text: /*
   * This file is part of Libav.
   *
   * Libav is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   *
   * Libav is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with Libav; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
   */
  
  #include <inttypes.h>
  #include <string.h>
  
  #include "libavutil/avassert.h"
  #include "libavutil/common.h"
  #include "libavutil/log.h"
  #include "libavutil/pixdesc.h"
  
  #include "vaapi_encode.h"
  #include "avcodec.h"
  
  static const char *picture_type_name[] = { "IDR", "I", "P", "B" };
  
  static int vaapi_encode_make_packed_header(AVCodecContext *avctx,
                                             VAAPIEncodePicture *pic,
                                             int type, char *data, size_t bit_len)
  {
      VAAPIEncodeContext *ctx = avctx->priv_data;
      VAStatus vas;
      VABufferID param_buffer, data_buffer;
      VAEncPackedHeaderParameterBuffer params = {
          .type = type,
          .bit_length = bit_len,
          .has_emulation_bytes = 1,
      };
  
      av_assert0(pic->nb_param_buffers + 2 <= MAX_PARAM_BUFFERS);
  
      vas = vaCreateBuffer(ctx->hwctx->display, ctx->va_context,
                           VAEncPackedHeaderParameterBufferType,
                           sizeof(params), 1, &params, &param_buffer);
      if (vas != VA_STATUS_SUCCESS) {
          av_log(avctx, AV_LOG_ERROR, "Failed to create parameter buffer "
                 "for packed header (type %d): %d (%s).\n",
                 type, vas, vaErrorStr(vas));
          return AVERROR(EIO);
      }
      pic->param_buffers[pic->nb_param_buffers++] = param_buffer;
  
      vas = vaCreateBuffer(ctx->hwctx->display, ctx->va_context,
                           VAEncPackedHeaderDataBufferType,
                           (bit_len + 7) / 8, 1, data, &data_buffer);
      if (vas != VA_STATUS_SUCCESS) {
          av_log(avctx, AV_LOG_ERROR, "Failed to create data buffer "
                 "for packed header (type %d): %d (%s).\n",
                 type, vas, vaErrorStr(vas));
          return AVERROR(EIO);
      }
      pic->param_buffers[pic->nb_param_buffers++] = data_buffer;
  
      av_log(avctx, AV_LOG_DEBUG, "Packed header buffer (%d) is %#x/%#x "
             "(%zu bits).\n", type, param_buffer, data_buffer, bit_len);
      return 0;
  }
  
  static int vaapi_encode_make_param_buffer(AVCodecContext *avctx,
                                            VAAPIEncodePicture *pic,
                                            int type, char *data, size_t len)
  {
      VAAPIEncodeContext *ctx = avctx->priv_data;
      VAStatus vas;
      VABufferID buffer;
  
      av_assert0(pic->nb_param_buffers + 1 <= MAX_PARAM_BUFFERS);
  
      vas = vaCreateBuffer(ctx->hwctx->display, ctx->va_context,
                           type, len, 1, data, &buffer);
      if (vas != VA_STATUS_SUCCESS) {
          av_log(avctx, AV_LOG_ERROR, "Failed to create parameter buffer "
                 "(type %d): %d (%s).\n", type, vas, vaErrorStr(vas));
          return AVERROR(EIO);
      }
      pic->param_buffers[pic->nb_param_buffers++] = buffer;
  
      av_log(avctx, AV_LOG_DEBUG, "Param buffer (%d) is %#x.\n",
             type, buffer);
      return 0;
  }
  
  static int vaapi_encode_wait(AVCodecContext *avctx,
                               VAAPIEncodePicture *pic)
  {
      VAAPIEncodeContext *ctx = avctx->priv_data;
      VAStatus vas;
  
      av_assert0(pic->encode_issued);
  
      if (pic->encode_complete) {
          // Already waited for this picture.
          return 0;
      }
  
      av_log(avctx, AV_LOG_DEBUG, "Sync to pic %"PRId64"/%"PRId64" "
             "(recon surface %#x).\n", pic->display_order,
             pic->encode_order, pic->recon_surface);
  
      vas = vaSyncSurface(ctx->hwctx->display, pic->recon_surface);
      if (vas != VA_STATUS_SUCCESS) {
          av_log(avctx, AV_LOG_ERROR, "Failed to sync to picture completion: "
                 "%d (%s).\n", vas, vaErrorStr(vas));
          return AVERROR(EIO);
      }
  
      // Input is definitely finished with now.
      av_frame_free(&pic->input_image);
  
      pic->encode_complete = 1;
      return 0;
  }
  
  static int vaapi_encode_issue(AVCodecContext *avctx,
                                VAAPIEncodePicture *pic)
  {
      VAAPIEncodeContext *ctx = avctx->priv_data;
      VAAPIEncodeSlice *slice;
      VAStatus vas;
      int err, i;
      char data[MAX_PARAM_BUFFER_SIZE];
      size_t bit_len;
  
      av_log(avctx, AV_LOG_DEBUG, "Issuing encode for pic %"PRId64"/%"PRId64" "
             "as type %s.\n", pic->display_order, pic->encode_order,
             picture_type_name[pic->type]);
      if (pic->nb_refs == 0) {
          av_log(avctx, AV_LOG_DEBUG, "No reference pictures.\n");
      } else {
          av_log(avctx, AV_LOG_DEBUG, "Refers to:");
          for (i = 0; i < pic->nb_refs; i++) {
              av_log(avctx, AV_LOG_DEBUG, " %"PRId64"/%"PRId64,
                     pic->refs[i]->display_order, pic->refs[i]->encode_order);
          }
          av_log(avctx, AV_LOG_DEBUG, ".\n");
      }
  
      av_assert0(pic->input_available && !pic->encode_issued);
      for (i = 0; i < pic->nb_refs; i++) {
          av_assert0(pic->refs[i]);
          // If we are serialised then the references must have already
          // completed.  If not, they must have been issued but need not
          // have completed yet.
          if (ctx->issue_mode == ISSUE_MODE_SERIALISE_EVERYTHING)
              av_assert0(pic->refs[i]->encode_complete);
          else
              av_assert0(pic->refs[i]->encode_issued);
      }
  
