_peek_si_internal(ctx->fragments.ptrs[0], ctx->fragments.sizes[0],
                             &ctx->si, ctx->decrypt_cb, ctx->decrypt_state);

  if ((res == VPX_CODEC_UNSUP_BITSTREAM) && !ctx->si.is_kf) {
    /* the peek function returns an error for non keyframes, however for
     * this case, it is not an error */
    res = VPX_CODEC_OK;
  }

  if (!ctx->decoder_init && !ctx->si.is_kf) res = VPX_CODEC_UNSUP_BITSTREAM;

  if ((ctx->si.h != h) || (ctx->si.w != w)) resolution_change = 1;

  /* Initialize the decoder instance on the first frame*/
  if (!res && !ctx->decoder_init) {
    VP8D_CONFIG oxcf;

    oxcf.Width = ctx->si.w;
    oxcf.Height = ctx->si.h;
    oxcf.Version = 9;
    oxcf.postprocess = 0;
    oxcf.max_threads = ctx->cfg.threads;
    oxcf.error_concealment =
        (ctx->base.init_flags & VPX_CODEC_USE_ERROR_CONCEALMENT);

    /* If postprocessing was enabled by the application and a
     * configuration has not been provided, default it.
     */
    if (!ctx->postproc_cfg_set &&
        (ctx->base.init_flags & VPX_CODEC_USE_POSTPROC)) {
      ctx->postproc_cfg.post_proc_flag =
          VP8_DEBLOCK | VP8_DEMACROBLOCK | VP8_MFQE;
      ctx->postproc_cfg.deblocking_level = 4;
      ctx->postproc_cfg.noise_level = 0;
    }

    res = vp8_create_decoder_instances(&ctx->yv12_frame_buffers, &oxcf);
    if (res == VPX_CODEC_OK) ctx->decoder_init = 1;
  }

  /* Set these even if already initialized.  The caller may have changed the
   * decrypt config between frames.
   */
  if (ctx->decoder_init) {
    ctx->yv12_frame_buffers.pbi[0]->decrypt_cb = ctx->decrypt_cb;
    ctx->yv12_frame_buffers.pbi[0]->decrypt_state = ctx->decrypt_state;
  }

  if (!res) {
    VP8D_COMP *pbi = ctx->yv12_frame_buffers.pbi[0];
    if (resolution_change) {
      VP8_COMMON *const pc = &pbi->common;
      MACROBLOCKD *const xd = &pbi->mb;
#if CONFIG_MULTITHREAD
      int i;
#endif
      pc->Width = ctx->si.w;
      pc->Height = ctx->si.h;
      {
        int prev_mb_rows = pc->mb_rows;

        if (setjmp(pbi->common.error.jmp)) {
          pbi->common.error.setjmp = 0;
          /* on failure clear the cached resolution to ensure a full
           * reallocation is attempted on resync. */
          ctx->si.w = 0;
          ctx->si.h = 0;
          vpx_clear_system_state();
          /* same return value as used in vp8dx_receive_compressed_data */
          return -1;
        }

        pbi->common.error.setjmp = 1;

        if (pc->Width <= 0) {
          pc->Width = w;
          vpx_internal_error(&pc->error, VPX_CODEC_CORRUPT_FRAME,
                             "Invalid frame width");
        }

        if (pc->Height <= 0) {
          pc->Height = h;
          vpx_internal_error(&pc->error, VPX_CODEC_CORRUPT_FRAME,
                             "Invalid frame height");
        }

        if (vp8_alloc_frame_buffers(pc, pc->Width, pc->Height)) {
          vpx_internal_error(&pc->error, VPX_CODEC_MEM_ERROR,
                             "Failed to allocate frame buffers");
        }

        xd->pre = pc->yv12_fb[pc->lst_fb_idx];
        xd->dst = pc->yv12_fb[pc->new_fb_idx];

