/*

  * This file is part of FFmpeg.

  *

  * FFmpeg 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.
  *

  * FFmpeg 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 FFmpeg; 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);
 
     vas = vaCreateBuffer(ctx->hwctx->display, ctx->va_context,
                          VAEncCodedBufferType,
                          MAX_OUTPUT_BUFFER_SIZE, 1, 0,
                          &pic->output_buffer);
     if (vas != VA_STATUS_SUCCESS) {
         av_log(avctx, AV_LOG_ERROR, "Failed to create bitstream "
                "output buffer: %d (%s).\n", vas, vaErrorStr(vas));
         err = AVERROR(ENOMEM);
         goto fail;
     }
     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 initialise 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);
         goto fail_at_end;
     }
 
     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;
 
         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;
     }
 
     vaDestroyBuffer(ctx->hwctx->display, pic->output_buffer);
     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:
     if (pic->output_buffer != VA_INVALID_ID) {
         vaUnmapBuffer(ctx->hwctx->display, pic->output_buffer);
         vaDestroyBuffer(ctx->hwctx->display, pic->output_buffer);
         pic->output_buffer = VA_INVALID_ID;
     }
     return err;
 }
 
 static int vaapi_encode_discard(AVCodecContext *avctx,
                                 VAAPIEncodePicture *pic)
 {
     VAAPIEncodeContext *ctx = avctx->priv_data;
 
     vaapi_encode_wait(avctx, pic);
 
     if (pic->output_buffer != VA_INVALID_ID) {
         av_log(avctx, AV_LOG_DEBUG, "Discard output for pic "
                "%"PRId64"/%"PRId64".\n",
                pic->display_order, pic->encode_order);
 
         vaDestroyBuffer(ctx->hwctx->display, pic->output_buffer);
         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;
 }
 

 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;
         }
     }
 
     // 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_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;
 }