      av_log(avctx, AV_LOG_DEBUG, "Input surface is %#x.\n", pic->input_surface);
  
      pic->recon_image = av_frame_alloc();
      if (!pic->recon_image) {
          err = AVERROR(ENOMEM);
          goto fail;
      }
  
      err = av_hwframe_get_buffer(ctx->recon_frames_ref, pic->recon_image, 0);
      if (err < 0) {
          err = AVERROR(ENOMEM);
          goto fail;
      }
      pic->recon_surface = (VASurfaceID)(uintptr_t)pic->recon_image->data[3];
      av_log(avctx, AV_LOG_DEBUG, "Recon surface is %#x.\n", pic->recon_surface);
  
      pic->output_buffer_ref = av_buffer_pool_get(ctx->output_buffer_pool);
      if (!pic->output_buffer_ref) {
          err = AVERROR(ENOMEM);
          goto fail;
      }
      pic->output_buffer = (VABufferID)(uintptr_t)pic->output_buffer_ref->data;
      av_log(avctx, AV_LOG_DEBUG, "Output buffer is %#x.\n",
             pic->output_buffer);
  
      if (ctx->codec->picture_params_size > 0) {
          pic->codec_picture_params = av_malloc(ctx->codec->picture_params_size);
          if (!pic->codec_picture_params)
              goto fail;
          memcpy(pic->codec_picture_params, ctx->codec_picture_params,
                 ctx->codec->picture_params_size);
      } else {
          av_assert0(!ctx->codec_picture_params);
      }
  
      pic->nb_param_buffers = 0;
  
      if (pic->encode_order == 0) {
          // Global parameter buffers are set on the first picture only.
  
          for (i = 0; i < ctx->nb_global_params; i++) {
              err = vaapi_encode_make_param_buffer(avctx, pic,
                                                   VAEncMiscParameterBufferType,
                                                   (char*)ctx->global_params[i],
                                                   ctx->global_params_size[i]);
              if (err < 0)
                  goto fail;
          }
      }
  
      if (pic->type == PICTURE_TYPE_IDR && ctx->codec->init_sequence_params) {
          err = vaapi_encode_make_param_buffer(avctx, pic,
                                               VAEncSequenceParameterBufferType,
                                               ctx->codec_sequence_params,
                                               ctx->codec->sequence_params_size);
          if (err < 0)
              goto fail;
      }
  
      if (ctx->codec->init_picture_params) {
          err = ctx->codec->init_picture_params(avctx, pic);
          if (err < 0) {
              av_log(avctx, AV_LOG_ERROR, "Failed to initialise picture "
                     "parameters: %d.\n", err);
              goto fail;
          }
          err = vaapi_encode_make_param_buffer(avctx, pic,
                                               VAEncPictureParameterBufferType,
                                               pic->codec_picture_params,
                                               ctx->codec->picture_params_size);
          if (err < 0)
              goto fail;
      }
  
      if (pic->type == PICTURE_TYPE_IDR) {
          if (ctx->codec->write_sequence_header) {
              bit_len = 8 * sizeof(data);
              err = ctx->codec->write_sequence_header(avctx, data, &bit_len);
              if (err < 0) {
                  av_log(avctx, AV_LOG_ERROR, "Failed to write per-sequence "
                         "header: %d.\n", err);
                  goto fail;
              }
              err = vaapi_encode_make_packed_header(avctx, pic,
                                                    ctx->codec->sequence_header_type,
                                                    data, bit_len);
              if (err < 0)
                  goto fail;
          }
      }
  
      if (ctx->codec->write_picture_header) {
          bit_len = 8 * sizeof(data);
          err = ctx->codec->write_picture_header(avctx, pic, data, &bit_len);
          if (err < 0) {
              av_log(avctx, AV_LOG_ERROR, "Failed to write per-picture "
                     "header: %d.\n", err);
              goto fail;
          }
          err = vaapi_encode_make_packed_header(avctx, pic,
                                                ctx->codec->picture_header_type,
                                                data, bit_len);
          if (err < 0)
              goto fail;
      }
  
      if (ctx->codec->write_extra_buffer) {
          for (i = 0;; i++) {
              size_t len = sizeof(data);
              int type;
              err = ctx->codec->write_extra_buffer(avctx, pic, i, &type,
                                                   data, &len);
              if (err == AVERROR_EOF)
                  break;
              if (err < 0) {
                  av_log(avctx, AV_LOG_ERROR, "Failed to write extra "
                         "buffer %d: %d.\n", i, err);
                  goto fail;
              }
  
              err = vaapi_encode_make_param_buffer(avctx, pic, type,
                                                   data, len);
              if (err < 0)
                  goto fail;
          }
      }
  
      if (ctx->codec->write_extra_header) {
          for (i = 0;; i++) {
              int type;
              bit_len = 8 * sizeof(data);
              err = ctx->codec->write_extra_header(avctx, pic, i, &type,
                                                   data, &bit_len);
              if (err == AVERROR_EOF)
                  break;
              if (err < 0) {
                  av_log(avctx, AV_LOG_ERROR, "Failed to write extra "
                         "header %d: %d.\n", i, err);
                  goto fail;
              }
  
              err = vaapi_encode_make_packed_header(avctx, pic, type,
                                                    data, bit_len);
              if (err < 0)
                  goto fail;
          }
      }
  
      av_assert0(pic->nb_slices <= MAX_PICTURE_SLICES);
      for (i = 0; i < pic->nb_slices; i++) {
          slice = av_mallocz(sizeof(*slice));
          if (!slice) {
              err = AVERROR(ENOMEM);
              goto fail;
          }
          pic->slices[i] = slice;
  
          if (ctx->codec->slice_params_size > 0) {
              slice->codec_slice_params = av_mallocz(ctx->codec->slice_params_size);
              if (!slice->codec_slice_params) {
                  err = AVERROR(ENOMEM);
                  goto fail;
              }
          }
  