#if CONFIG_MULTITHREAD
        for (i = 0; i < pbi->allocated_decoding_thread_count; ++i) {
          pbi->mb_row_di[i].mbd.dst = pc->yv12_fb[pc->new_fb_idx];
          vp8_build_block_doffsets(&pbi->mb_row_di[i].mbd);
        }
#endif
        vp8_build_block_doffsets(&pbi->mb);

/* allocate memory for last frame MODE_INFO array */
#if CONFIG_ERROR_CONCEALMENT

        if (pbi->ec_enabled) {
          /* old prev_mip was released by vp8_de_alloc_frame_buffers()
           * called in vp8_alloc_frame_buffers() */
          pc->prev_mip = vpx_calloc((pc->mb_cols + 1) * (pc->mb_rows + 1),
                                    sizeof(MODE_INFO));

          if (!pc->prev_mip) {
            vp8_de_alloc_frame_buffers(pc);
            vpx_internal_error(&pc->error, VPX_CODEC_MEM_ERROR,
                               "Failed to allocate"
                               "last frame MODE_INFO array");
          }

          pc->prev_mi = pc->prev_mip + pc->mode_info_stride + 1;

          if (vp8_alloc_overlap_lists(pbi))
            vpx_internal_error(&pc->error, VPX_CODEC_MEM_ERROR,
                               "Failed to allocate overlap lists "
                               "for error concealment");
        }

#endif

#if CONFIG_MULTITHREAD
        if (pbi->b_multithreaded_rd) {
          vp8mt_alloc_temp_buffers(pbi, pc->Width, prev_mb_rows);
        }
#else
        (void)prev_mb_rows;
#endif
      }

      pbi->common.error.setjmp = 0;

      /* required to get past the first get_free_fb() call */
      pbi->common.fb_idx_ref_cnt[0] = 0;
    }

    /* update the pbi fragment data */
    pbi->fragments = ctx->fragments;

    ctx->user_priv = user_priv;
    if (vp8dx_receive_compressed_data(pbi, data_sz, data, deadline)) {
      res = update_error_state(ctx, &pbi->common.error);
    }

    /* get ready for the next series of fragments */
    ctx->fragments.count = 0;
  }

  return res;
}

static vpx_image_t *vp8_get_frame(vpx_codec_alg_priv_t *ctx,
                                  vpx_codec_iter_t *iter) {
  vpx_image_t *img = NULL;

  /* iter acts as a flip flop, so an image is only returned on the first
   * call to get_frame.
   */
  if (!(*iter) && ctx->yv12_frame_buffers.pbi[0]) {
    YV12_BUFFER_CONFIG sd;
    int64_t time_stamp = 0, time_end_stamp = 0;
    vp8_ppflags_t flags;
    vp8_zero(flags);

    if (ctx->base.init_flags & VPX_CODEC_USE_POSTPROC) {
      flags.post_proc_flag = ctx->postproc_cfg.post_proc_flag;
      flags.deblocking_level = ctx->postproc_cfg.deblocking_level;
      flags.noise_level = ctx->postproc_cfg.noise_level;
    }

    if (0 == vp8dx_get_raw_frame(ctx->yv12_frame_buffers.pbi[0], &sd,
                                 &time_stamp, &time_end_stamp, &flags)) {
      yuvconfig2image(&ctx->img, &sd, ctx->user_priv);

      img = &ctx->img;
      *iter = img;
    }
  }

  return img;
}

static vpx_codec_err_t image2yuvconfig(const vpx_image_t *img,
                                       YV12_BUFFER_CONFIG *yv12) {
  const int y_w = img->d_w;
  const int y_h = img->d_h;
  const int uv_w = (img->d_w + 1) / 2;
  const int uv_h = (img->d_h + 1) / 2;
  vpx_codec_err_t res = VPX_CODEC_OK;
  yv12->y_buffer = img->planes[VPX_PLANE_Y];
  yv12->u_buffer = img->planes[VPX_PLANE_U];
  yv12->v_buffer = img->planes[VPX_PLANE_V];