          if (ctx->codec->init_slice_params) {
              err = ctx->codec->init_slice_params(avctx, pic, slice);
              if (err < 0) {
                  av_log(avctx, AV_LOG_ERROR, "Failed to initalise slice "
                         "parameters: %d.\n", err);
                  goto fail;
              }
          }
  
          if (ctx->codec->write_slice_header) {
              bit_len = 8 * sizeof(data);
              err = ctx->codec->write_slice_header(avctx, pic, slice,
                                                   data, &bit_len);
              if (err < 0) {
                  av_log(avctx, AV_LOG_ERROR, "Failed to write per-slice "
                         "header: %d.\n", err);
                  goto fail;
              }
              err = vaapi_encode_make_packed_header(avctx, pic,
                                                    ctx->codec->slice_header_type,
                                                    data, bit_len);
              if (err < 0)
                  goto fail;
          }
  
          if (ctx->codec->init_slice_params) {
              err = vaapi_encode_make_param_buffer(avctx, pic,
                                                   VAEncSliceParameterBufferType,
                                                   slice->codec_slice_params,
                                                   ctx->codec->slice_params_size);
              if (err < 0)
                  goto fail;
          }
      }
  
      vas = vaBeginPicture(ctx->hwctx->display, ctx->va_context,
                           pic->input_surface);
      if (vas != VA_STATUS_SUCCESS) {
          av_log(avctx, AV_LOG_ERROR, "Failed to begin picture encode issue: "
                 "%d (%s).\n", vas, vaErrorStr(vas));
          err = AVERROR(EIO);
          goto fail_with_picture;
      }
  
      vas = vaRenderPicture(ctx->hwctx->display, ctx->va_context,
                            pic->param_buffers, pic->nb_param_buffers);
      if (vas != VA_STATUS_SUCCESS) {
          av_log(avctx, AV_LOG_ERROR, "Failed to upload encode parameters: "
                 "%d (%s).\n", vas, vaErrorStr(vas));
          err = AVERROR(EIO);
          goto fail_with_picture;
      }
  
      vas = vaEndPicture(ctx->hwctx->display, ctx->va_context);
      if (vas != VA_STATUS_SUCCESS) {
          av_log(avctx, AV_LOG_ERROR, "Failed to end picture encode issue: "
                 "%d (%s).\n", vas, vaErrorStr(vas));
          err = AVERROR(EIO);
          // vaRenderPicture() has been called here, so we should not destroy
          // the parameter buffers unless separate destruction is required.
          if (ctx->hwctx->driver_quirks &
              AV_VAAPI_DRIVER_QUIRK_RENDER_PARAM_BUFFERS)
              goto fail;
          else
              goto fail_at_end;
      }
  
      if (ctx->hwctx->driver_quirks &
          AV_VAAPI_DRIVER_QUIRK_RENDER_PARAM_BUFFERS) {
          for (i = 0; i < pic->nb_param_buffers; i++) {
              vas = vaDestroyBuffer(ctx->hwctx->display,
                                    pic->param_buffers[i]);
              if (vas != VA_STATUS_SUCCESS) {
                  av_log(avctx, AV_LOG_ERROR, "Failed to destroy "
                         "param buffer %#x: %d (%s).\n",
                         pic->param_buffers[i], vas, vaErrorStr(vas));
                  // And ignore.
              }
          }
      }
  
      pic->encode_issued = 1;
  
      if (ctx->issue_mode == ISSUE_MODE_SERIALISE_EVERYTHING)
          return vaapi_encode_wait(avctx, pic);
      else
          return 0;
  
  fail_with_picture:
      vaEndPicture(ctx->hwctx->display, ctx->va_context);
  fail:
      for(i = 0; i < pic->nb_param_buffers; i++)
          vaDestroyBuffer(ctx->hwctx->display, pic->param_buffers[i]);
  fail_at_end:
      av_freep(&pic->codec_picture_params);
      av_frame_free(&pic->recon_image);
      return err;
  }
  
  static int vaapi_encode_output(AVCodecContext *avctx,
                                 VAAPIEncodePicture *pic, AVPacket *pkt)
  {
      VAAPIEncodeContext *ctx = avctx->priv_data;
      VACodedBufferSegment *buf_list, *buf;
      VAStatus vas;
      int err;
  
      err = vaapi_encode_wait(avctx, pic);
      if (err < 0)
          return err;
  
      buf_list = NULL;
      vas = vaMapBuffer(ctx->hwctx->display, pic->output_buffer,
                        (void**)&buf_list);
      if (vas != VA_STATUS_SUCCESS) {
          av_log(avctx, AV_LOG_ERROR, "Failed to map output buffers: "
                 "%d (%s).\n", vas, vaErrorStr(vas));
          err = AVERROR(EIO);
          goto fail;
      }
  
      for (buf = buf_list; buf; buf = buf->next) {
          av_log(avctx, AV_LOG_DEBUG, "Output buffer: %u bytes "
                 "(status %08x).\n", buf->size, buf->status);
  
          err = av_new_packet(pkt, buf->size);
          if (err < 0)
              goto fail_mapped;
  
          memcpy(pkt->data, buf->buf, buf->size);
      }
  
      if (pic->type == PICTURE_TYPE_IDR)
          pkt->flags |= AV_PKT_FLAG_KEY;
  
      pkt->pts = pic->pts;
  
      vas = vaUnmapBuffer(ctx->hwctx->display, pic->output_buffer);
      if (vas != VA_STATUS_SUCCESS) {
          av_log(avctx, AV_LOG_ERROR, "Failed to unmap output buffers: "
                 "%d (%s).\n", vas, vaErrorStr(vas));
          err = AVERROR(EIO);
          goto fail;
      }
  
      av_buffer_unref(&pic->output_buffer_ref);
      pic->output_buffer = VA_INVALID_ID;
  
      av_log(avctx, AV_LOG_DEBUG, "Output read for pic %"PRId64"/%"PRId64".\n",
             pic->display_order, pic->encode_order);
      return 0;
  
  fail_mapped:
      vaUnmapBuffer(ctx->hwctx->display, pic->output_buffer);
  fail:
      av_buffer_unref(&pic->output_buffer_ref);
      pic->output_buffer = VA_INVALID_ID;
      return err;
  }
  
  static int vaapi_encode_discard(AVCodecContext *avctx,
                                  VAAPIEncodePicture *pic)
  {
      vaapi_encode_wait(avctx, pic);
  
      if (pic->output_buffer_ref) {
          av_log(avctx, AV_LOG_DEBUG, "Discard output for pic "
                 "%"PRId64"/%"PRId64".\n",
                 pic->display_order, pic->encode_order);
  
          av_buffer_unref(&pic->output_buffer_ref);
          pic->output_buffer = VA_INVALID_ID;
      }
  
      return 0;
  }
  
  static VAAPIEncodePicture *vaapi_encode_alloc(void)
  {
      VAAPIEncodePicture *pic;
  
      pic = av_mallocz(sizeof(*pic));
      if (!pic)
          return NULL;
  
      pic->input_surface = VA_INVALID_ID;
      pic->recon_surface = VA_INVALID_ID;
      pic->output_buffer = VA_INVALID_ID;
  
      return pic;
  }
  
  static int vaapi_encode_free(AVCodecContext *avctx,
                               VAAPIEncodePicture *pic)
  {
      int i;
  
      if (pic->encode_issued)
          vaapi_encode_discard(avctx, pic);
  
      for (i = 0; i < pic->nb_slices; i++) {
          av_freep(&pic->slices[i]->priv_data);
          av_freep(&pic->slices[i]->codec_slice_params);
          av_freep(&pic->slices[i]);
      }
      av_freep(&pic->codec_picture_params);
  
      av_frame_free(&pic->input_image);
      av_frame_free(&pic->recon_image);
  
      // Output buffer should already be destroyed.
      av_assert0(pic->output_buffer == VA_INVALID_ID);
  
      av_freep(&pic->priv_data);
      av_freep(&pic->codec_picture_params);
  
      av_free(pic);
  
      return 0;
  }
  
  static int vaapi_encode_step(AVCodecContext *avctx,
                               VAAPIEncodePicture *target)
  {
      VAAPIEncodeContext *ctx = avctx->priv_data;
      VAAPIEncodePicture *pic;
      int i, err;
  
      if (ctx->issue_mode == ISSUE_MODE_SERIALISE_EVERYTHING ||
          ctx->issue_mode == ISSUE_MODE_MINIMISE_LATENCY) {
          // These two modes are equivalent, except that we wait for
          // immediate completion on each operation if serialised.
  
          if (!target) {
              // No target, nothing to do yet.
              return 0;
          }
  
          if (target->encode_complete) {
              // Already done.
              return 0;
          }
  
          pic = target;
          for (i = 0; i < pic->nb_refs; i++) {
              if (!pic->refs[i]->encode_complete) {
                  err = vaapi_encode_step(avctx, pic->refs[i]);
                  if (err < 0)
                      return err;
              }
          }
  
          err = vaapi_encode_issue(avctx, pic);
          if (err < 0)
              return err;
  
      } else if (ctx->issue_mode == ISSUE_MODE_MAXIMISE_THROUGHPUT) {
          int activity;
  
          do {
              activity = 0;
              for (pic = ctx->pic_start; pic; pic = pic->next) {
                  if (!pic->input_available || pic->encode_issued)
                      continue;
                  for (i = 0; i < pic->nb_refs; i++) {
                      if (!pic->refs[i]->encode_issued)
                          break;
                  }
                  if (i < pic->nb_refs)
                      continue;
                  err = vaapi_encode_issue(avctx, pic);
                  if (err < 0)
                      return err;
                  activity = 1;
              }
          } while(activity);
  
          if (target) {
              av_assert0(target->encode_issued && "broken dependencies?");
          }
  
      } else {
          av_assert0(0);
      }
  
      return 0;
  }
  
  static int vaapi_encode_get_next(AVCodecContext *avctx,
                                   VAAPIEncodePicture **pic_out)
  {
      VAAPIEncodeContext *ctx = avctx->priv_data;
      VAAPIEncodePicture *start, *end, *pic;
      int i;
  
      for (pic = ctx->pic_start; pic; pic = pic->next) {
          if (pic->next)
              av_assert0(pic->display_order + 1 == pic->next->display_order);
          if (pic->display_order == ctx->input_order) {
              *pic_out = pic;
              return 0;
          }
      }
  
      if (ctx->input_order == 0) {
          // First frame is always an IDR frame.
          av_assert0(!ctx->pic_start && !ctx->pic_end);
  
          pic = vaapi_encode_alloc();
          if (!pic)
              return AVERROR(ENOMEM);
  
          pic->type = PICTURE_TYPE_IDR;
          pic->display_order = 0;
          pic->encode_order  = 0;
  
          ctx->pic_start = ctx->pic_end = pic;
  
          *pic_out = pic;
          return 0;
      }
  
      pic = vaapi_encode_alloc();
      if (!pic)
          return AVERROR(ENOMEM);
  
      if (ctx->p_per_i == 0 || ctx->p_counter == ctx->p_per_i) {
          if (ctx->i_per_idr == 0 || ctx->i_counter == ctx->i_per_idr) {
              pic->type = PICTURE_TYPE_IDR;
              ctx->i_counter = 0;
          } else {
              pic->type = PICTURE_TYPE_I;
              ++ctx->i_counter;
          }
          ctx->p_counter = 0;
      } else {
          pic->type = PICTURE_TYPE_P;
          pic->refs[0] = ctx->pic_end;
          pic->nb_refs = 1;
          ++ctx->p_counter;
      }
      start = end = pic;
  
      if (pic->type != PICTURE_TYPE_IDR) {
          // If that was not an IDR frame, add B-frames display-before and
          // encode-after it.
  