  yv12->y_crop_width = y_w;
  yv12->y_crop_height = y_h;
  yv12->y_width = y_w;
  yv12->y_height = y_h;
  yv12->uv_crop_width = uv_w;
  yv12->uv_crop_height = uv_h;
  yv12->uv_width = uv_w;
  yv12->uv_height = uv_h;

  yv12->y_stride = img->stride[VPX_PLANE_Y];
  yv12->uv_stride = img->stride[VPX_PLANE_U];

  yv12->border = (img->stride[VPX_PLANE_Y] - img->d_w) / 2;
  return res;
}

static vpx_codec_err_t vp8_set_reference(vpx_codec_alg_priv_t *ctx,
                                         va_list args) {
  vpx_ref_frame_t *data = va_arg(args, vpx_ref_frame_t *);

  if (data) {
    vpx_ref_frame_t *frame = (vpx_ref_frame_t *)data;
    YV12_BUFFER_CONFIG sd;

    image2yuvconfig(&frame->img, &sd);

    return vp8dx_set_reference(ctx->yv12_frame_buffers.pbi[0],
                               frame->frame_type, &sd);
  } else {
    return VPX_CODEC_INVALID_PARAM;
  }
}

static vpx_codec_err_t vp8_get_reference(vpx_codec_alg_priv_t *ctx,
                                         va_list args) {
  vpx_ref_frame_t *data = va_arg(args, vpx_ref_frame_t *);

  if (data) {
    vpx_ref_frame_t *frame = (vpx_ref_frame_t *)data;
    YV12_BUFFER_CONFIG sd;

    image2yuvconfig(&frame->img, &sd);

    return vp8dx_get_reference(ctx->yv12_frame_buffers.pbi[0],
                               frame->frame_type, &sd);
  } else {
    return VPX_CODEC_INVALID_PARAM;
  }
}

static vpx_codec_err_t vp8_set_postproc(vpx_codec_alg_priv_t *ctx,
                                        va_list args) {
#if CONFIG_POSTPROC
  vp8_postproc_cfg_t *data = va_arg(args, vp8_postproc_cfg_t *);

  if (data) {
    ctx->postproc_cfg_set = 1;
    ctx->postproc_cfg = *((vp8_postproc_cfg_t *)data);
    return VPX_CODEC_OK;
  } else {
    return VPX_CODEC_INVALID_PARAM;
  }

#else
  (void)ctx;
  (void)args;
  return VPX_CODEC_INCAPABLE;
#endif
}

static vpx_codec_err_t vp8_get_last_ref_updates(vpx_codec_alg_priv_t *ctx,
                                                va_list args) {
  int *update_info = va_arg(args, int *);

  if (update_info) {
    VP8D_COMP *pbi = (VP8D_COMP *)ctx->yv12_frame_buffers.pbi[0];

    *update_info = pbi->common.refresh_alt_ref_frame * (int)VP8_ALTR_FRAME +
                   pbi->common.refresh_golden_frame * (int)VP8_GOLD_FRAME +
                   pbi->common.refresh_last_frame * (int)VP8_LAST_FRAME;

    return VPX_CODEC_OK;
  } else {
    return VPX_CODEC_INVALID_PARAM;
  }
}

extern int vp8dx_references_buffer(VP8_COMMON *oci, int ref_frame);
static vpx_codec_err_t vp8_get_last_ref_frame(vpx_codec_alg_priv_t *ctx,
                                              va_list args) {
  int *ref_info = va_arg(args, int *);

  if (ref_info) {
    VP8D_COMP *pbi = (VP8D_COMP *)ctx->yv12_frame_buffers.pbi[0];
    VP8_COMMON *oci = &pbi->common;
    *ref_info =
        (vp8dx_references_buffer(oci, ALTREF_FRAME) ? VP8_ALTR_FRAME : 0) |
        (vp8dx_references_buffer(oci, GOLDEN_FRAME) ? VP8_GOLD_FRAME : 0) |
        (vp8dx_references_buffer(oci, LAST_FRAME) ? VP8_LAST_FRAME : 0);