          for (i = 0; i < ctx->b_per_p; i++) {
              pic = vaapi_encode_alloc();
              if (!pic)
                  goto fail;
  
              pic->type = PICTURE_TYPE_B;
              pic->refs[0] = ctx->pic_end;
              pic->refs[1] = end;
              pic->nb_refs = 2;
  
              pic->next = start;
              pic->display_order = ctx->input_order + ctx->b_per_p - i - 1;
              pic->encode_order  = pic->display_order + 1;
              start = pic;
          }
      }
  
      for (i = 0, pic = start; pic; i++, pic = pic->next) {
          pic->display_order = ctx->input_order + i;
          if (end->type == PICTURE_TYPE_IDR)
              pic->encode_order = ctx->input_order + i;
          else if (pic == end)
              pic->encode_order = ctx->input_order;
          else
              pic->encode_order = ctx->input_order + i + 1;
      }
  
      av_assert0(ctx->pic_end);
      ctx->pic_end->next = start;
      ctx->pic_end = end;
  
      *pic_out = start;
  
      av_log(avctx, AV_LOG_DEBUG, "Pictures:");
      for (pic = ctx->pic_start; pic; pic = pic->next) {
          av_log(avctx, AV_LOG_DEBUG, " %s (%"PRId64"/%"PRId64")",
                 picture_type_name[pic->type],
                 pic->display_order, pic->encode_order);
      }
      av_log(avctx, AV_LOG_DEBUG, "\n");
  
      return 0;
  
  fail:
      while (start) {
          pic = start->next;
          vaapi_encode_free(avctx, start);
          start = pic;
      }
      return AVERROR(ENOMEM);
  }
  
  static int vaapi_encode_mangle_end(AVCodecContext *avctx)
  {
      VAAPIEncodeContext *ctx = avctx->priv_data;
      VAAPIEncodePicture *pic, *last_pic, *next;
  
      // Find the last picture we actually have input for.
      for (pic = ctx->pic_start; pic; pic = pic->next) {
          if (!pic->input_available)
              break;
          last_pic = pic;
      }
  
      if (pic) {
          av_assert0(last_pic);
  
          if (last_pic->type == PICTURE_TYPE_B) {
              // Some fixing up is required.  Change the type of this
              // picture to P, then modify preceding B references which
              // point beyond it to point at it instead.
  
              last_pic->type = PICTURE_TYPE_P;
              last_pic->encode_order = last_pic->refs[1]->encode_order;
  
              for (pic = ctx->pic_start; pic != last_pic; pic = pic->next) {
                  if (pic->type == PICTURE_TYPE_B &&
                      pic->refs[1] == last_pic->refs[1])
                      pic->refs[1] = last_pic;
              }
  
              last_pic->nb_refs = 1;
              last_pic->refs[1] = NULL;
          } else {
              // We can use the current structure (no references point
              // beyond the end), but there are unused pics to discard.
          }
  
          // Discard all following pics, they will never be used.
          for (pic = last_pic->next; pic; pic = next) {
              next = pic->next;
              vaapi_encode_free(avctx, pic);
          }
  
          last_pic->next = NULL;
          ctx->pic_end = last_pic;
  
      } else {
          // Input is available for all pictures, so we don't need to
          // mangle anything.
      }
  
      av_log(avctx, AV_LOG_DEBUG, "Pictures at end of stream:");
      for (pic = ctx->pic_start; pic; pic = pic->next) {
          av_log(avctx, AV_LOG_DEBUG, " %s (%"PRId64"/%"PRId64")",
                 picture_type_name[pic->type],
                 pic->display_order, pic->encode_order);
      }
      av_log(avctx, AV_LOG_DEBUG, "\n");
  
      return 0;
  }
  
  static int vaapi_encode_clear_old(AVCodecContext *avctx)
  {
      VAAPIEncodeContext *ctx = avctx->priv_data;
      VAAPIEncodePicture *pic, *old;
      int i;
  
      while (ctx->pic_start != ctx->pic_end) {
          old = ctx->pic_start;
          if (old->encode_order > ctx->output_order)
              break;
  
          for (pic = old->next; pic; pic = pic->next) {
              if (pic->encode_complete)
                  continue;
              for (i = 0; i < pic->nb_refs; i++) {
                  if (pic->refs[i] == old) {
                      // We still need this picture because it's referred to
                      // directly by a later one, so it and all following
                      // pictures have to stay.
                      return 0;
                  }
              }
          }
  
          pic = ctx->pic_start;
          ctx->pic_start = pic->next;
          vaapi_encode_free(avctx, pic);
      }
  
      return 0;
  }
  
  int ff_vaapi_encode2(AVCodecContext *avctx, AVPacket *pkt,
                       const AVFrame *input_image, int *got_packet)
  {
      VAAPIEncodeContext *ctx = avctx->priv_data;
      VAAPIEncodePicture *pic;
      int err;
  
      if (input_image) {
          av_log(avctx, AV_LOG_DEBUG, "Encode frame: %ux%u (%"PRId64").\n",
                 input_image->width, input_image->height, input_image->pts);
  
          err = vaapi_encode_get_next(avctx, &pic);
          if (err) {
              av_log(avctx, AV_LOG_ERROR, "Input setup failed: %d.\n", err);
              return err;
          }
  
          pic->input_image = av_frame_alloc();
          if (!pic->input_image) {
              err = AVERROR(ENOMEM);
              goto fail;
          }
          err = av_frame_ref(pic->input_image, input_image);
          if (err < 0)
              goto fail;
          pic->input_surface = (VASurfaceID)(uintptr_t)input_image->data[3];
          pic->pts = input_image->pts;
  
          if (ctx->input_order == 0)
              ctx->first_pts = pic->pts;
          if (ctx->input_order == ctx->decode_delay)
              ctx->dts_pts_diff = pic->pts - ctx->first_pts;
          if (ctx->output_delay > 0)
              ctx->ts_ring[ctx->input_order % (3 * ctx->output_delay)] = pic->pts;
  
          pic->input_available = 1;
  
      } else {
          if (!ctx->end_of_stream) {
              err = vaapi_encode_mangle_end(avctx);
              if (err < 0)
                  goto fail;
              ctx->end_of_stream = 1;
          }
      }
  
      ++ctx->input_order;
      ++ctx->output_order;
      av_assert0(ctx->output_order + ctx->output_delay + 1 == ctx->input_order);
  
      for (pic = ctx->pic_start; pic; pic = pic->next)
          if (pic->encode_order == ctx->output_order)
              break;
  
      // pic can be null here if we don't have a specific target in this
      // iteration.  We might still issue encodes if things can be overlapped,
      // even though we don't intend to output anything.
  
      err = vaapi_encode_step(avctx, pic);
      if (err < 0) {
          av_log(avctx, AV_LOG_ERROR, "Encode failed: %d.\n", err);
          goto fail;
      }
  
      if (!pic) {
          *got_packet = 0;
      } else {
          err = vaapi_encode_output(avctx, pic, pkt);
          if (err < 0) {
              av_log(avctx, AV_LOG_ERROR, "Output failed: %d.\n", err);
              goto fail;
          }
  
          if (ctx->output_delay == 0) {
              pkt->dts = pkt->pts;
          } else if (ctx->output_order < ctx->decode_delay) {
              if (ctx->ts_ring[ctx->output_order] < INT64_MIN + ctx->dts_pts_diff)
                  pkt->dts = INT64_MIN;
              else
                  pkt->dts = ctx->ts_ring[ctx->output_order] - ctx->dts_pts_diff;
          } else {
              pkt->dts = ctx->ts_ring[(ctx->output_order - ctx->decode_delay) %
                                      (3 * ctx->output_delay)];
          }
  
          *got_packet = 1;
      }
  
      err = vaapi_encode_clear_old(avctx);
      if (err < 0) {
          av_log(avctx, AV_LOG_ERROR, "List clearing failed: %d.\n", err);
          goto fail;
      }
  
      return 0;
  
  fail:
      // Unclear what to clean up on failure.  There are probably some things we
      // could do usefully clean up here, but for now just leave them for uninit()
      // to do instead.
      return err;
  }
  
  static av_cold int vaapi_encode_check_config(AVCodecContext *avctx)
  {
      VAAPIEncodeContext *ctx = avctx->priv_data;
      VAStatus vas;
      int i, n, err;
      VAProfile    *profiles    = NULL;
      VAEntrypoint *entrypoints = NULL;
      VAConfigAttrib attr[] = {
          { VAConfigAttribRateControl     },
          { VAConfigAttribEncMaxRefFrames },
      };
  
      n = vaMaxNumProfiles(ctx->hwctx->display);
      profiles = av_malloc_array(n, sizeof(VAProfile));
      if (!profiles) {
          err = AVERROR(ENOMEM);
          goto fail;
      }
      vas = vaQueryConfigProfiles(ctx->hwctx->display, profiles, &n);
      if (vas != VA_STATUS_SUCCESS) {
          av_log(ctx, AV_LOG_ERROR, "Failed to query profiles: %d (%s).\n",
                 vas, vaErrorStr(vas));
          err = AVERROR(ENOSYS);
          goto fail;
      }
      for (i = 0; i < n; i++) {
          if (profiles[i] == ctx->va_profile)
              break;
      }
      if (i >= n) {
          av_log(ctx, AV_LOG_ERROR, "Encoding profile not found (%d).\n",
                 ctx->va_profile);
          err = AVERROR(ENOSYS);
          goto fail;
      }
  
      n = vaMaxNumEntrypoints(ctx->hwctx->display);
      entrypoints = av_malloc_array(n, sizeof(VAEntrypoint));
      if (!entrypoints) {
          err = AVERROR(ENOMEM);
          goto fail;
      }
      vas = vaQueryConfigEntrypoints(ctx->hwctx->display, ctx->va_profile,
                                     entrypoints, &n);
      if (vas != VA_STATUS_SUCCESS) {
          av_log(ctx, AV_LOG_ERROR, "Failed to query entrypoints for "
                 "profile %u: %d (%s).\n", ctx->va_profile,
                 vas, vaErrorStr(vas));
          err = AVERROR(ENOSYS);
          goto fail;
      }
      for (i = 0; i < n; i++) {
          if (entrypoints[i] == ctx->va_entrypoint)
              break;
      }
      if (i >= n) {
          av_log(ctx, AV_LOG_ERROR, "Encoding entrypoint not found "
                 "(%d / %d).\n", ctx->va_profile, ctx->va_entrypoint);
          err = AVERROR(ENOSYS);
          goto fail;
      }
  
      vas = vaGetConfigAttributes(ctx->hwctx->display,
                                  ctx->va_profile, ctx->va_entrypoint,
                                  attr, FF_ARRAY_ELEMS(attr));
      if (vas != VA_STATUS_SUCCESS) {
          av_log(avctx, AV_LOG_ERROR, "Failed to fetch config "
                 "attributes: %d (%s).\n", vas, vaErrorStr(vas));
          return AVERROR(EINVAL);
      }
  
      for (i = 0; i < FF_ARRAY_ELEMS(attr); i++) {
          if (attr[i].value == VA_ATTRIB_NOT_SUPPORTED) {
              // Unfortunately we have to treat this as "don't know" and hope
              // for the best, because the Intel MJPEG encoder returns this
              // for all the interesting attributes.
              continue;
          }
          switch (attr[i].type) {
          case VAConfigAttribRateControl:
              if (!(ctx->va_rc_mode & attr[i].value)) {
                  av_log(avctx, AV_LOG_ERROR, "Rate control mode is not "
                         "supported: %x\n", attr[i].value);
                  err = AVERROR(EINVAL);
                  goto fail;
              }
              break;
          case VAConfigAttribEncMaxRefFrames:
          {
              unsigned int ref_l0 = attr[i].value & 0xffff;
              unsigned int ref_l1 = (attr[i].value >> 16) & 0xffff;
  