    return VPX_CODEC_OK;
  } else {
    return VPX_CODEC_INVALID_PARAM;
  }
}

static vpx_codec_err_t vp8_get_frame_corrupted(vpx_codec_alg_priv_t *ctx,
                                               va_list args) {
  int *corrupted = va_arg(args, int *);
  VP8D_COMP *pbi = (VP8D_COMP *)ctx->yv12_frame_buffers.pbi[0];

  if (corrupted && pbi) {
    const YV12_BUFFER_CONFIG *const frame = pbi->common.frame_to_show;
    if (frame == NULL) return VPX_CODEC_ERROR;
    *corrupted = frame->corrupted;
    return VPX_CODEC_OK;
  } else {
    return VPX_CODEC_INVALID_PARAM;
  }
}

static vpx_codec_err_t vp8_set_decryptor(vpx_codec_alg_priv_t *ctx,
                                         va_list args) {
  vpx_decrypt_init *init = va_arg(args, vpx_decrypt_init *);

  if (init) {
    ctx->decrypt_cb = init->decrypt_cb;
    ctx->decrypt_state = init->decrypt_state;
  } else {
    ctx->decrypt_cb = NULL;
    ctx->decrypt_state = NULL;
  }
  return VPX_CODEC_OK;
}

vpx_codec_ctrl_fn_map_t vp8_ctf_maps[] = {
  { VP8_SET_REFERENCE, vp8_set_reference },
  { VP8_COPY_REFERENCE, vp8_get_reference },
  { VP8_SET_POSTPROC, vp8_set_postproc },
  { VP8D_GET_LAST_REF_UPDATES, vp8_get_last_ref_updates },
  { VP8D_GET_FRAME_CORRUPTED, vp8_get_frame_corrupted },
  { VP8D_GET_LAST_REF_USED, vp8_get_last_ref_frame },
  { VPXD_SET_DECRYPTOR, vp8_set_decryptor },
  { -1, NULL },
};

#ifndef VERSION_STRING
#define VERSION_STRING
#endif
CODEC_INTERFACE(vpx_codec_vp8_dx) = {
  "WebM Project VP8 Decoder" VERSION_STRING,
  VPX_CODEC_INTERNAL_ABI_VERSION,
  VPX_CODEC_CAP_DECODER | VP8_CAP_POSTPROC | VP8_CAP_ERROR_CONCEALMENT |
      VPX_CODEC_CAP_INPUT_FRAGMENTS,
  /* vpx_codec_caps_t          caps; */
  vp8_init,     /* vpx_codec_init_fn_t       init; */
  vp8_destroy,  /* vpx_codec_destroy_fn_t    destroy; */
  vp8_ctf_maps, /* vpx_codec_ctrl_fn_map_t  *ctrl_maps; */
  {
      vp8_peek_si,   /* vpx_codec_peek_si_fn_t    peek_si; */
      vp8_get_si,    /* vpx_codec_get_si_fn_t     get_si; */
      vp8_decode,    /* vpx_codec_decode_fn_t     decode; */
      vp8_get_frame, /* vpx_codec_frame_get_fn_t  frame_get; */
      NULL,
  },
  {
      /* encoder functions */
      0, NULL, /* vpx_codec_enc_cfg_map_t */
      NULL,    /* vpx_codec_encode_fn_t */
      NULL,    /* vpx_codec_get_cx_data_fn_t */
      NULL,    /* vpx_codec_enc_config_set_fn_t */
      NULL,    /* vpx_codec_get_global_headers_fn_t */
      NULL,    /* vpx_codec_get_preview_frame_fn_t */
      NULL     /* vpx_codec_enc_mr_get_mem_loc_fn_t */
  }
};