              if (avctx->gop_size > 1 && ref_l0 < 1) {
                  av_log(avctx, AV_LOG_ERROR, "P frames are not "
                         "supported (%x).\n", attr[i].value);
                  err = AVERROR(EINVAL);
                  goto fail;
              }
              if (avctx->max_b_frames > 0 && ref_l1 < 1) {
                  av_log(avctx, AV_LOG_ERROR, "B frames are not "
                         "supported (%x).\n", attr[i].value);
                  err = AVERROR(EINVAL);
                  goto fail;
              }
          }
          break;
          }
      }
  
      err = 0;
  fail:
      av_freep(&profiles);
      av_freep(&entrypoints);
      return err;
  }
  
  static void vaapi_encode_free_output_buffer(void *opaque,
                                              uint8_t *data)
  {
      AVCodecContext   *avctx = opaque;
      VAAPIEncodeContext *ctx = avctx->priv_data;
      VABufferID buffer_id;
  
      buffer_id = (VABufferID)(uintptr_t)data;
  
      vaDestroyBuffer(ctx->hwctx->display, buffer_id);
  
      av_log(avctx, AV_LOG_DEBUG, "Freed output buffer %#x\n", buffer_id);
  }
  
  static AVBufferRef *vaapi_encode_alloc_output_buffer(void *opaque,
                                                       int size)
  {
      AVCodecContext   *avctx = opaque;
      VAAPIEncodeContext *ctx = avctx->priv_data;
      VABufferID buffer_id;
      VAStatus vas;
      AVBufferRef *ref;
  
      // The output buffer size is fixed, so it needs to be large enough
      // to hold the largest possible compressed frame.  We assume here
      // that the uncompressed frame plus some header data is an upper
      // bound on that.
      vas = vaCreateBuffer(ctx->hwctx->display, ctx->va_context,
                           VAEncCodedBufferType,
                           3 * ctx->aligned_width * ctx->aligned_height +
                           (1 << 16), 1, 0, &buffer_id);
      if (vas != VA_STATUS_SUCCESS) {
          av_log(avctx, AV_LOG_ERROR, "Failed to create bitstream "
                 "output buffer: %d (%s).\n", vas, vaErrorStr(vas));
          return NULL;
      }
  
      av_log(avctx, AV_LOG_DEBUG, "Allocated output buffer %#x\n", buffer_id);
  
      ref = av_buffer_create((uint8_t*)(uintptr_t)buffer_id,
                             sizeof(buffer_id),
                             &vaapi_encode_free_output_buffer,
                             avctx, AV_BUFFER_FLAG_READONLY);
      if (!ref) {
          vaDestroyBuffer(ctx->hwctx->display, buffer_id);
          return NULL;
      }
  
      return ref;
  }
  
  av_cold int ff_vaapi_encode_init(AVCodecContext *avctx,
                                   const VAAPIEncodeType *type)
  {
      VAAPIEncodeContext *ctx = avctx->priv_data;
      AVVAAPIFramesContext *recon_hwctx = NULL;
      AVVAAPIHWConfig *hwconfig = NULL;
      AVHWFramesConstraints *constraints = NULL;
      enum AVPixelFormat recon_format;
      VAStatus vas;
      int err, i;
  
      if (!avctx->hw_frames_ctx) {
          av_log(avctx, AV_LOG_ERROR, "A hardware frames reference is "
                 "required to associate the encoding device.\n");
          return AVERROR(EINVAL);
      }
  
      ctx->codec = type;
      ctx->codec_options = ctx->codec_options_data;
  
      ctx->va_config  = VA_INVALID_ID;
      ctx->va_context = VA_INVALID_ID;
  
      ctx->priv_data = av_mallocz(type->priv_data_size);
      if (!ctx->priv_data) {
          err = AVERROR(ENOMEM);
          goto fail;
      }
  
      ctx->input_frames_ref = av_buffer_ref(avctx->hw_frames_ctx);
      if (!ctx->input_frames_ref) {
          err = AVERROR(ENOMEM);
          goto fail;
      }
      ctx->input_frames = (AVHWFramesContext*)ctx->input_frames_ref->data;
  
      ctx->device_ref = av_buffer_ref(ctx->input_frames->device_ref);
      if (!ctx->device_ref) {
          err = AVERROR(ENOMEM);
          goto fail;
      }
      ctx->device = (AVHWDeviceContext*)ctx->device_ref->data;
      ctx->hwctx = ctx->device->hwctx;
  
      err = ctx->codec->init(avctx);
      if (err < 0)
          goto fail;
  
      err = vaapi_encode_check_config(avctx);
      if (err < 0)
          goto fail;
  
      vas = vaCreateConfig(ctx->hwctx->display,
                           ctx->va_profile, ctx->va_entrypoint,
                           ctx->config_attributes, ctx->nb_config_attributes,
                           &ctx->va_config);
      if (vas != VA_STATUS_SUCCESS) {
          av_log(avctx, AV_LOG_ERROR, "Failed to create encode pipeline "
                 "configuration: %d (%s).\n", vas, vaErrorStr(vas));
          err = AVERROR(EIO);
          goto fail;
      }
  
      hwconfig = av_hwdevice_hwconfig_alloc(ctx->device_ref);
      if (!hwconfig) {
          err = AVERROR(ENOMEM);
          goto fail;
      }
      hwconfig->config_id = ctx->va_config;
  
      constraints = av_hwdevice_get_hwframe_constraints(ctx->device_ref,
                                                        hwconfig);
      if (!constraints) {
          err = AVERROR(ENOMEM);
          goto fail;
      }
  
      // Probably we can use the input surface format as the surface format
      // of the reconstructed frames.  If not, we just pick the first (only?)
      // format in the valid list and hope that it all works.
      recon_format = AV_PIX_FMT_NONE;
      if (constraints->valid_sw_formats) {
          for (i = 0; constraints->valid_sw_formats[i] != AV_PIX_FMT_NONE; i++) {
              if (ctx->input_frames->sw_format ==
                  constraints->valid_sw_formats[i]) {
                  recon_format = ctx->input_frames->sw_format;
                  break;
              }
          }
          if (recon_format == AV_PIX_FMT_NONE) {
              // No match.  Just use the first in the supported list and
              // hope for the best.
              recon_format = constraints->valid_sw_formats[0];
          }
      } else {
          // No idea what to use; copy input format.
          recon_format = ctx->input_frames->sw_format;
      }
      av_log(avctx, AV_LOG_DEBUG, "Using %s as format of "
             "reconstructed frames.\n", av_get_pix_fmt_name(recon_format));
  
      if (ctx->aligned_width  < constraints->min_width  ||
          ctx->aligned_height < constraints->min_height ||
          ctx->aligned_width  > constraints->max_width ||
          ctx->aligned_height > constraints->max_height) {
          av_log(avctx, AV_LOG_ERROR, "Hardware does not support encoding at "
                 "size %dx%d (constraints: width %d-%d height %d-%d).\n",
                 ctx->aligned_width, ctx->aligned_height,
                 constraints->min_width,  constraints->max_width,
                 constraints->min_height, constraints->max_height);
          err = AVERROR(EINVAL);
          goto fail;
      }
  
      av_freep(&hwconfig);
      av_hwframe_constraints_free(&constraints);
  
      ctx->recon_frames_ref = av_hwframe_ctx_alloc(ctx->device_ref);
      if (!ctx->recon_frames_ref) {
          err = AVERROR(ENOMEM);
          goto fail;
      }
      ctx->recon_frames = (AVHWFramesContext*)ctx->recon_frames_ref->data;
  
      ctx->recon_frames->format    = AV_PIX_FMT_VAAPI;
      ctx->recon_frames->sw_format = recon_format;
      ctx->recon_frames->width     = ctx->aligned_width;
      ctx->recon_frames->height    = ctx->aligned_height;
      ctx->recon_frames->initial_pool_size = ctx->nb_recon_frames;
  
      err = av_hwframe_ctx_init(ctx->recon_frames_ref);
      if (err < 0) {
          av_log(avctx, AV_LOG_ERROR, "Failed to initialise reconstructed "
                 "frame context: %d.\n", err);
          goto fail;
      }
      recon_hwctx = ctx->recon_frames->hwctx;
  
      vas = vaCreateContext(ctx->hwctx->display, ctx->va_config,
                            ctx->aligned_width, ctx->aligned_height,
                            VA_PROGRESSIVE,
                            recon_hwctx->surface_ids,
                            recon_hwctx->nb_surfaces,
                            &ctx->va_context);
      if (vas != VA_STATUS_SUCCESS) {
          av_log(avctx, AV_LOG_ERROR, "Failed to create encode pipeline "
                 "context: %d (%s).\n", vas, vaErrorStr(vas));
          err = AVERROR(EIO);
          goto fail;
      }
  
      ctx->input_order  = 0;
      ctx->output_delay = avctx->max_b_frames;
      ctx->decode_delay = 1;
      ctx->output_order = - ctx->output_delay - 1;
  
      if (ctx->codec->sequence_params_size > 0) {
          ctx->codec_sequence_params =
              av_mallocz(ctx->codec->sequence_params_size);
          if (!ctx->codec_sequence_params) {
              err = AVERROR(ENOMEM);
              goto fail;
          }
      }
      if (ctx->codec->picture_params_size > 0) {
          ctx->codec_picture_params =
              av_mallocz(ctx->codec->picture_params_size);
          if (!ctx->codec_picture_params) {
              err = AVERROR(ENOMEM);
              goto fail;
          }
      }
  
      if (ctx->codec->init_sequence_params) {
          err = ctx->codec->init_sequence_params(avctx);
          if (err < 0) {
              av_log(avctx, AV_LOG_ERROR, "Codec sequence initialisation "
                     "failed: %d.\n", err);
              goto fail;
          }
      }
  
      ctx->output_buffer_pool =
          av_buffer_pool_init2(sizeof(VABufferID), avctx,
                               &vaapi_encode_alloc_output_buffer, NULL);
      if (!ctx->output_buffer_pool) {
          err = AVERROR(ENOMEM);
          goto fail;
      }
  
      // All I are IDR for now.
      ctx->i_per_idr = 0;
      ctx->p_per_i = ((avctx->gop_size + avctx->max_b_frames) /
                      (avctx->max_b_frames + 1));
      ctx->b_per_p = avctx->max_b_frames;
  
      // This should be configurable somehow.  (Needs testing on a machine
      // where it actually overlaps properly, though.)
      ctx->issue_mode = ISSUE_MODE_MAXIMISE_THROUGHPUT;
  
      return 0;
  
  fail:
      av_freep(&hwconfig);
      av_hwframe_constraints_free(&constraints);
      ff_vaapi_encode_close(avctx);
      return err;
  }
  
  av_cold int ff_vaapi_encode_close(AVCodecContext *avctx)
  {
      VAAPIEncodeContext *ctx = avctx->priv_data;
      VAAPIEncodePicture *pic, *next;
  
      for (pic = ctx->pic_start; pic; pic = next) {
          next = pic->next;
          vaapi_encode_free(avctx, pic);
      }
  
      if (ctx->va_context != VA_INVALID_ID) {
          vaDestroyContext(ctx->hwctx->display, ctx->va_context);
          ctx->va_context = VA_INVALID_ID;
      }
  
      if (ctx->va_config != VA_INVALID_ID) {
          vaDestroyConfig(ctx->hwctx->display, ctx->va_config);
          ctx->va_config = VA_INVALID_ID;
      }
  
      if (ctx->codec->close)
          ctx->codec->close(avctx);
  
      av_buffer_pool_uninit(&ctx->output_buffer_pool);
  
      av_freep(&ctx->codec_sequence_params);
      av_freep(&ctx->codec_picture_params);
  
      av_buffer_unref(&ctx->recon_frames_ref);
      av_buffer_unref(&ctx->input_frames_ref);
      av_buffer_unref(&ctx->device_ref);
  
      av_freep(&ctx->priv_data);
  
      return 0;
  }
  